Water Resources Policy Planning and Management Project

Irrigation Sector Planning Report

Suzan Taha

Preface

Table of Contents

List of Tables

List of Figures

1. Introduction

2. Irrigated Land in Jordan

3. Estimation Of Water Use / Requirements For Irrigation

4. Comments on the Results

5. Recommendations

6. Outlook For Irrigation

ANNEX 1 : Computation of Overall Irrigation Efficiency.

ANNEX 2 : Glossery of Terms Related with the Computation of

Irrigation Requirements.

ANNEX 3 : List of Surface Basins and Subbasins in Jordan

ANNEX 4 : List of Public and Private Irrigation Areas in

Operation during 1988/89.

ANNEX 5 : List of the Crops and Cropping Calendars Adopted

for Each Agroclimatological Zone as Applied in

the

1988/89 Water Requirements Computations.

ANNEX 6 : List of Water Resources Associated with Areas

Without Records, 1988/89 Monthly Discharge and

Salinity Values of Each Source,

ANNEX 7 : List of Water Resources Associated With Areas

With Available Records, 1988/89 Monthly

Irrigation Diversions and Salinity Values of Each

Source

ANNEX 8 : List of 1988/89 Monthly Domestic Abstractions

from the Springs.

ANNEX 9 : Sample of input data and output results of Refer-

ence Grass Evapotranspiration "REF-ET" program

for 1988/89.

ANNEX 10 : List of 1988/89 Reference Grass

Evapotranspiration Results For Representative

Stations In Each Agroclimatological Zone.

ANNEX 11 : 1988/89 Monthly "Total Rainfall, No. of Rainy

Days and Rainfall Frequency" for each

Agroclimatological Zone.

ANNEX 12 : Sample Output of 1988/89 Water Requirements

Computations done by the IRRMAST Spreadsheet.

ANNEX 13 : List of Monthly Crop's Evapotranspiration Repre-

senting 1988/89 Climatic conditions Per

Agroclimatological Zone.

ANNEX 14 : List of Monthly Net Irrigation Requirements

Representing 1988/89 Climatic Conditions Per

Agroclimatological Zone.

ANNEX 15 : Summary Tables of Irrigation Abstractions/ Re-

quirements, Evapotranspiration and Return Flow

Results for the Year 1988/89:

Table 1 : Annual Results by Village.

Table 2 : Annual Results by Zone.

Table 3 : Annual Results by Region.

Table 4 : Annual Results by Surface Drainage Basins and

Subbasins.

Table 5 : Sample of Monthly Results by Village.

Table 6 : Sample of Monthly Results by Zone.

Table 7 : Sample of Monthly Results by Region.

Table 8 : Sample of Monthly Results by Surface Drainage

Basins and Subbasins.

3

MAPS

MAP 1 : Boundary of Irrigation Regions and

Agroclimatological Zones in Jordan.

MAP 2 : Location and Extent of Cropped Irrigated Areas by

Irrigation Source Type.

MAP 3 : Boundary of Surface Basins and Subbasins.

4

PREFACE

The available water is one of the most scarce resources in

Jordan and as such has always been a major constraint for

development. Great efforts have been made in developing the

water resources sector allowing investments of about one sixth

of the national budget. These efforts will need to be continued

also in the years to come.

Of the various water use in the country irrigated agricul-

ture accounts for about 75% of water consumed, and has as such

created the need for a comprehensive study under the scope of

works of formulating a National Water Masterplan.

This report aims at studying the role of irrigation in

Jordan, in food security and overall economy, the rate of expan-

sion of developed areas for irrigation within the last 2

decades, the contribution of the agriculture sector to Jordan

Gross Domestic product, the impact of irrigation infrastructure,

types of crops, cropping patterns, and crops location on water

consumption.

Other main purposes of this study include the computation

of the Irrigation Water Requirement based on the cropping

pattern representing the year 1988/89, the identification of the

volume of irrigation diversions throughout Jordan including

information on the different sources of irrigation (ground

water, surface water, and springs), estimation of return flow

amounts and actual irrigation consumption in each project area.

5

Irrigation Water Demand

Table of Contents

Content Page

1. Introduction .............................................. 1

1.1 Agriculture In Jordan ................................ 1

1.2 Agricultural Area .................................... 2

1.3 Development of Irrigation In Jordan .................. 2

1.4 Historical Trends .................................... 3

1.4.1 Cultivated Areas .............................. 3

1.4.2 Irrigated Areas ............................... 4

1.4.3 Productivity Trends ........................... 4

2. Irrigated Land in Jordan (1988/89) ........................ 5

2.1 Data Sources ......................................... 6

2.2 Summary of Irrigated Areas: Location and Extent ...... 6

2.3 Comments on the Data Collected ........................

3. Estimation of Water Use / Requirement For Irrigation .......

3.1 Historical Trends .....................................

3.2 Approach ..............................................

3.3 Data Sources ..........................................

3.3.1 Village Information Data Base ..................

3.3.2 Agroclimatological Zones Data Base .............

3.3.3 Water Resources Data Base ......................

3.4 Water Use In Areas With Records (Jordan Valley) .......

3.5 Water Use In Areas Without Records (Uplands) ..........

3.5.1 Net Irrigation Requirement .....................

3.5.1.1 Monthly Reference Crop Evapotranspiration ETo

3.5.1.2 Average Planting Date

3.5.1.3 Length of Growing Season

3.5.1.4 Crop Coefficients, Kc

3.5.1.5 Crop Evapotranspiration, ETc

3.5.1.6 Daily Average Rainfall

6

3.5.1.7 Effective Rainfall, Peff

3.5.1.8 Monthly Rainfall Frequency

3.5.1.9 Late Season Depletion, LSD

3.5.1.10 Cumulative Net Effective Precipitation Dur-

ing The Offseason, CNEPO

3.5.1.11 Allowable Depletion During The Initial Peri-

od, ADI

3.5.1.12 Minimum Possible Irrigation Depth, MPID

3.5.1.13 Preplant Irrigation depth

3.5.2 Gross Irrigation Water Requirement, GIR

3.5.2.1 Overall Irrigation Efficiency

3.5.2.2 Leaching Requirements, LR

3.6 Return Flow

3.7 Net Irrigation Consumption

3.8 Actual Evapotranspiration

3.9 Programming Approach

3.9.1 General Steps

3.9.2 Computation Examples

4. Comments on the Results

5. Recommendations

5.1 Survey on Irrigated Lands

5.2 Irrigation Efficiency

5.3 Data Related to Water Use

5.4 Data Related to the Computation of Net Irrigation Require

ments

5.5 Data Related to Water Quality

6. Outlook For Irrigation

6.1 Food Security

6.2 Potential For Increased Irrigated Area.

7. References

7

List of Tables

1. Gross Domestic Product at 1990 Prices and Sectors'

Contribution in Million JD, (1970-1990).

2. Cumulative Areas Developed for Irrigation in the Jordan

Rift Valley by Irrigation System Type, (1966-1991).

3. 1988/89 Distribution of Irrigated Areas by Groups of Crops

For Each Region in Jordan, Du.

4. Cultivated Areas and related Production in Jordan by Groups

of Crops (1973-1988).

5. Irrigated, Rainfed and Cultivated Areas in Jordan, (1980-

1988), 000 Du.

6. Area and Production of Irrigated Summer Vegetables, (1973-

1988).

7. Area and Production of Irrigated Winter Vegetables in Jor-

dan, (1973-1988).

8. Trends of Irrigation and Total Water Use in Jordan, (1985-

1990), MCM.

9. Average Food Balance for Some Important Food Products in

Jordan for the Period 1982-1987

8

List of Figures

1. Jordan Gross Domestic Product at 1990 Prices and Secto-

rs'Contribution in Million JD, (1970-1990)

2. Cumulative Areas Developed for Irrigation in the Jordan

Valley by Irrigation System Type, (1966-1991)

3.A Cropped Irrigated Areas by Groups of Crops Per Region for

the Year 1988/89

3.B Percentage Of Cropped Irrigated Areas Per Region for the

Year 1988/89

4. Cultivated Areas, Production and Yield by Group of Crops

(1973-1988),

5. Irrigated, Rainfed and Cultivated Areas in Jordan, (1980-

1988)

6. Irrigated Summer Vegetables Areas, Production and Yield,

(1973-1988)

7. Irrigated Winter Vegetables Areas, Production and Yield,

(1973-1988)

8.A Variation of Irrigation and Total Water Use from Surface

and Groundwater Sources, (1985-1990).

8.B Irrigation Water Use from Surface and Groundwater Sources,

(1985-1990).

9. Net Irrigation Requirements, Reference Evapotranspiration

and Effective Rainfall by Regions for the year 1988/89 in

MM.

10. Variation of Gross and Net Irrigation Water Requirements,

by Regions and Zones, 1988/89.

11. Variation of Net Irrigation Requirements/Consumption and

Variation of Predicted Evapotranspiration and Total Actual

Evapotranspiration per Zone for 1988/89, in MM.

1

1. Introduction

Jordan is a semi-desert country with a land area on the

East Bank of the Jordan River of about 89,206 sq.kms. The

population is concentrated in the North West Highlands, with

altitudes averaging 800 meters and a relatively temperate

climate. The land slopes gently to the desert of the East and

the South East, and rainfall declines sharply. To the West the

land falls steeply to the Rift Valley formed by the Jordan River

and Dead Sea, with altitudes as low as 400 meters below sea

level. Jordanian territory includes a 25 km stretch of

coastline on which the seaport of Aqaba is situated on the

Northern shores of the red sea.

The climate varies from semi-arid to arid. Summer maximum

temperatures average 32oC in the Highlands, and 35

oC to 38

oC in

the Southern Desert and the Jordan Valley. Winter maximum

temperatures average 14oC to 17

oC in the Highlands and Southern

Desert, with minimum temperatures of 1 oC to 4

oC and occasional

snowfalls in the Highlands. In the Jordan Valley, however,

winter maximum temperatures average 21oC and minimum

temperatures rarely fall below 8oC to 10

oC, permitting round year

cultivation.

Rainfall exceeding the limit for reliable rainfed agricul-

ture (300 millimeters annually) covers only 4% of the land area

in the North, North Western Highlands and Jordan Valley. Areas

receiving less than 350 mm, cover 96% of the land area. Rain

falls during the winter months, and it is of sporadic nature

especially in the desert areas. It drains mostly into the

ground and into the Valleys leading to the two main rivers, the

Jordan River, flowing into the Dead Sea in the Western part of

Jordan, and its tributary the Yarmouk along the Northern

frontier with Syria.

1.1 Agriculture in Jordan

The major transformation for Jordanian agriculture took

place in the 1970's when this sector witnessed unprecedented

growth rates; real agricultural GDP grew at an annual rate of

18% between 1975 and 1980. Increased land and water resources

devoted to agriculture and the shift to high value horticultural

2

crop production contributed most to this rapid growth.

Jordan's small domestic market made its agricultural sector

depend heavily on foreign trade, with as much as 60% of its

horticultural production being exported to regional markets.

Horticultural exports continued to grow until 1982 when reduced

economic activity in the oil-producing gulf states impacted

regional and domestic demand, the latter being affected by

reduced remittances. Furthermore, the apreciation of the real

effective exchange rate of Jordan's currency relative to its

export competitors in 1988, contributed to the decline in the

export market.

In 1984, a dramatic price decline reduced sectoral GDP by

20%, (Table 1). However, modest increases in domestic demand

and expanding exports of processed vegetables assisted in

recovery thereafter. By 1988,agricultural GDP exceeded the peak

attained in 1983, and in 1989 agricultural exports responded to

the increased prices resulting from the 1988 currency

devaluation, whereby the volume of horticultural exports

increased by 60% over the 1988 level.

As demonstrated by Table 1, the structure of the Gross

Domestic Product in Jordan indicates that the economy is heavily

service oriented. Agriculture's contribution to the Gross

Domestic Product was only 7.1% in 1990, while the contribution

of the industry and the remaining sectors amounted to 17.2% and

75.8% respectively. See also Fig. 1.

Although the relative importance of the agricultural sector

contribution is rising in absolute figures, from 51 Million JD's

in 1979 to 185 Million JD's in 1990, its percentage contribution

to the country's GDP remained almost constant throughout the

years.

1.2 Agricultural Area

About 684,200 ha (7.7% of the total area of the country)

are normally used for agriculture:-

a) 176,300 ha ( 25.8% of agricultural area ) are

normally fallowed.

3

b) 93,700 ha ( 13.7% of agricultural area ) can still

be reclaimed.

c) 414,200 ha ( 60.5% of agricultural area ) are

normally cultivated.

1.3 Development of Irrigation in Jordan

In the early 1950's the total population of the East Bank

of the Jordan River was only 0.6 million, concentrated in the

uplands, where water was relatively abundant. Agriculture was

confined largely to rainfed farming and livestock raising. The

uneven distribution of rainfall during the year, its variability

and unreliability has made traditional, dryland farming a high

risk enterprise to meet the rapidly growing domestic market and

the expansion in population.

Irrigated Agriculture has developed and expanded from a few

scattered seasonally irrigated farms in the 1950's to a more

mature and planned irrigated farms in the 1970's. Irrigation

has gained tremendous momentum after increased public

investments in land and water development in the Jordan Valley

and Southern Ghors, and the increased private investment in

Irrigation and new technologies.

Up until the 1960's only limited use was made of the exist-

ing surface water resources. The introduction of modern

irrigated agriculture has transformed the demand for water.

Developed irrigation facilities now covers approximately 30,216

ha in the Jordan Valley, 4,650 ha in the Southern Ghors, using

mostly surface water, 200 ha in Wadi Araba, and approximately

31,684 ha in the uplands, using mostly ground water.

Of the 30,216 ha developed in the Jordan Valley about 5,975

ha have been developed for irrigation under the King Abdullah

Canal (KAC) 14.5 Km extension project, of which about 1,700 ha

are currently irrigated by private farm wells. All developed

areas under that scheme will be cultivated once land

distribution is completed and additional resources are made

available. Table 2 shows the areas developed for irrigation

under each project in the Jordan Rift Valley and the cumulative

of these areas by the irrigation system type since 1966 when the

first stage of K.A.C. was commissioned up until 1991. Fig. 2

represent the cumulative developed areas by their system type of

4

irrigation during the same period.

1.4 Historical Trends

1.4.1 Cultivated Areas

Cultivated areas in Jordan fluctuate widely from one year

to another due mainly to variations in climatic conditions.

Although field crops occupy the bulk of these areas, there has

generally been a shift from cereal and field crops production to

higher value horticultural production. Table 4 shows that areas

planted with field crops in the early 1970's constituted in

average about 86% of the total cultivated areas. However, this

percentage dropped to its lowest of 43% in 1983/84 as more areas

were dedicated to trees and vegetables, and have since

recuperated and contributed to 68% of the total cultivated areas

in 1986/87, due to increased government incentives for cereal

production through purchase at promotional prices.

Planted fruit areas increased continuously over the past

two decades, as did vegetables areas through 1983. Of the total

areas dedicated to horticultural crops, fruit trees areas com-

prised 45% in 1973/74. By 1985/86 the distribution of horticul-

tural crops had witnessed a transformation tilting more towards

trees plantation which realized its maximum at 65% of the horti-

cultural area in 1986/87, (Table 4) and (Fig. 4).

1.4.2 Irrigated Areas

Data reviewed on irrigated areas in Jordan showed a modest

increase in the total irrigated areas. Irrigated areas peaked

in 1982/83 at about 60,010 ha, and has remained around that

plateau since then. See Table 5 and Fig. 5.

Starting in the mid 1970's a smooth and continuous growth

occured in the irrigated summer vegetables areas in the

Highlands and the Jordan Valley, reaching their maximum of

12,310 ha and 17,380 ha in 1983/84 and 1984/85 respectively.

These areas have declined to 72% and 40% of their respective

highs, in 1986/87.

Table 6 and Fig. 6 indicate that until 1984/85 the Jordan Valley

contributed 52% to 67% of the total irrigated summer vegetables

areas. This contribution, however, had continued to decline

thereafter, reaching its low at about 43% in 1987/88.

5

As for irrigated winter vegetables, the Jordan Valley

doubtlessly still occupies the bulk of these areas due to its

unique climatic conditions which allow for round year cultiva-

tion. See Table 7 and Fig. 7.

1.4.3 Productivity

a. Field Crops

Prior to 1983/84, field crops in general experienced wide

fluctuations in yield ranging between 20.1 kg/du and 92.4 kg/du.

The highest value attained in 1982/83 dropped drastically to

47.0 kg/du in 1983/84, but have since then been continuously in-

creasing, reaching its peak of 100.6 kg/du in 1986/87. See

Table 8 and Fig.8.

b. Tree Crops

Identifying productivity trends in tree crops is difficult

when planted areas are increasing annually, Table 8. Depending

upon the particular tree crop, production usually commences

three to six years after planting, increasing gradually until

reaching a yield plateau at maturity.

Tree crops demonstrated relative constant yields as

derived from aggregate production and planted area data,

indicating that productivity has actually increased. This

productivity, however, will be fully reflected only when recent

plantings mature.

c. Vegetables

Yields of vegetables have experienced substantial

productivity increases. Table 8 shows that despite the decline

in the planted vegetables areas between 1982/83 and 1986/87, a

yield plateau of 2515 kg/du was realized in the latter year.

The overall growth in crop production witnessed during the past

two decades was, therefore, primarily achieved through the

increased productivity of vegetables and tree crops

(horticultural) production.

Historical data reviewed on summer irrigated vegetables in

6

the Jordan Valley and the highlands, indicate that the

productivity of summer vegetables in the latter exceeded most of

the time that of the Jordan Valley "with some occasional

exceptions". The differences were highly pronounced between

1984/85 and 1985/86, but have since then been converging. See

Table 9, and Fig. 9.

On the other hand, productivity of irrigated winter

vegetables in the highlands has always demonstrated

significantly lower values than those attained in the Jordan

Valley as reflected by table 10, and Fig. 10.

7

2. IRRIGATED LAND IN JORDAN (1988/89)

2.1 Data Sources

In order to compute the crops water requirement and esti-

mate the present irrigation demand for water, information about

all the irrigated areas in Jordan and the relative distribution

of irrigated crops had to be collected.

Use was made of the Ministry of Agriculture (MOA) records

of private and public irrigation areas in operation in 1988/89

in both the uplands and the Southern Ghors. Although the MOA

inventory was not inclusive of all irrigated villages in the

Kingdom, its records of irrigated areas appeared to be the most

complete. They included summer and winter irrigated crops for

all villages in each governorate.

Monthly irrigated areas of the public schemes in the

Jordan Valley, were obtained from the Jordan Valley Authority

(JVA).

Further analysis had to be made on these monthly figures to

estimate the seasonal cropped irrigated areas based on the

cropping calendar representing the region in which each project

is located.

2.2 Summary of Irrigated Areas: Location and Extent

The present irrigated areas in dunums may be grouped and

compared with those obtained from the National Water Masterplan

prepared in 1977 according to the following:-

a) Crops Grown in dunums

Present(1988/89) Water Masterplan

Vegetables 262,859 45% 185,600 55%

Fruit Trees 216,602 38% 86,400 26%

Field Crops 98,646 17% 64,000 19%

b) Surface Drainage Basins

Present (1988/89) Water Masterplan

8

Jordan River 399,971 69.19% 253,700 75.51%

Dead Sea 60,159 10.41% 43,800 13.04%

Wadi Araba N. 45,268 7.83% 23,400 6.96%

Wadi Araba S.

and Red Sea 45,722 7.91% 4,900 1.49%

Azraq 12,456 2.15% 4,400 1.30%

W.Hammad 1,250 0.22% 0 0.00%

Jafer 13,221 2.29% 5,800 1.73%

Irrigated areas can also be summarized in each of the

twelve agroclimatological zones previously identified in the

National Water Master Plan of Jordan, 1977 and adopted by this

report, The distinct agroclimatological zones were classified

according to topographic features, rainfall quantities and

climatic conditions. Since conditions in the same zone are

sufficiently uniform, the same parameters were used for all

villages located within the defined zone. These parameters

include Evapotranspiration of Reference Crop, ETo, Effective

Rainfall, Rainfall Frequency, Cropping Calendar and Crop Coeffi-

cients. The above classification facilitated the Water Require-

ment estimation for the great number of villages with irrigated

agriculture. The delineated zones are listed below :

1) Northern Jordan Valley

2) Southern Jordan Valley

3) Southern Ghors

4) Northern Highlands (Kufranja Area)

5) Northern Highlands (Jarash Area)

6) Northern Highlands (Wadi Es Sir Area)

7) Northern Highlands (Zarqa Area)

8) Southern Highlands

9) Southern Mountains

10) Western Desert

11) Eastern Desert

12) Southern Desert

The following table shows the cropped irrigated areas

in each of the above zones:-

Zone No. Area in Dunums

9

Zone 1 146,390

Zone 2 82,082

Zone 3 32,739

Zone 4 13,862

Zone 5 40,449

Zone 6 15,735

Zone 7 54,006

Zone 8 39,138

Zone 9 11,701

Zone 10 83,386

Zone 11 14,043

Zone 12 44,515

Finally, irrigated areas can be grouped according to

the Irrigation Regions in the Jordan, whereby each region is

comprised of one or more of the above Agroclimatological Zones

as follows:

1) Jordan Valley Region : Zones 1 and 2

2) Southern Ghors Region : Zone 3

3) Highlands Region : Zones 4 through 9

4) Western Desert Region : Zone 10

5) Eastern Desert Region : Zone 11

6) Southern Desert Region: Zone 12

Map 1 shows the boundaries of both Irrigation Regions and

Agroclimatological Zones and in Jordan.

The distribution of irrigated lands (in dunums) by groups

of crops grown in each of the above regions is listed below.

Field Fruit Vegetables Total

Crops Trees Winter Summer

J.Valley 24,623 69,057 70,048 64,744 228,472

S.Ghors 195 3,026 20,089 9,430 32,740

H.Lands 15,101 98,118 7,086 54,586 174,891

W.Desert 16,057 31,181 2,263 33,885 83,386

E.Desert 1,270 12,660 0 113 14,043

S.Desert 41,400 2,560 500 55 44,515

Total 98,646 216,602 99,986 162,812 578,046

10

From this table it could be recognized that Vegetables in

the Jordan valley constitue 51% of the total Vegetable area in

Jordan of which 52% are Winter Vegetables and 48% are Summer

Vegetables. This is due to the suitability of climatic and soil

conditions to grow Vegetables in this Region and more than once

per year, which in turn offers higher crop intensities than

irrigated areas in other regions. It also shows that the Fruit

Trees are mostly located in the Highlands Region. Fig. (3a)

clearly shows the distribution of the above areas by groups of

crops in each region.

The above irrigated areas in the Jordan Valley are those

areas with available cropping pattern. Another irrigated areas

in the Jordan Valley with no available cropping pattern include:

about 1120 du. in Abu Zeigan and 2200 du. in Wadi Shu'eib, in

addition to the areas irrigated upstream of the Jordan River

Side Wadis, estimated at 9000 du. leading to a total irrigated

area of about 590,000 du.

in Jordan. Fig. (3b) shows the percentages of the total

irrigated areas in each region in Jordan from which we can

conclude that the Jordan Valley constitute the Highest

percentage of cropped irrigated areas (40%) from any other

region in Jordan.

2.3 Comments on the Data Collected

The Ministry of Agriculture (MOA), the Department of

Statistics (DOS) and the Jordan Valley Authority (JVA) are the

principal government bodies engaged in assembling data related

to irrigated areas in Jordan. Frequently, data obtained from

these sources are not based on the same survey methods, and

sampling criteria are not similar. Thus, different information

were often obtained for specific areas. Moreover, villages

appearing in the DOS files do not necessarily coincide with

those of MOA's, and the types of data offered vary

significantly. This report includes only the areas appearing in

the MOA and JVA files. Unaccounted-for areas include Abu

Zeigan, Wadi Shu'eib and additional areas irrigated upstream of

the Jordan River Side Wadis, where not used in our database.

Other areas evidently do exist as suggested by the Lands and

Survey Department (LASD) and the DOS records, but have not been

incorporated in our database due to incomplete data regarding

11

the total acreages and the relative distribution of the crops.

Considerable effort is required to enhance cooperation between

the various government agencies involved, to improve the data

and information on irrigated land that would suit the needs of

improved water resources management and planning as outlined in

Section 5 of this report.

12

3. ESTIMATION OF WATER USE / REQUIREMENT FOR IRRIGATION

3.1 Historical Trends

While looking at the historical trends of water use, it

appears that the uses of water are increasing from one year to

another, either as a water used for irrigation or as a total

water use (table 8) and (Fig. 8a) regardless of the slight

decrease in 1986. It could be also noticed that on the average

about 75% of the total water uses were used for irrigation.

The variation of water uses from one year to another

depends mainly on the requirements which have been increased due

to the expansion of cropped irrigated areas, the continuous

growth in population which in turn has significantly increased

the demand of water supply and due to the development of the

industrial

sector which also added to the water demand in Jordan. This has

make use of the available surface water in addition to

developing the groundwater sources wherever it is possible. The

surface water uses in a certain year are varies with the

available surface water supply which is mainly affected by the

intensity of rainfall in that year. On the other hand the

groundwater uses have been steadily increased from one year to

another. Table 11 (with Fig.11A) show that there is a slight

dicrease in the irrigation water used from surface water sources

in 1986 parallel to the slight decrease in the availability of

surface water supply of the same year while the irrigation water

used from groundwater sources continued to increase in the said

year and in the following years not depending on the

availability of water supply. From the same figure it has also

been noticed that on the average about 92% of the surface water

was used for irrigation and 62% of the groundwater was used for

the same purpose.

When examining the irrigation water uses from different

sources, which on the average constituted 54% and 46% from

Surface and Groundwater sources respectively, it could be

clearly noticed that the past years which expanded from 1985 to

1990 have witnessed an observed variation between surface water

and groundwater uses for irrigation. In another word, the

irrigation water uses from surface water sources has exceded the

13

uses from groundwater sources during the period 1985-1988

(Fig.8B), despite this the groundwater use for irrigation

continued to increase until it exceeded the uses from the

surface water sources in the years 1989,1990. This may give a

serious indication about the continuous exploitation of

groundwater sources from which the discharge may exceed the safe

yield of the aquifer, once it happened, a continuous drop of

water level is expected which in turn will affect the quality of

the groundwater aquiferes and in the long run it may dry up some

springs.

3.2 Approach

Under the scope of works of formulating this Masterplan, an

inventory of 1988/89 irrigation projects: location by sub-basin,

area, crop, source of water, type of irrigation,

evapotranspiration, estimated irrigation requirements and

abstractions, and return flow were required. In addition, a

similar inventory corresponding to an average, wet and dry year,

together with typical monthly distribution had to be

established. Most of the data pertaining to the 1988/89

conditions have been collected and summarized, and are

currently ready for use during this phase of the project.

1988/89 irrigation areas obtained from the Ministry of

Agriculture were used to represent cropped irrigated areas in

each village and were entered into the General Village

Information Data Base / Cropped Irrigated Area Data Base

described below.

The Irrigation Water Requirements, Reference Evapotranspi-

ration estimates, Overall and On-farm Irrigation Efficiency for

the said year and corresponding to each agroclimatological zone

were constituted the Agroclimatological Zones Data Base.

Because actual irrigation withdrawals from springs, wadis

and wells in the uplands are generally not measured, a detailed

strategy for estimating irrigation abstractions was formulated

by the project irrigation expert Dr. R. Allen. The approach of

this strategy is to estimate withdrawals based on comparisons

between gross irrigation water requirements computed according

to total irrigated areas and total potential discharges using

14

the capacities information of the water source(s) associated

with the irrigated areas. Elsewhere in the Valley, available

monthly irrigation diversions were used as the actual irrigation

withdrawals. In the Southern Ghors irrigation diversions were

not availabe for 1988/89. Thus, the same analysis used for the

uplands was adopted for this area. The analyses proceeds on a

month by month basis and on a village by village basis for

increased accuracy after which all the Results could be summa-

rized and presented according to surface basins and subbasin on

a monthly or annual basis.

List of surface basins and subbasins in Jordan and their

related boundaries, are shown in Annex 3 and Map 3 respectively.

Information required for the assessment of irrigation

abstractions include monthly irrigation water requirements by

crop for each of the 12 agroclimatic zones; documented irrigated

areas by crop and by village obtained from the Ministry of

Agriculture; and coordinates, actual abstractions whenever

available, capacities, salinities and domestic abstractions of

wells, springs and side wadis throughout the kingdom. Analyses

in this report are made for the 1988/89 base year, for all the

irrigation sources in the Kingdom excluding side wadis in the

uplands, due to unavailable data sources. Analysis for represen-

tative years for dry, average and wet conditions and side wadis

should be made in the next phase of this project.

A data base system was developed to process the large

amount of information required to complete this assessment. The

data base is partitioned into three independent units or data

bases. They include: 1) Village Information data base; 2)

Agroclimatological zones data base; and 3) Water Resources data

base. In order to achieve the results from the data base system

developed, sub data bases were formulated for this purpose.

Information used in these data bases is described as follows:

A. VILLAGE INFORMATION DATA BASE

A.1 General Village Sub-Data Base

- Village name

- Village identification including governorate

- Village coordinates

15

- Agroclimatological zone number in which the vil-

lage is located

- Basin identification number

- Sub basin identification number

- Proximity to nearest wadi

- Return Flow Type

A.2 Cropped Irrigated Area Sub-Data Base

- Village identification

- Planted crops

- Irrigated area of each crop

- Electrical Conductivity of the "Saturation Ex-

tract" of the soil.

A.3 Village Water Resources Sub-Data Base

- Village identification

- Associated Water resource identification

B. AGROCLIMATOLOGICAL ZONES DATA BASE

B.1 Irrigation Efficiency Sub-Data Base

- Agroclimatological Zone identification number

- Selected year

- On-farm Irrigation Efficiency

- Overall irrigation efficiency

B.2 Crop Evapotranspiration Sub-Data Base

- Agroclimatological Zone identification number

- Selected year

- Month

- Planted crops

- Monthly Crop evapotranspiration

B.3 Net Irrigation Requirements Sub-Data Base

- Agroclimatological Zone identification number

- Selected year

16

- Month

- Planted crops

- Monthly Crop Net irrigation requirements

C. WATER RESOURCES DATA BASE

This was divided into three categories:

Wells

Springs

Side Wadis

For each of the three irrigation sources the following sub-

data bases were identified:

C.1 General Resource Sub-Data Base

- Water resource identification number

- Water resource name and type

- Owner

- Coordinates

- Altitude

- Village code

- Governorate

- Drainage Basin

- Sub-Drainage Basin

- Water use

C.2 Discharge Sub-Data Base

- Water resource identification

- Selected year

- Monthly discharge value or irrigation abstraction

of the water resource

C.3 Domestic Abstraction Sub-Data Base

- Water resource identification

- Selected year

- Monthly domestic abstraction from the water re-

source

C.4 Electrical Conductivity Sub-Data Base

17

- Water resource identification

- Electrical conductivity

A detailed description of data base procedures are outlined

later in section 3.9 of this report. Output of data processing

is listed in annex 15.

3.3 Data Sources

3.3.1 Village Information Data Base

- Each irrigated village or project area was identified vis

the Agroclimatological zone identified in the National Water

Masterplan of Jordan, 1977 and according to the surface basin

and/or subbasin. This was used to estimate the monthly crops'

gross water requirement of the village based on the selected

year climatic conditions prevailing within the zone in which it

is located, and determine demand for irrigation in each drainage

basin and/or subbasin. All water sources available in WAJ (Water

Authority of Jordan) records were then linked with the villages

according to their location and proximity to the irrigated

areas.

- Use was made of the topographic maps available in WAJ to

estimate the distance of each village from a drainage wadi.

This information was used to estimate the proportion of return

flow which directly reenters the surface flow in wadis by

seepage and the percentage which enters the ground.

3.3.2 Agroclimatological Zones Data Base

- Agrometeorological data used for calculating reference

crop evapotranspiration (ETo) were obtained for representative

evaporation station in each climatic zone from WAJ and MD

(Meteorological Department) records. Interpolation was made to

calculate some missing data using in some cases information

available on the nearest station.

- Monthly Rainfall data and frequency in each agroclimato-

logical zone were obtained from WAJ records.

- In order to calculate the net irrigation water requirmen-

18

ts, data related to climatic conditions were obtained and crop

parameters were established for each climatic zone. A

Spreadsheet program (IRRMAST) was developed by the Project

Irrigation Consultant R. G. Allen and was used to compute the

net irrigation water requirements for all crops in each zone.

- Data concerning Maximum Root Depth, Max Depletion

Percentage, Crop Coefficients for Mid & Late Season and Crop

Development Stages were all selected for each crop using the FAO

Irrigation and Drainage Paper 24. Crop parameters not covered by

FAO-24 were estimated by the Project Irrigation Consultant.

- Crop calendars for the highlands and desert regions were

obtained from the National Center For Agricultural Research And

Technology Transfer (NCARTT). Crop calendars for the Jordan

Valley and Southern Ghors were prepared in close collaboration

with JVA officials.

Crop Calenders are listed in annex 5.

- Supporting data on the methods of irrigation in each

village in the uplands were obtained from the results of the

annual agricultural survey held by the Department of Statistics

(DOS) in 1989. The survey covered all irrigated lands with

ownership areas equal or exceeding 200 du, and showed for each

village areas irrigated in each season and irrigation methods.

Use was made of this survey as a cross reference to verify the

irrigated areas obtained from the MOA inventory. The DOS and the

MOA sources proved to be substantially different. The two

series of data could not be reconciled making it rather

impossible to establish any sort of linkage between the two

sources. Not all the villages covered by the MOA files were

included in the DOS agricultural survey, and so was the

opposite. The former could be explained by fragmented

ownerships in the villages not appearing in the DOS survey, thus

violating its sampling criterion for that year. This criterion

also happens to change with years, therefore not allowing the

construction of consistent time series data with regards to the

development of on-farm efficiency with years.

In view of the above, a broader use was made of this

survey, whereby areas irrigated with different techniques were

assimilated for all the villages located in the same zone. The

19

percentage areas irrigated with surface, sprinklers and drip

were considered to be representative of all the villages in the

same zone and were later used for the estimation of a weighted

on-farm irrigation efficiency for each agroclimatilogical zone.

Data pertaining to the distribution of irrigation methods

in the Jordan Valley were obtained from JVA Operation and

Maintenance records. Summary of areas of irrigated vegetables

under each method was available for January 1989. Areas under

each method were added for all the development areas within the

same zone and the percentage areas irrigated with the different

techniques were adopted to represent prevailing methods of

irrigated vegetables for all seasons.

Whenever data were not available, pooling of information

from the different sources in addition to consultations with the

concerned officials were done. All the assumptions made are

discussed in the appropriate Sections of this report.

- Since the type of delivery system depends on the source

of irrigation water to which it is linked, information regarding

the distribution of irrigated areas according to the source of

irrigation had to be established based on the results obtained

from the annual agricultural survey held by the Department of

Statistics for the year 1989. The sampling criterion used in

this survey included irrigated lands with ownership areas equal

to or exceeding 200 dunums. The results of the above survey

were compiled and were broadly used as a guideline to estimate

the percentage areas irrigated from the different source types

in each agroclimatological zone. For lack of further

information the latter was considered representative for all the

villages within the same zone.

As shown later in ANNEX 1 (Computation of Overall

Irrigation efficiency), the percentage areas irrigated from the

different sources of irrigation were used for the estimation of

delivery system efficiency in each zone and the subsequent

computation of the Gross Water Requirement for each village.

3.3.3 Water Resources Data Base

In order to assess actual irrigation withdrawals, informa-

tion concerning capacities of the source of irrigation water

20

associated with each village had to be assimilated. The Water

Authority of Jordan (WAJ) and the Lands and Survey Department

(LASD) records provided the foundation line that served the

purpose of this assessment, " with the following reservations":-

- Agricultural Wells Data Records

Data obtained from WAJ included aquifer tests which com-

prised of information regarding the tested yield, the salinity

of the water pumped out of the well at the date of testing and

the location of the well. The Latest available Quality tests

data were also reviewed.

a) A source of error might arise since the tested yield

in our computations was considered as the actual

pumpage rate due to the absence of measurements

regarding the capacity of the pumps installed on the

wells. Furthermore, whenever tested yield of certain

wells were not available use was made of the

preliminary assessments made by WAJ regarding the

irrigation withdrawals from these wells.

b) Because not all irrigation wells are routinely moni-

tored for salinity another source of error had to be

accepted during the preparation of this report.

Salinity values of the water source (essential for

leaching requirements computations) are usually

measured during the initial pumping tests of

irrigation wells, and do not indicate the updated

quality of the pumped water. These values were used

whenever more recent quality tests data were missing.

Multiple salinity values, whenever available, were

averaged to represent the salinity of the water

source. If no salinity record was available for a

certain well then the salinity of the nearest well

within the same aquifer was used.

c) In the process of identifying the wells used for irri-

gation, a decision had to be made about the villages

listed in the MOA files and not appearing in WAJ

files. Therefore, it was assumed that transfer of

water from wells in adjacent villages was made.

21

- Springs Data Records

LASD provided data about all the irrigated lands in each

village with water rights to adjacent springs. Springs without

water rights can still be used however for irrigation. WAJ has

only an inventory of the springs measured by its field staff,

which were previously identified in the Technical Paper No. 51

on spring flow data in Jordan prior to October 1985. Other

springs and seeps evidently do exist but are inaccessible by

WAJ.

The latest survey carried out by the Authority in Sep. 1989

showed the status of each spring ( dry or running), the nearest

village, its importance to domestic supply and its present use.

This was utilized to identify all the springs used

simultaneously for both irrigation and domestic abstractions

whenever a spring was linked to WAJ water supply networks.

Because the data originated from several sources,

frequently they did not fit together. Due to lack of

appropriate documentation, time, and budgetary constraints

hindering field surveys, several assumptions had to be made.

These included the following:-

a) Water used locally from the springs for drinking by

the inhabitants of the nearby village, was considered

negligible in this study.

b) It was assumed that only the springs associated with

the MOA documented irrigated villages were used for

irrgation during 1988/89. Irrigated areas with water

rights to adjacent springs not included in the MOA

records were not included.

c) Several cases were encountered whereby it was

physically impossible for a spring to irrigate the

associated village when the latter is located way

upstream, unless the village's boarders extended to

the spring's vicinity. Moreover, it was difficult to

establish the boarders of each village. It was

therefore decided to consider the available data as

they appeared in the original WAJ files regardless of

the validity of the above argument.

22

d) Although discharge values of the springs were

regularly measured, they were not done on a monthly

basis for all springs. Springs are divided into three

administrative classes, namely A, B, and C.

Class A springs are measured once a month. These

springs were selected both for their importance as

water resources, and as indicators of changes in

ground water flow.

Class B springs are measured at three months

intervals. This includes many important springs as

well. Interpolation between the available readings of

1988/89 was done to estimate the values of

intermediate missing months. This procedure will have

to be refined such that interpolated figures would

reflect the behaviour of the ground water

flow...during the same year. This could be done by

looking at the monthly variations of discharge for

adjacent springs that emerge from the same aquifer as

that of the examined spring.

Class C springs with minor discharge values includes

all other springs for which one annual discharge mea-

surement is taken. The discharge values thus recorded

at the time of measurement in 1988/89 was considered

representative of all months of the year. Although

not frequently encountered, when flow measurements

data for the said year were missing, the 1987/88

values were considered. Since Class C springs have

minor flows, it is believed that such a measure would

have a negligible effect on our water use assessment.

Finally, in the absence of recent records for some of

these springs, the average discharge value found for

each of these springs in the Technical Paper No. 51

was adopted despite the very limited number of

historical measurements available for this class of

springs.

e) Whenever multiple values of salinity for a spring were

available for 1988/89, they were averaged to obtain a

23

representative value to be used in the leaching re-

quirements computations. In case of unavailble data

for any site, salinity values were estimated according

to the formation water quality based on available

measurements for adjacent springs emerging from the

same aquifer.

- Side Wadis Data Records

Discharge data along the side wadis in Jordan are not

available. Discharge for side wadis is only measured at the

outlet of the catchment area. This makes the identification of

the amount of water available for irrigation from the side wadis

in the upland areas quite difficult. It is realized that some

of the irrigated lands may receive water from the wadi above the

measurement point, however, there was no immediate way to

identify neither the irrigated acreages and the full gross

irrigation requirement, nor what the original source discharge

was. Therefore, it was tentatively assumed during the

preparation of this report that only springs' flows were

available for irrigation in the uplands areas. Water use from

side wadis in the uplands has to be identified in the next phase

of the project based on the suggestions outlined in Section 4.

3.4 Water Use in Project Areas of the Jordan Valley

The Jordan Valley Authority keeps monthly records of the

total water flowing into and out of each project in the Jordan

Valley. Although operational records include documented

deliveries to the farm gate, there is no way to identify how

much water was diverted at the source of irrigation supply, or

at the lateral turnouts, which correspond to farm gate

deliveries. Furthermore, the losses presented in JVA books are

accounting losses which represent the closing part in each

project's water budget and do not include unauthorized

withdrawals or poor nonrepresentative delivery measurements. It

is highly recommended that estimated losses from the conveyance

and distribution system should be based on actual physical

losses and observations in the future. In the absence of such

measurements, the documented losses were assumed to be equally

distributed among the different water use components of each

project, and the accounting efficiency was used thereafter to

estimate the amount of irrigation diversions by dividing

24

reported on-farm deliveries by the accounting efficiency. Gross

Irrigation Requirement is then compared with actual water

diverted at the source to find out the irrigation abstractions

from which the irrigation return flows could be computed.

3.5 Water use in Areas Without Records (Uplands)

Data sources and information for the Jordan Valley irriga-

tion projects are much more detailed than those for highlands

and desert area of the kingdom. Information related to actual

irrigation abstractions in the uplands were scarce. In fact,

the absence of relevant records made it difficult to estimate

how much water the different crops were receiving under the

conditions prevailing in the various areas and seasons. For

this reason, it was decided to estimate actual irrigation

withdrawls and consumption from irrigation water sources;

springs, wells and side wadis, using the data base system

developed for this purpose. Decisions regarding actual

irrigation usage were based on comparisons made between the

gross irrigation requirement based on total irrigated areas in

each village and the total capacity of the water sources

associated with that village. If the sum of the sources' water

after deducting amounts used for domestic purposes and other

uses exceeded the gross irrigation requirement, then the

associated sources were more than adequate to supply the

irrigation requirements of the relative documented irrigated

areas in that village, and only the gross irrigation water

requirement was assumed to be abstracted. If, however, the

opposite was true then all sources' water in excess of domestic

and other uses was diverted for irrigation.

3.5.1 Net Irrigation Water Requirements (NIR)

NIR is the depth of irrigation water, exclusive of effec-

tive precipitation and moisture stored in the root zone near the

end of the growing season, required consumptively for crop

production. It includes the amount of water to moisten the soil

prior to planting, whenever it is needed.

A specially designed Irrigation Master Spreadsheet (IRRMA-

ST) was used to compute the net irrigation requirement for each

agroclimatological zone represented by selected weather

stations. Parameters used and intermediate computations made

25

included the following:-

3.5.1.1 Monthly Reference Crop Evapotranspiration (ETo)

ETo is defined as " the rate of evapotranspiration from an

extensive surface of 8-15 cm tall, green grass cover of

uniform height actively growing, completly shading the

ground and not short of water.

The 1988/89 monthly potential evapotranspiration estimates

for the following selected stations were used as the

monthly grass reference evapotranspiration of the

agroclimatological zones they represent:-

- Zone 1 Average ETo of El-Baqura and Deir Alla sta-

tions.

- Zone 2 ETo of South Shuneh station.

- Zone 3 ETo of Ghor Safi station.

- Zone 4 Average ETo of Samar and Deir Alla stations.

- Zone 5 Average ETo of Irbid, Baq'a and Ras Muneef

stations.

- Zone 6 ETo of Mushaqqar station.

- Zone 7 ETo of Amman Airport station.

- Zone 8 ETo of Rabba station.

- Zone 9 ETo of Shoubak station.

- Zone 10 ETo of Um Jmal station.

- Zone 11 ETo of Azraq North station.

- Zone 12 Average ETo of Aqaba and Qa'Disi stations.

REF-ET program provided by Dr. R. Allen was used to compute

ETo for each zone. This program allows monthly

computations by different methods using several forms of

the Penman and other equations for all the above stations.

These methods include the following:-

- Penman-Monteith (PMon)

- 1982 Kimberly Penman (KPen)

- FAO-ID-24 Corrected Penman (FcPn)

- 1963 Version of Original Penman (63Pn)

- 1985 Hargreaves (Harg)

- FAO-ID-24 Radiation (FRad)

- FAO-ID-24 Blaney-Criddle (FB-C)

26

- FAO-ID-24 Pan Evaporation (FPan)

Monthly estimates of potential evapotranspiration (ETp)

reported in WAJ monthly summaries were compared to the

results of the above methods and were found to be in good

agreement with the 1963 version of the Penman equation and

the 1989 version of the Penman-Monteith resistance equation

by Allen et al (1989). An average value of monthly ETo

obtained by these two methods was therefore adopted.

The weather data used in REF-ET program were as follows:

- Weather station elevation, m

- Weather station latitude, deg.

- Mean max daily air temperature,oc

- Mean min daily air temperature,oc

- Average daily vapor pressure, mb

- Mean daily wind speed, km/day

- Percent of sunshine hours, decimal

- Pan evaporation, mm/d

A sample of input data and output results of ETo

computations in addition to the Eto results for

representative stations are shown in Annex 9 and Annex 10

respectively.

3.5.1.2 Average Planting Date

Average planting date for the crop was established for

winter and summer plantings in the Uplands and for the

major planting seasons in the Jordan Valley.

3.5.1.3 Length Of Growing Season

Length of growing season was represented by the total

number of days from planting until harvesting date. The

growing season length was entered for each crop in each

zone.

3.5.1.4 Crop Coefficients Kc

Crop Coefficient is the ratio between crop evapotranspirat-

27

ion (ETc) and the reference crop evapotranspiration (ETo) of

a disease-free crop grown in a large field under optimum

soil water and fertility conditions and achieving full

production.

Using the FAO-24 procedure, Crop Coefficients were computed

by the IRRMAST program. Initial crop coefficient (Kci) for

seasonal crops was calculated using an equation which

replicates Figure 8 of FAO-24. This equation required the

knowledge or estimation of Eto and irrigation/rainfall

wetting frequency during the initial growth stage period.

The Kci values for perennial crops were entered as constants

using the corresponding tables from FAO-24. The mid season

(Kcms) and harvest (Kchv) crop coefficients in addition to FAO

initial, crop development, mid season, and late season

lengths were entered from the FAO-24 publication . Using

the three FAO crop coefficient values and development

stages the IRRMAST program allows the FAO crop coefficient

curves to be stretched or compressed to better fit actual

conditions based on the crop's actual growing season length

entered for each zone. The latter procedure has an impor-

tant influence on resulting estimates of irrigation water

requirements.

3.5.1.5 Crop Evapotranspiration, ETc

ET crop is defined as the rate of evapotranspiration of a

disease-free crop growing in a large field under non re-

stricting soil water and fertility conditions and achieving

full production potential; mm/day.

The monthly crop evapotransipiration (ETc) was computed

according to the following equation:

ETci = Kci*EToi

Where

ETci = crop evapotranspiration for month i

EToi = reference evapotranspiration for month i

Kci = crop factor for month i

28

Results of monthly crop evapotranspiration for each zone

are shown in ANNEX 13.

3.5.1.6 Daily Average Rainfall

Because rainfall changes rapidly with distance and eleva-

tion, and because there is a high density of rainfall guag-

ing stations in Jordan, use was made of Jordan's 1988/89

isohyetal map from which areal rainfall distribution was

used to determine average annual precipitation in each

agroclimatological zone. The monthly distribution of rain-

fall in each zone was then assumed to follow that of a

selected rain guage station representing that zone. The

monthly total rainfall thus obtained was converted into

daily average rainfall for use by the IRRMAST program.

See ANNEX 11.

3.5.1.7 Effective Rainfall (Peff)

Effective Rainfall depends on factors like physical soil

characteristics, slope, rainfall intensities, and degree of

ground cover. Most of these factors could not be

determined in detail. Therefore, the effective rainfall

was taken as 70% of daily average rainfall. The 30% loss

represents losses due to interception and occasional runoff

during intense events. Peff was assumed to be zero for crops

grown in green houses.

3.5.1.8 Monthly Rainfall Frequency

Monthly Rainfall Frequency represents the interval in days

between two rainy periods in the month. It is required for

calculating the crop coefficient during the initial growth

stage and is computed by dividing the number of days per

month by the number of rainy days for which precipitation

exceeds 2 mm/day. See ANNEX 11.

3.5.1.9 Late Season Depletion (LSD)

Late season depletion is calculated to include the practice

of utilizing moisture stored in the root zone near the end

of the growing season, without replacing it. This soil

moisture depletion is then replenished by precipitation

29

during offseason, or by a future preplant irrigation.

Late season depletion was computed as the minimum of 1) the

allowable depletion (AD) based on available moisture (AM),

management allowed depletion percentage (MADP) and maximum

rooting depth (Rz max) of a full grown crop; and 2) a User

Specified Maximum Allowed Depletion (USMD) due to cultural

or other requirements.

The allowable depletion in mm is computed as:

AD = AM (MADP/100) (Rz max)

Whereby, AM is the total available water stored in the root

zone (one or two days after irrigation) represented by the

soil water content between field capacity and wilting

point. AM varies with the type of soil and was set in

average to 150 mm/m soil depth. The MADP represent the

level of maximum allowed soil water depletion tolerated to

maintain potential crop growth and it varies with the type

of crop. MADP and Rz max were obtained from FAO-24, Table

39.

The User Specified Maximum Allowed Depletion (USMD) for

root crops such as carrots, potatoes and onions was set to

10mm to assure a moist soil during harvest to facilitate

extraction of the crop from the soil without damage to the

crop in order to produce acceptable yields. While for

other crops such as wheat and barley, which tolerate higher

depletion levels, USMD was set to 100mm.

3.5.1.10 Cumulative Net Effective Precipitation During The

Offseason (CNEPO)

Cumulative Net Effective Precipitation during the offseason

is calculated so that the actual soil moisture depletion at

the planting date can be computed based on the estimated

late season depletion amount and net precipitation accumu-

lated between harvest and planting dates.

3.5.1.11 Allowable Depletion During the Initial Period

(ADI)

30

AD is used to represent the amount of moisture which may be

deficient in a dry seed bed and that is required to moisten

the seed bed. It is computed as:

ADI = AM (MADP/100) (Rz I)

Whereby, Rz I is the root depth during the initial period,

Rz I for an annual crop (planted each year) and was

estimated as the planting depth of the seed plus 5 to 10 cm

to represent upward movement of moisture toward the seed,

and rapid, downward development of the roots during the

initial period. A typical value used was 0.15 m. For

perennial crops, a value of 0.7 m was used.

3.5.1.12 Minimum Possible Irrigation Depth (MPID)

MPID is the minimum depth of water that can physically be

added to the soil due to constraints in the irrigation

application system. A surface system may have to apply

40mm as an average irrigation depth in order to push enough

water across the basin or along the furrow to just

infiltrate 5mm at the furthest point. Therefore, one could

say that the MPID is 40 for a surface irrigation system.

Because drip and sprinkler irrigation systems can be better

controlled, the MPID for these systems is near zero.

Therefore, the MPID for the spreadsheet computations were

weighted according to the percentage of surface, drip and

sprinkler systems in the agroclimatic area as:

MPIDavg = MPIDsurf * % Surface

3.5.1.13 Preplant Irrigation Depth

In general, the preplant irrigation depth, if needed, was

set equal to the minimum physically possible net irrigation

depth, unless the ADI less net precipitation or the Late

Season Depletion less the Cumulative Net Effective Precipi-

tation during the nongrowing season is greater than this

amount. In this case, the preplant irrigation depth was

set equal to the maximum of these three values. The

preplant irrigation amount is subject to the consideration

that the same crop is planted each year, and just once per

31

year, on the same land unit.

Finally, the Net Irrigation Water Requirement is computed

as follows:-

If in the open field, then:

If ETc i > 0 then:

NIRi = Max ((ETc i - Peff i )(Daysi), -0.5AD) + PPIi -LSDi

Otherwise:

NIRi = PPIi - LSDi

If in a plastic house, then:

NIRi = ETc i (Days) +PPIi - LSDi

The maximum of net ETc and -0.5AD is used in the first

equation so that excess precipitation during rainy months

(where ETc i - Peff i is negative) does not exceed the average

ability of the soil to retain it in the root zone. This

average ability (or capacity) is estimated to be one half

of the maximum allowable depletion of the soil. A future

review could improve this approach by surveying for each

irrigated area the actual soil depth and the available

water holding capacity. These data together with root

depth and capillary rise provide adequate information to

compute the maximum water storage in the soil for each crop

or group of crops.

It should be noted here that, whenever negative values of

NIR were encountered during months when effective

precipitation exceeded evapotranspiration requirements,

such values were added to the following month. Negative

values at the end of the growing season were discarded and

were set to zero. This way, the total NIR included the

benifit and effect of useable excess precipitation during

the negative value months.

32

Sample output of NIR computations done by IRRMAST program

in addition to the monthly NIR results for each crop in

each zone are shown in ANNEX 12 and ANNEX 14 respectively.

3.5.2 Gross Irrigation Water Requirement (GIR) (FAO 24)

GIR is equal to the Net Irrigation Requirement plus the

amount of water required to compensate for water losses during

conveyance and application and for leaching of accumulated salts

from the root zone; i.e GIR is the irrigation requirement at the

source of irrigation supplies. It is a function of the net

irrigation requirement, salt concentration of irrigation water

and the type of irrigation system according to the following

equation:-

GIR = NIR/ Effov/(1-LR)

Where

NIR = Monthly Net Irrigation Crop Water Requirement

Effov = Overall Irrigation Efficiency, decimal.

LR = leaching ratio, decimal.

As mentioned earlier, computations of monthly GIR

proceeded on a village by village basis using information on the

monthly crop water requirements, and overall efficiency of the

corresponding agroclimatological zone, in addition to the

leaching requirements computed for every documented village.

The estimation of project irrigation efficiency and leach-

ing requirements are discussed below:-

3.5.2.1 Irrigation Efficiency

As explained earlier in Section 3.2.2 of this report, rele-

vant data on irrigated areas with the different irrigation

techniques were not readily available for all the MOA docu-

mented irrigated villages. Therefore, a methodology was

adopted to estimate the overall irrigation efficiency in

each agroclimatological zone. As detailed data on the

actual conditions were lacking, the overall efficiency thus

estimated is thought to be realistic and representative for

all the villages in the same zone.

33

Details of the methodology employed to compute projects'

irrigation efficiencies are described in ANNEX 1 of this

report.

3.5.2.2 Leaching Requirements (LR)

LR is the minimum amount of irrigation water used to

control soil salinity. Soil salinity is mainly affected by

the quality of irrigation water, irrigation methods and

practices, rainfall and soil conditions. The leaching

ratio was computed based upon average crop tolerance

obtained from FAO-29, and the weighted average salinity of

irrigation water of the sources asssociated with the

documented irrigated areas at each village. The leaching

Ratio is computed according to the following equation (from

FAO-29):-

LR =ECw / (5ECe - ECw)

Where

ECw is the average electrical conductivity of the

irrigation water of the water sources associated with each

village, dS/m (or mmhos/cm). ECw for each source was

obtained from WAJ and JVA files.

ECe is the electrical conductivity of the saturation

extract of the soil, dS/m. It represents the average crop

tolerance level before crop yields begin to decrease.

Typical ECe values in dS/m assuming no reductions in crop

yields, were obtained from FAO-29.

The above equation was used in project areas where the drip

system is used as the primary method of irrigation, such as

in the Southern Ghors, where salinity problems are

frequently encountered. However, with on-farm irrigation

efficiency below 80%, it was assumed that the total deep

percolation losses from normal irrigation practices were

used in controlling salinity. Comparison was made between

the water needed for leaching in excess of the crop's total

annual Net Irrigation Requirement, and percolation losses.

34

Extra water for leaching was assumed to be needed whenever

the following was applicable:-

If (NIR/(1-LR)) - (NIR/EFFon-farm) = X > 0

Where:

NIR = Total Annual Net Irrigation Crop

Water Requirement.

Effon-farm = On-farm Irrigation Efficiency, decimal.

LR = leaching ratio computed earlier,

decimal.

and

NIR/1-LR = Water required to meet crop Net Water

Requirement and leaching.

NIR/EFFon-farm = Water required to meet crop Net Water

Requirement and deep percolation losses

Then the leaching Ratio was modified according to the fol-

lowing equation:-

LRmod = X / (NIR + X)

Where

LRmod = Modified Leaching Requirement

Estimates are based on assumbtion of a 100% leaching effi-

ciency. Inclusion of a leaching less than 100% efficient

may be necessary under some conditions, but such a factor

should be determined under field conditions.

35

3.6 Return Flow (RF)

As outlined in Section 3.9 of this report, return flow is

set equal to the following:

If the Irrigation Abstractions (IrrAbs) is less than the

Gross Irrigation Requirement (GIR) then:

RF = IrrAbs (1-NIR/GIR)(IrrAbs/GIR)

The (IrrAbs/GIR) term in the above equation is included to

approximate the relative increase in irrigation efficiency when

supplies are less than requirements. This assumes that irriga-

tors become more efficient in utilizing the scarce resource.

If, on the other hand, IrrAbs was equal to GIR, then:

RF = GIR - NIR

Return Flow in areas irrigated from wells is assumed to

return to the local ground. The percentage of irrrigation

return flows going back to the groundwater system has to be

identified under field conditions. It depends on such factors

as the level of the water table, type of soil, and local

climatic conditions. In areas irrigated from Side Wadis in the

uplands, it is assumed that percolated quantities will reappear

in the wadi bed. However, losses in the Jordan Valley and

Southern Ghors are assumed to go to the ground regardless of the

irrigation source type. Where irrigation water originates from

springs, the return flow is assumed to go to the ground, provid-

ed that the topographic features of the irrigated village allow

that.

Finally, whenever irrigation water originates from more

than one source type, the portions of return flow which goes to

the ground and to the surface are generally determined in view

of proximity of the village to a nearby wadi. If the irrigated

lands are greater than 1 Km from a wadi then all deep

percolation is assumed to go to the ground. If the lands are

within 1 Km of a wadi, then it is assumed that an amount

proportionate to the distance makes its way to the groundwater,

with the balance going to the wadi. Other factors taken into

consideration include topographic features and the presence of

36

high water table.

3.7 Net Irrigation Consumption (NIC)

This is the actual diverted irrigation water which is evap-

orated from the village. It does not include evaporated effec-

tive precipitation.

NIC = IrrAbs - RF

3.8 Total Actual Crop Evapotranspiration (TAET)

This is the actual rate of evapotranspiration (including

effecective precipitation) which might be equal or less than the

predicted crop evapotranspiration, depending on the level of

available soil water, salinity, field size and other causes. It

is set equal to:

TAET = ETc - (NIR - NIC)

3.9 Programming Approach

The following approach was used to program the data base to

make the necessary computations needed to estimate the present

water use of irrigation water in the Kingdom. The DB

programming language of DBASE IV was utilized to carry out the

required computations.

3.9.1 General Steps

The general steps or "loops" are described below. The

general structure of these steps has been described using a

"Basic" language structure. This is done only to facilitate

expression. The actual form of the computation steps corresponds

to the programming requirements of the DBASE language.

FOR EACH CLIMATIC SCENARIO (88-89, Dry, Average, Wet):

FOR B = 1 to Number of BASINS

FOR S = 1 to Number of SUBBASINS in BASIN #B

FOR V = 1 to Number of Villages in SUBBASIN #S

37

FOR M = 1 to to 12 Months

FOR I = 1 #Water Sources for Village V

Find Monthly Information for Water Source

from Well, Spring, or Wadi DataBases (Q, ECw,

etc)

Determine monthly total sum of source water

for the village (total and by type

ofsource):

SUMsources m,v = SUMsources m,v + (Qm,i - other abstra-

ctions) * no. hrs/day * no. days/mo. (Units

of SUMsources m,v are m3/month)

If source is a well then:

SUMwells m,v = SUMwells m,v + (Qm,i - other abstrac-

tions for well) * no. operation hrs/day *

no.days/mo.

If source is a spring then:

SUMsprings m,v = SUMsprings m,v + (Qm,i - other abst-

ractions for spring) * no. hrs/day * no.

days/mo.

If source is a wadi then:

SUMwadis m,v = SUMwadis m,v + (Qm,i - other abstrac-

tions for wadi) * no. hrs/day * no. days/mo.

Determine weighted EC value for sources

sumECw,m,v = sumECw,m,v + ECw i * (Qm,i - other

abstractions)

Determine the percentage (or ratio) of each

source type:

Wellsm,v = SUMwells m,v / SUMsources m,v

38

Springsm,v = SUMsprings m,v / SUMsources m,v

Wadism,v = SUMwadis m,v / SUMsources m,v

Ave ECw,m,v = sumECw,m,v / SUMsources m,v

NEXT I

NEXT M

Determine an average monthly value for Ave ECw,m,v:

Ave ECw,v = SumAve ECw,m,v /12

Get ET and NIR information from the corresponding

Irrigation Water Requirement Sub-Data Base for the

appropriate Agroclimatic zone and Climatic Scenario

for each crop and for each of 12 months. Also get on-

farm (Effon-farm) and overall irrigation efficiencies

(Effov) from the Irrigation Efficiency Sub-Data Base

for the appropriate Agroclimatological zone in

addition to ECe information for each crop .

FOR M = 1 to 12 (Months)

FOR C = 1 to No. Crops (41 or so)

Compute Leaching Requirement:

LRc,v = (ave ECw,v)/(5ECe c - ave ECw,v)

If LRc,v > 1-EFF on-farm THEN:

Assuming (1/(1-LRc,v))-(1/EFF on-farm) = X

Then the modified leaching Ratio is:

LRmod c,v = X / (1+X)

Otherwise, LRmod c,v = 0

39

Compute Gross Irrigation Requirement:

GIRm,c = NIRm,c/(Effov(1- LRmod c,v))

(m3/du)

SUM GIR, ET, and NIR across all crops:

sumGIRm,v = sumGIRm,v + GIRm,c * AREAc,v

sumNIRm,v = sumNIRm,v + NIRm,c * AREAc,v

sumETm,v = sumETm,v + ETm,c * AREAc,v (m3)

NEXT C

Compute the Irrigation Abstraction for

Month M for Village V:

- For areas with no records:

IF sumGIRm,v > SUMsources m,v THEN:

IrrAbsm,v = SUMsources m,v

(this assumes that all source water in

excess of domestic and other uses is

diverted to irrigation).

IF sumGIRm,v <= SUMsources m,v THEN:

IrrAbsm,v = sumGIRm,v

(this assumes that the source quantity

exceeds the gross irrigation water re-

quirement. Therefore, only the gross

irrigation water requirement is assumed

to be abstracted. The balance of the

source for wadis and springs is assumed

to return to the wadi. For a well, it

can be assumed that the well is turned

off).

- For JVA commanded areas with

available records:

SUMsources m,v = IrrAbsm,v

40

Compute the Return Flow for Month M for

Village V:

FOR WELLS:

if SUMsources m,vfor 24hr x no. days/mo op-

eration < sumGIRm,v then:

Assume Continuous Operation since

the source is less than the re-

quired GIR and:

RFm,v,w = IrrAbsm,v (1-

NIRm,v/GIRm,v)(IrrAbsm,v/GIRm,v)(Well-

sm,v)

The (IrrAbsm,v/GIRm,v) term in the

above equation is included to ap-

proximate the relative increase in

irrigation efficiency when

supplies are less than

requirements. This assumes that

irrigators become more efficient

in utilizing the scarce resource.

Wellsm,v is the relative proportion

of wells in the total water source

(computed previously).

if SUMsources m,v for 24hr x no. days/mo

operation >= sumGIRm,v then:

The well source is more than ade-

quate to fulfill the gross irriga-

tion water requirement, and the

well will likely be turned off

during surplus periods.

Therefore:

RFm,v,w = (GIRm,v - NIRm,v) Wellsm,v

where RFm,v,w represents deep perco-

41

lation during month m for village

v, for wells and Wellsm,v is the

relative proportion of wells in

the total water source (computed

previously).

Return flow from wells is assumed

to go to the ground.

FOR SPRINGS and WADIS :

- For areas with no records

if SUMsources m,v for 24hr x no. days/mo

operation < sumGIRm,v then:

Assume Continuous Operation since

the source is less than the requi-

red GIR, and:

RFm,v,s = IrrAbsm,v (1-

NIRm,v/GIRm,v)(IrrAbsm,v/GIRm,v)(Wadi-

sm,v+

Springsm,v)

The (IrrAbsm,v/GIRm,v) term in the

above equation is included to ap-

proximate the relative increase in

irrigation efficiency when

supplies are less than

requirements. This assumes that

irrigators become more efficient

in utilizing the scarce resource.

if SUMsources m,v for 24hr x no. days/mo

operation >= sumGIRm,v then:

The water source is more than ade-

quate to fulfill the gross irriga-

tion water requirement, and the

42

excess flow will be discharged to

a nearby wadi. Therefore:

RFm,v,s = (Wadim,v + Springsm,v)*

(GIRm,v-NIRm,v)

where RFm,v,s represents deep perco-

lation from irrigation

infiltrating below the root zone

during month m for village v. It

is assumed that return flows from

Side wadis in the uplands would

return to the surface water and

that the percolated quantities

will reappear in the wadi bed, and

return flows from springs return

to the ground provided there were

no significant Wadi courses in the

vicinity of the irrigation area.

Return flow in the Jordan Valley

and Southern Ghors are assumed to

go to the ground.

- For JVA commanded areas with

available records:

if SUMsources m,v which is equal to the Ir-

rigation Abstractions < sumGIRm,v then:

RFm,v,s = IrrAbsm,v (1-

NIRm,v/GIRm,v)(IrrAbsm,v/GIRm,v)(Wadi-

sm,v)

if SUMsources m,v >= sumGIRm,v then:

RFm,v,s = (Wadim,v)(SUMsources m,v-NIRm,v)

Return flows in the Jordan Valley

are assumed to go to the ground.

FOR WELLS, WADIS and SPRINGS:

43

Determine the portion of RF which

goes to the ground and the portion

which is goes to the surface (wa-

di). Assume that 20% of the

percolated flow which reaches a

wadi is lost to seepage and evapo-

ration by natural plants.

Assume that if the irrigated lands

are greater than 1 km from a wadi,

that all deep percolation goes to

ground. If the lands are within 1

km of a wadi, then assume that an

amount proportionate to the dis-

tance makes it way to the ground,

with the balance going to the

wadi. Return flow computations

are subject to the following con-

siderations:-

If SUMsources m,v < sumGIRm,v then:

Both wells and springs sources are

less than adequate to fulfill the

gross irrigation water

requirement, and it is most likely

that all sources will be used for

irrigation.

If X = distance from Irrigated

land to Wadi and

If X >= 1 km, then

RFm,v,GR = RFm,v,w + RFm,v,s

where,

RFm,v,w = IrrAbsm,v (1-

44

NIRm,v/GIRm,v)(IrrAbsm,v/GIRm,v)(Well-

sm,v)

and

RFm,v,s = IrrAbsm,v (1-

NIRm,v/GIRm,v)(IrrAbsm,v/GIRm,v)

(Wadism,v+Springsm,v)

and all return flows are assumed

to go into the groundwater.

If X < 1 km, then

RFm,v,GR = X/1 (RFm,v,w + RFm,v,s)

RFm,v,SURF = (1-X/1)

(RFm,v,w + RFm,v,s)(.8)

RFm,v = RFm,v,GR + RFm,v,SURF

where RFm,v,GR is the return

flow for month m, village v

returning to the ground, m3-

/mo, and RFm,v,SURF is the return

flow returning to a surface

wadi. RFm,v is total return

flow for month m and village

v.

If SUMsources m,v >= sumGIRm,v then:

IrrAbsm,v = sumGIRm,v

check if SUMwells m,v are sufficient

to fulfill the gross irrigation

water requirement. Wells are as-

sumed to be used first.

45

If SUMwells m,v >= sumGIRm,v then

all water in the amount of gross

irrigation water requirement is

assumed to be abstracted from

wells and

Wellsm,v,modified = IrrAbsm,v/sumGIRm,v

= 100%

and

Springsm,v,modified = zero

If X >= 1 km, then

RFm,v,GR = RFm,v,w + RFm,v,s

where,

RFm,v,w = (GIRm,v-NIRm,v)(100%)

and

RFm,v,s = zero

and all return flows are assumed

to go to the ground.

If X < 1 km, then

RFm,v,GR = X/1 (RFm,v,w)

RFm,v,SURF = (1-X/1)

(RFm,v,w)(.8)

RFm,v = RFm,v,GR + RFm,v,SURF

where RFm,v,GR is the return

flow for month m, village v

returning to the ground, m3/-

mo, and RFm,v,SURF is the return

flow returning to a surface

46

wadi. RFm,v is total return

flow for month m and village

v.

If SUMwells m,v < sumGIRm,v then

All water in the amount of

SUMwells m,v is abstracted from wells,

with the balance of the gross

irrigation water requirement

abstracted from springs.

Therefore,

Wellsm,v,modified = SUMwells m,v/sumGIRm,v

and,

Springsm,v,modified = (sumGIRm,v

-SUMwells m,v)/SumGIRm,v

If X >= 1 km, then

RFm,v,GR = RFm,v,w + RFm,v,s

where,

RFm,v,w = (GIRm,v-NIRm,v)(Wellsm,v)

and

RFm,v,s = (GIRm,v - NIRm,v)

(Springsm,v)

and all return flows are assumed

to go to the ground.

If X < 1 km, then

RFm,v,GR = X/1 (RFm,v,w + RFm,v,s)

RFm,v,SURF = (1-X/1)

(RFm,v,w+RFm,v,s)(.8)

47

RFm,v = RFm,v,GR + RFm,v,SURF

where RFm,v,GR is the return

flow for month m, village v

returning to the ground, m3/-

mo, and RFm,v,SURF is the return

flow returning to a surface

wadi. RFm,v is total return

flow for month m and village

v.

Compute the Net Irrigation Consumption

for Month M for Village V:

(This is the actual diverted irri-

gation water which is evaporated

from the village. It does not

include evaporated effective pre-

cipitation).

NICm,v = IrrAbsm,v - RFm,v

Compute the Total Actual Evapotranspi-

ration for Month M for Village V:

(TAET includes NIC plus evaporated

precipitation)

TAETm,v = sumETm,v - (sumNIRm,v - NI-

Cm,v)

(sumNIRm,v - NICm,v can be thought of

as representing the consumptive

deficit of irrigation water)

Sum up Monthly Values into Annual To-

tals:

AnnualGIRv = AnnualGIRv + sumGIRm,v

AnnualNIRv = AnnualNIRv + sumNIRm,v

AnnualETv = AnnualETv + sumETm,v

AnnualIrrAbs= AnnualIrrAbsv +

IrrAbsm,v

48

AnnualRFv = AnnualRFv + RFm,v

AnnualRFv,GR = AnnualRFv,GR + RFm,v,GR

AnnualRFv,SURF = AnnualRFv,SURF +

RFm,v,SURF

AnnualNICv = AnnualNICv + NICm,v

AnnualTAETv = AnnualTAETv + TAETm,v

AnnualSources v = AnnualSources v

+ SUMSources m,v

Store Monthly values of GIR, NIR, ET,

IrrAbs, RF, NIC, TAET and SumSources

for village v

Sum Monthly Values for Villages in Sub-

Basin

GIRs,m = GIRs,m + sumGIRm,v

NIRs,m = NIRs,m + sumNIRm,v

ETs,m = ETs,m + sumETm,v

IrrAbss,m = IrrAbss,m + IrrAbsm,v

RFs,m = RFs,m + RFm,v

RFs,m,GR = RFs,m,GR + RFm,v,GR

RFs,m,SURF = RFs,m,SURF + RFm,v,SURF

NICs,m = NICs,m + NICm,v

TAETs,m = TAETs,m + TAETm,v

SUMsources s,m = SUMsources s,m

+ SUMsources m,v

Sum Monthly Values for Villages in

Basin

GIRb,m = GIRb,m + sumGIRm,v

NIRb,m = NIRb,m + sumNIRm,v

ETb,m = ETb,m + sumETm,v

IrrAbsb,m = IrrAbsb,m + IrrAbsm,v

RFb,m = RFb,m + RFm,v

RFb,m,GR = RFb,m,GR + RFm,v,GR

RFb,m,SURF = RFb,m,SURF + RFm,v,SURF

NICb,m = NICb,m + NICm,v

TAETb,m = TAETb,m + TAETm,v

SUMsources b,m = SUMsources b,m

+ SUMsources m,v

NEXT MONTH (M)

49

Store Annual values of GIR, NIR, ET, ArrAbs,

RF, NIC, TAET and SumSources for village v

Sum Annual Values for Villages in SubB-

asin

AnnualGIRs = AnnualGIRs +

AnnualGIRv

AnnualNIRs = AnnualNIRs +

AnnualNIRv

AnnualETs = AnnualETs + AnnualETv

AnnualIrrAbss = AnnualIrrAbss

+ AnnualIrrAbsv

AnnualRFs = AnnualRFs + AnnualRFv

AnnualRFs,GR = AnnualRFs,GR + Annu-

alRFv,GR

AnnualRFs,SURF = AnnualRFs,SURF +

AnnualRFv,SURF

AnnualNICs = AnnualNICs +

AnnualNICv

AnnualTAETs = AnnualTAETs + Annual-

TAETv

AnnualSources s = AnnualSources s

+ SUMSources v

NEXT VILLAGE

50

Sum Annual Values for Villages in Basin

AnnualGIRb = AnnualGIRb + AnnualGIRs

AnnualNIRb = AnnualNIRb + AnnualNIRs

AnnualETb = AnnualETb + AnnualETs

AnnualIrrAbsb = AnnualIrrAbsb

+ AnnualIrrAbss

AnnualRFb = AnnualRFb + AnnualRFs

AnnualNICb = AnnualNICb + AnnualNICs

AnnualTAETb = AnnualTAETb + AnnualTAETs

AnnualSources b = AnnualSources b

+ SUMSources s

NEXT SUBBASIN

Store Totals for the SUBBASIN

NEXT BASIN

Store Totals for the BASIN

REPEAT for the NEXT SCENARIO

Results are listed in a summary tables in ANNEX 15 of this

report.

51

3.9.2 Computation Examples for Springs

Example 1:

GIR = 1000 m3

NIR = 600 m3

Source = 700 m3

ET = 650 m3

Since the Source < GIR, then

IrrAbs = Source = 700 m3

Since the Source < GIR, then

RF = 700(1-600/1000)(700/1000) = 196 m3

NIC = 700-196 = 504 m3 (total evap. of diverted irrig. wat)

TAET = 650-(600-504) = 554 m3 (total evap., incl eff.

prec)

Example 2:

GIR = 1000 m3

NIR = 600 m3

Source = 500 m3

ET = 650 m3

Since the Source < GIR, then

IrrAbs = Source = 500 m3

Since the Source < GIR, then

RF = 500(1-600/1000)(500/1000) = 100 m3

NIC = 500-100 = 400 m3 (total evap. of diverted irrig. wat)

TAET = 650-(600-400) = 450 m3 (total evap., incl eff. prec)

Example 3:

GIR = 1000 m3

NIR = 600 m3

Source = 1200 m3

ET = 650 m3

Since the Source > GIR, then

52

IrrAbs = GIR = 1000 m3

Since the Source >= GIR, then

RF =1000 - 600 = 400 m3

NIC =1000-400=600 m3 (total evaporation of diverted irriga

gation water)

TAET =650-(600-600)=650 m3 (total evaporation including

effective precipitation)

53

4. Comments on the results

As mentioned befor, detailed results could be presented on

a village by village basis (see ANNEX 15 Table 1) but it would

be more reasonable to build up conclusions based on Zones and/or

Region basis which gives a clear picture about the requirements

of areas related to climatic conditions. Summarizing the results

of the computations ANNEX 15 Table 2, it appears that the Gross

Irrigation Water Requirements estimated at 649 MCM at 1988/89

climatic conditions fall within the expected range for the

cropped irrigated areas that were analyzed by this study. Of

this total, 271 MCM represents the Gross Irrigation Requirements

for the Jordan Valley areas. It does not, however, include areas

with no available cropping pattern, or areas developed but not

irrigated. There are 29,512 ha developed for irrigation in the

Jordan Valley inclusive of 5,975 ha developed under the KAC 14.5

Km Extension which were partly irrigated by wells, leaving the

remaining areas fallow.

Results of the Net Irrigation Requirements NIR per unit

area seems to be highest in the Eastern Desert Region (Zone11),

it amounts to 950 mm (Fig 9). This mainly affected by many fac-

tors; high Evapotranspiration levels, low Rainfall volumes and

adopted Cropping Pattern, mainly Fruit Trees represent 90% of

the total cropped area in that region. Similarly, the Southern

Desert Region (Zone 12) shows high NIR value of 704 mm due to

the same factors with Cropping Pattern dominated by Field Crops

at the rate of 93% of the total cropped area of that region see

(ANNEX 15 Table 3). Future attention must be taken when planting

crops of high water consumption with respective to locations and

water availability for irrigation.

The variation between Gross and Net Irrigation Requirements

results reflect the variation of system efficiencies in the

different Regions. Fig.10 presents these variations by Zone and

Region from. It indicate that the lowest variation occures in

the Southern Ghors Region (Zone 3), which actually enjoyes the

most efficient irrigation system with an overall efficiency of

72%. On the other hand, the largest variation occurs in Zone 4,

which is a part of the Highlands Region and represent the least

efficient irrigation system in the Jordan with an overall

efficiency of 41%.

54

Results of the annual irrigation abstractions in Jordan do

not include those from side wadis that were utilized to irrigate

areas outside the Jordan Valley Puplic Schemes. As noted earlier

in Section 3.3 of this report, discharge data along the side

wadis are not available, and are only measured at the outlet of

the catchment area. It is suggested that irrigated areas from

side wadis should be identified in the next phase of the

project, and point flow analysis for each catchment area be

carried out this would enable the estimation of the base flow at

any point of the stream based on upstream springs' discharges

and abstractions. Use can be made of the irrigation

abstractions from the springs, obtained in this phase of the

project. The difference between the sum of all springs sources

contributing to the base flow less the total upstream

absractions based on point flow analysis in each catchment area,

should approximate measurements recorded at the outlet of the

catchment area.

Estimated water use for irrigation in the Jordan Valley

amounted to 242 MCM, of which 210 MCM are the estimated water

use for the commanded area. It should be noted that this amount

does not include spills and uses for any purpose other than

irrigating actual cropped areas. Miscellaneous uses include

water pumped out from KAC at Deir Alla for domestic uses in

Amman, subsurface drainage, water rights, MOA gardens, pumping

stations at Abu Zeighan, etc..

Irrigation abstractions in the Southern Ghors is estimated

at 23 MCM used for irrigating the 3,274 ha cropped in

1988/89. It is considered to be a reasonable estimates when

compared with the JVA estimates of irrigation water uses of

about 26 MCM in 1991 corresponding to a cropped area of 4,000

ha. According to JVA, the said amount was used exclusively for

irrigation and does not include water allocated for washing

pipes and filters.

The estimated irrigation abstractions from wells and

springs are in the order of 224 MCM and 23 MCM respectively.

These amounts fall somehow below those of WAJ estimates, which

could be justified by different reasons. First is that, WAJ

estimates of irrigation abstractions from wells are based on the

total wells' tested yield and 14 hrs of operation per day

throughout 267 days a year. WAJ preliminary estimates were

55

initially used in areas where irrigation water originates from

more than one source type; i.e wells and springs/or Side Wadis.

Use was made of the Net Irrigation Requirement information to

modify assumptions made by WAJ with regards to the monthly and

annual operating hours. Due to lack of information on the

irrigated acreages from each source type, the distribution of

irrigation abstractions according to the irrigation source was

based on fixing the amounts of water used for irrigation from

the wells. Wells are hence assumed to be used first, since

there must have been some reason for these wells in the first

place. However, there is no way to verify whether farmers pump

out water in excess of their crops irrigation water

requirements. Elsewhere in the areas irrigated from either wells

or springs only, continuous operation over the month was assumed

and the source capacity is compared with the gross irrigation

requirement in order to estimate the actual abstractions.

Other main reasons contributing to the discrepancies ob-

served between the irrigation water use estimates in this report

and those of WAJ include, Errors in linking water sources to

villages. As explained earlier no complete records are main-

tained that document all irrigated lands and the source of

irrigation water, and frequently arbitrary decisions had to be

made about the village's relative sources. And finally, the

results of this report does not cover all irrigated villages in

Jordan or those irrigated areas with no available cropping

pattern. For details please refer back to Section 3.3.

Return flow results are represented by two portions, one

that directly goes to Surface estimated at 8.1 MCM and the other

make its way to Ground which estimated at 188 MCM. The later

portion does not necessarily add to the Groundwater table, most

of it lost as evaporation or reappear in the Surface water

system or partially goes to the Groundwater system. From the

results it appears that the largest amounts of return flow are

in the Jordan Valley Region which also posseses the largest

amounts of irrigation diversions. However, The irrigation

diversions from side wadis in this region not governed by the

comparisons with the Gross Irrigation Requirements but it

considered to be the actual irrigation diversions which may

contribute to the large amounts of return flow results in that

region.

56

For more accurate figures on the assessment of the return

flow which goes to either Surface or Groundwater system, it is

suggested that the Balance Modle of the Surface Drainage basins

could be used for this purpose which considered the total

amounts that feed the basin inflow from certain sources and the

amount of outflow measurement of the catchment area. The

difference between the two amounts would represent the portion

of irrigation return flow that add to the surface water system

plus the amount that comes from some seepes. It also consider

that of the total return flow that goes to the ground, only 10%

may be added to the groundwater table.

Results of the Net Irrigation Consumption (NIC) represent

the amount of actual diverted irrigation water which is

evaporated excluding the evaporated effective precipitation.

When large quantities of NIC results appear, this means that the

Irrigation Abstractions are high and occasionaly the Irrigation

Requirements of that area are also high. The same is said to be

true when large amounts of Total Actual Evapotranspiration

results also appear which represent the total actual amounts

that evapotranspirated including the NIC plus evaporated

precipitation. A comparison between the variation of NIR and NIC

and the variation of ET and TAET would give the same reflection

of the consumptive deficit of irrigation water Fig.11. Logicaly

this is true but according to the results of this report it is

not necessarly true i.e the maximum variation between NIR and

NIC or between ET and TAET that occures in Zone 8 (Southern

Highlands) not necessarly indicte maximum level of consumptive

deficit of irrigation water but it may be due to unavailable or

incomplete data on the water resources used to irrigate areas in

that Zone or due to incorrect allocation of water resource and

the associated village that irrigate in the same mentioned Zone.

57

5. Recommendations

This report established a detailed procedure for the

assessment of irrigation water requirements and water use of the

irrigated agriculture in Jordan. Future reviews might require

the extension and/or refinement of the program developed for

this purpose to enable it to deal with more details. The

database can also be extended and/or modified based on improved

data availabilty. A separate input/output model might have to

be developed for the Jordan Valley Area such that the Gross

Irrigation Requirements can be computed for each project area,

based on the corresponding overall efficiency instead of a

weighted overall efficiency representing the zone in which it is

located.

Surveys have to be carried out to modify assumptions made

during the preparation of this report to supplement existing

data. These assumptions should become the subject of future

surveys.

5.1 Surveys on Irrigated lands

A full scale survey should be considered as a joint effort

to be undertaken by the agencies involved. The survey on the

lands irrigated from wells, springs and side wadis made thus far

by the DOS could be extended to include cropping pattern.

Adequate cooperation between the DOS and MOA should be ensured.

Analysis of data provided by LASD confirm earlier conclusions

with regards to the incompleteness of the MOA records.

Communication between the agencies concerned is therefore highly

recommended. All surveys should be geared to to ugrade the

knowledge on the actual irrigated acreages, irrigation water

requirements and uses. Land use surveys would have to include

the following:-

- Irrigated Area including areas kept fallow

- Location; Village Name

- Area cropped in Summer

- Area cropped in Winter

- Area used for two crops simultaneously including types

of crops. Notice that all the above information would help

identify cropping intensity

58

- Source of Irrigation:-

If source is Wells, then indicate the following:

- No. of operating wells used for irrigating the area

- Name of Owner, if private well

- Operating time; hrs/day * No. of operating days

per each month.

If source is a Spring or Side Wadi, then indicate the

source identification by name

- Cropping Pattern, including information on the

method of irrigation used for each crop.

- Type of Conveyance and distribution system used; piped

system, cement canals or open ditches.

The above land use survey should also include all areas

with water rights to springs and side wadis. These areas should

be dealt with carefully in close collaboration with the Lands

and Survey Department, (LASD). LASD maintain records of all

such lands. They include such information as: village, spring's

name, land basin name, unit number, area of the land with water

rights, owner's name, and water quota. These records, however,

do not tell anything about the actual areas irrigated each year.

Areas with water rights have to be identified separately and

then, following the same recommendations outlined above, areas

irrigated each year can be identified easily.

Data gathered based on the above recommendations would have

an important implication on the design of the Village

Information database and its sub-data bases. These would have

to be modified to include for each village the cropped areas

which are irrigated from each source type.

5.2 Irrigation Efficiency

Data on the Overall Irrigation Efficiency in the private

schemes were scarce. Field observations should be carried out

in sample areas representing the agroclimatic zones, to

determine the actual application, conveyance and distribution

efficiency. Areas with limited water resources and those with

sufficient water should be studied separately.

59

In the Jordan Valley data records should be extended to

include irrigation diversions at the farm turnouts which corre-

spond to the documented farm deliveries. Accurate and timely

measurement of inflow water, lateral turnout and farm turnout

discharges and spills is required to identify the actual

administrative and physical losses in each of the conveyance and

distribution systems. This should be supplemented by actual

physical losses and field observations in the future.

Realizing the importance of improved measurements in the

Jordan Valley, JVA has already made a first step in this respect

under phase II of the Computerized Management Information System

Project. This phase includes the implementation of a computer-

ized water management module and the installation of a net of

water flow measurement devices throughout the valley. Water

meters should be installed at critical locations such that the

determination of actual water diverted at the project inlet and

to each component therafter, can be made possible.

5.3 Data Related to Water Use

Until continuous and systematic monitoring of pumpage rates

from wells throughout the Kingdom is implemented, land use

survey as outlined earlier, would have provisionally to deal

with estimated pumpage rates based on inquiries made during a

dry, average and wet conditions to provide data about the

operating time during each month of the year.

In the absence of information related to the actual irriga-

tion abstractions from springs, the approach adopted in this

report for such assessment would still have to be used for

future estimations, provided that a more complete set of data is

ensured.

The survey on land use suggested above, should help

identify the areas irrigated from side wadis and the gross

irrigation requirement can therefore be tentatively assumed to

be abstracted. If however, side wadis discharge measurements

were made at regular intervals along the wadi, then comparison

can be nade between the source capacity and the Gross Irrigation

Requirement of the relative irrigated area. The Irrigation

Abstractions would then assume the least value.

60

Finally, installation of flow meters on wells and

developing inflow/outflow water balance models in each catchment

area based on regular field surveys and measurements should be

of great benifit.

5.4 Data Related to the Computation of Net Irrigation Require-

ments

- The extent to which actual dew formation could affect

the consumptive use of water in the desert regions with

relatively humid air, should be evaluated.

- Rainfall-runoff-infiltration models for local topograph-

ic -soil systems tested under field conditions through adequate

guaging installations (rainfall, surface inflow/outflow and

evapotranspiration) in small trial catchments, should help

produce information on the actual and potential infiltration

rates corresponding to the specific soil conditions.

5.5 Data Related to Water Quality

An intensive national water quality program should be

adopted to cover the whole kingdom and update the existing

quality data. Special emphasis should be placed on areas irri-

gated from water resources of inferior quality. Studies to

reliably assess the effect of King Talal Reservoir on the direct

use for agriculture and the immediate environment are needed.

61

6. Outlook For Irrigation

6.1 Food Security

Performance of food production in Jordan is constrained by

lack of rainfall and hostile topography. Rainfall exceedining

the limit necessary for rainfed agriculture covers about 4% of

the country's area. The variability of rainfall throughout the

rainy season and interannually confines rainfed cultivated areas

to about 4.5 million du. Large portions of cultivable areas are

fallowed, and, on average 2.5 million du are cropped each year.

Productivity of rainfed agriculture constrained by highly

skewed land tenure with many small fragmented farms and high

slopes in the mountainous areas limiting the use of machinery

and output, cover about 22% ... of the value of the total food

requirements for the 1992 population estimated at 4 Million.

Government investments in irrigation projects in the Jordan

Valley, and increased private sector activities in developing

irrigation outside the Valley, drawing primarily from

groundwater resources, boosted the irrigated areas to 59,000 ha

in 1988/89. With the introduction of advanced technology in

irrigation, plasticulture and acquisition of modern inputs of

agriculture, irrigated areas representing only 8.4% of the

cultivable lands in Jordan contribute about 16% of the value of

food. An irrigated hactare in Jordan is hence capable of

producing five to eight times the value of produce of a rainfed

hectare.

Despite the noticeable growth in the output of fruits,

vegetables and livestock products, the agricultural sector in

Jordan has not been able to meet the increasing demand for

certain food products. This has resulted in increasing

dependency on food and livestock imports, which increased from

an annual average of JD 94.4 million for the period 1976 - 1980

to JD .... million for the period 1985 - 1990, representing ...%

of the total imports during the latter period. Table ( 9 )

shows the annual average food..... balance for some important

food products for the period 1982-1987. The percentage of food

self sufficiency range between 0% for rice and sugar and 25% for

red meat. The local production of some vegetables such as

potatoes account for 71% of the total amount needed, and is more

62

than sufficient to ensure the present needs of the population

such as with tomatoes and cucumber.

6.2 Potential for Increased Irrigated Areas

Systems already built

Development of irrigation in Jordan is shared between the

governmentand the private sector. Public irrigation projects

started in the Jordan Valley in the late 1940's and early 1950's

by building small irrigation schemes on some of the side wadis

which diverted and distributed the base flows of the wadis to

their command areas. Planned investments in the irrigation

sector resulted in significantdevelopment of surface water

sources and expansion of the irrigation infrastructure.

Intensive irrigation projects were implemented based on the 1955

Baker Harza Master Plan Report of Yarmouk-Jordan Valley Project

which aimed at the full development of the water resources

available to the valley. Large scale development of the surface

water resources and the related networks for irrigation in the

Jordan Rift Valley has been the prominent government role

through the Jordan Valley Authority. Developed irrrigation

facilities presently include storage dams,associated hydraulic

structures, and irrigation networks. Areas developed for

irrigation has increased from 12,527 ha in 1966 to 30,216 ha in

1989 and currently covers about 4,650 ha in the Southern Ghors

and 200 ha in Wadi Araba.

Irrigation netwotks in the Jordan Valley primarily offtake from

a main carrier, the 110 Km long King Adullah Canal (KAC) fed

from the Yarmouk River and from several side wadis some of which

have storage dams with an aggregate storage capacity of 108 MCM.

63

ANNEX 1

Computation of Overall Irrigation Efficiency

For Each Agroclimatological Zone

64

Computation of Overall Irrigation Efficiency

Irrigation water requirements at the root of the plants for an

irrigation area planted according to the average cropping

pattern adopted for that area, can be calculated from the crops

net irrigation requirements and the cropping pattern.

Irrigation water requirements at the farm gate can be derived

from the irrigation water requirements at the root dividing

these figures by the on-farm irrigation efficiency.

Irrigation Water Requirements at the water source is derived

from the Irrigation water requirements at the root divided these

figures by the on-farm irrigation efficiency and the efficiency

of the delivery system used for irrigation (Main conveyance and

distribution). Thus, the Overall Irrigation Efficiency has

three major components:-

1) The on-farm irrigation application efficiency

2) The distribution efficiency

3) The main convevance efficiency

Both 2 and 3 above constitute the delivery system efficiency

used in the analysis below and referred to herinafter as DSE.

Since relevant data on irrigated areas with the different

irrigation techniques and the delivery methods were not readily

available for all the MOA documented irrigated villages, the

following theoretical approach was adopted to estimate the

overall irrigation efficiency in each agroclimatological zone.

1) On-farm irrigation application efficiency

The on-farm irrigation application efficiency depends on the

method of irrigation and the season, according to the following

table produced by HARZA 1988.

Table ( 1 ) On-Farm Irrigation Efficiency

Irrigation Method Winter Spring Summer Autumn

Drip 0.84 0.84 0.84 0.84

Surface 0.65 0.60 0.55 0.60

65

Sprinkler 0.75 0.67 0.60 0.67

An average on-farm irrigation efficiency for surface irrigation

can be computed as follows:

(0.65 * 4 Mo.+0.6 * 2 Mo.+0.55 * 4 Mo.+0.6 * 2 Mo.)/12 = 0.6

Whereby, winter's duration is 4 months ( Nov. - Feb. )

spring's duration is 2 months ( Mar. - Apr. )

summer's duration is 4 months ( May. - Aug. )

autumn's duration is 2 months ( Sep. - Oct. )

Similarly, an average on-farm irrigation efficiency for:-

Sprinklers irrigation is equal to: 0.67

and for

Drip irrigation is equal to : 0.84

Table ( 2 ) Average On-Farm Irrigation Efficiency

Irrigation Method Average On-Farm Irrigation Efficiency

Surface 0.60

Sprinkler 0.67

Drip 0.84

The on-farm irrigation methods are divided over the areas irri-

gated in each agroclimatological zone as in Table ( 3 ) below.

Zones 1,2, and 3 represent the agroclimatic conditions

prevailing in the North and South Valley and Southern Ghors; i.e

areas commanded by the Jordan Valley Authority (JVA). The

vegetables areas irrigated with the different methods were

obtained from JVA Operation and Maintenance department for the

month of January 1989. The same distribution was adopted for

winter and summer vegetables throughout the year. JVA records

did not include irrigated field crops and fruit trees.

According to JVA officials, all irrigated field crops and 90% of

irrigated trees areas were under surface irrigation , with the

remaining 10% under sprinklers. The percentage areas irrigated

under each method computed for each zone was utilized as

representative of all the projects' areas within the same zone.

66

Elsewhere in the Kingdom, 85% of the irrigated trees areas were

assumed to be under surface irrigation (upon DOS

recommendation); the remaining being under sprinklers. Further

use was made of the results of the annual agricultural survey

conducted by the Department of Statistics (DOS) in 1989. The

DOS survey covered irrigated areas in the Kingdom exceeding or

equal to 200 dunums. Areas irrigated with the different methods

were assimilated for all the villages located in the same zone

and were adopted to broadly represent the distribution of

irrigation methods in the corresponding agroclimatiological

zone.

67

Table ( 3 ) Distribution of Irrigation Methods Over

the Zones

Zone No. % Area Irrigated By Each Method

Surface Sprinkler Drip

Zone 1 62.35 11.79 25.87

Zone 2 43.99 2.28 53.73

Zone 3 5.45 2.50 92.05

Zone 4 92.33 1.18 6.48

Zone 5 68.38 7.04 24.58

Zone 6 86.19 0.00 13.81

Zone 7 43.39 11.78 44.83

Zone 8 59.75 0.00 40.25

Zone 9 79.57 0.36 20.08

Zone 10 76.42 0.16 23.42

Zone 11 94.40 0.00 5.60

Zone 12 8.91 87.95 3.13

Applying the average on-farm irrigation efficiency (Table 2) to

the distribution of methods in Zone 1 for example yields a

weighted on-farm irrigation efficiency of:-

100 / ( 0.6235*100/0.6 + 0.1179*100/0.67 + 0.2587*100/0.84 ) =

0.66

The above figure implies that an area of 1 ha with a crop water

requirement at the root of 100 mm or 1000 m3/ha requires

(100 / 0.66 ) = 151.5 mm of irrigation water at the farm gate.

Similarly, the weighted on-farm irrigation efficiency is

averaged in each zone according to the distribution of

irrigation methods prevailing in that zone. The results are

shown in Table ( 4 ) below.

Table ( 4 ), Weighted Average Annual Farm Irrigation Efficiency

Per Zone

Zone 1 0.66

Zone 2 0.71

Zone 3 0.82

Zone 4 0.61

68

Zone 5 0.65

Zone 6 0.62

Zone 7 0.70

Zone 8 0.68

Zone 9 0.64

Zone 10 0.64

Zone 11 0.61

Zone 12 0.67

2) Delivery System Efficiency

The total annual irrigation requirements by given types of crops

in a given area also depends on the water use efficiency of the

irrigation system present in that area. Table ( 5 ) indicates

that nine types of delivery systems can be distinguished in the

country depending on the source of irrigation water;

groundwater, springs and side wadis.

JVA Operation records indicate that the delivery system

efficiency of the conveyance and distribution system in the

areas irrigated from the King Abdullah Canal ( K.A.C ) through

concrete lined surface canals averages 62%... with a system that

has been used for more than 20 years, as is the case in the

first 78 Km of the K.A.C. The delivery system efficiency for

the same areas irrigated through pressurized distribution pipes

averages 74%... throughout the year for the more recently

constructed 18 Km extension.

As for the remaining areas in the valley whose irrigation is

independent of the King Abdullah Canal and which are linked to

the highly efficient pressurized system such as the North East

Ghor Irrigation Complex, Zarqa Triangle Project, and Hisban-Ka-

frein, the delivery system efficiency (excluding on-farm irriga-

tion efficiency) ranges between 0.85 and 0.92 depending on the

losses incurred prior to the entry of water to the pressurized

pipe network.

Experience of JVA and WAJ officials indicate that water

extracted from wells is usually pumped out into pipes with an

estimated efficiency of 0.95. These pipes feed storage ponds

constructed by farmers. From these ponds water is pumped using

sprinkler or drip irrigation methods. Otherwise water is pumped

into the highest point of the farm and further distributed using

69

surface irrigation methods.

As for the areas irrigated from springs and side wadis in the

remaining zones, water is usually conveyed to the farm through

open concrete lined canals (referred to hereinafter as CC sys-

tem), or open earth ditches (OD system). The substitution of

open earth ditches with concrete lined open canals is a task

undertaken by the Water Authority of Jordan (WAJ), whereby

interested farmers throughout the Kingdom apply for the replace-

ment of the existing earth canals in their farms.

Although WAJ do not keep records of the total length of the

earth canals existing in the Kingdom, they estimate it at 125

Km. However, WAJ records show that the total length of concrete

lined canals in all the governorates of Jordan approximates

204.5 Km; i.e about 62% of the open (concrete lined and earth)

canals in Zones 4-12 are cement canals with an estimated

efficiency of 0.85:- 204.5 / (204.5 + 125) = 0.62

For lack of further data, it was assumed that the areas

irrigated from concrete lined canals is proportional to their

length.

Table ( 5 )

Source of Prevailing System System

Irrigation System Efficiency Abreviation

Side Wadis Concrete lateral 0.62 CS

surface distribution canals

linked to the first 78 Km

King Abdullah Canal in the

Jordan Valley

Concrete lateral surface 0.76 PS

distribution canals linked

to pressurized pipes (as in

the North Crossings in th

Jordan Valley)

Pressurized distribution 0.74 CP

pipes linked to 18 Km

Extension K.A.C. in the

Jordan Valley

70

Pressurized pipes: Zarqa 0.87 PPz

Triangle Project in the

Jordan Valley, and Southern

Ghor Irrigation Project in

the Southern Ghors

Pressurized pipes: North 0.85 PPn

East Ghor Irrigation Project,

and Wadi Arab Project in the

Jordan Valley

Pressurized pipes: Hisban- 0.92 PPh

Kafrein Project in the Jordan

Valley

Side Wadis Cement canals 0.85 CC

and Springs

Open ditches 0.4-0.7 OD

Wells Pipes 0.95 P

The irrigation source types are divided over the areas

irrigated in each agroclimatological zone as in Table ( 6 )

below. Areas linked to the previously identified systems in the

Jordan Valley were based on the average areas irrigated from

each system during 1988/89.

The distribution of irrigated areas according to the source of

irrigation in the uplands was based on the results of the annual

agricultural survey held by the Department of Statistics in

1989. Areas irrigated from the different source types were

aggregated across all the villages located in the same

agroclimatological zone. The percentage area irrigated from

each source type was subsequently estimated for each zone.

Although the DOS sampling criterion in the survey was based on

irrigated land holdings equal or exceeding 200 dunums, the

resulting distribution was adopted as representative of all the

irrigated villages in the same zone.

Table ( 6 ) Distribution of Irrigated Areas According

to the Source of Irrigation

71

Zone No. % Area Irrigated By Each Source

Wells Springs Side Wadis Miscellaneous

Zone 1 0.99 0.57 98.44 0.00

Zone 2 43.74 1.32 54.95 0.00

Zone 3 8.95 0.00 91.05 0.00

Zone 4 0.00 74.61 25.39 0.00

Zone 5 39.83 38.04 22.12 0.00

Zone 6 11.69 47.95 39.45 0.92

Zone 7 93.10 1.73 4.56 0.61

Zone 8 15.38 82.04 2.42 0.17

Zone 9 98.26 1.74 0.00 0.00

Zone 10 97.96 2.02 0.00 0.01

Zone 11 93.83 6.17 0.00 0.00

Zone 12 100.00 0.00 0.00 0.00

Table ( 7 ) shows the distribution of irrigated areas in each

zone according to the prevailing delivery system identified with

each source.

Taking Zone 1 as an example, about 0.99 of the irrigated lands

get their water from wells through pipes (P system) with an

estimated efficiency of 0.95, 0.57% of the same areas are irri-

gated from springs through open concrete lined canals (CC) with

an estimated efficiency of 0.85. In addition, about 57.6% of

the irrigated lands acquire their water from KAC through con-

crete lined surface distribution canals (linked to CS delivery

system), 3.17% are irrigated from pressurized pipes linked to

KAC (CP), 16.57% have their water diverted directly from the

source under the North East Ghor Irrigation Complex scheme

(PPn), and so on...

72

Table ( 7 ) Distribution of Irrigated Areas in the

Agroclimatological Zones According to the

Prevailing

Delivery Systems Identified With Each Source

Zone No. % Area Irrigated By Each Source

WELLS SPRINGS SIDE WADIS

P CC OD CS CP PPh PPn PPz PS CC OD MISC.

Z1 0.99 0.57 - 57.60 3.17 - 16.57 18.09 0.58 2.43 - -

Z2 43.74 1.32 - 0.18 42.61 10.46 - 1.19 - 0.50 - -

Z3 8.95 - - - - - - 91.05 - - - -

Z4 - 46.26 28.35 - - - - - - 15.74 9.65 -

Z5 39.83 23.59 14.46 - - - - - - 13.72 8.41 -

Z6 11.69 29.73 18.22 - - - - - - 24.46 14.99 0.92

Z7 93.10 1.07 0.66 - - - - - - 2.83 1.73 0.61

Z8 15.38 50.86 31.17 - - - - - - 1.50 0.92 0.17

Z9 98.26 1.08 0.66 - - - - - - - - -

Z10 97.97 1.25 0.77 - - - - - - - - 0.01

Z11 93.83 3.83 2.35 - - - - - - - - -

Z12 100.00 - - - - - - - - - - -

Applying the delivery systems' efficiencies (Table 5 ) to the distri-

bution of the irrigated areas according to the delivery systems

prevailing in Zone 1 yields the following weighted delivery system

efficiency for that zone:

1/(.0099/0.95+.0057/0.85+.576/0.62+ 3.17/.74+.1657/0.85+.1809/0.87+

.0058 /0.76+.0243/0.85) = 0.70

Similarly, a weighted delivery system efficiency DSE (main conveyance

and distribution) for the prevailing irrigation systems in each zone

applied proportionally over the areas they irrigate is calculated and

tabulated below:-

Table ( 8 ) Weighted Delivery Systems' Efficiency

Per Zone

Zone 1 0.70

Zone 2 0.84

Zone 3 0.88

73

Zone 4 0.67

Zone 5 0.76

Zone 6 0.70

Zone 7 0.92

Zone 8 0.70

Zone 9 0.94

Zone 10 0.94

Zone 11 0.93

Zone 12 0.95

Finally, the overall irrigation efficiency in each zone is derived by

the multiplication of the weighted annual farm irrigation efficiency

obtained from table ( 4 ), by the corresponding weighted delivery

systems' efficiency. The result is shown in table ( 9 )

below:-

Table ( 9 ) Weighted Overall Irrigation Efficiency

Per Zone

Zone 1 0.46

Zone 2 0.60

Zone 3 0.72

Zone 4 0.41

Zone 5 0.49

Zone 6 0.43

Zone 7 0.64

Zone 8 0.48

Zone 9 0.60

Zone 10 0.61

Zone 11 0.56

Zone 12 0.63

The above estimates of the Overall Irrigation Efficiency in each zone

were adopted for all the irrigated areas within the same zone and

were entered in the Agroclimatological Zones Data Base under the

Irrigation Efficiency Sub-Data Base. They were further used for the

computation of monthly crops' Gross Irrigation Water Requirement

associated with irrigated village.

74

ANNEX 2

Glossery of Terms

Related with the Computation

Of

Irrigation Requirements

75

ANNEX 3

list of Surface Basins and Subbasins in Jordan

76

ANNEX 4

List of Public and Private Irrigation Areas in

Operation during 1988/89

77

ANNEX 5

List of the Crops and Cropping Calendars Adopted

for Each

Agroclimatological Zone

As Applied in The

Water Requirements Computations

78

ANNEX 6

List of Water Resources Associated with

Areas Without Records,

1988/89 Monthly Discharge and Salinity Values

of Each Source,

79

ANNEX 7

List of Water Resources Associated With Areas

With Available Records,

1988/89 Monthly Irrigation Diversions

and

Salinity Values of Each Source

80

ANNEX 8

List of 1988/89 Monthly Domestic Abstractions

from

the Springs.

81

ANNEX 9

Sample of Input Data and Output Results

Of

Reference Grass Evapotranspiration "REF-ET" program

For 1988/89

82

ANNEX 10

List of 1988/89 Reference Grass Evapotranspiration Results

For Representative Stations

in Each

Agroclimatological Zone

83

ANNEX 11

1988/89 Monthly "Total Rainfall, No. of Rainy Days

and Rainfall Frequency"

For Each

Agroclimatological Zone.

84

ANNEX 12

Sample Output of 1988/89 Water Requirements Computations

Done by IRRMAST Program

ANNEX 13

List of Monthly Crop's Evapotranspiration Representing

1988/89 Climatic Conditions

Per

Agroclimatological Zone

ANNEX 14

List of Monthly Net Irrigation Representing

1988/89 Climatic Conditions

Per

Agroclimatological Zone

ANNEX 15

Summary Tables of Irrigation Requirements/Abstractions,

Evapotranspiration and Return Flow

Results for the Year 1988/89

REFERENCES

Department of Statistics

National Accounts Department

National Accounts Files

Department of Statistics

Results of the Annual Agricultural Survey, 1989

Survey of the Irrigated Areas in the Highlands

FAO Irrigation and Drainage Paper 24

Crop Water Requirements

FAO Irrigation and Drainage Paper 29

Water Quality for Agriculture

Five Year Plan For Economic And Social Development

1986 - 1990

Ministry of Planning

Haskoning and Jouzy & Partners

Rehabilitation and upgrading of the King Abdullah Canal

Interim Report, Volume 1, Main Text

October, 1990

Jordan, Towards an Agriculture Sector Strategy

World Bank, June 12, 1990

Jordan Valley Authority

Feasibility Report for the North Ghors Conversion Project

Amman, February 1987

Jordan Valley Authority

Annual Report of Operation and Maintenance Department in the

Southern Ghors and Wadi Araba 1990-91

Jordan Valley Authority Operation records, 1989

Operation and Maintenance Department, Jordan Valley & Southern

Ghors

Ministry of Agriculture

Directorate of Agricultural Economics and Planning

Division of Statistics

Amman, August 1989

Agricultural Statistics Indicators 1981-1988

Ministry of Agriculture

Directorate of Agricultural Economics and Planning

Division of Statistics

Amman, August 1989

Annual Agricultural Report 1989

Ministry of Agriculture files, 1989

Department of Agricultural Economics

Multilingual Technical on Irrigation and Drainage

International Commision on Irrigation and Drainage

Egyption National Committee for Irrigation and Drainage

National Water Masterplan of Jordan

Volume V, Irrigation Water Demand

July, 1977

The Jordanian Food Balance For the period 1982-1987

Jordan University

Hamdan, M.R., 1990

Water Authority of Jordan

Groundwater Monitoring Division???

Water Authority of Jordan

Groundwater Studies Division???

Water Authority of Jordan

Irrigation Department

Springs' Development Section

Water Authority of Jordan

Surface Water Monitoring Division???

Water Authority of Jordan

Surface Water Studies Division???