Manajemen Basis Data dalam SIG

Sistem Informasi Geografis

Sistem Manajemen Basis Data SIG

SIG merupakan perangkat pengelolaan basis data (DBMS =

Data Base Management System) dimana interaksi dengan

pemakai dilakukan dengan suatu sistem antar muka dan

sistem query dan basis data dibangun untuk aplikasi

multiuser.

SIG merupakan perangkat analisis keruangan (spatial analysis)

dengan kelebihan dapat mengelola data spasial dan data non-

spasial sekaligus.

Sistem Manajemen Basis Data SIG

Syarat pengorganisasian data:

Volum kecil dengan klasifikasi data yang baik;

Penyajian yang akurat;

Mudah dan cepat dalam pencarian kembali (data retrieval) dan penggabungan (proses komposit).

Tipe Data Data lokasi:

Koordinat lokasi

Nama lokasi

Lokasi topologi (letak relatif: sebelah kiri danau A, sebelah kanan pertokoan

B)

Data non-lokasi:

Curah hujan

Jumlah panen padi

Terdiri dari variabel (tanah), kelas (alluvial), nilai luas (10 ha), jenis (pasir)

Data dimensi waktu (temporal):

Data non-lokasi di lokasi bersangkutan dapat berubah dengan waktu (misal:

data curah hujan bulan Desember akan berbeda dengan bulan Juli)

Desain Konseptual

Data Model

A data model is a formal specification for the entities, their

attributes and all relationships between the entities for the GIS.

The purpose of a data model is to make it possible for both user

and GIS analyst agree on the data definitions which is

represented completely rigorous and unambiguous fashion.

Desain Konseptual

Deep Ocean

Shelf

Upper Slope

Rise Lower Slope

Plateau or Terrace

Building Located on Parcel

Resides Owned

by

Occupant Joe Jones Owner Apex Co.

Simple Entity – Relationship (E-R) Diagram

Entities represented as rectangles, relationship as diamonds and attributes as ellipses.

Desain Konseptual

E-R Model

• Entities;

• Relationships between entities;

• Attributes of entities or relationships.

• Belonging to;

• Set and subset relationships;

• Parent-child relationships;

• Component parts of an object.

1. Parts of E-R Model:

2. Types of normal relationships:

3. Rules for identifying

entities, relationships,

and attributes:

• A common noun corresponds

to an entity type;

• A transitive verb corresponds

to a relationship type;

• An adjective corresponds to

an attribute type.

Desain Konseptual Each entity and its attribute map into one or more relational

tables.

Each relationship is a regular relationship executed by the relational database query system or a spatial relationship and if it is not a standard operation then the indicated operation which usually includes a complex computation need to be written (using Avenue Script/Macro Language).

Rise

Area terbangun Bangunan kantor

Bangunan rumah sakit

Bangunan sekolah

Bangunan pertokoan

Koordinat Letak

Luas

Milik

Desain Konseptual Metadata is “information about data”: (i) describe the characteristics of the data (entity

and attributes) using its standard name, and (ii) provide information on its accuracy and

its source and its archiving provision.

Important functions of metadata: provide (i) a basic data description of a data set; (ii)

information for data transfer / sharing; (iii) information for entries into clearinghouses

to catalogue the availability of data.

Metadata should serve as: (i) a documentation and data management tool; (ii) data

definition, source documentation, management and updating, data archiving and

retention requirement; (iii) information to support database description for spatial data

clearinghouses.

Desain Konseptual

Deep Ocean

Shelf

Upper Slope

Rise Lower Slope

Plateau or Terrace

An example of metadata tables:

1. Organization Information

Name of Organization

Department

Room/Suite#

Number & Street Name

City

State

Zip Code

Phone Number

Fax Number

Contact Person

Extension Number

E-mail Address

Internet Address

Comments

2. Reference Information

Filename

File Format

Availability

Cost

File Internet Address

Metadata Created By

Date Metada Created

Metadata Updated By

Date Metadata Updated

Metadata Standard Name

Comments

5. Attribute Information

Data Object Name

Data Attribute Name

Attribute Description

Attribute Filename

Code Set Name

Code Set Description

Measurement units

Accuracy Description

Comments

Perencanaan DB

The quality of information

Information is stored in a database;

Bad construction and data error will give Garbage instead of

Geographic Information System;

What kind of map projection will be used;

What scale is the data;

What is the coverage;

How much attribution should be included;

What is the attribute data format;

What is the data reliability;

How fast is it to be retrieved.

Perencanaan DB Information required for database design:

A complete list of data, properly defined and checked for

validity and consistency (from the master data list, E-R data model, and metadata entries);

A list of potential data source (maps, aerial photos, tabular

files, digital files) cataloged and evaluated for accuracy and completeness (from available data survey);

The list of functional capabilities required from the GIS

(from needs assessment). Such as visualization, spatial analysis, statistical analysis and modeling.

Perencanaan DB

Entities,

Attributes, and

Spatial Object

Deep Ocean Rise

Lower Slope

Plateau or Terrace

Perencanaan DB

Plan for data sharing

Benefits of data sharing include: (i) the development of much

larger database for far less cost; (ii) the development of more

efficient interaction between public agencies; and (iii) all

agencies shared the same up-to-date database / information.

Database maintenance requires two efforts: ongoing user

training (how to maintain the database) and user support (who

will be responsible for updating which data).

Perencanaan DB

Designing the Database

Most of databases in GIS software packages are based on the

relational database model;

Two choices of using data table: as much data in one table or

small/compact data in one table;

How you will represent the data: point, line, polygon, network,

etc.

Konstruksi DB

Database construction/conversion is the process of building

the digital database from the source data - maps and tabular

files.

The main emphasis is management of the activity and quality

assurance / quality control of the converted data.

Konstruksi DB

Data Conversion

Manual digitizing using a digitizing tablet and cursor tool

(puck);

Scanning (converts lines and text into series of pixels);

Raster to Vector Conversion (convert series of pixels into series

of (x,y) coordinates points), this facility is usually provided by a

GIS software;

Hybrid solution (overlaying vector format data with an image

provides a powerful graphic display tool;

Konstruksi DB • Map graphics represent all of the features (entities) on a map as

points, lines, areas, or pixels;

• Tabular databases contain the attribute information which describe the entities (building, parcel, etc.);

• A common key (graphics data index) must be established between the map graphics and the tabular database records to create a link.

Graphics Data Index

Konstuksi DB

Raster Data (pixels)

Raster GIS Data

Graphics Grid / Raster Value Attribute Table

1 1 1 1 2 2

1 1 1 2 2 2

1 1 2 2 2 2

1 3 3 3 3 2

3 3 3 3 3 3

3 3 3 3 3 3

Cell Value Real World Entity

1 Lake

2 Wooded

3 Built-up

Konstuksi DB

Vector GIS Data

Vector GIS Data

Vector GIS Polygon Layer Polygon Attribute Table

Polygon Identity Attribute

Numbet

1 Lake

2 Wooded

3 Built-up

1 2

3

Basis Data Relasional

Basis Data relasional menggunakan tabel dua

dimensi yang terdiri atas baris dan kolom untuk

memberi gambaran sebuah berkas data.

Basis Data Relasional

MHS

NPM

Nama

Alamat

10296832

Nurhayati

Jakarta

10296126

Astuti

Jakarta

31296500

Budi

Depok

41296525

Prananingrum

Bogor

50096487

Pipit

Bekasi

21196353

Quraish

Bogor

Basis Data Relasional

MKUL

KDMK

MTKULIAH

SKS

KK021

P. Basis Data

2

KD132

SIM

3

KU122

Pancasila

2

Basis Data Relasional

NILAI

NPM

KDMK

MID

FINAL

10296832

KK021

60

75

10296126

KD132

70

90

31296500

KK021

55

40

41296525

KU122

90

80

21196353

KU122

75

75

50095487

KD132

80

0

10296832

KD132

40

30

Basis Data Relasional

Keuntungan:

Bentuknya sederhana

Mudah melakukan berbagai operasi data

Basis Data Relasional

Sumber:

Dinar D.A. Putranto,

‘Pendekatan Basisdata

Berorientasi Obyek untuk

Manajemen Tata Ruang Kota’,

Disertasi Doktor, ITB, 2000.

Hybrid & Integrated System Pengertian 1: Struktur data vektor dan struktur data raster dapat dipadukan pada suatu

sistem, dengan melengkapi fasilitas konversi vektor ke raster dan raster ke vektor. Selain itu juga disediakan fungsi-fungsi untuk mengolah masing-masing struktur data

Pengertian 2: Data SIG terdiri dari dua bentuk data: yaitu data grafis yang menyatakan entitas obyek dan data attribut. Data grafis yang terdiri dari data koordinat dan data topologi disimpan di berkas yang terpisah dari data atribut. Data atribut ditangani oleh database management system. Penggabungan kedua tipe data dilakukan melalui suatu kode identifikasi, misal kode identifikasi poligon, garis atau titik. Hal yang sama juga dapat dilakukan „linkage‟ antara grid-cell modules dengan database management system.

Pengertian 3: Operasional SIG secara keseluruhan yang terdiri dari SIG software, CAD software, Image Processing software, GPS software, Open-Source components, DBMS system

Hybrid & Integrated System

Hybrid & Integrated System