Post on 29-Mar-2023
Estimating the “memory of landscape” to predict
changes in archaeological settlement patterns
Philip VerhagenLaure Nuninger
Frédérique BertoncelloAngelo Castrorao Barba
CAA2015 SienaSession 5D – 2 April 2015
VU University Amsterdam
THE ROLE OF SOCIO-ENVIRONMENTAL DYNAMICS
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• settlement patterns are dynamic with creations, abandonments, reoccupations …
• where did communities settle during the past ?
• what drives their choices? – the environmental conditions? – the landscape’s potential for movement or control
of territories?– socio-economic considerations? – all of them?
analysing the settling conditions of archaeological sites can help to assess the factors that play a role in the transformations of ancient settlement systems
VU University Amsterdam
socio-environmental
visibility, accessibility
environmentalslope, aspect, solar radiation
socio-culturalheritage, hierarchy,
networks
PREDICTIVEVARIABLES
subsistence production
access and control
durability, path dependence
THEORETICALCONCEPTS
contextual analysisstatistical comparisonpredictive modelling
cross-regional
diachronic
ANALYSISTECHNIQUES
MODEL BUILDING BLOCKS
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THE “MEMORY OF LANDSCAPE”
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• where people settle, they manage the landscape– clearing– parcellation– soil improvement
• managed landscapes can be attractive to new settlement– even when they have been abandoned for some time
• the “memory of landscape” may therefore be a predictive variable
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CALCULATING HERITAGE
AB
CD
E
300 400 5002001001-100-200-300-400-500
• settlement A is surrounded by other settlements with different life spans
• at the moment that A starts its occupation, there already is “memory of landscape” at its location– the “heritage” of A is the weight of duration of
occupation in its surroundings, prior to the period under study
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TEMPORAL WEIGHT
B = 100 x 1 + 100 x 0.8 + 100 x 0.6
= 240
C = 100 x 0.8
= 80
D = 0
E = 50 x 1 + 100 x 0.8 + 100 x 0.6 + 100 x 0.4 + 100 x 0.2 + 100 x 0
= 250
• temporal weight: linear decay, 0.2 per century– after 5 centuries, there will be no more influence of previous
occupation
-500 -400 -300 -200 -100 0 100 200 300 400 5000
50100150200250300350
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SPATIAL WEIGHT
• spatial weight: distance decay based on Epanechnikov kernel density function
• neighbourhood for kernel density is set to 1000 m– 500 m is supposed to be the average size of the exploitation
zone for Roman rural settlement– assumption: the surroundings of this exploitation zone have been
attractive for new settlement as well• heritage is then calculated for each grid cell in
study area, and for each century
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0.00.20.40.60.81.0
distance from site
weig
ht
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STUDY AREA
• study area: Argens-Maures region (Var, Provence)- extensively studied for Archaeomedes and
Archaedyn programmes
- rugged terrain, approx. 35 x 45 km- archaeological inventory 800 BC – 800 AD- centuries studied:- 2nd BC, 1st BC, 1st AD and 5th AD
- potential problems- chronological resolution- reliability of survey
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SITE LOCATION ANALYSIS
• location of new settlements per century
- no-heritage areas (HER0)underrepresented-> effect of survey reliability?
- areas with strongheritage (HER3-4) become more important with time- -> path dependency?
% heritage class in the
landscape
% heritage class new
settlements
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ENVIRONMENT OR HERITAGE?
• MaxEnt modelling using environmental context (slope, aspect, solar radiation) and heritage
quality of prediction
contribution of variablesperiod heritage (%)
environment (%)
IIBC 73.6 26.4IBC 62.3 37.7IAD 56.4 43.6VAD 91.7 8.3
period AUC nIIBC 0.719 36IBC 0.672 67IAD 0.694 146VAD 0.793 45
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• use of bias filter changes contribution of variables
• effects on model quality are less marked- predictions were only moderately strong anyway
EFFECTS ON MODEL RESULTS
environment (%)
environment (%)
26.4 37.037.7 45.543.6 67.78.3 11.8
period heritage (%)
heritage (%)
IIBC 73.6 63.0IBC 62.3 54.5IAD 56.4 32.3VAD 91.7 88.2
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period AUC AUCIIBC 0.719 0.688IBC 0.672 0.667IAD 0.694 0.695VAD 0.793 0.797
VU University Amsterdam
CONCLUSIONS
• “memory of landscape” seems to influence the location of new settlements- predictive power is only moderately strong - though
stronger thanenvironmental context
- path dependency can be hypothesized- survey intensity should be taken into account
• heritage variable needs closer scrutiny- potentially conflates two variables1. heritage of abandoned settlements and their
surroundings2. heritage in surroundings of existing settlements -> these settlements are not available for reoccupation
• testing in other areas necessary17