Archaeological Applications Of Gis

Archaeological Applications Archaeological Applications of GIS of GIS Jo Dyson Jo Dyson

GIS and Mapping Technician GIS and Mapping Technician Room MB 25 Room MB 25

[email protected]@worc.ac.uk

IntroductionIntroduction• GIS offers archaeologists an exciting and

powerful research tool

• The data is both spatial and temporal and is therefore suited to the basic principles of GIS

• Main applications• Cultural Resource Management• Historic Environment Record (HER) • Landscape Analysis

How do Archaeologists use How do Archaeologists use GIS?GIS?

Analysing DataAnalysing Data• Density analysis of selected features or artefact types across a site, or of site types across a region• Analysis of clustering, proximity, orientation, intervisibility, and other spatial relationships • Visualizing 3D relationships• Visualizing time series • Archaeological Predictive modelling

Questions that can be answered Questions that can be answered using GISusing GIS

• Location – what artefacts have been found along the proposed route of the new road

• Trend – how does the density of primary debris change as one moves away from the historic hearth

• Routing – does the medieval track way follow the most energy efficient route

• Pattern – are burial cairns distributed uniformly across the landscape – or are they clustered on SE facing slopes

• Modelling – where would you find Mesolithic campsites

First use of GIS in Archaeology First use of GIS in Archaeology

• Gaffney and Stančič (1991) Work based on Island of Hvar, Croatia

• Created a DEM from topographic map at scale of 1:50,000

First use of GIS in ArchaeologyFirst use of GIS in Archaeology

• Used Site Catchment Analysis (SCA) on hillforts • Hillforts functioned as a central place for large numbers

of inhabitants due to location in landscape and labour required

• Hillforts were situated on hilltops and surrounded by large stone ramparts

What is Site Catchment Analysis? What is Site Catchment Analysis? • Technique for analysing the locations of archaeological sites by the economic resources which are available to them

• The farther from the site, the resources are, the greater the economic cost of exploiting them

First use of GIS in ArchaeologyFirst use of GIS in Archaeology

• Used Visibility Analysis on the Greek Towers of Hvar

• Built to allow town of Pharos to be alerted of any danger approaching them

• Towers would have used fire or smoke signals to send message – assumes clear line of sight between them - can be tested with GIS

• Discovered that tower at Maslinovik would have been able to see tower at Tor and pass message back to Pharos

Wroxeter Hinterland Project Wroxeter Hinterland Project

• Gaffney et al (2007)• First use of GIS in

archaeology as database for all information relating to project : geophysics, aerial imagery, field walking, OS mapping and find spots etc

Wroxeter Hinterland ProjectWroxeter Hinterland Project

Stonehenge Landscapes Stonehenge Landscapes

• Exon et al (2000) • Aim of the project was to

digitally explore the relationships of the monuments around Stonehenge and how these relationships have changed over time

• Groundbreaking to the extent that the readers were able to see and question the data on a CD, provided with book

Stonehenge LandscapesStonehenge Landscapes

• Discovered that there was a key relationship between the monuments and the topography

• First to study the Stonehenge landscape using GIS. It transformed archaeologist’s views on the Stonehenge landscape as the GIS showed the already well-studied area in a new light

• The project demonstrates GIS ability to interpret data as opposed to just a data storage tool

Arroux River Valley region of Arroux River Valley region of Burgundy, France Burgundy, France

• Madry and Cumley (unknown date)

• Predictive modelling of archaeological sites

• Created a DEM and then did various analysis to work out archaeological site locations

Analysis required to create Analysis required to create Predictive ModelPredictive Model

ElevationSurvey dataSlopeGeologyAspect

Buffers for Analysis of Data Buffers for Analysis of Data

• Distance to ancient roads• Distance to rivers/waterways • Distance to hillforts

Line of Site AnalysisLine of Site Analysis• The old Celtic road

network connecting the hillforts tended to follow within the line-of-sight of the hillforts, rather than take more direct paths even if they are less direct or require a steeper climb

The Predictive Model The Predictive Model

• Find new sites based on known site locations

• Roman sites follow rivers and roads on lower elevation

• Celtic sites are located within uplands

Laxton Castle, NottinghamshireLaxton Castle, Nottinghamshire

• Combined use of GPS, GIS, Geophysics and historical mapping to understand castle and its environs

• C12th Motte and Bailey Castle

Laxton Castle, NottinghamshireLaxton Castle, Nottinghamshire

Tutbury Castle, StaffordshireTutbury Castle, Staffordshire

• C11th Motte and Bailey castle

• Similar techniques used as LaxtonCastle

Tutbury Castle, StaffordshireTutbury Castle, Staffordshire

King Edward I Castles in North King Edward I Castles in North Wales Wales

• My BA and MA dissertation work

• BA: Viewshed (Visibility) Analysis and Cost Surface Analysis (CSA)

• MA: Sensuous Viewsheds or 3D Visibility Analysis and used GIS in conjunction with Autodesk 3D Studio Max to create castle models

Visibility Analysis and Cost Surface Visibility Analysis and Cost Surface AnalysisAnalysis

First you need to know the ‘cost’ over all types of terrainNormally this means calculating cost from for example the slope grid… 4 miles/hr

3 miles/hr

2 miles/hr

Not forgetting the effect of slope distance

Distance shown on map

Slope distance

What is CSA? What is CSA?

CSACSA

• GIS recognises the sea as best route

• GIS has worked out that the shortest route between the castles is across the sea is, due to the fact that the sea is the lowest point on the DEM

• Therefore, the computer automatically assumes the sea is the quickest and easiest route to take

• This is a limitation of the GIS program Harlech to Flint CSA ±

CSACSA

Harlech to Conwy CSA with equation

±

Sensuous (or 3D) Visibility Analysis Sensuous (or 3D) Visibility Analysis

Mobile GIS in Archaeological Mobile GIS in Archaeological Fieldwork and SurveyFieldwork and Survey

• GPS combined with ArcGISArcPad on PDA or Notebook

Displaying of Archaeological Data Displaying of Archaeological Data

Historic Environment Record (HER) Historic Environment Record (HER)

• Gloucestershire County Council

• HER holds 24,000 records and is constantly updated

• Uses an Oracle database linked to ArcGIS

Historic Landscape Historic Landscape Characterisation (HLC) Characterisation (HLC)

• HLC is concerned with mapping our entire historic landscape

• Work usually done by Local Authorities

• To build a HLC database, using a GIS and digital mapping, vector polygons are created to give a particular landscape type to a block of land

• A landscape type could be woodland, military, or residential

• Each type is given its own colour and displayed in the GIS as an additional layer. Changes to the landscape can be shown over time by switching the layers on and off

Wolverhampton in 1880Wolverhampton in 1880

Legend

Blue is Extractive

Pink is Settlement

Red is Commercial

Yellow is Recreational


Legend

Blue is Extractive

Pink is Settlement

Red is Commercial



Legend

Blue is Extractive

Pink is Settlement

Red is Commercial


Wolverhampton: Surviving Wolverhampton: Surviving Terrace HousesTerrace Houses

Legend

Green is Circa 1910

Blue is Circa 1900

Purple is Circa 1880

Green is Wolverhampton City Boundary

Red is Main Roads (Modern Roads)

Advantages of using GIS in Advantages of using GIS in Archaeology Archaeology

• Allows large amounts of data to be analysed

• And interpreted in a fraction of the time

i.e can look at large geographical areas and combine spatial with data with a textual database

• Makes textural data more appealing

Advantages of using GIS in Advantages of using GIS in ArchaeologyArchaeology

Large scale issues• Ancient landscapes• Distribution of sites• Trade networks across

Europe• Analysis of settlement

patterns

Small scale issues • Recording individual

stones in a monument.• Analysis of distribution of

artefacts at a site• Site management

Scales of Analysis for an Archaeological Site Scales of Analysis for an Archaeological Site or Sites or Sites

Advantages of using GIS in Advantages of using GIS in ArchaeologyArchaeology

• Combines data. Integrate vector data (point plotted artefacts, features, excavation units) with raster data (photographs, geophysical data, remote-sensing images, interpolated artefact density surfaces).

• Relate tabular data to vector data. Scaleable – works at the site level, local level, regional, and global levels.

• Provides archaeologists with a new means of interpreting prehistoric and historic landscapes (archaeological predictive modelling)

Issues Surrounding the use of GISIssues Surrounding the use of GIS

• The information is only as good as the original data source and is dependent upon the expertise and experience of the researcher

• Bias to regional landscape based studies

• GIS is atemporal and only able to deal with spatial phenomena in a single instant of time – although this has been accommodated by use of time slices

Issues Surrounding the use of GISIssues Surrounding the use of GIS

• Gives ‘a picture of past landscapes which the inhabitant would hardly recognise’ (Thomas 1993)

• GIS has a positivist and scientific bias• Some data does not lend itself to digital capture (e.g. soil

types rarely change as abruptly as the lines demarking the distribution on a map will show)

• GIS does not take into account the seasonal variation of vegetation cover or how a landscape may have been vegetated

• GIS is ocular-centric – you only ‘see’ the landscape, not experience it in any other way

Is it just pretty pictures?

Future uses of GIS in ArchaeologyFuture uses of GIS in Archaeology

• Move towards humanistic and environmental approaches – Llobera 1996

• Move towards 3D-GIS: Mossel Bay Archaeology Project (MAP) South Africa

• Modelled caves to find out about the behaviour of early humans and how they reacted to environmental change

SummarySummary

• The history of GIS in archaeology

• How GIS is used by archaeologists

• The advantages and disadvantages of using GIS in archaeology

• Possible future uses of GIS in Archaeology

Technology

Archaeological Applications Of Gis