Geographical Information Systems (GIS) Week 3 (21/02/07) © Richard Haddlesey

Lecture aims To build on the concepts of DBMS learnt in previous lectures and to apply geo-referencing to them To build on the concepts of DBMS learnt in previous lectures and to apply geo-referencing to them To familiarise the student with the concepts of a GIS To familiarise the student with the concepts of a GIS To learn the key features of using ArcGIS 9 To learn the key features of using ArcGIS 9

programme Week 3 Week 3 Define what we mean by GIS and why it is useful in archaeology Discuss the development of GIS in archaeology Discuss appropriate hardware and software systems, their advantages and disadvantages Introduce co-ordinate systems Provide some background to the module case study

Programme WEEKS 4-7 Consider Raster and Vector graphics Discuss the use of databases in GIS Examine 3D applications

What is a GIS? Geographical Information Systems / Science Geographical Information Systems / Science "... a powerful set of tools for collecting, storing, retrieving at will, transforming, and displaying spatial data from the real world for a particular set of purposes." (Burrough 1986) "... a powerful set of tools for collecting, storing, retrieving at will, transforming, and displaying spatial data from the real world for a particular set of purposes." (Burrough 1986) A GIS is a computer system capable of capturing, storing, analyzing, and displaying geographically referenced information; that is, data identified according to location. (USGS website (02/2007)) A GIS is a computer system capable of capturing, storing, analyzing, and displaying geographically referenced information; that is, data identified according to location. (USGS website (02/2007))

What is a GIS? Spatially referenced database (geodatabase) Spatially referenced database (geodatabase) Integrating technology Integrating technology Computer Aided Mapping / Computer Aided CartographyComputer Aided Mapping / Computer Aided Cartography Image Processing, particularly of remote sensed dataImage Processing, particularly of remote sensed data Computer graphics / data visualisationComputer graphics / data visualisation Spatial analysis and statistical softwareSpatial analysis and statistical software Database technologyDatabase technology

What a GIS is not A software package A software package A map A map A GPS (Global Positioning System) A GPS (Global Positioning System)

Key GIS Concepts A geographic information system is a system for the management, analysis, and display of geographic data A geographic information system is a system for the management, analysis, and display of geographic data Maps and globesMaps and globes Geodatabases (DBMS)Geodatabases (DBMS) Logic workflowsLogic workflows metadatametadata

Key GIS Concepts Marble (1987) defined four subsystems: Marble (1987) defined four subsystems: 1. Data Entry handles all the translation of raw or partially processed spatial data into an input stream of known and carefully controlled characteristics, 2. Data Storage and Retrieval subsystem or spatial database. This is responsible for storing spatial, topological and attribute information, and maintaining links with external database systems, 3. Manipulation and Analysis takes care of all data transformations, and carries out spatial analysis and modelling functions, 4. Visualisation and Reporting subsystem returns the results of queries and analyses to the user in the form of maps and other graphics as well as text. 5. We might also add a 5. User interface to this list

The importance of GIS The British Government (Dept. of the Environment) stated in 1988 that the impact of GIS on spatial analysis was as significant as the invention of the microscope and telescope were to science, the computer to economics and the printing press to information dissemination. It is the biggest step forward in the handling of geographic information since the invention of the map

Why use GIS in archaeology? Archaeology is a spatial discipline Archaeology is a spatial discipline We work in all 3 dimensions We work in all 3 dimensions It allows us to re-examine past theories It allows us to re-examine past theories Allows us to analyse several maps in one easy package and select specific data attributes using layers Allows us to analyse several maps in one easy package and select specific data attributes using layers

Spatial information Spatial phenomenonExplanatory factors Seasonal Hunter-Gatherer camps within a landscape The availability of resources A hierarchy of settlements within a regionTerritorial spacing and proximity to market The distribution of watchtowers along a defensive structure (e.g. Hadrians wall) Carefully structured and formalised intention linked to a specific functional requirement The location of coarse potsherds in the plough soilThe result of a number of quasi-random post- depositional forces The position of a zone of decoration on the body of a ceramic vessel The physical manifestation of a symbolic-ideological design The arrangement of earthworks and stones at a Neolithic henge site The unplanned, accumulated product of everyday ritual practice The suggested zodiacal arrangements of monuments around the site of Glastonbury in Southeast Britain The tendency of the human eye to see structures in apparently random patterns of dots Discard of bone debris around a hearthThe functional requirements of bone-marrow extraction undertaken whilst sitting around a smoky fire The Nazca lines and geo-glyphsProcessional routes and pathways

Adoption of GIS in archaeology Adopted by US archaeologists, mainly CRM (e.g. Kvamme) for Predictive modelling of site locations Adopted by US archaeologists, mainly CRM (e.g. Kvamme) for Predictive modelling of site locations Reflects type of the archaeological work and theoretical orientationReflects type of the archaeological work and theoretical orientation Still a major topic of investigation in the US e.g. Westcott & Brandon AdoptionStill a major topic of investigation in the US e.g. Westcott & Brandon Adoption later in the UK, then other European countries later in the UK, then other European countries In Europe, the impetus for GIS adoption was more from researchers than managersIn Europe, the impetus for GIS adoption was more from researchers than managers Little interest in predictive modelsLittle interest in predictive models Far more analytical uses of technologyFar more analytical uses of technology Potential for GIS for archaeological management quickly realised, although implementation remains limitedPotential for GIS for archaeological management quickly realised, although implementation remains limited

How do we communicate the location of something to another person? What happens if that place is not in Britain? Jones 1997, chapter 4

Co-ordinate systems (1) Cartesian co-ordinates Easting Northing Polar Planar co-ordinates Distance Angle You will be familiar with two co-ordinate systems:

Co-ordinate systems (2) Both the previous two systems are fine over short distances as both assume the world is flat Parallel Meridian

Co-ordinate systems (3) Map Projections: transforming a representation of the world in 3D to a representation on a planar surface The Mercator projection has straight meridians and parallels that intersect at right angles. Scale is true at the equator or at two standard parallels equidistant from the equator. The projection is often used for marine navigation because all straight lines on the map are lines of constant azimuth

Co-ordinate systems (4) Transverse Mercator projections Transverse Mercator projections result from projecting the sphere onto a cylinder tangent to a central meridian. Transverse Mercator maps are often used to portray areas with larger north-south than east-west extent. Distortion of scale, distance, direction and area increase away from the central meridian. 49 o N, 2 o W Scale 0.996

The Universal Transverse Mercator (UTM) projection is used to define horizontal positions world-wide by dividing the surface of the Earth into 6 degree zones, each mapped by the Transverse Mercator projection with a central meridian in the centre of the zone. UTM zone numbers designate 6 degree longitudinal strips extending from 80 degrees South latitude to 84 degrees North latitude. UTM zone characters designate 8 degree zones extending north and south from the equator Co-ordinate systems (5) Transverse Mercator projections

Any problems with projections? Co-ordinate systems (6) The shape of the Earth (geoid) has been refined a number of times. Each change affects all projected co- ordinate systems

Case study

Moncayo Archaeological Survey

Moncayo Archaeological Survey (east of Magallón)

Neolithic and Bronze Age activity

Sites on surface on plateau and in gully sections

Neolithic site at Cabezo Agudo

Ambel study area

Valdequnquera Valley

Fuente del Ojo

Sequences below Fuente del Ojo

Valdequnquera Roman villa

Valdequnquera Roman villa (fieldwalking finds)