Geographical Information System – GIS

LOOM.02.331

anto.aasa@ut.ee

GIS and spatial planning

National

Regional

Local

Scal

e

Level of Detail

Time H

orizo

n

Strategic (National Dev. Plan)National Goals and development policy

Tactical (Regional guidelines – SpatialStrategy)

Articulation of Strategies

After Keane, M et al & Lee DB

Implementation(Development Plans)

Land use, Housing, Roads

GIS functions

• Mapping and visualization;

• administration of geographical information;

• data collecting and updating;

• geographical analysis.

GIS in spatial planning

GIS asdatabases

Planning DecisionSupport systems

Modelling & SimulationActivities

PublicParticipation and

InformationAccess

Geographic information system (GIS)

• Mutually related complex of software and data

– Watching geographical information,

– Administration of geographical information,

– Analysis of spatial relationships and patterns,

– Modelling of spatial processes.

GIS

• Hardware

• Software

• Database

– Geographical space

– Theme (attributes)

• Operations

• Human resource

History

• First person who placed different layers on top of each other?

Cholera deaths in London

John Snow 1854

History• 1963: first nation-wide GIS - Canada• 1966: first raster-GIS• 1972: first civil use remote sensing satellite Landsat 1 • 1978: first satellites of NAVSTAR (development of GPS technology)• 1979: first vector-GIS –ODYSSEY GIS• 1981: Esri ARC/INFO • 1986: MapInfo – first desktop GIS• 1994: beginning of standardization of spatial data and infrastructure

(OpenGIS consortium)• 1996: first Internet based GIS products• 1996: first Internet based map service MapQuest• 2000: over 1 million professional GIS users in world, over 5 million

„average“ GIS users• Today: everyone can „GIS“

Area of use

• Land survey, cartography• Logistics• Aviation• Real estate• Military forces• Trade• Local authority• Science• Infrastructure management• …• Spatial planning

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Important factors for spatial analysis

• Location data

• Attribute data

• GIS

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Spatial databases & GIS

• Location: spatial vs descriptive?

– N 48° 21’ 17’’ E 11° 47’ 15’’

– Germany, Munich airport

• Relation between objects

– Distances

– Patterns

Location:

• Descriptive

• Spatial

• Network

• Everything, what happens in real world has geographical coordinates

– X

– Y

– Z

– time

• (also in virtual space)

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Location

• Map and database must be in same projection and datum

– Datum – model of the earth

– Projection – curved surface to flat plane

• Earth is not ideal sphere but geoid (potato-shaped)

– Earth model: ellipsoid

• Map projection – method of representing the surface of Earth on a plane

– All map projections distort the surface in some fashion

• Error minimization

Representation of spatial data

• Real world is too complex

• Simplified models

– Maps

– Cartography

http://www.colorado.edu/geography/gcraft/notes/datum/datum_f.html

Modelling the real world

• Discrete objects

• Continuous fields

Visualization of invisible objects / phenomenas (Augmented, Mixed Reality)

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Distortions

– area,

– direction,

– scale,

– distance.

http://blog.perrygeo.net/2005/12/11/tissot-indicatrix-examining-the-distortion-of-2d-maps/

Model accuracy

Augmented reality

VectorPoint

Line

Polygon

Shp-layer:

Representation of geoinformation in GIS

• objects

– points,

– lines,

– polygons;

• raster;

• attributes.

Raster

slope Elevation shading Population density

ortophoto Landuse concentration

Lat | Lon | Value26.466 |58.478 | 165 … | … | …

Vector layer

• Attributes table:

– Rows: map objects

– Columns: attributes

– Queries (SQL)

• Layer based model:

– One theme for every layer

– One data type for every layer (point, line, polygon, raster)

Elevation

Perception

• Use of color

– Traditions of visualising certain object types

• orientation

• Symbols

• Colors

Perception

• Map (data) scale

– the ratio of a distance on the map to the corresponding distance on the ground (e.g. 1:400 000)

• Generalization

– Simplifying of objects

Measurements accuracyModel accuracyAmount of data

Generalization

GIS output

• Table

• Graph

• Report

• Thematic map

• Something else?

What is the aim?

Internet maps

• Geoportal of Estonian Landboard

• Open Street Map

• Google Map

• Bing Map

• …

Creating GIS

• Reality model (description of the real world)

• Data model (database structure and technology)

• Representation model (rules for datarepresentation)

– e.g. Roads on top of rivers

Management of spatial data

• Raster model

– Rectangular regular grid of pixels

• Vector model

– Points, lines, polygons (functions determining theshape and form of objects)

Processing of geographical data

• Processing of the initial data for achievementof goals

– Queries (response to relevant conditions)

– Spatial analysis (description of place, attribues and relationships between them)

Quality of spatial data

• Completeness (missing, redundant data)

• Consistence

• Location correctness

• Up-to-date

• Thematic correctness

Seminar 1

• Simple thematic maps in:

– Q-GIS (Quantum GIS) http://www.qgis.org/en/site/

– R & RStudio

• http://www.r-project.org/

• https://www.rstudio.com/