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Geographic Information Systems. GIS Definition. Locations. Networks. Areas. Because most information has a spatial component ESRI, GE SmallWorld. 1. GIS is Important. GIS is Important. It helps temporal reasoning as well S. H. Gage, J. Helly and M. Colunga, GIS/EM4 2000. GIS is Useful.
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Geographic Information Systems GIS Definition
Locations Networks Areas Because most information has a spatial component ESRI, GE SmallWorld 1. GIS is Important
GIS is Important It helps temporal reasoning as well S. H. Gage, J. Helly and M. Colunga, GIS/EM4 2000
GIS is Useful • The “W” questions Where, what, when, why, how, who, what if… • GIS shows “what” are “where”, and helps us to think other “W”s • It helps generate and test hypothesis
GIS integrates various information Social Factors Biodiversity Engineering Land Use Environmental Considerations It allows us to see the “whole” Courtesy: USGS
GIS is Useful • GIS is used by a wide range of disciplines • It changed the way we operate • It opened many opportunities
A Few Facts • NCGIA/NSF grants • GIS programs in government agencies • GIS consulting firms and contracts • GIS conferences, journals, and professional societies • http://erg.usgs.gov/isb/pubs/gis_poster • http://www.ncgia.ucsb.edu • http://www.ucgis.org
2. What is a GIS • An early effort, Ian McHarg, 1969
What is a GIS • A process oriented definition: A GIS is a computer-based system that provides for the collection, storage, analysis, and display of geo-referenced data. • A problem solving oriented definition: A decision support system involving the integration of spatially referenced data in a problem solving environment.
What is a GIS • Data • Information • Knowledge • Intelligence • (DIKI)
Software People Data Network Procedures Hardware What is a GIS • GISystems and GIScience GISystems refers to software and hardware, and is used as a tool to support a project GIScience refers to the particular field of scientific study http://www.ncgia.ucsb.edu http://www.ucgis.org
3. Related Fields • Manual cartography • DBMS (Data base management system) • CAD (Computer-aided drafting) • Computer Mapping • AM/FM (Automated Mapping/Facility Management) • LIS (Land information system) • GIS
Spatial Operations GIS is not just mapping. It does spatial operations. For example, it helps to find: • Where is object A? • Where is A in relation to place B? • How many occurrences of type A are there within distance D of B?
How many cardiovascular patients have a cardiologist within 5 miles? ESRI, GE SmallWorld
Spatial Operations • What is the value of function Z at position X? • How large is B (area, perimeter, count of inclusions)? • What is the result of intersecting various kinds of spatial data?
Where are the potential areas of disease? Who are the populations at risk now and in the future? Geographic Analysis of Disease Risk
Spatial Operations • What is the path of least cost, resistance, or distance along the ground from X to Y along pathway P? • What is at point X1, X2? • What objects are next to objects having certain combinations of attributes?
5. Readings • Chpt 1