Geographic Information Systems

1. Geographic Information Systems Babu Ram Dawadi, IOE Pulchowk Campus

2. Definition • A Geographic Information System (GIS) is a computer based system that facilitates the phases of data entry, data analysis and data presentation especially in cases when we are dealing with georeferenced data. • A Geographic Information System (GIS) is a computer-based mapping tool that enables geographic or spatial data capture, storage, retrieval, manipulation, analysis, modeling and presentation of the real world scenario. Basically, GIS is working on the principle of geography. Geography or GIS is now proving its potential and widely accepted by inter-disciplinary experts at various levels to better manage the earth’s resources.

3. Def… • GIS is a System of computer software, hardware and data, and personnel to help manipulate, analyze and present information that is tied to a spatial location – • spatial location– usually a geographic location • information– visualization of analysis of data • system– linking software, hardware, data • personnel– a thinking explorer who is key to the power of GIS

4. History of GIS

5. History of GIS

6. History of GIS

7. GIS Software • The geoprocessing engines of GIS • Major functions • Collect, store, mange, query, analyze and present • Key terms • Program – collections of instructions to manipulate data • Package– integrated collection of programs • Component – self-contained, reusable software building blocks

8. Functionality Architecture User Interface Applications Geographic Tools Analysis Output Translation Customization Editing Display Data Manager Spatial Reference Data Access Vector Raster

9. Autodesk ESRI Intergraph MapInfo Smallworld Viewer AutoCAD LT ArcReader GeoMedia Viewer ProViewer Custom Desktop World ArcView GeoMedia MapInfo Professional Spatial Intelligence Profess-ional AutoCAD / Map ArcEditorArcInfo GeoMedia Pro MapInfo Professional Smallworld GIS Hand-held OnSite ArcPad IntelliWhere MapXtend Scout Database Server GIS Server ArcSDE Uses Oracle Spatial SpatialWare Part of Smallworld GIS Component In several products Map Objects Part of GeoMedia MapX, MapJ Part of Smallworld GIS Internet MapGuide ArcIMS GeoMedia Web Map, GeoMedia Web Enterprise MapXtreme, MapXSite Smallworld Internet Applic- ation Server CAD AutoCAD Map In several products In several products In several products Part of Smallworld GIS Product Families

10. GIS Software Classification Number of Users Cost Internet Viewer Component Hand-held Desktop Professional Functionality

11. ArcSDE Unifies Spatial Data Access • ArcGIS Desktop Applications • ArcIMS , ArcExplorer, ArcPad • MapObjects • Third-Party applications ArcSDE Services SQL Server Oracle Informix IBM DB2

12. First, Spatially Enable The Data… Data Is Independent of Application ArcSDE ArcIMS ArcGIS SQL Server High Availability, High Performance, Secure, Scalable

13. GIS Internet Enterprise Today Applications Browsers Web Web Server Broker Databases

14. Future GIS Internet Enterprise Applications Browsers Web Broker Web Server Services Databases

15. Distributed GIS Development • New Concept – g.net architecture • leveraging emerging web technologies • Web services • GIS technology for applications over the web • Mapping • Metadata • GIS Functionality • Spatial Data sharing and distribution • Extends ArcGIS Systemconcept • Desktop Applications • Back Office Servers • Distributed “Services” via the Internet

16. GIS Portal GIS Portal GIS Portal G.net Architecture Building Blocks • Network architecture (Distributed) • Loosely Coupled • Internet Standards • Many GeoServices • Many Clients • Metadata Servers • Open / Interoperable • Full GIS capabilities GIS Users Connect and UseCheckout and Use Search Catalog and Find World Wide Web • Publish GIS Data & Services • Document in Catalog Metadata Server Author, Manage, Serve Catalogs Author, Manage, Serve Geographic Information Collections

17. ESRI Direction“Software for G.Net” ArcGIS Used to build • Data • Maps • Models • Applications • Metadata ArcIMS • Serve GIS • Data • Maps • Apps GIS Web Services Array of GIS Clients Access and use GIS data and services • ArcReader • Map Objects for Java • ArcGIS Desktop & Extensions • ArcPad ArcSDE Used to manage • Data • Metadata • Transactions ArcGIS • Author and Manage Metadata • Build Catalog Metadata & Catalog Services GIS Clients ArcIMS • Manage Metadata • Provide Search Services ArcSDE Used to manage and distribute • Metadata

18. 3-Stages of GIS • Data preparation and entry: the early stage in which data about the study phenomenon is collected and prepared to be entered into the system. • Data Analysis: the middle stage in which collected data is carefully reviewed and, for instance, attempts are made to discover patterns • Data Presentation: the final stage in which the results of earlier analysis are presented in an appropriate way

19. Importance & Applications • B: Business • I: Industries • G: Government • A: Academy • A: Aircraft • M: Military

20. Major Area • Natural Resource Management • Wildlife habitat, • Wild and scenic rivers, • Recreation resources, • Floodplains, • Wetlands, • Agricultural lands, • Forests. • Facilities Management • Locating underground pipes and cables, • Balancing loads in electrical networks, • Planning facility maintenance

21. Application contd… • Land Management • Zoning and subdivision planning, • Land acquisition, • Environmental impact policy, • Water quality management, • Maintenance of ownership. • Info. Based Street Network • Address matching, • Location analysis or site selection, • Development of evacuation plans.

22. How GIS assume Greater Significance • Which is the best route between kalanki and ratnapark having minimal road intersection with good road and lesser traffic jam during peak hours? • Identify the roads served by Metro water tank in kalanki with a population between 1,000 and 1,500? • Which part of Gandaki zone has less literacy rate with unemployed youth between 20 and 30 years of age? • Where are the potential aquifers located away from agricultural land with good road connectivity within 50 km of Kathmandu for groundwater extraction? • Identify the apartment houses in new road not following building codes to withstand earthquake.

23. Spatial data and Geoinformation • spatial data; we mean data that contains positionalvalues. Often we can say in more precise phrase geospatial data as a further refinement, which then means spatial data that is geo-referenced • By information, we mean data that has been interpreted by a human being • Geo-information is a specific type of information that involves the interpretation of spatial data.

24. The real world and representation of GIS • we usually are trying to represent some part of the real world as it is, as it was, or perhaps as we think it will be • A computerized system can help to store such representations. • Static Model • Maps & Databases: at any point in time, they represent a single state of affairs. Usually developments or changes in the real world are not easily recognized in these models. • Dynamic Model • Simulation

25. Maps.. • The best known models of the real world are maps • A map is a miniature representation of some part of the real world • GIS and the map is very closely related to each other • maps can deal with questions/answers relating to basic components of spatial or geographic data: location (geometry), characteristics, (thematic attributes) and time, and their combinations

26. Map Types • Topographic maps: A topographic map visualizes, limited by its scale, the Earth’s surface as accurately as possible. This may include infrastructure (egg, railroads and roads), land use (eg, vegetation and built-up areas), relief, hydrology, geographic names and reference grid • Thematic maps: A thematic map represents the distribution of the particular themes; we can distinguish socio-economic theme and the physical themes using these maps.

27. Spatial Databases • A spatial database system is a database system • It offers spatial data types in its data model and query language • It supports spatial data types in its implementation, providing at least spatial indexing and efficient algorithms for spatial join. a spatial database is a collection of spatially referenced data that acts as a model of reality -a database is a model of reality in the sense that the database represents a selected set or approximation of phenomena -these selected phenomena are deemed important enough to represent in digital form -the digital representation might be for some past, present or future time period (or contain some combination of several time periods in an organized fashion)

28. Spatial Databases… • Spatial DB store representations of geographic phenomena in the real world to be used in a GIS. • They are special in the sense that they use other techniques that tables to store these representations because it is not easy to represent geographic phenomena using tables. • spatial phenomena exist in a two or three dimensional Euclidean space ( a model of space in which locations are represented as coordinates- (x, y) in 2D; (x, y, z) in 3D- and notions like distance and direction have been defined with the usual formulas).

29. Spatial DB.. • A database may contain collection of: