Introduction to GIS.pptx
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The document provides an introduction to Geographic Information Systems (GIS), explaining its definition, functions, components, and significance in analyzing spatial data. It highlights the importance of geography in understanding both physical and human interactions with the environment and outlines how GIS serves as a powerful tool for data collection, analysis, and visualization. Additionally, it details the various components of GIS, including hardware, software, data, and personnel, along with the advantages of using GIS for efficient decision-making and integration of spatial information.
Introduction to GIS.pptx
- 2. Introduction to GIS • What is GIS? G ? I ? S? Geographical Information System
- 3. What is Geography? Definition: Geography is the study of the world's environment and man's interaction within the environment.” Geography has two “strands” or parts: 1.PHYSICAL: The study of the earth's natural features, such as mountains, rivers, soil, vegetation, and weather 2. HUMAN: (Cultural) The study of human cultures and man made features. “All kinds of resources are used to study geography, but the most common are MAPS.”
- 4. Why Geography is important? • Why are we more interested in spatial data today than 100 years ago? Reference: Bolastad, 2008
- 5. Why GIS is Important? • What is Where? : – Query information to find location Or • Where is what? – Obtain information from a location • Applied geography, in the form of maps and spatial information, has served discovery, planning, cooperation, and conflict for at least the past 3,000 years (Bolstad) • Impact of spatial information on our lives?
- 6. Type ……. Species ……. Heights ……. Use ……. O O X South, Y West Location Information: Where is it? Attribute Information: What is it? There are two ways of explaining any element/object on the Earth GIS can tell us Where and What
- 7. GIS is about Geospatial Information • Geography/Geospatial: Information about places on earth • Not only Where and What but time is also important What is Where, When?
- 8. S in GIS? • S as in System – Technology (for acquiring and managing GIS data) • S as in Science – Concept behind the technology. Theoretical foundation on which GISystems are based • S as in Studies – Societal context (social, legal, and ethical issues related to GIS application)
- 9. Simpler Definitions • A GIS helps us gather and use spatial data (Bolstad) • A computer system which can hold and use data describing places on the earth's surface.
- 10. GIS... A GIS is not simply a computer system for making pretty maps. More importantly a GIS... • ... is an analysis tool • ... links spatial data with geographic information about a particular feature on a map • ... can use the stored attributes to compute new information about map features
- 11. A more Comprehensive Definition • A GIS is a computer-based system to aid in the collection, maintenance, storage, analysis, output, and distribution of spatial data and information.
- 12. • A powerful set of tools for collecting, storing, retrieving at will, transforming and displaying spatial data from the real world. (Burrough, 1986) • Any manual or computer based set of procedures used to store and manipulate geographically referenced data. (Aronoff 1989) Some other popular definitions of GIS
- 13. • A decision support system involving the integration of spatially referenced data in a problem solving environment. (Cowen 1988) how to deal with stuff in space. • Systems that know (Herrington 1998) Some other popular definitions of GIS
- 14. Conventional Ways to Store Data DATABASES •A Database comprises of tables having fields with specific data structure. •The tables are linked with each other through various common fields.
- 15. Conventional Ways to Store Data MAPS •Map can be defined as “A Facility for displaying interpretation of geographic information on a flat surface.” •Location information describes the position of a particular geographic feature on earth's surface & provides the basis for representing spatial relationships between these features.
- 16. Databases Vs Maps Bad Visual Interpretation Bad Searching Very good Searching Very Good Visual Interpretation What? if link together
- 18. Capture Store Query Analyze Display Output Collecting data using different data structures and technologies – GPS, RS, Digitizing, etc. Data stored in the form of databases, spatial files, drawings, images, etc. A GIS must provide utilities for finding specific features based on their location or attribute values A GIS must have the ability to answer questions regarding the interaction of spatial relationships between multiple datasets There must be tools for visualizing the spatial information in the form of maps Results of display should be able to be output in a variety of formats Basic GIS Functions
- 20. GIS Functions Storing Data Tables
- 21. GIS Functions Spatial Query Query: Select Florida on map
- 25. GIS Functions Output - Maps (Topographic, Statistical, 3D, Contour etc) - Atlases - Reports (Write-ups etc) - Charts, Graphs Hard Copy - General Applications - Special Applications - Customized Applications - Web-based Applications - Mobile Applications - Multimedia - Product Presentation Soft Copy
- 26. GIS Key Components 1. GIS hardware 2. GIS software 3. GIS data (maps, images, database, etc.) 4. People 5. Methods
- 27. GIS Components Hardware Hardware is the computer system on which software operates
- 29. • GIS software provides the functions and tools to store, analyze, and display and disseminate spatial data and information • Many public domain commercially available software packages in the market • ESRI (Environmental Systems Research Institute) line of products a good example (including ArcGIS) GIS Components Software
- 30. GIS Components Software Key components to GIS software: 1. An easy-to-use graphical user interface (GUI) 2. Tools for entering and manipulating geographic information 3. Tools that support geographic query, analysis and visualization 4. A database management system (DBMS)
- 31. Functions Commonly Provided by GIS Software Reference: Bolstad, 2008
- 32. GIS Components GIS Data Map + Database • Virtual or digital maps (virtual representation of world) • Map = Spatial representation of features • Database = Feature attributes Data Sources • Available through various sources like profit and non-profit organizations, academic institutions, government agencies
- 33. GIS Components GIS Data Flood Zones Wetlands Landcover Electric Lines Gas Pipe Lines Soils Land Ownership Transportation Surface Waters Boundaries Geodetic Control Elevation Satellite Imagery GIS Combines Data from Many Sources
- 36. Attribute Type GIS Data • Nominal: descriptive information associated with a spatial entity – country name: Bangladesh, Pakistan, India, …. – highway class: Major highway, local streets, …. – crop type: Maize, cotton, wheat, …. – etc • Ordinal: rank order or scale by their values. Such as small, medium, large (soil erosion class, drainage class…). Does not infer a specific scale. • Interval/ratio: numeric items where both order and absolute difference in magnitude. Real numbers usually on a linear scale (area, length, weight, height etc.)
- 37. GIS Components Peoples • GIS personnel may include – GIS technologist to design and maintain the system – GIS users (analyst, manager, etc.)
- 38. Other GIS Components • Supporting institution • Protocol for use
- 39. Some Advantages of GIS • Automation of procedures involving geographic data (map making, calculation of area, slope, etc., and planning and management activities) • Integration of data from different independent domains • Visual Interpretation of spatial data depending on various criteria • Perform Spatial Queries and complex Spatial Modeling (what if scenarios) • More
- 40. • Geo-spatial data are better maintained in a standard format • Revision and updating are easier • Easier to search, analyze and represent • More value added as well as thematic product • Geo-spatial data can be shared and exchanged freely • Working productivity is improved and more efficient • Time and money are saved • Better decisions in short span of time GIS Benefits