GIS Geographical Information System a tool

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GISGeographical Information System(a tool)

• Presented by
• Jhumur Halder
• TBTE 415

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What is GIS?

• Integrated collection of computer software and
  data
• View and manage information about places
• Retrieve data
• Analyze spatial relationships
• Model spatial processes

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Why GIS?

• It is a tool
• - to make map
• - to analyze data
• - to see the results in the form of
  interactive map
• that reveal how things work together
• - allow the most important decisions

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A GIS contains

• Map Layers
• - vector- points, lines, polygon
• - raster- numerical value
• Database

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Rasters

• A raster is a matrix of identically sized square
  cell( pixel)
• Each cell in a raster stores a value
• (quantity of something like rainfall, temp.
  elevation)
• Satellite images, aerial photographs, scanned map
  are rasters

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Features

• Map layers contain features
• Information about the features stored in a table
• Attribute table for a layer includes
• - each features shape- point, line, polygon
• - ID number
• - name
• - other things
• Features on a map linked to the info of table.
• Features have spatial relationships
• New feature can be created from areas of overlap

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GIS tasks

• Category 1
• - Mapmaking
• - Editing
• - Spatial analysis
• Category 2
• - Database design
• - Data management

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Arc GIS

• Desktop- manage, integrate, analyze your data,
• Online- access 2D maps, 3D maps, reference
  layers, contribute your own data

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Arc GIS Desktop

• Arc view, Arc Editor and Arc Info share a common
  user interface and can freely exchange maps and
  data.

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Exploring ArcMap

• File type
• - .mxd

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Arc catalog

• Application for managing geographic data
• Spatial data comes in different formats-
• Geodatabases
• Coverages
• Shapefiles- green icon-point, line, polygon
• CAD files
• Rasters
• TINs

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Browsing map data

• ArcCatalog gives info about spatial data
• Data folder contains
• a geodatabase (.mdb)
• feature class(point, line,polyg)
• shape file (.shp)
• layer file (.lyr)

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Querying data

• Several ways to retrieve unseen info about
  features
• - identifying features
• - selecting features interactively
• - selecting features by attributes
• Arc GIS Demonstration

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GIS in K-12

• Develop spatial thinking
• Maps for decision making
• eg. where will be suitable place for
  something to build.
• Demonstration arc gis explorer

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Spatial analysis

• Spatial thinking is a cognitive skill
• GIS foster spatial thinking skill
• - inquiry process
• - solving problem in real world context

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conclusion

• Still GIS is not getting overwhelming acceptance
  in curriculum
• It is time consuming