1. GIS DATAANALYSIS
ď Raster to Vector Conversion
ď Spatial analysis through vector overlay
Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
Dr. Arindam Sarkar
Department of Geography
Purash Kanpur Haridas Nandi College
PO: Kanpur, District: Howrah
2. GIS data type
Spatial data: It is related to geometry of spatial feature
Attribute data: It is associated with information about the spatial feature
Spatial data:
⢠It represent spatial feature of the Earthâs surface on map (plane surface)
⢠Location of each feature is determined by Cartesian coordinate system (x,y axis, geographic grid:
latitude and longitude)
⢠Types of Spatial data: Discreet feature data and Continuous feature data.
⢠Discreet feature are those that do not exists between observations, form separate entities and are
individually distinguishable (Dent,1999)
⢠Example of discreet feature data: Ponds, wells, road, agricultural land etc.
⢠Continuous feature exists spatially between observations (Dent,1999)
⢠Example of Continuous feature data: Precipitation , elevation, soil pH etc.
GIS data model
⢠Raster data model
⢠Vector data model
Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
3. Spatial data
Raster data Vector data
Topological Non topological
High-level data Simple data
TIN Regions Dynamic segmentation
Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
4. Raster Vector
ďśRaster data use a matrix of square areas to
define where feature are located.
ďśThese square is also called pixels, cells and
grids, typically are of uniform in size.
ďśRaster data is used for capturing, storing and
analyzing data such as elevation, temperature,
soil organic matter etc.
ďśRaster data format are also used to store
aerial photograph and satellite imagery.
ďśRaster is made up of pixel (or cells). Each
pixel has an associated value (DN value).
ďśDigital image is an example of raster data set.
ďśEach pixel value correspondence with a
particular colour.
ďś Vector data uses X.Y coordinate to define the
location of a points, lines and polygons , that's
corresponds to map feature.
ďś Vector data are excellent for capturing and
storing spatial details.
ďśVector data consists of individual points,
which (2D format data) are stored as pairs of
(X,Y) CO-Ordinates.
ďśThe point may be joined in a particular order
to create line or joined into closer rings to create
polygons.
Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
5. GIS data analysis
Raster data analysis Vector data analysis
Map manipulationBuffering
⢠Point buffer
⢠Line buffer
⢠Area buffer
(Polygon
buffer
Vector data overlay
⢠Point-in-polygon
⢠Line-in-polygon
⢠Polygon-on-polygon
Distance
measurement
Reclassification
Raster data overlay
⢠Point-in-polygon
⢠Line-in-polygon
⢠Polygon-on-polygon
Terrain mapping
⢠BPD or DEM
⢠Contour map
⢠Hill shade map
Terrain analysis
⢠Slope map
⢠Aspect map
Spatial interpolation
Global method
⢠Trend Surface Analysis
⢠Regression models
Local method
⢠Thiessen Polygons
⢠Density Estimation
⢠Inverse Distance
Weighted (IDW)
⢠Thin âplate Splines
⢠Kriging
Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
6. Raster data overlay
ďś Point-in-polygon
ďś Line-in-polygon
ďś Polygon-on-
polygon
Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
7. Vector Map overlay
⢠Point-in-
polygon
⢠Line-in-
polygon
⢠Polygon-on-
polygon
⢠Point-in-
polygon.
⢠Line-in-
polygon
Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
8. Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
9. Map Overlay method
1.Clipping
2.Erase or delete
3.Split
4.Identity
5.Union
6.Intersect
Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
10. Spatial data editing
Digitization â error due to digitization
Types of error occur
due to digitization
⢠Location error
⢠Topological error
(over shoot , under
shoot)
Topological and non-topological editing
Edge matching
Non-topological editing
⢠Delete
⢠Move
⢠Cut
⢠Paste
⢠Reshape
⢠Split
⢠Merge
Manipulation feature
⢠Line simplification
⢠Densification
⢠SmoothingDr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com
11. Dr. Arindam Sarkar , Department of Geography
Purash Kanpur Haridas Nandi College Website: https://pkhnm.ac.in/
Email ID: arindam.srkr1@gmail.com