This document provides an overview of geographic information systems (GIS). It defines GIS as a computer-based system for capturing, storing, editing, analyzing, managing and displaying spatial or geographic data. It then lists the typical hardware and software components of a GIS, including computers, scanners, plotters, printers, and spatial and attribute databases. The document outlines several applications of GIS, such as forest monitoring, resource inventory, and land use planning. It also discusses vector and raster data structures and compares the advantages and disadvantages of each.

1. H.K.S.L.AKSHAMAL
USJP

2. • GIS……?????
Computer based system.
The term discribes information
system designed to capture, store,
edit, analysis,manage and display
all type of spatial or geographical
data………

3.  Computer
 Scaner
 Pen plotter
 Printer

4.  Spatial database- Those are spatially referance data.
Ex: roads, house, bus stop…
 Attribute database- They are not spatially referance.
But always add values for spatial data.

5. Data
queriee
Data
modelling
Decision
making
Real world
Data
input

6.  Forest cover monitoring.
 Resource inventory.
 Forest clasification.
 Damage assessment.
 Management plan preparation.
 Landuse planning and management.
 EIA

7.  Natural resource mapping. (Soil, water)
 Highway/Expressway mapping.
 Mineral exploration

8.  Quick reproduction in different scales.
 Easy interpretation.
 Quick update.
 Linking multi thematic maps.
 Accurate data.
 Better prediction and analysis.

9.  Expensive software.
 Difficult to intergrate with traditional maps.

10.  Scale manipulation. (zooming.)
 Map update.
 Logical operation.
 Reclassification of maps.
 Map overlay.
 Proximity analysis/ Buffer zone.

11.  Vector-: spatially referance… Each point has a
known position. Each point have different X & y
values….
 Raster-: Also spatially referance.. But extract
position can not be identified..

12. ADVANTAGES-
 Good
representation of
data.
 Use small file size.
 Accurate map
output.
 Complex data
structure.
 Expensive
technology
 Analysis is complex.
DISADVANTAGES
-

13. ADVANTAGES
 Simple data
structure.
 Cheap technology.
 Analysis is simple.
 Same grid cell for
several attribute.
 Large data volume.
 Inefficient use of
computer storage.
 Difficult network
analysis.
 Less accurate &
attractive maps.
 Loss of information
when using large cell.
DISADVANTAGES

14. THANK YOU………