Global Information System (GIS)

GIS and EA Engr. Mansoor-Ul-Hassan Siddique Government of Pakistan

Formal Definition of GIS “ A system for capturing, storing, checking, integrating, manipulating, analysing and displaying data which are spatially referenced to the Earth. This is normally considered to involve a spatially referenced computer database and appropriate applications software�

Chorley Report, 1987

What GIS can do?

What would happen if . . .

Achemical leaked into a riv er?

Is there a correlations between . . .

The location of cattle colony and the spread of water- borne disease Has . . .

Population pattern changed ov er the last ten years?

Is there a spatial pattern related to . . .

Car ownership in our area?

GIS comprises of: 

Tools to execute four operations on geo-referenced data:     

Data input Storage Management Analysis Output

Type of Information 

Spatial   



Maps Post Codes Census Report

Management   

Financial Statement EIA Guidelines Schematic Diagram

What is Spatial Data? 

Grid co-ordinate



Place Name



Longitude -Latitude



Post Code



Distance and bearing

Numerical Data

Maps to Display Spatial Data

200’

Sta. 94, DOC 4.9

Stream,3 Former Land Fill

100’ FOREST

URBAN

FOREST

200’

100’

WELL

Duvall, pop 1170 AGRICULTURE

Snoqualmie River, 1

Brush Creek, 2

GIS Organizes Data in Layers Land use Soils Streets Hydrology Parcels

Sites of Ecological Importance

Overlaying Component Maps

Water Quality

Landscape Consideratio ns

Development A (e.g., Industrial Plant) Development B (e.g., road scheme)

Complete Composite Map

The Compilation of an Overlay Map from Various Component Maps

GIS System Architecture and Components

Data Input

Query Input

Output: Display and Reporting

Geographic Database

Transformation and Analysis

Use of GIS in Environmental Studies



Monitoring environmental risk



Modeling storm-water runoff



Management of watersheds, floodplains, wetlands, forests, aquifers



Environmental Impact Analysis



Hazardous or toxic facility siting



Groundwater modeling and contamination tracking

Features of GIS for EA 

Description and distribution of natural resources



Identification of environmental stress



Description of project stress



Assessment of response



Risk assessment



Assess effectiveness of mitigation measures