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THE APPLICATION OF GEOGRAPHIC INFORMATION SYSTEMS IN ENVIRONMENTAL
IMPACT ASSESSMENT IN AFRICA: CHALLENGES AND OPPORTUNITIES
MLENGE FANUEL MGENDI*
University College of Lands and Architectural Studies UCLAS; P.o. Box 35176, Dares Salaam, Tanzania.
Email: mlenge@usa.net
KEYWORDS: Environmental Impact Assessment (EIA), Geographic Information Systems (GIS), Environment, Environmental
Information Systems (EIS), Africa, Tanzania.
SUMMARY
Environmental Impact Assessment (EIA) involves collection of data used to predict the potential impacts of proposed
activities. The environmental problems vary both in space and in time, hence cannot be tackled without consideration of the
spatial and temporal contexts. The capacity to map, monitor and model the spatial component of the environmental problems
offered by the Geographic information Systems (GIS) can successfully be used in conducting the EIA. This paper discusses
the challenges and opportunities of the use of GIS in EIA in Africa, zooming in on Tanzania.
INTRODUCTION
Environmental Impact Assessment (EIA) can generally be
defined as a formal study process used to determine the
environmental consequences of a proposed development
project. (6) . The Geographic Information System Systems
(GIS) offer a special environment to deal with the spatial
properties of a project. (8) GIS can be applied in all EIA
stages: from the generation, storage and display of the
thematic information relative to the vulnerability of the
affected resources, to impact prediction and quantification,
evaluation and finally, presentation. (5)
There have been initiatives of linking GIS to Regional ElAs
in different locations such as industrial ElAs in India,
Transportation ElAs in Malaysia and Water Resources and
Thermal Power ElAs in Thailand. Several applications of
GIS integration to EIA are also reported in the UK. (7) . GIS is
found to be a very effective tool for conducting EIA studies
and it can be used for various environmental applications. (2)
The adoption, adaptation and applications of GIS together
with Remote Sensing (RS) and Geographic Positioning
Systems (GPS) in other continents have not only shown that
they provide better and timely resource and environmental
information, their combined analytical and integrative power
has also been found to provide the greatest opportunity to
stimulate and understand the spatial and temporal dynamics
of the real world in a comprehensive manner. (10)
APPLICATION OF GIS IN EIA
GIS have emerged as very powerful technologies because
they allow integration of data and methods in ways that
support traditional forms of geographical analysis, such as
map overlay analysis as well as new types of analysis and
modelling that are beyond the capability of manual methods
A study on the role of GIS in improving environmental
assessment effectiveness revealed that GIS was used for a
wider range of EIA applications as anticipated by the
researchers (Joao & Fonseca (1997), in Looijen (1997)).
In order to determine how EIA practitioners use GIS, a
questionnaire was sent to 98 environmental consultants in
the United Kingdom and Portugal. In the questionnaire each
practitioner was asked to fill what type of GIS operation was
used for which particular EIA stage. The EIA stages
included: screening and scoping, description of the project,
description of baselin'e conditions, impact identification,
prediction of impact magnitude, assessment of impact
magnitude, impact mitigation and control, public consultation
and participation, and monitoring and auditing.
Preliminary results of that study - based on 36 recipients -
showed the use GIS in different EIA stages:
• Screening and scoping: data gathering, spatial
modelling, impact assessment and calculation of impact
magnitude.
• Project description: geographical context of the project.
• Baseline conditions description: documentation of
environmental aspects and attributes, including
biophysical inventories.
• Impact Identification: overlay analysis, e.g. the
distribution of pollutants with resource maps or the
integration of air quality modelling and habitat suitability
analysis.
• Impact magnitude prediction: quantitative assessment
of the percentage of a resource (conservation area)
affected by a pollution or the creation of impact
magnitude maps derived form the integration of the
result of risk and air quality modelling with other data
layers, e.g. soil susceptibility to acidification.
• Impact significance: spatial distribution of the impact
and the variation between the different project
alternatives, including the zero alternative.
• Mitigation & control: model and map distribution of
pollutants. The result can be used to concentrate
Currently on study leave at International Institute for Aerospace Survey and Earth Sciences (ITC).
Box ¡77, Post bus 6, ~500AA Enschede. The Netherlands Email: mgendi@ilc.nl
