EIAxpert is an interactive, rule-based
for environmental impact assessment.
It is designed for a screening level assessment of
development projects at a pre-feasibility stage.
The system can operate with a minimum of data and information about the
project, its alternatives, and the environmental setting by drawing on a
generic knowledge and rule base as well as a regional geographical
information system and a set of data bases.
EIAxpert is a generic, completely data driven assessment tool
that can easily be configured for a broad range of application domains and
The original implementation was designed for the
Lower Mekong Basin
(commissioned by the Mekong Secretariat)
for the assessment of water resources development
projects, and uses checklists and assessment rules derived from the
Asian Development Banks Environmental Guideline Series
(Fedra et al, 1991).
A related river basin management information system, that can be
configured as a framework for EIAxpert is
The generic EIAxpert system includes:
A data base and interactive editor tools for water resources
development projects, that allow to maintain (and compare) multiple
alternatives for each project;
A two-layer, hierarchical
geographical information system,
covering the entire river basin as well as the areas immediately affected
by individual projects. The GIS uses both vector data and satellite
A set of data bases, eg., on meteorology, hydrography, or water
quality observations, but also environmental technologies such as waste
A knowledge base with checklists, rules, background information
and guidelines and instructions for the analyst;
The inference engine, that guides the analyst through a projects
assessment in a simple menu-driven dialogue;
and a Summary Report generator, that summarizes and evaluates
the impact assessment and provides a hardcopy report.
Through the rules of the expert system, external models
(for batch execution or interactive, in this case again with a fully
web-based interface and thus easily integrated) can be
invoked as part of the inference procedure.
Models can be used to calculate impacts of reduced flow, waste
water discharges, land use changes, etc., or to estimate project
parameters such as irrigation water demand, or changes to the
The Knowledge Base:
The expert system uses IF .... THEN rules for a qualitative
assessment of potential environmental problems.
The knowledge base of the Mekong system contains well above 1000
nested rules. The rule base is linked to a hypertext system that provides
explanations of terms and concepts, background information, and
instructions for the user.
A knowledge base browser allows inspection of individual rules, and a
recursive explain function WHY can trace the symbolic reasoning
of the system step by step.
EIAxpert is designed for incremental assessments; with more
information becoming available during the various project preparation
stages, a more refined analysis becomes possible.
Different users can contribute to a projects assessment, and several
versions of a project and project alternatives can be maintained