EIAxpert: An Expert System for screening-level   EIA




Fedra, K., Winkelbauer, L. and Pantulu. V.R. (1991)
Expert Systems for Environmental Screening.
  An Application in the Lower Mekong Basin.   RR-91-19. International Institute for Applied Systems Analysis. A-236l Laxenburg, Austria. 169p.



1   Environmental Impact Assessment: Background and State of the Art

Human activities, such as those that relate to large scale water resources development projects, construction, agriculture, energy, industry and development projects, considerably affect the natural environment. These effects or impacts occur during the construction phase, the operational life time of a project, and in many cases, as with waste disposal sites, may continue long after closure of a plant or site or the completion of a development activity. Consumption of natural resources, including space, water, air and biota, and the generation of wastes including the dissipation of energy and noise, usually lead to a degradation of the natural, and above all, the human environment.

Environmental considerations are becoming increasingly important components of planning. Many countries, pioneered by the 1969/70 National Environmental Policy Act (NEPA) of the United States, have introduced appropriate legislation calling for the explicit consideration of environmental impacts in the planning and decision making process for large projects. For an international comparison of Environmental Impact Assessment (EIA) procedures and examples from various countries, including developing countries, see e.g., Munn, 1979 for an international overview including the CMEA countries; Gresser, Fujikura and Morishima, 1981, for Japan; Clark, Gilad, Bisset et al., 1984, for developing countries; or the Asian Development Bank (ADB, 1988) for selected member countries.

The landmark legislation of NEPA contains three major provisions (Liroff, 1976), by which it:

  1. Established environmental quality as a leading national priority by stating a national policy for the environment;

  2. Made environmental protection part of the mandate of all federal agencies, establishing procedures for the incorporation of environmental concerns into agency decision making. In particular, it requires federal agencies to prepare an environmental impact statement for major actions or projects that can affect the environment;

  3. Established a Council on Environmental Quality in the Executive Office of the President to oversee and coordinate all federal environmental effort.

Environmental impact statements, as regulated by the Act, must contain:

  • A description of the proposed action, its purpose, and a description of the environment affected;

  • The relationship to land use plans, policies, and controls for the affected areas;

  • The probable environmental impacts, positive and negative, direct and indirect, and possible international implications;

  • A discussion of alternatives;

  • The probable negative impacts that cannot be avoided or mitigated;

  • The relationship between local and short-term use and long-term considerations;

  • An irreversible commitments of resources;

  • A description of federal actions to mitigate and offset adverse effects and

  • Comments from reviewers.

Numerous regulations or guidelines for environmental impact statements follow this basic pattern, with some variations. One of the more recent is the Council Directive of the Commission of the European Community (CEC, 1985). The Directive on the assessment of the effects of certain public and private projects on the environment (85/337/EEC, June 1985) requires comprehensive environmental assessments of projects and installations involving hazardous materials. These assessments are to include consideration of the production and storage of materials such as pesticides, pharmaceuticals, paints, etc. A broad analysis of the direct and indirect effects on people, environment, property and cultural heritage is also foreseen and the evaluation of alternatives is required.

EIA requires the qualitative and quantitative prediction and analysis of the impacts of human activities on the environment. Ideally, environmental considerations should be given equal weight as economic and technological considerations and be an integrated part of planning from the earliest stages. Further, the often long-term environmental, and thus social, costs should be included in a project's assessment and the minimization and mitigation of environmental costs should be a definitive part of the design.

For water resources projects in general, and river basin development projects in particular, impacts on the environment include:

  • Land use and pollution during construction (of a dam/reservoir or irrigation project), including temporary, secondary problems caused by construction teams, transportation, equipment, etc.;

  • Impacts on the environment during operation of the project due to alterations in the environment such as change of water flow and subsequent downstream effects, discharge of wastes into the atmosphere, water, and soil, possibly causing environmental and human health hazards, as well as those due to related or induced activities;

  • Impacts on, or pollution of, the environment and acute hazards to man during abnormal operating conditions such as extreme floods or accidents such as dam breaks, or anaerobic water in reservoirs or hydrogen sulfide fish kills during and after reservoir filling;

  • Environmental degradation due to the consumption or exploitation of renewable and non-renewable natural resources, in particular, land required for the project;

  • Secondary environmental impacts due to changes in land use, population density, and the socio-economic structure around a new reservoir or development project.

Comprehensive impact assessment, however, should also look at the positive impacts, i.e., environmental improvements that are possible directly (e.g., material substitution or hydropower replacing fossil fuel) or indirectly (due to increased revenues) as a consequence of a new development project. Further, impact analysis should be a comparative, not an absolute assessment: the opportunity costs (in terms of the projects not chosen, including the alternative of no project at all, in favor of a given one) have to be considered.

Environmental impacts depend on two major factors:

  • The choice and scale of the project and its technology, pollution control and mitigation measures, and the operating conditions (such as reservoir operating rules) and management of a project;

  • The location of the activity, i.e., the specific environment that will be impinged upon and which may in turn affect the project.

While the technological aspects can be treated at a generic, site-independent level and thus with generic data that can be compiled a priori, the site-specific part requires a case-by-case study and local data collection effort as part of an environmental assessment.

Numerous sources of information on environmental impacts, pollutants, waste management, environmental standards and criteria, impact assessment methods and software tools exist in the scientific literature, the publications, manuals and guidelines of numerous institutions and government agencies, or in public and commercial data bases and information services. These sources of information provide necessary and critical inputs to the various impact assessment methods and therefore deserve special attention.

Methods for the assessment of environmental impacts range from simple checklists and qualitative impact matrices to much more complex computer-based approaches using, for example, simulation modeling and optimization, geographical information systems (GIS), or expert systems techniques. The methods of assessment also ought to include some of the more important aspects, such as legal, procedural and institutional components, that may differ widely from country to country and from project to project.

Methods that do have a track record of repeated use, and have been described in the respective literature, include, for example:

  • Graphic overlay methods (McHarg, 1968; Dooley and Newkirk, 1976)
  • USGS Matrix (Leopold, Clarke, Hanshaw et al., 1971)
  • Network Analysis (Sorensen, 1971; Sorensen, 1972)
  • Cross-impact Simulation (Kane, 1972)
  • EES: Environmental Evaluation System (Dee et al., 1973)
  • HEP: Habitat Evaluation Procedures (US Fish and Wildlife Service, 1976)
  • Decision Analysis (Keeney and Raiffa, 1976)
  • WRAM: Water Resources Assessment (Solomon, Colbert, Hansen et al., 1977;
  • Hansen, Solomon et al., 1978)
  • EQA: Environmental Quality Assessment (Duke et al., 1977)
  • METLUND Landscape Planning Model (Fabos et al., 1978)
  • Goals Achievement Matrix (Hill, 1968)
  • WES: Wetland Evaluation System (Galloway, 1978)
  • AEAM: Adaptive Environmental Assessment (Holling, 1978)
  • EQEP: Environmental Quality Evaluation Procedure (Duke, 1979)
  • CBA: Cost--Benefit Analysis and related methods: numerous authors
  • Interactive Systems Analysis and Decision Support (Fedra, Li, Wang et al., 1987; Fedra, Karhu, Rys et al., 1987; Fedra, 1988; Fedra, 1991).
  • Expert Systems (Fedra et al., 1991; NEW BOOK ON MY DESK).

In terms of causality considered, methods are based on checklists or questionnaires, cross-impact matrices, or complex network analysis involving second- and higher-order effects and feedback. In terms of formats, they range from narrative and qualitative descriptions to various attempts at quantification and formalization, from monetization to graphical methods.

In terms of procedures, they may involve experts or expert teams and panels, workshops or public hearings, to court proceedings. In terms of tools, they may be based on guidelines and manuals or involve computer-based tools. Usually, any practical impact assessment involves a combination and mixture of several such components.

EIA procedures and approaches are often organized around checklists of data collection and analysis components (e.g., De Santo, 1978; Munn, 1979; Bisset, 1987; Biswas and Geping, 1987). Basic components of the assessment process are:

  • A description of the current environment, which usually includes such elements as rare or endangered species, special scenic or cultural components;

  • A description of the proposed project or activity, covering technological, socio-economic, and administrative and managerial aspects;

  • A description of expected impacts, with emphasis on irreversible change and the consideration of mitigation strategies and project alternatives, including the alternative to not undertake the project;

  • and, depending on the mandate given, a comparative evaluation of options.

Obviously, the prediction of impacts is the most difficult part. Approaches range from purely qualitative checklist-based matrix approaches (Leopold, Clarke, Hanshaw et al., 1971), expert panels and workshop techniques (Holling, 1978), system diagrams and networks, to various computer-based modeling techniques (Kane, Vertinsky and Thompson, 1973; Thompson, Vertinsky and Kane, 1973; Gallopin, 1977; Patten, 1971; Walters, 1974; Bigelow, De Haven, Dzitzer et al., 1977; Fedra, Paruccini and Otway, 1986), or any combination of these approaches. However, most of the accepted and routinely used tools of EIA are not based on the use of computers, but on more or less formalized qualitative assessment procedures. Also, most methods are somewhat general, and have been developed in a context other than the impact assessment of water resources projects. Few of the methods discussed below are associated with concrete tools: they are approaches rather than tools, and where tools have been developed, they have been adapted to very specific applications.

While a large number of impact assessment methods have been developed and more or less successfully applied worldwide, few, if any, are specifically geared toward water resources development projects with their specific hydrological dimensions. Most of the available techniques are ecological and resource oriented, designed to evaluate a given project or a set of alternatives. They are not, as a rule, designed to provide substantive input to the planning and design phase of a development project, which should be the ultimate goal of environmental impact assessment techniques.

Some of the most flexible and universal tools of impact assessment are certainly models and related information and decision support systems, implemented on computers.

The use of computers as a major tool for EIA is nowhere near as common as it could or should be. Problems, in developing countries in particular, range from the availability of the necessary computer hardware to the expertise in developing, maintaining, and using more or less complex software systems (e.g., Ahmad and Sammy, 1985). Further, lack of quantitative data is often cited as a reason for not using computers and simulation models.

However, the availability of increasingly powerful and affordable computers grows rapidly (Fedra and Loucks, 1985; Loucks and Fedra, 1987), and so does computer literacy among technical professionals. grows rapidly (Fedra and Loucks, 1985; Loucks and Fedra, 1987), and so does computer literacy among technical professionals. Even very powerful super-micro computers have become somewhat more affordable, and technical workstations are approaching the price class of personal computers. Many of the reasons cited for not using computers in environmental assessment are in fact problems that the computer can help overcome.


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