EIAxpert: An Expert System for screening-level EIA
Fedra, K., Winkelbauer, L. and Pantulu. V.R. (1991)
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:
Environmental impact statements, as regulated by the Act, must contain:
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:
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:
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:
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:
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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