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where:

EIUj = environmental impact units for jth alternative EQj = environmental quality scale value for ith factor and j th alternative PIU = parameter importance units for ith factor

Use of the Battelle EES consists of obtaining baseline data on the seventy-eight environmental factors and, through use of their functional relationships, converting the data into EQ scale values. These scale values are then multiplied by the appropriate PIUs and aggregated to obtain a composite EIU score for the baseline setting. For each alternative being evaluated, the anticipated changes in the seventy-eight factors must be predicted. The predicted factor measurements are converted into EQ scale values using the appropriate functional relationships. The EQ scale values are then multiplied by the PIUs and aggregated to arrive at a composite EIU score for each alternative. This numerical system displays tradeoffs between the alternatives in terms of specific environmental factors, intermediate components, and categories. Profes sional judgment is necessary in the interpretation of the numerical results, with the focus on comparative analyses, rather than specific numerical values.

As noted earlier, the Battelle EES was developed for environmental impact considerations related to water resources projects. It has been used directly or in modified form in several water resources projects. For example, it was used on the Pa Mong Water Resources Project in South Thailand (Economic and Social Commission for Asia and the Pacific 1990) and in modified form for other water resources projects (Lohani and Halim 1990). The general approach of the EES can be applied to other project types through selection of pertinent environmental factors, assignment of importance weights, and the development of appropriate functional relationships for the factors. The approach used in the Battelle EES has been applied to a rapid transit system (Smith 1974), a waterway navigation project (School of Civil Engineering and Environmental Science and Oklahoma Biological Survey 1974), and to highway projects, pipeline projects, channel improvement projects, and wastewater treatment plants (Dee et al. 1973).

FIG. 2.5.2 Battelle environmental evaluation system. Numbers in parentheses are parameter importance units. Numbers enclosed in boxes represent the total (Dee et al. 1972).

Another example of a weighting-scaling checklist for water resources projects is the Water Resources Assessment Methodology (WRAM) developed by the U.S. Army Corps of Engineers (Solomon et al. 1977). Table 2.5.5 lists the details of the methodology. Key elements include the selection of an interdisciplinary team; selection and inventory of assessment variables (environmental factors); impact prediction, assessment, and evaluation; and documentation of the results. Impact prediction, assessment, and evaluation is the element that includes weighting and scaling. The weighted ranking technique (un-ranked paired comparison technique) is used to determine the relative factor importance coefficient (FIC) for each assessment variable. Importance weight assignments are required for each study and should reflect the importance of the variables in the given geographical location. Impact scaling in the WRAM uses functional graphs (relationships), linear proportioning, or the development of alternative choice coefficients (ACCs).

In the late 1970s and early 1980s the concept of com-mensuration was introduced into the water resources planning vocabulary. Commensuration refers to measuring different things by a single standard or measure (Lord, Deane, and Waterstone 1979). In essence, commensuration develops common units of measurement of various plans, with these units serving as the basis for tradeoff analysis among the plans. Lord, Deane, and Waterstone noted that the four components of commensuration are:

1. To identify the factors which are commensurable

2. To determine whose value judgments about those factors are to be considered

3. To discover what those value judgments are

4. To combine the judgments of all selected individuals into a single collective set of judgments

As a result of the emphasis on commensuration, several water resources methods were developed; the methods are basically weighting-scaling, -rating, or -ranking checklists. Four examples of these methods are discussed. Brown, Quinn, and Hammond (1980) address impact scaling for alternative water development plans, with particular emphasis on environmental and social impacts. Mumpower and Bollacker (1981) developed the Evaluation and Sensitivity Analysis Program (ESAP), which is a computerized environmental planning technique to evaluate alternative water resource management plans.

TABLE 2.5.5 THE WRAM FOR TRADEOFF ANALYSIS INVOLVING ENVIRONMENTAL IMPACTS (SOLOMON ET AL. 1977)

Element Delineation

TABLE 2.5.5 THE WRAM FOR TRADEOFF ANALYSIS INVOLVING ENVIRONMENTAL IMPACTS (SOLOMON ET AL. 1977)

Element Delineation

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