Several activities are required to conduct an environmental impact study, including impact identification, preparation of a description of the affected environment, impact prediction and assessment, and selection of the proposed action from a set of alternatives being evaluated to meet identified needs. The objectives of the various activities differ, as do the methods for accomplishing the activities (Lee 1988). The term method refers to structured scientific or policy-based approaches for achieving one or more of the basic activities. Table 2.2.1 contains a delineation of eighteen types of methods arrayed against seven activities that are typically associated with an EIA study. An x in the table denotes that the listed method type is or may be directly useful for accomplishing an activity. However, the absence of an x for any given type of method does not mean that it has no usefulness for the activity; it merely suggests that it may be indirectly related to the activity.
Based on the information in Table 2.2.1, the following observations can be made:
1. Each type of method has potential usefulness in more than one EIA study activity.
2. Each EIA activity has three or more method types which are potentially useful.
3. In a given EIA study, several types of methods will probably be used even though the study may not completely document all of the methods used. Several reviews of actual method adoption in the EIA process have sug gested lack of widespread usage; however, this usage probably reflects a focus on a few of the types of methods (such as matrices or checklists), and not the more inclusive list of methods contained in Table 2.2.1.
4. Each of the types of methods have advantages and limitations; examples of these for checklists, decision-focused checklists, matrices, and networks are described in subsequent sections.
5. While numerous types of methods have been developed, and additional methods are being developed and tested, no universal method can be applied to all project types in all environmental settings. An all-purpose method is unlikely to be developed due to lack of technical information as well as the need for exercising subjective judgment about predicted impacts in the environmental setting where the potential project may occur. Accordingly, the most appropriate perspective is to consider methods as tools which can be used to aid the impact assessment process. In that sense, every method should be project- and location-specific, with the basic concepts derived from existing methods. These methods can be called ad hoc methods.
6. Methods do not provide complete answers to all questions related to the impacts of a potential project or set of alternatives. Methods are not "cookbooks" in which a successful study is achieved by meeting the requirements of them. Methods must be selected based on appropriate evaluation and professional judgment, and
Was this article helpful?