Five categories of methods have been developed for use in the assessment and analysis of environmental effects. The methods are:
Descriptions and examples of the methods are included in the pages that follow. It is important to recognise at the outset, however, that these methods vary in detail, data requirements, sophistication of analysis, and costs. Thus, the scale of a proposed development must be taken into consideration when deciding on an appropriate method.
Large scale development proposals cannot be analysed sufficiently with methods that merely identify effects, nor can cumulative effects be easily incorporated into some of the methods that emphasise only primary effects, such as checklists and overlays. On the other hand, the methods are not mutually exclusive such that several can be used in one assessment. For example, a checklist might be used to assist in scoping significant issues, and a scaling and weighting technique might then be used to analyse the overall environmental effects of these significant issues.