Environmental sensitivity mapping — what,why and how

Terms such as environmental stability, resilience or sensitivity are verbal abbreviations or abstractions for particular features of environmental stress-response relationships. An environmental planning map must take account of the range of possible stresses, responses, and stress-response relations, assess the significance of each, and express the most significant in a form immediately useable by planning engineers. The most critical part of this process is predicting the form of the stress-response relation for each stress and response. This is done essentially by comparison with similar environmental units elsewhere where the actual responses of particular stresses are already known. The level of precision attainable in an environmental planning map depends on the extent and relevance of information available for comparison: on the degree of similarity between the ecosystems and stresses where the responses are known and those for which the map is being prepared. The collection of environmental data from the area concerned, by aerial and ground survey, is of course also essential, but such data are of limited value without the background information required to predict the consequences of particular actions in the course of development.