A systems approach to Environmental Sensitivity Index (ESI) mapping for oil spill contingency planning and response

Oil spills can devastate ecosystems and severely impact water quality. The Environmental Sensitivity Index (ESI) was developed to reduce the environmental consequences of a spill and help prioritize the placement and allocation of resources during cleanup efforts. The successful use of analog and digital geographic information system versions of the Esl concept during the past ten years has led to improvements and refinements, including (1) the development of tidal inlet protection strategy maps produced before a spill that specify the type of response (e.g., boom, skimmer) and where and how to place it, (2) new large format seasonal summary maps, (3) geographic expansion of the Esr concept inland to classify the sensitivity of rivers using a river Reach Sensitivity Index (RSI), (4) regional watershed analysis to identify hazards and potential spill consequences, and (5) the identification of unusually sensitive areas to environmental damage if there is a hazardous liquid pipeline accident.