An environmental sensitivity index map is a diagram that provides a concise summary of coastal resources that could be at risk in the event of an oil spill

The symbols on an ESI map are color coded and prioritized for clean up by how sensitive they are to oil.

An environmental sensitivity index (ESI) map compiles information for coastal shoreline sensitivity, biological resources, and human resources. This information is used to create cleanup strategies before an accident occurs so that authorities are prepared to take action in the event of such a spill. Advance planning reduces the harmful consequences of oil spills and cleanup.

ESI maps have many features that make them great tools for spill response teams. The maps use geographic information system techniques in order to combine regional maps with data on biological and human resources in an area, as well as information on sensitive shorelines. The resources are given ranks and color coded based on their sensitivity to oiling. Organizations can use the synthesized data to create efficient and effective cleanup strategies.

Researchers in the Office of Response and Restoration work with state, federal, and industrial agencies to create ESI maps.

For more information:

Environmental Sensitivity Maps, Office of Response and Restoration

Environmental Sensitivity Index Mapping (pdf, 1.6Mb)