What is an Environmental Sensitivity Index map?

An Environmental Sensitivity Index (ESI) map is a very useful tool for organizations wanting to design response and cleanup procedures for a specific coastal area in the event of an oil spill.  The actual map is a diagram depicting a coastline area and the human and biological resources and shoreline sensitivity to an oil spill in that area.  An ESI map is created using geographic information system (GIS) techniques to combine the shoreline map with info on the biological and human resources present in that area.  The resources and aspects on the maps are typically ranked and color coded by their sensitivity to an oil spill. 

The figure below shows an ESI map for the San Diego Bay and it's vicinity as provided by NOAA. 

As you can see the map is color coded and uses different symbols and pictures to depict different human and biological resources and animal species.