BOR Population at Risk studies are used to determine the possible magnitude of loss of life in the event of a dam failure. Inundation extent, population at risk, and life loss estimation are the three components commonly considered in failure consequences. Remotely sensed data play a major role in determining population locations and densities. Decennial census data are not updated at a rate that keeps pace with a region’s population growth or change. The timely acquisition of imagery allows for the most accurate measure of people at risk. Lidar data provide a critical component for the loss of life analysis process, giving accurate topography that in turn leads to accurate determination of the areas of inundation where population may be at risk. Current high-resolution imagery then gives BOR scientists the ability to locate and enumerate residences and other buildings where people live and work. Everyone that lives downstream of a dam benefits from the knowledge gained from these remotely sensed data, as well as the emergency responders that are called upon to locate and assist citizens.
https://www.usbr.gov/ssle/damsafety/
B.F. Sisk Dam, California - Seismic Failure Inundation shown as red outline.