NSF Ecological Research Helps Solve National Problem

The coast is a hazardous place to live. To spread the risk of living on the coast we spread that risk to those who live inland through federally subsidized insurance. FEMA manages this program and is charged by congress to determine the rates of change of our shorelines (erosion and accretion) to help set insurance rates.

In the 1980s the method FEMA looked at was to take the shoreline position at the time of the first available metric aerial photographs and the position as seen on the most recent photo and measure the change and divide by the number of years. With that rate projections of the hazard for the next 30 years could be estimated. Scientists at the University of Virginia helped FEMA in this work (Robert Dolan)

In the 1990s, the UVa team convinced FEMA to look at all photographs between the earliest and latest and find the average rate for the period from the rates measured between each photographic pair.

Both methods assume that the change is linear (doesn't change) over time. The NSF supported Virginia Coast Reserve LTER program proved that rate does change over time and the direction of change reverses from time to time (most recently in 1969). We then proved that this is so not just at the LTER site but from Florida to New Jersey. Now we have show that the change in the direction of change also happened in the 1870s at Hog Island. And we show that it also happened at Cape Hatteras, N.C. and Cape May, N.J. in the 1870s. At the VCR we have evidence that earlier reversals also happened.

So how do we subsidize beach home owners to reduce their risk of living on the coast when the hazard reverses itself from time to time.

The causes of the reversals are in the contemporary Climate Changes that have taken place (sea level rise and changes in the frequency of weather systems moving through the area.)