A REGIONAL TEST OF THE BRUUN RULE ON SHORELINE EROSION

Abstract Sea-level rise has been quantitatively related to shoreline retreat by the Bruun Rule. This relationship was verified on a field scale along the 336-km shoreline on the Virginia Chesapeake Bay. Relative sea level rise in this area is as high as 5.43 mm/yr, and mean longterm shore retreat is 0.98 m/yr. The model was applied individually to 146 beach units in the area, and the results were compiled regionally. This long-term, regional setting where seasonal or local variations in process are averaged out, is believed to be the context in which the model has physical meaning. The erosion rate predicted by the Bruun Rule fits the long-term measured rate with a 3% error. The fit of the Bruun Rule for the Virginia Chesapeake Bay shoreline system demonstrates that sea-level rise can account for all shore retreat in the system