RESPONSE OF A SHORELINE SAND WAVE TO BEACH NOURISHMENT

摘要

On Egmond beach, The Netherlands, the trough of a shoreline sand wave was filled by a beach nourishment. Monthly monitoring over a 4 year period revealed that the shoreline sand wave recovered in about half a year, exhibiting an amplitude that exceeded the pre-nourishment one. The more rapid response of the lower elevation contours relative to the higher elevated ones resulted temporarily in beach steepening in the trough area and flattening in the crest area. A first comparison to similar time-scale (months) variations in wave conditions revealed neither evidence that the shoreline sand wave amplitude would tend to flatten during high energetic conditions nor that it would tend to grow under high-angle incident waves. The role of the slowly evolving nearshore morphology and its effects on the nearshore flow field at the monthly time-scale need further study.