Reprinted from: 



Proceedings of Coastal Zone'89 . 

 American Society of Civil Enginee 

 pp. 607-621, 1989. 



PREDICTION OF BEACH FILL RESPONSE TO VARYING 

 WAVES AND WATER LEVEL 



Magnus Larson 1 and Nicholas C. Kraus 2 



ABSTRACT 



This paper describes simulations of storm- induced beach erosion per- 

 formed with a newly developed numerical model of beach profile evolu- 

 tion. One synthetic hurricane and one synthetic extratropical storm 

 representing typical storms with approximate 2-5 year return period 

 are used to examine the erosion of two beach fill configurations and 

 subsequent post-storm recovery process. Eroded volume and contour 

 movement are evaluated as a function of storm surge, grain size, and 

 time . 



INTRODUCTION 



Over an interval of just a few hours, storms can produce serious damage 

 and life- threatening situations on the coast by rapid erosion of the beach and 

 upland inundation. The water motion, sand transport, and resultant rapid 

 beach change associated with storms can usually be considered as a two-dimen- 

 sional process occurring primarily in the shore-normal direction, and this 

 assumption will be made here. 



A relatively benign cross -shore counterpart of storm action is the season- 

 al change in beach width, with a wide beach and berm built by small, low- 

 steepness waves in summer, and a narrow beach cut back by high, steep waves in 

 winter. Winter waves and storms often produce one or more shore -parallel bars 

 composed primarily of sand eroded from the beach face. Under the more gentle 

 post-storm recovery waves and summer waves, these bars move toward shore and 

 gradually deflate as sand is removed from them by wave action and returned to 

 shore. 



This paper presents example results of simulations of beach profile change 

 produced by hypothetical storms calculated with a newly developed 



(1) Assistant Professor, Department of Water Resources Engr . , Institute of 

 Science and Technology, University of Lund, Box 118, Lund, Sweden S-221-00. 



(2) Senior Research Scientist, Coastal Engineering Research Center, U.S. Army 

 Engineer Waterways Experiment Station, 3909 Halls Ferry Road, Vicksburg, 

 Mississippi 39180-6199. 



Ill 



