Reprinted from: 



Proceedings of Coastal Zone '89 . 

 American Society of Civil Engineers 

 pp. 595-606, 1989 



DUNE EROSION-FREQUENCY OF STORM OCCURRENCE RELATIONSHIPS 



Norman W. Schef frier 1 , Member ASCE 



ABSTRACT 



This paper discusses the development and implementation of a numerical 

 modeling methodology for making quantitative predictions of dune 

 erosion induced by storm surge hydrographs of known frequency of 

 occurrence. Results are in the form of site-specific maximum dune 

 face recession versus frequency of occurrence curves. These curves 

 can be used to assess the degree of protection afforded by an existing 

 dune and berm complex or to evaluate the cost-effectiveness of various 

 beach renourishment alternatives. The modeling approach was used to 

 provide design criteria necessary for the development of a comprehen- 

 sive storm erosion protection plan for locations along the north New 

 Jersey shoreline. 



INTRODUCTION 



The feasibility of any construction project is usually a function of the 

 building cost versus the expected design life of the structure. What is the 

 effective life of a structure before it is completely or partially destroyed 

 by the combined action of tides and storm surge, and will the expected 

 benefits exceed the projected costs over this lifetime? Construction costs 

 can be accurately estimated; however, design life estimates require some means 

 of estimating the frequency and severity of local storm events and the effect 

 of those events on the structure. 



Stage -frequency diagrams provide an estimate of the relationship between 

 peak storm surge elevation and frequency of occurrence. These relationships 

 are based on site-specific observations of historical storm surge data. These 

 data provide an accurate estimate of the frequency at which damage can be 

 expected to occur at a given elevation above mean sea level, but this proce- 

 dure may not be appropriate for a structure located on or behind a protective 

 dune line. Unless the storm surge completely overtops or breaches the dune 



(1) Research Hydraulic Engineer, Research Division, Coastal Engineering 

 Research Center, U.S. Army Engineer Waterways Experiment Station, 3909 Halls 

 Ferry Road, Vicksburg, MS 39180-6199. 



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