OVERWASH PROCESSES AND FORE DUNE ECOLOGY, 

 NAUSET SPIT, MASSACHUSETTS 



by 



Robert E. Zaremba 



and 



Stephen P. Leathevman 



I. INTRODUCTION 



1. Purpose and Scope . 



Along the east coast of the United States, many barrier beaches are under- 

 going landward retreat as the sea level rises. Human development of these 

 barriers has resulted in an increasing conflict between natural processes and 

 artificial stabilization. Jetties, groins 5 and seawalls are being used to 

 stabilize the shoreline with varying degrees of success. Artificially con- 

 structed dunes are being used successfully in many developed areas as barriers 

 to the inland penetration of waves and storm surges (Knutson, 1980) . 



This research was undertaken to provide the scientific data necessary to 

 understand the natural dynamics of a northeast barrier beach. Before wide- 

 spread use can be made cf stabilization techniques, it is necessary to evalu- 

 ate tht- consequences of manipulation of barrier environments with relation to 

 unalterable physical processes and the limits of biological systems. 



Coastal research to date has focused on either ecological, or geological 

 processes; only a few projects have been designed to consider the interaction 

 between vegetation and the physical factors which shape barrier beaches. This 

 is the first detailed study undertaken to gather and analyze data on the 

 effect of physical processes, principally overwash, on plant coiaaiunitiea and 

 physiographic features of barrier beaches in the northeast. Nauset Spit, Cape 

 Cod, Massachusetts, was chosen for this investigation because overwash has 

 frequently occurred along this retreating shoreline and historical information 

 is available for the past 3S0 years. 



2 . Research Approach . 



Varicus techniques were used to provide insight into the dynamics of a 

 northeast barrier beach system. A range of information collected during 

 different time frames was examined to evaluate the role of overwash and fore- 

 dune processes in barrier beach dynamics. Overwash procasses were described 

 from field data collected during several sinor storms and during a major 

 northeaster in February 1978. The response of vegetation to overwash burial 

 and the colonisation of washovers ware studied using data collected between 

 1977 and 1979. Vegetative-physiographic transects were constructed along 

 Nauset Spit to document the development of plant cosxunities and isorphalogical 

 features on barrier environments that have a well-documented history. Verti- 

 cal aerial photography and U.S. Coast Survey maps were used to determine the 

 changes in shoreline position and tsta'or barrier environments during the past 

 122 years. Earlier charts, maps, and accounts expanded these data back to the 

 early 1600*s, in a qualitative sense. Finally, cores and radiocarbon peat 

 dates were used to define the geologic evolution of ths barrier. 



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