is complicated by numerous interrelationships among the various causal 

 factors as well as among the response elements- 



This study is mainly a "search procedure" for identifying inter- 

 actions among subsets of the numerous variables that operate in the 

 natural beach environment. A number of "causes" and "effects" common to 

 the general environment are measured and evaluated, consistent with avail- 

 able time and resources. Least-squares techniques are employed in this 

 search for relationships between the various individual "effects" and their 

 attendant "causes." 



When the beach-ocean-atmosphere complex is considered as a whole, 

 it is evident that no single functional equation can at present fully 

 express the complex interrelations that occur in nature. The tendency 

 has been to "fragment" the system into portions, either in controlled 

 wave-tank experiments or studies of a limited number of variables in the 

 field, that may help explain some facets of the many phenomena composing 

 the whole. It is one purpose of this paper to refrain from expressing 

 the data to be presented, either within the framework of process-response 

 models (Krumbein and Sloss, 19^3^ Chapter 7; Whitten, I96U), or as more 

 formal deterministic models. Rather, the intent is to "sort out" sets of 

 variables to see whether they may provide a basis on which more formal 

 models can be erected. 



The method used here is a form of sequential multiple linear re- 

 gression to be described later. It is recognized that this is only one 

 of several search procedures that may be used, and it is anticipated that 

 opportunity may arise for extending the study in later publications by 

 using alternative methods, such as factor analysis and discriminant func- 

 tions, to see whether some optimixm model for search can be identified. 



Area of Investigation 



This study was conducted at Virginia Beach, Virginia, an oceanic 

 beach situated near the entrance to Chesapeake Bay, at the center of the 

 mid-Atlantic Bight (fig. LA). The study was concentrated along a strip 

 of shoreline between 6 l/k and 8 miles south of Cape Henry (fig. 13). A 

 relatively small, controlled inlet occiors near the center of the study 

 strip. (The strip is bounded by the northern and southern transects of 

 figure IC). A study by Harrison, Krumbein, and Wilson (196U) indicates 

 that the influence of the inlet on the adjacent beach is confined to a 

 zone 5OO-9OO feet to either side of its mouth and that it exerts no 

 measureable influence at the northern or southern transects where all of 

 the measurements for this study were made. 



Surveys by the U. S. Army Corps of Engineers show that beach 'slopes 

 in the foreshore area range from about 1:1? to 1:28, while beach slopes 

 between roughly the 6 and 20-foot contours range between 1:50 and 1:60 

 (U. S. Congress, 1953^ P- 13)- Details of beach profile modifications 

 in the study area are presented by Harrison and Wagner (196^), along 

 with several maps of the near shore bottom that show the presence of 



