COASTAL DUNES 



H. T. U. Smith 

 University of Kansas 



Contract Nonr-583(06) 

 Task NR 387-012 



INTRODUCTION 



Most of the papers presented at this symposium are concerned with projects which are 

 well along toward completion. I am perhaps at somewhat of a disadvantage in discussing a 

 project which is only beginning, and therefore have little in the way of results or conclusions 

 to offer. I will endeavor, however, to outline some of the main points of interest in my project 

 and provide some degree of orientation in (a) the study of coastal sand dunes, (b) the practical 

 implications of such studies with particular reference to terrain intelligence through air photo 

 interpretation, and (c) engineering problems encountered in dune terrain. 



OCCURRENCE OF COASTAL DUNES 



Sand dunes of various sizes and shapes are widespread along the low-lying coasts of the 

 world, and in many regions occupy up to 10 percent of the total length of the shoreline. In some 

 places, of course, they occupy much more of the shoreline. They are found along the coasts of 

 both arid and humid regions, in all latitudes, bordering a wide range of types of inland terrain, 

 and occur both on the mainland and on barrier islands. In all areas where coastal dunes occur, 

 effective planning of engineering and military operations requires that due consideration be 

 given to the special characteristics of dune terrain. 



In addition to coastal areas proper, the shores of inland seas and lakes, ancient abandoned 

 shorelines now well above water level, and the beds of dry lakes in arid regions all provide 

 sites for dune topography. 



The scale of the dune topography ranges widely from place to place. In height, the dunes 

 range from less than 10 feet to more than 200 feet. In some places, as along the southern and 

 eastern shores of Lake Michigan, dunes constitute the highest hills, if not the only hills, of the 

 coastal region. In considering width, it is the width of the dune belt rather than the individual 

 dunes which is significant, and this also ranges widely, from less than 100 feet to many miles. 

 Height and width do not necessarily vary together. 



The terrain on the inland side of the coastal dune belt may be of many varieties. In some 

 places it is essentially flat, in other places it is hilly. In many localities, swampy ground or 

 actual ponds and lakes are found on the inland border, and in fewer areas there are continuous 

 bodies of water. 



In the United States, examples of coastal dunes are numerous. Along the Atlantic coast, 

 narrow zones of low dunes are common from Florida to North Carolina, and limited areas of 

 higher dunes are found near Kittyhawk, North Carolina; Cape Henry, Virginia; Cape Henlopen, 

 Delaware; and Cape Cod, Massachusetts. Along the Gulf Coast, dunes occur at many places in 

 Florida and Texas, the largest area being in southern Texas. On the Pacific Coast, important 

 dune areas are located near Los Angeles, San Luis Obispo, Monterey, San Francisco, and 

 Eureka, in California; along roughly one third of the Oregon coast; and at many points along the 

 coast oif Washington. In the Great Lakes area, dunes of unusual size border the southern and 

 eastern shores of Lake Michigan. In Europe, coastal dunes are widespread along the coasts of 

 north Germany, Denmark, Belgium, northern France, and the Bay of Biscay, and more sparsely 



51 



