FOREWORD 
Few data are available on the patterns of sorting and size gradation 
of sediments at the mouths of tidal inlets. Also lacking is a rapid, 
objective, and statistically rigorous method for defining the limits of 
the effects of the ebb flow from an inlet on the normal littoral process 
of sorting and size gradation. This study was undertaken with the objective 
of formulating a general model of the distribution of sorting and mean size 
parameters around the mouth of an inlet, for a rather restricted set of 
dynamic conditions. A further objective was the testing of trends in 
patterns of sedimentation predicted by the model by means of a rapid method 
of formal statistical analysis known as trend-surface analysis. 
Diagrams showing steps in the development of the conceptual fluid 
process-sediment response model are presented, as well as a series of trend- 
surface and residual maps for the observed natural inlet data. An objective 
method for delineating the pattern, magnitude, and limits of inlet in- 
fluence on the otherwise unaltered beach sediments is also presented. 
This report was prepared by Dr. Wyman Harrison, Associate Marine 
Scientist of the Virginia Institute of Marine Science, in vursuance of 
Contract DA-49-055-CIVENG-63-6 with the U. S. Army Coastal Engineering 
Research Center, in collaboration with Dr. William C. Krumbein, Professor 
of Geology, Northwestern University, and consultant to the Coastal Engineer- 
ing Research Center,andMr.W. Stanley Wilson, graduate student at the 
Virginia Institute of Marine Science. 
This study was supported by the Coastal Engineering Research Center 
(formerly the Beach Erosion Board of the Corps of Engineers), under the 
general supervision of J. V. Hall, Jr., G. M. Watts, and N. E. Taney of 
the Engineering Development Division. The Computing Center at Northwestern 
University extended every cooperation, and the programs used in the 
analysis were largely developed with supporting funds from the Geographic 
Branch of the Office of Naval Research, under general supervision of Miss 
Evelyn Pruitt and R. A. Alexander. 
Mr. C. Kiley, Virginia Beach City Engineer, and Mr. A. Gregg aided by 
laying groundwork for the field work. The following graduate students of 
the Virginia Institute of Marine Science aided in sampling: Messrs. M. P. 
Lynch, R, Morales-Alamo, R. B. Stone, C. Kyte, and R. Tuck. Lt. G. M. 
Griswold, U. S. Navy Fleet Weather Facility, arranged for aerial photo- 
graphic coverage of the study area. Wave data were furnished by the 
Research Division of the Coastal Engineering Research Center. The U. S. 
Army Transportation Corps, Ft. Story, Virginia, provided amphibious 
support for offshore sampling. Weather data were supplied by the U. S. 
Weather Station at Ft. Story. 
This report is published under authority of Public Law 166, 79th 
Congress, approved July 31, 1945, as supplemented by Public Law 172, 
88th Congress,approved November 7, 1963. 
