Abstract: Coefficient "k" in "a-b-c^hellip" Model

L. D. Entsminger, R. S. Banks, W. F. Tanner

The coefficient "k" is a dimensionless quantity which relates the immersed weight of sediment, i, to the longshore component of wave power, P_L, which transports it parallel with the coast. The relation is stated by the formula i = kP_L; k has a theoretical maximum value of unity and is an estimate of the efficiency of the system of unidirectional littoral transport. Several factors affect the accuracy of k: maturity of the system, reversals of the drift direction, whether P_L and i are measured directly or indirectly, average and catastrophic P_L values through time, length of study time, and masking of sand quantity by leakage into or from the system.

Two previous values of k exist: (1) Komar and Inman's instantaneous measurement, k - 0.77, and (2) May and Tanner's estimate k = 10^-2 to 10^-3. The area of study extended from Anna Maria Key to Captiva Island, Florida. The i values were obtained from hydrographic surveys spanning 20 years. The P_L values were obtained from computer modeling of various wave heights and periods. Several values of k were obtained in the general range of 10^-3 to 10^-4. The specific results of this work are applicable only to the study area.

AAPG Search and Discovery Article #90978©1975 GCAGS-GC Section SEPM Annual Meeting, Jackson, Mississippi