LONG-TERM GOAL

To understand the physics of sediment transport by waves and currents and to use that understanding to predict the evolution of nearshore bathymetry given the nearshore fluid velocity field and seafloor sedimentology and stratigraphy. A secondary goal is to interpret the environment of deposition and the offshore wave climate from the sedimentary record. SCIENTIFIC OBJECTIVES Present objectives are to identify characteristic bedform patterns and their modes of evolution in the nearshore enviroment at Duck, North Carolina using side-scan sonar images; to describe bedload transport over non-planar bed geometries, with particular application to megaripples; and to generate computer simulation models for evolution of nearshore morphology. APPROACH Field observations motivate laboratory studies of bedload transport and bedform evolution under controlled conditions, which are in turn used to develop and test both discrete-particle and cellular automata computational models for bedload transport and bedform evolution. Figure 1. Nearshore wave-ripple patterns in the vicinity of a single channel-spanning fixed megaripple bedform in a 2.4-m-wide laboratory wave channel. Waves propagate from left to right