Interim Report on Masonboro Inlet, North Carolina, Movable-Bed Model Tests

The movable-bed model study of Masonboro Inlet was undertaken to evaluate model predictions of inlet response to a major improvement project when verification is based on preconstruction conditions. Masonboro Inlet was chosen for the study because prototype survey data were available for the preconstruction condition of the inlet area, and hydrographic surveys had been performed at approximately six-month intervals subsequent to construction of the north jetty. The initial plan of study was to verify the model for the prejetty prototype data, install the north jetty, then operate the model for the period necessary to simulate the passage of time to the date of the latest hydrographic survey. Model results were to be compared to the prototype data to ascertain how well the model predicted the bed changes that occurred in nature. Only two of the four prototype prejetty hydrographic surveys were usable for model adjustment and verification. The time interval between the surveys was nine months (from the end of October 1964 to the first of August 1965). This nine-month interval was not adequate for model verification since there was insufficient change in the inlet hydrography to provide a satisfactory verification data base.