Experimental Study on Shoreline Erosion Using the EM2 Geomodel

The Texas coastline is exposed to the dynamic zone of current convergence. Storm surge caused by hurricanes and tropical storms can remove large quantities of sand from the shoreline, resulting in eroding vast areas of land and destroying property. The study objective is to investigate the possible shoreline protection solutions. A schematic shoreline model using the Em2 Geomodel was developed to simulate erosion caused by Hurricane Ike (HDR Project No. 166742 report) with the average erosion rate as 60 ft /day, i.e. 2.5 inches every 5 minutes. A series of experiments were set up to reach 2.5 inch / 5 minutes with an equivalent shoreline slope 2% as the field geometry under the wave condition generated by manually pushing a wood block. Three common shoreline erosion control measures: lining the shoreline with rocks (A), with vegetation (B), and the implementation of jetties (C) were applied. The experiment results demonstrate that method (A) does not work as well as anticipated, while method (B) and (C) can reduce 50% of the erosion. A wave generator has been designed to control wave motion and an empirical total longshore sediment transport equation has been determined for the wave generator under different water depth, wave conditions, and slopes of the beach. Three erosion control measures have been tested under the same wave condition using wave generator, the results also indicate method (B) and (C) can reduce the erosion effectively, while the method (A) does not reduce the erosion.