Dr Till J. J. Hanebuth works in the Geosystems Research Lab at Coastal Carolina University. He came to speak with our school about his research into coastal management. “We want to control our coastline,” he told the students. “What we build is stationary, while the coastlines change.” In an attempt to preserve our coastlines, there have been several beach nourishment projects. These involve scooping sand from the bottom of the ocean and transporting it to the beach to replace sand that has been washed away. However, this is not always the best solution. Apart from being very expensive, it can be very damaging to the ocean environment, and it is getting harder and harder to find areas with the right kind of sand. Beach nourishment is also not permanent, so it must be repeated again and again.
Dr Hanebuth’s most recent project revolves around Georgetown Harbor. In 1950, developers decided to create a “shortcut” into the harbor, cutting through the land to create what is now Goat Island. This made the harbor more accessible to boats, which was a great boost for the local economy. However, this shortcut changed the water currents in the bay, and over time the bottom of the harbor filled up with silt. It became so shallow that many ships could no longer enter the harbor. To fix this, the city has been forced to dredge the harbor repeatedly to allow ships to enter. Dredging is incredibly expensive and does not work as a long-term solution. Dr. Hanebuth’s job is to research the currents in the harbor and come up with a way to counteract this problem.
Dr. Hanebuth created a computer program that would simulate the tides and the currents in the harbor so that he could test potential solutions. The obvious solution would be to close off the shortcut, but Dr. Hanebuth’s research shows that this could have disastrous effects. With nowhere else for the water to go, it would flow through the harbor too quickly and wash away boats and docks, as well as potentially causing flooding. Another idea was to place two giant underwater “hairdryers” at the entrance to the harbor to direct water flow and wash away the silt. Right now, the most promising solution appears to be blocking off part of the shortcut, creating an increased flow in the harbor without the full force that would come from completely closing it.
“I am used to working with scientists,” Dr. Hanebuth told us. “But now I am working with city managers.” It remains to be seen how Georgetown will resolve the problem of its lost harbor, but Dr. Hanebuth’s research and computer models provide much-needed information to help Georgetown make a sensible plan of action.