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| Washing Away — The Sinking of Louisiana
Louisiana, as well as the entire South Central United States, is sinking under the weight of the Mississippi River mud that makes up the geography of the region. The situation is spawning what LSU professor Roy Dokka calls a “slow disaster.” Already portions of Louisiana Highway 1 are significantly lower than they were 20 years ago. Some areas of the state are sinking as much as one inch a year, which increases the risk of flooding and throws off the timing of evacuation plans in case of a major storm. 
A recent survey of Louisiana Highway 1 between Raceland and Grand Isle prompted National Geodetic Survey Director Charles Challstrom to state in a letter to Colonel Mike Brown of the Louisiana Office of Emergency Preparedness that “vertical control” — the elevation of surveyors’ markers in the state — was “inaccurate and inadequate.” “We can’t run from the fact that the coast is sinking, so we have to figure out how to deal with its effects,” said Dokka, who heads the Louisiana Spatial Reference Center (LSRC) at LSU and is a faculty member in the University’s Department of Civil & Environmental Engineering. “Louisiana will have to develop plans to mitigate this subsidence and technologies to handle what’s happening here long before it has to be done anywhere else. Then we can export those technologies and their spinoffs to other states and other places around the world." Some of the technology for monitoring statewide elevation change is already in place. Using computers, global positioning system satellites, and fixed monitoring stations throughout the state, the LSRC is capable of measuring land movement as small as a few millimeters a year. It’s on the cutting edge of geoinformatics technology, Dokka said.
Besides monitoring land subsidence, the LSRC is working under the auspices of the national Geodetic Survey to reestablish the accuracy of surveyors’ benchmarks in the state. Both of these undertakings go hand-in-hand with the major effort facing Louisiana right now — curbing the loss of the state’s wetland. The marshes of coastal Louisiana, which comprise the seventh largest delta in the world, are disappearing every year at a rate equivalent to a half-mile-wide corridor stretching the approximately 60 miles from Baton Rouge to Lafayette. With the loss of these buffer zones, flooding and storm surges from hurricanes and other large storms will increasingly put life and property at risk.
On top of that, the economic and environmental importance of these wetlands extends beyond Louisiana to the country as a whole, which is why the Governor’s Office has initiated the “America’s Wetlands” campaign to raise awareness of the problem throughout the United States. “Knowing where and how fast the land is sinking is key to doing anything about it,” Dokka said. “Using the tools available with LSRC, we’ll know where to focus our efforts. You can’t do anything without a place to start. Remember that it’s not just the marshes that are sinking, it’s also the surrounding land where people live.” Written by LSU Office of University Relations
Related Links LSU Department of Civil &
Environmental Engineering |
