Radar and satellite data show the effects of man-made structures that have disrupted the tidal flow into wetlands and pose a danger to their health. The red frames show the location of particular areas of concern. Photo by University of Miami
MIAMI, June 29 (UPI) -- Disruptions to the tidal inundation process along coastal Louisiana are having a tangible effect on wetlands, but scientists think they have identified the biggest causes and hope to find ways to mitigate their effects.
Man-made canals and levees are at fault for nearly two-thirds of the interruptions to tidal inundations essential to maintaining ecosystems the state depends on for commercial and recreational fishing, tourism and the oil and gas industry, according to the study.
In addition to the economic concerns, the wetlands also provide storm protection, flood control and habitats for wildlife. However sea level rise, land subsidence and infrastructure development, in addition to the canals and levees, have increased loss of wetlands along the coast.
"Our analysis showed that tidal inundation along Louisiana's coastline is restricted to narrow areas due to the presence of man-made canals and levees that disrupt the regular tidal flow through the coastal wetlands," Dr. Shimon Wdowinski, a research professor of marine geosciences at the University of Miami, said in a press release. "To protect these valuable resources, it is important to study them and quantify what is causing wetland loss in coastal Louisiana."
For the study, published in the journal Remote Sensing, researchers reviewed data on the coastline recorded between 2006 and 2011 by the Advanced Land Observation Satellite and between 2003 and 2008 by the Canadian satellite Radarsat-1.
The researchers found man-made canals limit the natural tidal inundation process along about 45 percent of the state's coast, while disruptions to tidal flow from levees make up 15 percent. The effect of man-made structures caused vertical tidal changes of up to 30 centimeters and horizontal tidal flow was limited to between 5 and 15 kilometers from open waters.
"This study demonstrates that human infrastructure development along coastal areas have long-term consequences on the ability of coastal wetlands to adapt to sea-level rise and other processes that reduce the size of coastal wetlands," said Talib Oliver-Cabrera, a doctoral student at the University of Miami.