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Task 6: Evaluate Land Losses Related to Oil and Gas ProductionObjectivesLand losses in Louisiana and Texas are partly related to a relative rise in sea level resulting from natural compactional subsidence and eustacy. Despite abundant data concerning land losses, the contribution resulting from induced subsidence around oil and gas fields is still unknown. The objectives of this task are:
Methods This task involves evaluating the magnitude and extent of land losses near oil and gas production between the Mississippi delta and the central Texas coast, an area that encompasses most of the coastal wetlands as well as many large oil and gas fields. Fields producing within wetland habitats can be identified from maps published for both states. Locations of these fields can then be compared with maps illustrating long-term rates of land losses in Texas and Louisiana. Land losses can be detected on low-altitude aerial photographs or other images that document lineations as well as abrupt changes in surface elevation, soil moisture, or land-water relations. Aerial photographs used in the National Wetlands Inventory conducted by the Fish and Wildlife Service, National Wetlands Research Center are available to investigate subsidence around producing fields in Louisiana and Texas. Anomalous high rates of wetland losses can be determined by comparing losses near producing fields with those in nearby areas away from the fields. The initial work will involve mapping surficial changes, digitizing land areas affected by subsidence, and calculating average rates of land loss around the fields selected in Task 2. This can be accomplished by comparing recent aerial photographs with photographs taken before significant oil and gas production began. This task will be coordinated with the Louisiana Coastal Subsidence project that will examine natural rates of subsidence in the Mississippi delta over geological time scales. « Geophysical Methods | Publications » |
U. S. Department of the Interior | U.S. Geological Survey
