PARENT SESSION
Oral Session #60: Remote Sensing and GIS. Presiding: A. Gallant.
Thursday, August 9, 2001. 8:00 AM to 12:00 PM. Hall of Ideas E.
Land cover change in the upper Barataria Basin Estuary, Louisiana, from 1972-1992: Increases in wetland area.
NELSON, STACY1, SORANNO, PATRICIA1, QI, JIAGUO1, 1
ABSTRACT- The Barataria Basin, Louisiana, is an extensive wetland and coastal estuary system of great economic and intrinsic value. High rates of wetland loss along the coastal margin have been well documented. However, little information exists on whether freshwater wetlands in the upper basin have changed. Our objectives were to quantify land cover change in the upper basin from 1972-1992, and determine land cover transition rates among land cover types. We classified Landsat MSS imagery into six land cover types: agriculture, urban, bottomland hardwood forest, swamp forest, freshwater marsh, and open water. Significant changes in land cover occurred within the upper Barataria Basin over the study period. Urban land increased from 8% to 17%, primarily due to conversions from agricultural land. Swamp forest increased from 30% to 41% due to conversions from bottomland hardwood and freshwater marsh. High rates of land subsidence within the Louisiana-Mississippi River deltaic plain are one of the primary causes of wetland loss along coastal margins of Louisiana. However, within the upper freshwater wetland areas, land subsidence actually appears to cause increases in the total amount of wetland area. Our results show that the upper Barataria Basin has increased in wetland area at a rate of 689ha/yr from 1972-1992. These results suggest that changes in the upper freshwater portions of coastal estuaries can be large and quite different from patterns observed in the more saline coastal margins.
KEY WORDS: Barataria Basin (Louisiana USA), remote sensing, wetland change detection, land subsidence