GPS-BASED ANALYSIS OF SHORELINE CHANGE, 1995-2005, MAD ISLAND MARSH PRESERVE, MATAGORDA COUNTY, TEXAS

摘要

A combination of a global positioning system (GPS), high-resolution aerial photographs and a geographic information system (GIS) was used to measure shoreline change at Mad Island Marsh Preserve during the period 1995 - 2005. The magnitude and direction of shoreline change was found to vary between five contrasting shoreline types included in the study. Compared to earlier studies that suggested erosion occurred along all sections of shoreline in the study area between 1941 and 1993, this study found sections of shoreline that had essentially stabilized and others where previously documented erosion had slowed considerably. The reason(s) for these changes is uncertain - two possibilities are that a progressively-widening wave-cut platform is dissipating barge-generated wave energy or that the exposure of dense root mats along some receding shorelines is increasing resistance to wave erosion. A concrete erosion control mat emplaced along one section of shoreline in 1996 was found to have been unsuccessful, because soil had been washed out from under the concrete.