During the past 50 years, coastal Louisiana has suffered catastrophic land loss due to both natural and human causes. This loss has increased storm vulnerability and amplified risks to lives, property, and economies-a fact underscored by Hurricanes Katrina and Rita. Drawing Louisiana's New Map reviews a restoration plan proposed by the U.S. Army Corps of Engineers and the State of Louisiana, finding that, although the individual projects in the study are scientifically sound, there should be more and larger scale projects that provide a comprehensive approach to addressing land loss over such a large area. More importantly, the study should be guided by a detailed map of the expected future landscape of coastal Louisiana that is developed from agreed upon goals for the region and the nation.
What is it like to lose your front porch to the ocean? To watch saltwater destroy your favorite fishing holes? To see playgrounds and churches subside and succumb to brackish and rising water? The residents of coastal Louisiana know. For them hurricanes are but exclamation points in an incessant loss of coastal land now estimated to occur at a rate of at least twenty-four square miles per year. In Losing Ground, coastal Louisianans communicate the significance of place and environment. During interviews taken just before the 2005 hurricanes, they send out a plea to alleviate the damage. They speak with an urgency that exemplifies a fear of losing not just property and familiar surroundings, but their identity as well. People along Louisiana's southeastern coast hold a deep attachment to place, and this shows in the urgency of the narratives David M. Burley collects here. The meanings that residents attribute to coastal land loss reflect a tenuous and uprooted sense of self. The process of coastal land loss and all of its social components, from the familial to the political, impacts these residents' concepts of history and the future. Burley updates many of his subjects' narratives to reveal what has happened in the wake of the back-to-back disasters of Hurricanes Katrina and Rita.
Beach erosion is a chronic problem along open-ocean shores of the U.S. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate info. regarding past and present trends and rates of shoreline movement, and a need for a comprehensive analysis of shoreline movement. This report on states bordering the Gulf of Mexico (Florida, Alabama, Mississippi, Louisiana, and Texas) summarizes the methods of analysis, interprets the results, provides explanations regarding the historical and present trends and rates of change, and describes how different coastal communities are responding to coastal erosion in 2004 (prior to Hurricanes Katrina and Rita). Illustrations.
State of Disaster: A Historical Geography of Louisiana’s Land Loss Crisis explores Louisiana’s protracted efforts to restore and protect its coastal marshes, nearly always with minimal regard for the people displaced by those efforts. As Craig E. Colten shows, the state’s coastal restoration plan seeks to protect cities and industry but sacrifices the coastal dwellers who have maintained their presence in this perilous place for centuries. This historical geography examines in turn the adaptive capacity of those living through repeated waves of calamity; the numerous disjointed environmental management regimes that contributed to the current crisis; the cartographic visualizations of land loss used to activate public coastal policy; and the phases of public input that nevertheless failed to give voice to the citizens most impacted by various environmental management strategies. In closing, Colten situates Louisiana’s experience within broader discussions of climate change and recovery from repeated crises.
This short textbook describes the processes of coastal land loss in Southeast Louisiana, including the geology, ecology, and human life ways of the Mississippi River Delta Gulf Coast. This book is published open-access by the Center for Human-Environmental Research (CHER) and is freely available to all parties who would like to use it.
Loss of coastal land has been occurring along the Upper Texas Gulf Coast over the historical record. This loss of land will continue into the future, probably at increasing rates due to accelerated sea-level rise caused by global warming (i.e. the "greenhouse effect"). Three scenarios for shoreline retreat and land loss to the year 2050 are developed for the uppermost 200 km of the Texas Coast, between Sabine Pass and the mouth of the Trinity River. The scenarios (baseline, low-rise and high-rise) integrate best available estimates of sea-level rise in the next century with empirical relations between relative sea-level rise and shoreline movement during a baseline period (1930-1974 or 1982, depending on the availability of shoreline movement data) for each of 10 shoreline segments. Loss of coastal land results from both erosion and submergence of the coastline due to relative sea-level rise. Relative sea-level (RSL) rise, in turn, encompasses eustatic rise and land-surface subsidence. Baseline rates of RSL rise at Pier 21 on Galveston are 6.9 mm/yr (1930-1974) and 7.6 mm/yr (1930-1982). Data from nonsubsiding tidal gages along the Florida Gulf Coast are used to define a 2.2 mm/yr baseline rate of eustatic rise within the Gulf of Mexico. Land-surface subsidence accounts for the residual 4.7 and 5.4 mm/yr. Land-surface subsidence within the study area is the result of undifferentiated natural consolidation of clay-rich sediments and regional subsurface depressurization caused by production of oil and gas. Groundwater pumpage is minimal within the area and is not considered a cause of subsidence, although large-scale pumping in the metropolitan Houston area has probably caused subsidence along the eastern shore of Trinity Bay. The baseline scenario assumes a constant rate of RSL rise, resulting in a rise of 0.45-0.49 m by 2050. At 2050, RSL rises of 0.66-0.70 min the low-rise scenario and 0.88-0.92 m in the high-rise scenario are predicted by combining low- and high-rise estimates of eustatic rise developed from a synthesis of nine recently published projections with a constant baseline rate of subsidence. The multiplicative factors of approximately 1.5 for the low-rise and 2.0 for the high-rise scenario are calculated from the ratios of projected RSL rise to baseline RSL rise at 2050. These factors are integrated into the baseline relation between RSL rise and shoreline movement to estimate shoreline displacement and subsequent loss of land by 2050 in each of the 10 shoreline segments. The estimated net change of land area by 2050 for the entire study area coastline is -17.2 km2 (4248 acres) in the baseline scenario, -25.2 km2 (6224 acres) in the low-rise scenario, and -33.8 km2 (8349 acres) in the high-rise scenario. Shoreline retreat and land loss scenarios developed in this study represent conservative estimates. Recent rates of relative sea-level rise (between 1958 and the mid-1980s) at Pier 21 and at Sabine Pass exceed 11 mm/yr, 50-60% higher than the calculated long-term rates of 6.9 and 7.6 mm/yr, used as the baseline for this analysis. Therefore projected RSL rise by 2050 are conservative and may underestimate shoreline displacement and coastal land loss. These projections should be considered in the future development of and use of the Texas Coast.
