Doctor of Philosophy / Department of Geography / Kevin P. Price / A major strategy in response to rapid degradation and loss of Louisiana’s coastal wetlands has been the construction of siphon diversion projects. The diversions are designed to reintroduce nutrient enriched freshwater from the Mississippi River into wetland ecosystems to combat saltwater intrusion and stimulate marsh growth. The lack of consensus regarding the effects of river diversions on nutrient enrichment of wetland ecosystems is coupled with major concerns about eutrophication. Locating, assessing, and monitoring eutrophic marsh vegetation represent major challenges to understanding the impacts of freshwater diversions. As a result, this study was undertaken to investigate the feasibility of modeling eutrophication vulnerability of a coastal Louisiana marsh receiving turbid Mississippi River water. The major objective was to integrate remotely sensed data with field measurements of vegetation biophysical characteristics and historical ecosystem survey data to delineate landscape patterns suggestive of vulnerability to eutrophication. The initial step in accomplishing this goal was to model the spatial distribution of freshwater impacts using satellite image-based turbidity frequency data associated with siphon diversion operation. Secondly, satellite and spectroradiometer band combinations and vegetation indices optimal for modeling marsh biophysical characteristics related to nutrient enrichment were identified. Finally, satellite image data were successfully integrated with measures of historical and concurrent marsh biophysical characteristics to model the spatial distribution of eutrophication vulnerability and to elucidate the impacts of freshwater diversions.

In thirty years, the number of second homes for recreation fishers in coastal Terrebonne Parish has grown from 244 in the late 1970s to an estimated 2,500 in 2005. This thesis considers the ramifications of the tourism boom along the parish's historically isolated and undeveloped coastline. Four coastal communities are examined: (1) Montegut, Pointe-aux-Chenes and Isle de Jean Charles; (2) Cocodrie and Chauvin; (3) Dulac; and (4) Dularge and Theriot. The research question is twofold: Why has coastal tourism been allowed to develop in the fragile wetlands that protect residents from dangerous storms?; and What does tourism development mean for the indigenous American Indian and Cajun people who live along the coast? The author argues the proliferation of recreation fishing camps has had a serious dislocating effect on coastal Terrebonne's population, and the ongoing development of the tourism industry will devastate culturally rich bayou regions.

This research investigated the feasibility and benefits of integrating geospatial technology with traditional ecological knowledge (TEK) of an indigenous Louisiana coastal population in order to assess the impacts of current and historical ecosystem change to community viability. The primary goal was to provide resource managers with a comprehensive method of assessing localized ecological change in the Gulf Coast region that can benefit community sustainability. Using Remote Sensing (RS), Geographic Information Systems (GIS), and other geospatial technologies integrated with a coastal community's TEK to achieve this goal, the objectives were (1) to determine a method for producing vulnerability/sustainability mapping products for an ecosystem-dependent livelihood base of a coastal population that results from physical information derived from RS imagery and supported, refined, and prioritized with TEK, and (2) to demonstrate how such an approach can engage affected community residents who are interested in understanding better marsh health and ways that marsh health can be recognized, and the causes of declining marsh determined and addressed. TEK relevant to the project objectives collected included: changes in the flora and fauna over time; changes in environmental conditions observed over time such as land loss; a history of man-made structures and impacts to the area; as well as priority areas of particular community significance or concern. Scientific field data collection measured marsh vegetation health characteristics. These data were analyzed for correlation with satellite image data acquired concurrently with field data collection. Resulting regression equations were applied to the image data to produce estimated marsh health maps. Historical image datasets of the study area were acquired to understand evolution of land change to current conditions and project future vulnerability. Image processing procedures were developed and applied to produce maps that detail land change in the study area at time intervals from 1968 to 2009. This information was combined with the TEK and scientific datasets in a GIS to produce mapping products that provide new information to the coastal restoration decision making process. This information includes: 1) what marsh areas are most vulnerable; and 2) what areas are most significant to the sustainability of the community.

Extreme weather events can result in natural disasters, and climate change can cause these weather events to occur more often and with more intensity. Because of social and physical vulnerabilities, climate change and extreme weather often affect coastal communities. As climate change continues to be a factor for many coastal communities, and environmental hazards and vulnerability continue to increase, the need for adaptation may become a reality for many communities. However, very few studies have been done on the effect climate change and mitigation measures implemented in response to climate change have on a community’s adaptive capacity. This single instrumental case study will examine the effects of climate change and policy responses to climate change on the Pointe-au-Chien Indian Tribe located in Pointe aux Chenes, Louisiana, in order to discover how climate change affects the adaptive capacity of an indigenous population intricately tied to the surrounding ecosystem. This study will provide information on how the community plans to adapt to climate change, and the urban planning and hazard mitigation methods that can be used to facilitate the process. It also posits how government agencies can empower local communities to participate in mitigation planning, and provide local knowledge in order to make those plans more effective. As climate change continues to affect our coastal environments, it will continue to have an effect on our coastal communities. Understanding the strength and longevity of community adaptation in Pointe aux Chenes will help the community respond to the changes and increasing hazards in the environment. This understanding can be applied to all coastal communities facing similar challenges the world over.