Delta Dynamics: Understanding Process, Pattern, and People Using Remote Sensing and Systems Analysis in Coastal Louisiana and Amazon River Delta

My dissertation research spans several topics in spatial landscape theory. In the first project, I examined the temporal dynamics of land loss in the Lower Mississippi River Delta (LMRD), with a focus on identifying temporal stability and spatial patterns of loss. After creating composite images that were classified into land and water, I developed and used a novel stability index to quantify the transitionary behavior of land and water pixels. I found that while most land in LMRD is lost in a single transition (nearly 75%) the remaining 25% of the land area undergoes multiple transitions between land and water before permanently transitioning to water. This indicates that there dynamic nature of deltaic land loss and the importance of repeated measurements across varying time scales to understand delta stability. For the second part of the LMRD project, I used multi-sensor analysis to analyze land loss and fragmentation at varying spatial, temporal, and spectral resolutions. I found that finer spatio-temporal resolution more effectively removes atmospheric anomalies, such as cloud and haze, and improves quantitative estimates of land loss. At the same time, higher spectral resolution allowed us to differentiate land and water better. In a third project on the Amazon River Delta (ARD), I applied a novel methodology using multilayer network analysis coupled with remote sensing approaches to improve spatial estimates of urban flood vulnerability in Belem, Brazil. I created an adjusted vulnerability index using indicator variables to improve on estimates from urbanicity, permeability, and link to flooding potential. I found that there are stark differences in vulnerability between planned and unplanned settlements. Through my dissertation research, I have provided evidence for the importance of using high spatial and temporal resolutions in delta landscapes. The novel methods that I have developed provide better estimates of land loss and the associated vulnerability to flooding in delta environments. This work can be extended to other delta regions of the world in future research to assess vulnerability as sea-level continues to rise and populations in delta environments increase.