Ibrahim, ElSayed Ali Hermas (2005-08). Analyzing the connectivity potential of landscape geomorphic systems: a radar remote sensing and GIS approach, Estufa Canyon, Texas, USA. Doctoral Dissertation.
Thesis
Connectivity is considered one of the fundamental aspects that influences the rate of mass movement in the landscape. The connectivity aspect has been acknowledged from various conceptual geomorphic frameworks. None of these provided a developmental methodology for studying the connectivity of geomorphic systems, especially at the scale of the fluvial system. The emphasis in this research is placed on defining variables of the geomorphic systems that influence the connectivity potential of these systems. The landscape gradient, which is extracted from the Digital Elevation Model (DEM), and the surface roughness, which is extracted from radar images, are used to analyze the connectivity potential of geomorphic systems in the landscape. Integration of these variables produces a connectivity potential index of the various geomorphic systems that compose the fluvial system. High values of the connectivity potential index indicate high potential of the geomorphic system to transport mass whereas the low values indicate low potential of the geomorphic system to transport mass in the landscape. Using the mean values of the connectivity potential index, the geomorphic systems in the landscape can be classified into geomorphic systems of low connectivity potential, geomorphic systems of intermediate connectivity potential and geomorphic systems of high connectivity potential. In addition to the determination of the relative connectivity potential of various geomorphic systems, the connectivity potential index is used to analyze the system-wide connectivity. The ratios between the connectivity potential index of the upstream geomorphic systems and the connectivity potential index of the downstream geomorphic systems define system-wide connectivity in the landscape. High ratios reflect the high potential of the upstream geomorphic systems to transport mass in the downstream direction. Low ratios indicate the influence of the downstream geomorphic systems in maximizing mass movement in the upstream geomorphic systems. The presence of high and low ratios suggests the presence of a high system-wide connectivity. As the ratio approaches unity, mass movement is minimized in the landscape indicating low system-wide connectivity. Applying the above approach to Estufa Canyon, Texas, illustrated that Estufa Canyon is a dynamic fluvial system with high system-wide connectivity.
