| dc.description.abstract | The spatial morphological structure of the topography is notoriously difficult to map and characterize in relation to geodynamic processes due to the complex coupling of tectonic, geologic, climate, and surface processes that generate relief, as well as issues of topographic information representation, scale dependency, and spatial and semantic uncertainty. Consequently, we do not know where or at what rate relief production occurs except at specific sample locations. Furthermore, we lack the techniques to objectively extract process-related information from a digital elevation model even though much of that information is present and can be interpreted subjectively. The primary objective of this research was therefore to improve our understanding of mountain geodynamics by conceptualizing, designing, and implementing a framework for representing and interrogating the spatial topographic morphological structure (TMS) and process-form relationships for mapping and characterizing process regimes in northern Pakistan.
The TMS framework was found to be effective for mapping process regimes. Specifically, 31 basins in the central Karakoram were identified as predominantly shaped by glacier erosion or by bedrock river incision based on mapped terrain units and spatial constraints imposed by basin structure. Process regimes of glacial downwasting and supraglacial lake development and intermoraine drainage and sediment flux were mapped on the surface of Baltoro Glacier based on simple process-form relationships represented in TMS networks. The TMS-erosion relationship was also investigated, though no clear relationship could be identified between basin-averaged land-surface and terrain-unit parameters and predicted erosion rate and measured beryllium-10 concentrations. A linear relationship was identified between beryllium-10 production rate and concentrations, and further research will better characterize this relationship and determine if it can be used to predict cosmogenic nuclide concentrations and erosion rates. Future research on topics of semantic modeling, uncertainty characterization, scale dependency, and topographic influence on erosion rate will improve our understanding of process-form relationships and scale-dependent mountain geodynamics through objective, structure-based interpretations of the land surface. | |
