GEOMORPHOMETRIC CHARACTERIZATION OF TOPOGRAPHIC STRUCTURE AND TECTONICS IN THE KARAKORAMHIMALAYA, PAKISTAN

Understanding the role of surface processes and the nature of coupled systems in topographic evolution of the Karakoram Himalaya is notoriously difficult. Issues involving climate forcing, erosion rates, erosion-uplift dynamics, and the scale-dependencies of surface process and coupled systems are not yet adequately addressed due to methodological limitations associated with charaterizing the spatial complexity of mountain geodynamics. Graph theory provides an analytical framework for evaluating complex mountain topographic structure and tectonics as a system of connected morphometric conditions that can characterize process-form relationships, scale dependencies, and polygenetic topographic evolution. Consequently, we utilized graph theory and spatial analysis to characterize the spatial structure of topography in the Karakoram to identify coupled erosion-upift and deformation zones. Specifically, we utilized the Shuttle Radar Topography Mission (SRTM; 30 m) digital elevation model to characterize the mesoscale relief structure, spatial complexity, and topographic anisotropy in relation to surface processes and tectonics. Topographic properties were used to semantically model geomorphological features that serve as nodes for establishing linkages and spatial networks. Network analysis was then conducted to generate network properties for characterizing tectonic zones, geologic structure, lithological variations, and surface process regimes. Preliminary results indicate that topographic structure dominated by fluvial and glacial processes exhibit distinct scale-dependent patterns. Similarly, coupled erosion-uplift zones are highlighted by relief production and extreme relief. Furthermore, tectonic deformation and lithology variations exhibit scale-dependent network patterns and properties. Our results demonstrate that network properties, including node density, preferred link orientation, and network anisotropy, can be used to better characterize various aspects of mountain geodynamics and enables the evaluation of polygenetic topographic evolution and process-regime mapping. We demonstrate new methods that facilitate scientific visualization, information synthesis, and mapping.