Mountain process regime characterization using a topographic morphological structural framework

Abstract

ABSTRACT Complex mountain geodynamics are difficult to decouple due to forcing factors, feedback mechanisms, and system couplings that arise from interacting atmospheric, surface, and tectonic processes. The operational-scale dependencies and process–form relationships that govern the spatio-temporal extent of process regimes, which in turn govern relief production, have yet to be adequately characterized and mapped. This research establishes a topographic morphological structural framework for representing and querying the spatial organizational structure of the topography that governs, and is governed by mountain geodynamics. The spatial scale-dependent structure of the topography is accounted for using land-surface parameters and land-surface partitioning into distinct terrain units that represent important aspects of the geomorphological system. The properties and spatial topology of terrain units provide constraints for modeling process–form relationships, which are represented as process–form indices and synthesized using logistic regression to empirically detect glacial and bedrock river incision process regimes at the basin-scale for 31 basins in the Central Karakoram at about 80% accuracy. The topographic morphological structural framework approach provides a mechanism for tractable representation of scale-dependent topographic structure for automated characterization of the land surface, providing insight into polygenetic geomorphological systems and systems coupling through defined process–form relationships.