Mountain process regime characterization using a topographic morphological structural framework

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.

KEYWORDS:

• Topographic structure
• mountain geodynamics
• geomorphometry
• Karakoram
• process regimes

Acknowledgments

We are grateful for the assistance of Drs. Da Huo and Zhaohui Chi for theoretical and technical consultation. We thank Drs. Ryan Ewing, Lewis Owen, Andrew Klein, and Anthony Filippi for their disciplinary insight. We thank Sandia National Laboratories, the National Park Service, and Texas A&M University for providing resources that directly or indirectly made this research possible.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The study’s findings were produced with the SRTM v3 DEM, which is freely available through the United States Geological Survey, and the Rankl et al. (2014) glacier inventory available through PANGAEA (DOI: 10.1594/PANGAEA.873278).

10BeSupplementary material

Supplemental data for this article can be accessed here.