| Digital terrain analysis of mountain topography is widely utilized for mapping landforms, assessing the role of surface processes in landscape evolution, and estimating the spatial variation of erosion. Numerous geomorphometry techniques exist to characterize terrain surface parameters, although their utility to characterize the spatial hierarchical structure of the topography and permit an assessment of the erosion/tectonic impact on the landscape is very limited due to scale and data integration issues. To address this problem, scale-dependent geomorphometric and object-oriented analyses is used to characterize the hierarchical spatial structure of mountain topography. Specifically, a high-resolution digital elevation model is used to characterize complex topography in the Shimshal Valley in the Western Himalaya of Pakistan. To accomplish this, terrain objects were generated (geomorphological features and landforms) including valley walls, drainage basins, slope facets, and elemental forms based upon curvature. Object-oriented analysis is used to characterize object properties accounting for object size, shape, and morphometry. The spatial overlay and integration of terrain objects at various scales define the nature of the hierarchical organization. Results indicate that variations in the spatial complexity of the terrain hierarchical organization are related to the spatio-temporal influence of surface processes and landscape evolution dynamics. Terrain segmentation and the integration of multi-scale terrain information permits further assessment of process domains and erosion, tectonic impact potential, and natural hazard potential. |
