Hazards and accessibility: combining and visualizing threat and open infrastructure data for disaster management

High Mountain Asia’s rivers, which serve more than a billion people, receive a significant portion of their water budget in the form of snow. We develop an algorithm to track timing of the snowmelt season using passive microwave data from 1987 to 2016. We find that most of High Mountain Asia has experienced shorter melt seasons, earlier snow clearance, and earlier snowmelt onset, but that these changes are highly spatially and temporally heterogeneous.

We evaluate the 12 m TanDEM-X DEM for geomorphometry and compare elevation accuracy (using over 300 000 dGPS measurements) and geomorphic metrics (e.g., slope and curvature) to other modern satellite-derived DEMs. The optically generated 5 m ALOS World 3D is less useful due to high-frequency noise. Despite improvements in radar-derived satellite DEMs, which are useful for elevation differencing and catchment analysis, lidar data are still necessary for fine-scale analysis of hillslope processes.