Landslides in High Mountain Asia after climate change
Abstract
Rainfall-triggered landslides are a major hazard in High Mountain Asia. Climate change has the potential to alter the distribution of landslide hazard by changing the amount, location, and timing of extreme . Global climate models offer insight into this phenomenon beyond the relatively short period for which rainfall and landslide data have been collected consistently. We generated 30-member precipitation ensembles for the time periods 1961-2000 and 2061-2100 with the Geophysical Fluid Dynamics Laboratory Forecast-oriented Low Ocean Resolution (FLOR) model, a fully coupled global climate model with 50-km resolution in the atmosphere and land. Next, we used precipitation from both ensembles as inputs for the Landslide Hazard Assessment model for Situational Awareness, which couples landslide susceptibility with 7-day rainfall accumulations. The utility of global climate models for landslide modeling was also validated by comparing the historical performance of a nudged configuration of FLOR—with nudged winds from MERRA2 reanalysis and sea surface temperatures restored to OISST analysis (Optimum Interpolation Sea Surface Temperature)—against the performance of satellite-based precipitation observation. Then we compared the frequency of hazardous precipitation across all time periods. Finally, we identified potential exposure at century's end by overlaying the distribution of modeled changes in potential landslide activity with the Global Population Projection Grids Based on Shared Socioeconomic Pathways (SSPs). The 21st-century ensembles showed much more frequent landslide-triggering precipitation in the Himalayan region; relatively few sites are expected to experience decreases. While the highest rates of increase were located in relatively unpopulated areas in all scenarios, many glacial lakes are currently located in these areas. Cascading hazards such as glacial lake outburst flooding and landslide damming of rivers could still impact large populations downstream. In addition to identifying potential changes in extreme precipitation and their impacts on regional hazards, this research revealed the value of interdisciplinary teams to climate research.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.C21E1400S
- Keywords:
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- 0720 Glaciers;
- CRYOSPHEREDE: 0758 Remote sensing;
- CRYOSPHEREDE: 0798 Modeling;
- CRYOSPHEREDE: 1863 Snow and ice;
- HYDROLOGY