Extreme Precipitation-induced Concurrent Disasters Risk Assessment
through Socio-economic and Topographic Vulnerability
Abstract
The warming climate intensifies the frequency and intensity of extreme
precipitation events, leading to increases in precipitation-induced
disasters. Precipitation-induced disasters such as flooding, landslide,
and debris flow possess the potential risk of damage to socio-economic
activity. The losses due to concurrent hazards in a region not only
depend on the intensity and frequency but also socio-economic condition,
topography, and exposure to the affected region. Recent advancements in
risk mapping have shown approaches to measure the vulnerability to
disaster but not accounting for concurrent hazards can lead to
underestimation of risk. Here we propose the framework to assess the
risk of concurrent precipitation-induced disasters while incorporating
socio-economic, topographic, and land use information. In Kerala, India,
the Periyar river basin is selected as a testbed for analysis
considering 2018 extreme precipitation events. We perform 2D
hydrodynamic flood inundation modeling to analyze the spread of the
flood with the Spatio-temporal simulations of shallow landslides and
debris flows using infinite slope-based stability and erosion models to
identify the exposure of disaster. We evaluate socio-economic
vulnerability and topographic vulnerability using disparate techniques
from census demographic data and digital elevation model data
respectively and exposure using land use information. The risk mapping
is performed at the taluka (sub-district) level in the Periyar basin.
Our results show better land-use planning considering multi-hazard
vulnerability assessments reduces the exposed risk and would be
beneficial for risk mitigation measures in high-risk areas