Kirschbaum

Multi-sensor Impact Analysis of cascading hazards and transportation corridors in Nepal

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Every year in Nepal, hundreds of fatalities occur and hundreds of thousands of people are impacted as a result of cascading landslide hazards triggered by heavy rainfall, seismic activity, snow melt, and glacial lake outbursts. Building arterial road networks in the Himalaya is viewed as a key enabler for development, bringing access and communication to the predominantly rural population. However, the rollout of poorly aligned and constructed roads can increase the geohazard susceptibility of an area, causing landslides. This work takes a multi-sensor, multi-variable view to address the cause and effect relationships of cascading hazards along transportation corridors in Nepal, exploiting high resolution optical data, synthetic aperture radar, hydrometeorological products, topography, and socioeconomic data. The goal of the proposed work is to provide scientific tools for actionable landslide disaster risk reduction and provide metrics for near real-time hazard assessment as a pathway to achieve efficient, scalable actions. This suite of tools and model products will be coordinated with the HiMAT team and directly contribute to GMELT, providing end users in this region with improved situational awareness of cascading hazard impacts at relevant space and time scales within Nepal. The specific proposal objectives include:

1. Data synthesis: Fusion of optical imagery, Synthetic Aperture Radar data, and high-resolution digital elevation models to map landslides along key road corridors (main highways and new road construction);
2. Susceptibility and runout mapping: Model the terrain’s susceptibility to landslide initiation and generate runout simulations from satellite-based, modeled and in situ parameters;
3. Cascading hazard triggers: Establish cascading hazard triggering relationships for hydrometeorological variables and earthquake triggers to apply in a dynamic regional landslide hazard model;
4. Regional hazard modeling and forecasting: Incorporate NASA data and potentially products from the GMELT toolbox within a landslide hazard model to estimate the spatiotemporal distribution of past, current and future landslide hazard;
5. Risk assessment: Integrate data on hazard, exposure, and vulnerability to identify critical links in the transportation networks and assess potential risk and economic impacts of disruptions from landslides;
6. Engagement: Collaborate with the HiMAT team, local and regional policy makers, practitioners, and other end users to guide development of tools for direct application in hazard assessment, situational awareness, regional planning and policy making.
7. Dissemination and Integration: Disseminate the resulting data and tools and provide guidance on their integration with existing decision support and early warning tools. The proposed work leverages newly available and multi-decadal time series of satellite-based remotely sensed imagery to demonstrate how optical data, radar data, precipitation, topography, soil moisture, and other variables can be integrated to develop a new capability and capacity to better understand the frequency, hazard, and risk of landslide hazards and their impact upon critical infrastructure. The interdisciplinary proposal team provides end-to-end expertise to address all elements of the cascading hazard process, including hydrometeorological and seismic triggers, landslide mapping, hazard modeling and runout, infrastructure assessment, and disaster risk assessment and reduction. The outcome of this proposal’s basic and applied research foci will be a suite of tools that adds new critical information to existing decision-making processes and systems on hazard mitigation and preparedness across a range of spatial and temporal scales.