Rethinking geohazard monitoring under extreme weather: a call for a coupled weather–terrain framework

As extreme weather events become increasingly recurrent under a non-stationary climate, catastrophic geohazards are emerging beyond historically recognized hotspots and established monitoring footprints. Yet extreme rainfall is not spatially uniform: its intensity, duration, and localization can be substantially modulated by terrain through orographic lifting, moisture convergence, and topographic controls on atmospheric flow. This weather–terrain coupling effect can generate localized extreme rainfall and create hydro-mechanical forcing that may trigger landslides, debris flows, and cascading hazards even in areas historically classified as relatively stable. Current warning strategies, largely calibrated against historical rainfall–hazard records at monitored sites, have limited capacity to anticipate such emerging hazards in poorly instrumented or previously unaffected terrain. By treating meteorological forcing and terrain susceptibility as largely separate components, these approaches may overlook the spatially heterogeneous amplification of extreme rainfall by topography, leaving critical blind spots in regional geohazard monitoring. Here, the proposed framework is intended primarily for hydro-meteorologically triggered slope failure hazards, including landslides, flow slides, debris flows, and related cascading impacts.