Near‐Surface Geomechanical Properties and Weathering Characteristics Across a Tectonic and Climatic Gradient in the Central Nepal Himalaya

Shallow bedrock strength controls both landslide hazard and the rate form of erosion, yet regional patterns in near-surface mechanical properties are rarely known quantitatively due to challenge collecting situ measurements. Here we present seismic geomechanical characterizations shallow subsurface across central Himalayan Range Nepal. By pairing widely distributed 1D shear wave velocity surveys engineering outcrop descriptions per Geological Strength Index classification system, evaluate landscape-scale characteristics their relation environmental factors affect rock strength. We find that is more dependent on degree chemical physical weathering, rather than mineral textural differences between metamorphic lithologies found Himalaya. Furthermore, weathering varies systematically with topography. Bedrock ridge top sites highly weathered have S-wave velocities typical soils, whereas near valley bottoms tend be less characterized by high estimates rock. Weathering hillslopes significantly variable, resulting range channel endmembers. speculate variability hillslope environment may partly explained episodic nature mass wasting, which clears away material where scars recent. These results underscore heterogeneity highlight need account for variable when estimating parameters analysis.