Geoecology and mass movement in the Manaslu-Ganesh and Langtang-Jugal Himals, Nepal

This study describes and explains the spatial distribution of mass movement in the central Nepal Himalaya. Judgments were formulated on the origin and rates of mass movement using field evidence, topographic maps, geologic maps, and SPOT imagery. Mass movement scars were mapped in the field during a 240-km traverse of the Langtang-Jugal Himal and a 300-km traverse of the Manaslu-Ganesh Himal. Chi-square analyses revealed that the frequency of slope failures varies with slope aspect, and position above/below the Main Central Thrust (MCT). Human disturbance did not account for a statistically significant increase in mass movement, except in sites occupied by mid-slope roads and where excessively steep slopes, marginal for agriculture or grazing, have been deforested.