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 ma ps, 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 M anaslu-Ganesh Himal. Chi-square analyses revealed that the frequency of slo pe failures varies with slope aspect, and position above/below the Main Cen tral Thrust (MCT). Human disturbance did not account for a statistically si gnificant increase in mass movement, except in sites occupied by mid-slope roads and where excessively steep slopes, marginal for agriculture or grazi ng, have been deforested. (C) 1998 Elsevier Science B.V. All rights reserve d.