Environmental influences on landslide activity: Almora Bypass,Kumaun Lesser Himalaya

Landslides are self-organizing and self-referenced systems. The conditions which lead to their emergence along Himalayan highways are not the same as those which govern their subsequent evolution. Landslides originate at sites which differ from average conditions by having significantly higher, steeper roadcuts, carved into steeper hillsides, with more finely bedded but less steeply dipping rocks, and fewer trees upslope. These variables do not correlate with measures of landslide size. Landslide morphometric variables correlate with other landslide variables and with few external factors. The system exhibits independence (autopoiesis) from its environment. Additionally, landslides dominated by rock-mechanical processes tend to produce lower angle outfalls from higher, north-facing, roadcuts than those dominated by soil-mechanical processes which are associated with greater depths of below-soil regolith. However, the outfall volumes produced by the landslides of different type are similar. These findings are generated from statistical (correlation/T-test/stepwise discriminant) analyses of data produced by a field survey of average environmental conditions, and the morphometry and environmental contexts of 88 landslides, on 7.6 km of the Almora Bypass.