High Resolution 1:10,000 scale Mapping Strategy of Multi ... - NDMA

Mass wasting is a generic term referring to the downslope movement of soil or rock
material under the influence of gravity. Landslides is nearly a synonymous term,
implying a surface of failure along which slippage, flow, or fall occurs. Varnes
classification system for landslides (Varnes, D.J., 1975, Slope movements in the
western United States, in Mass Wasting: Geoabstracts, Norwich, p. 1-17) is the most
widely-used and is reproduced in Table 1. Classification of landslide types (adapted
from Varnes’ (1975).
Type of movement Type of material
APPENDIX V
METHODOLOGY FOR HAZARD MAPPING OF
LANDSLIDES
LANDSLIDE AND SLOPE STABILITY ANALYSIS MODELING
Bedrock unconsolidated sediment or soil
Falls Rockfall Debris Fall Earth fail
Slides Rotational Roack Slump Debris Slump Earth Slump
Translational Rock Block slide Debris Block slide Earth Block slide
Flows Rock Slide Debris Slide Earth Slide
Rock Flow Debris Flow Earth Flow
Complex Combination of two or more types
Table App 5.1: Classification of landslides
The three primary types of landslides, falls, slides, and flows, are distinguished on
38