A numerical classification of selected landslides of the débris slide-avalanche-flow type

Numerous classifications of landslides have been proposed based on a variety of classificatory criteria. Several writers have mentioned the difficulties of distinguishing accurately between landslides classed by Sharpe (1938) and Varnes (1958) as débris slides, débris avalanches, and débris flows. A sample of 92 such landslides from the greywacke hill country of the North Island of New Zealand is classified on the basis of as many as 19 numerical and 43 disordered multistate attributes. The results of the agglomerative polythetic classifications do not help to distinguish these landslide phenomena clearly. Until some distinctive criteria characterizing landslides of this type are identified the use of unsatisfactory simple classifications is recommended.