The Role of Landslides in Slope Development in the High Rainfall Tropics

摘要

In this study are briefly reviewed the aims of a research project on the role of landslide development in the high rainfall tropics. The degree to which these aims are realized is discussed as are the type and character of other problems requiring investigation. The following conclusions were reached, in these studies in the Australian Trust Territory of New Guinea, as reported in earlier technical reports: (1) There are statistically significant relations between landslide size and frequency, and rock and vegetation type; (2) Types of landslides vary markedly from lithology to lithology; (3) There are critical minimum angles for the initiation of each landslide type; (4) Denudation by landsliding is of the order of 1 foot every 400 years in New Guinea, except in areas where spectacular earthquakes occur, where rates as great as 1 foot in 233 years may be noted; (5) Aerial photographs may be used to estimate landslide denudation with considerable accuracy; (6) There was a high degree of internal consistency between methods of measuring the rate at which new landsliding takes place. These included discussions with New Guinean Highland peoples; using aerial photographs of different ages to count new landslides per unit time; estimating with air photographs and field work, rates of revegetation or landslides. (Author)