Characteristic of mass movement in Riam Kanan watershed, Indonesia

Abstract

Mass movement occurred in upstream in Riam Kanan Watershed due to this area is part of Meratus Mountain. The objective of study is to analyse the vulnerability class of mass movement in the upstream of Riam Kanan Watershed and to analyse the characteristics of the mass movement in the upstream of Riam Kanan Watershed based aspects of morphology and morphogenesis. This study used the survey method, to determine the vulnerability class mass movement using slope maps and vegetation density map. Aspects of morphology and morphogenesis are used to determine the characteristics of mass movement. Aspects of morphology are slope of hill. Aspects of morphogenesis includes soil depth and rock weathering. The research area is dominated by medium and high vulnerability classes i.e. 54,804.47 Ha and 36,546.04 Ha. The mass movement type in the landform of weak eroded of denudation hills, metamorphic rock material (D1) is rotational landslides and rock fall. Rotational landslide has the characteristic of slope > 25°, the soil thickness ranges from 1-2 m and occurring of rock weathering. Rock fall has the characteristic of slope > 45°, about 30 cm of soil thickness, low vegetation density, further weathering.