DefinePK

Abstract

Soil characteristics, being soil the outer part of the lithosphere, greatly affect the occurrence of landslides, but there is still a little research explaining how they interact in order to trigger a landslide. This research aims to identification the soil characteristic that causing landslides in Bengkelekila Sub-District, North Toraja District in South Sulawesi, Indonesia. Ten undisturbed samples (for physical and micro morphological analyses) and eight for soil texture were collected. The measured soil physical parameters were bulk density, particle density and soil permeability. Results show that the porosity and permeability below 30 cm tend to be lower, which cause water saturation of the topsoil after heavy rains and therefore favors the occurrence of landslides. Soil micro morphology showed sub horizontal planar voids, high mineral weathering and striated b-fabrics resulting from swelling-shrinking phenomena, and clay coatings in pores in the subsurface horizons, reducing hydraulic conductivity and triggering landslides.