Analysis of discharge and area of the debris Flow Based on Geological Structural and Rainfall Levels in The slopes of Mount Abang, Kintamani.
I Nengah Sinarta, Putu Ika Wahyuni, Putu Aryastana

Universitas Warmadewa

Abstract

Geological structural and rainfall intensity cause the parameters of the soil shear strength to decline, especially in the surface layer of soil in volcanic rocks that have not experienced weathering. Related to these conditions, a study of geological structural and rainfall intensity against the hazard of a landslide was destroyed on the slopes of Mount Abang, especially in the Abang Batu Village. This area had previously experienced a landslide and debris flow so that the community had fled.
Soil investigation for sampling at two boreholes on a slope hazard to the community and public facilities. Geological analysis based on interpretation of slope outcrops, average rainfall analysis of the Thiessen Polygon Method and Analysis of design flood discharge using the Nakayasu Synthetic Unit of Hydrograph Method.
Based on the results of geological mapping and rock outcrops in the study area in the form of volcanic breccia rocks covered by weathering rocks that have become sandy silt or silt at an altitude of 500-2000 meters above sea level, slope inclination of 20%-40%. Flood discharge plan on the Intermittent River with a repeat of 5 years, 10 years of; 86.37 m3/s; 92.25 m3/sec. These conditions are based on the modeling of the extent of debris flow covering an area of 5167 m2. Such a large area of inundation indicates that the Abang Batu village area has a high hazard to debris flow.

Keywords: Debris Flow, Volcanic Breccia, Intermittent River

Topic: Civil Engineering