Geomorphology and structural geology characterization of landslide prone area in Riau-West of Sumatra Highway

Abstract

Research areas are prone to landslides hazard. Detail location is in the Tanjung Balik area, Pangkalan Koto Baru Sub District, Lima Puluh Kota District, West Sumatra Province. Located is along the Riau - West of Sumatra Province Highway throughout kilometers 10-15. Coordinate are between 00°08'40»-0°11'20»N and 100°45'20»-100°47'00»E. The research objectives determine the geomorphological conditions, drainage patterns, and structural geology in the research area. The methods are geological survey and geomorphological analysis. The results of the analysis concluded that the geomorphology of the research area was classified into two, namely Structural Steep Hills Geomorphology Unit (S2) and Denudation Slightly Steep Hill Geomorphology Unit (D3). The Structural Steep Hills Geomorphology Unit (S2) is in the Southern region of the research area with distribution percentage around 27%, while the Denudation (S2) dominates in the North, West, East and slightly in the South with a distribution percentage around 73%. Drainage pattern is classified as sub-dendritic types. Geological analysis of structures from joint readings shows the main stresses that have relatively north-south direction.