The Quantitative Geomorphology of Upper Citarik Watershed and Its Implication to the Flash Flood Potential

¹ Department of Applied Geology, Faculty of Geological Engineering, Universitas Padjadjaran, Sumedang, Indonesia
² Department of Science Geology, Faculty of Geological Engineering, Universitas Padjadjaran, Sumedang, Indonesia
³ Faculty of Earth Science, Universiti Malaysia Kelantan, Malaysia

^* Corresponding author: raditya.rendra@unpad.ac.id

Abstract

The research area is the Upper Citarik Watershed, located in the eastern Bandung Basin, West Java, Indonesia. This research aims to identify the quantitative geomorphology, especially the morphometry of the Upper Citarik Watershed, and its implication for the potential of flash floods. This research was conducted through a studio analysis with the support of thematic maps such as geological and slope maps. The parameters used in this morphometry calculation consist of linear aspects (stream order, stream length, mean stream length, stream length ratio, bifurcation ratio, and mean bifurcation ratio); areal aspect (drainage density, drainage texture, form factor, ratio of circularity, ratio of elongation, and length of overland flow); and relief aspects (watershed relief and relief ratio). The research results show that the Upper Citarik Watershed consists of 17 sub-watersheds that share relatively similar characteristics, including elongated shape with high relief and rather steep - steep slopes. It is predominantly composed of volcanic rocks and slow rising of flash flood. It shows that from a quantitative geomorphology perspective, the research area has high resistance to flash floods. Land use changes need to be a concern to prevent a significant decrease in the ability of land to deal with the flash floods.