3D model and morphometry of the Beringin watershed as an effort for flash flood disaster risk reduction in Semarang

Geography, Geography Department, Semarang State University, 50229 Semarang, Indonesia

^* Corresponding author: ariyani.ideas@gmail.com

Abstract

The Beringin watershed is one of the watersheds (DAS) located in Semarang, Central Java, Indonesia. During 2010 – 2017 in this watershed area, there have been 8 flood disasters, the last two of which changed from an inundation flood to a flash flood type. The objective of this research is to investigate the characteristics of the rivers or the morphology of the watershed by 1) creating a three-dimensional spatial model of the Beringin watershed and describing its physical profiles and shapes, 2) arranging a satellite imagery map of the settlement at risk of flash flood disaster surrounding the watershed, 3) mapping the morphometric of the watershed, which consists of the landslide potential, the narrowing of river bodies and calculating the peak discharge in order to get the trigger factor of the flash flood, and 4) mapping the vulnerability of the Beringin watershed to minimize the flash flood disaster risk. The research method conducted was a combination of qualitative and quantitative approaches. Clearly, that the output of this research will contribute to the conservation of the Beringin watershed whose outcome is the reduction of the flash flood disaster risk affecting the communities surrounding the Beringin watershed.