Aplication Of GIS Based Morphometric And Land Cover Analysis to Evaluate Flood Potential in The Wai Batu Gantung Watershed, Ambon City, Indonesia. Nabila Kalsum Tuanany - Emi Sukiyah - Boy Yoseph CSSSA - Arini Syafri
Faculty Of Geological Engineering, Padjadjaran University
Abstract
This study analyzes morphometric parameters and land cover conditions to assess their relationship with flood potential in the Wai Batu Gantung Watershed, Ambon City, Indonesia. Watershed delineation and sub-watershed division (BGt1 - BGt6) were carried out using SRTM DEM data through hydrological analysis in ArcGIS 10.8. The morphometric parameters analyzed include the bifurcation ratio (Rb), drainage density (Dd), and texture ratio (Rt), while land cover classification was obtained from the overlay of land use maps and high resolution satellite imagery. The results indicate that the Wai Batu Gantung watershed has bifurcation ratios (Rb) ranging from 1.3 to 2.0, drainage density (Dd) value from 3.1 to 4.4, and ratio texture (Rt) values between 0.38 and 2.07. these variations show that the drainage pattern is influenced by geological structures and lithological conditions. Land cover analysis reveals that shrub vegetation dominates most of the watershed (81-100%), whila settlement areas are limited to BGt2 (1%) and BGt4 (8%), located in the middle and lower zones. The integration of morphometric characteristics and land cover indicates that areas with higher drainage density and coarse texture, combined with increasing built-up areas, exhibit greater flood potential. Maintaining vegetation cover in the upper watershed and controlling land conversion in the middle and downstream zones are therefore essential for sustainable watershed management in Ambon City.
Keywords: ambon city, drainage density, flood potential, land cover, morphometric analysis
