Spatial Modelling for the Calculation of River Capacity: Case Study Downstream Area of Wanggu River Kendari

Abstract Spatial modelling of flood-prone areas will provide maximum results if it is supported by the accuracy data acquired, mainly related to elevation or area’s topography. generated from accurate topographic can estimate river’s carrying capacity. This study built a spatial model using aerial, terrestrial, and hydrographic surveys. Aerial surveys were conducted UAV corrected terrestrial surveys, GCP, ICP. Testing carried out comparing current field velocity with 2D Hec-Ras numerical simulations variation manning coefficient. The combination produces cross-sectional river, which used in calculating capacity calculated simulation method software verified mathematical approach based on flood hydrograph curve. showed that horizontal GCP was 2.8 cm vertical 6.5 cm. testing aerial photographs measured (ICP) have Mean Absolute Percentage Error (MAPE) value 5.81%. According model, roughness 0.06-0.09. 1.700.766 m3, verification are 1.683.433 m 3 difference 1.02%.