Rainfall-Runoff Simulation for Water Availability Estimation in Small Island Using Distributed Hydrological Model wflow

Abstract

Hydrological data in Indonesia, especially in the small islands, is minimal, including spatial distribution and temporal completeness. It will affect the accuracy of water availability estimation for water resources management interest. One of the solutions that can be undertaken is applying rainfall-runoff modeling to obtain the discharge value at a specific location. This study aims to determine surface water availability in each sub-catchment of the small island by implementing the hydrological model. The wflow model is applying to perform the model. This model uses input data including Digital Elevation Model (DEM), landuse, soil, Leaf Area Index (LAI), rainfall, evapotranspiration, and observation of river discharge for the calibration process. As a result, this island consists of 30 catchments with some potential catchments, namely Cao, Sakita, and Tatamo, that have a 90% dependable flow of 4213.3 L/s, 3803.6 L/s 8117 L/s, respectively. The result of water availability in Morotai Island is highly expected to be the reference for water resources management, especially for tourism and urban development.