GIS-Based Flood Mitigation of Deli River

Structural actions to reduce floods such as the construction of reservoirs, dikes or dams are considered incapable of fully controlling the floods. Hence, information on flood risks through flood risk map is an obligatory to prevent and minimize losses caused by the floods. Regulation of Minister of Home Affairs no. 33 of 2006 on general guidelines for disaster mitigation states that one of the important things in disaster mitigation is the availability of information and map of disaster prone areas for each type of disaster. This study aimed to determine the potential and risk of flooding in Deli River by integrating software of Hydrologic Engineering Center-River Analysis System (HEC-RAS) with Geographic Information System (GIS). The design debit calculation conducted in four periods, 10, 25, 50 and 100 years. There are four districts, Medan Labuhan, Medan Marelan, Medan Deli and Medan Belawan, discovered as flood-prone areas. 14 sub-districts from four districts are potentially impacted by floods, namely Kota Bangun, Titi Papan, Tanah Enam Ratus, Rengas Pulau, Paya Pasir, Labuhan Deli, Besar, Martubung, Sei Mati, Pekan Labuhan, Nelayan Indah, Belawan Pulau Sicanang, Belawan Bahagia, and Belawan Bahari. Four evacuation points and 14 alternative paths also obtained based on the flood mapping.