HYDROLOGICAL PREDICTION FOR MAPPING THE POTENCY OF BREAK IN THE SAGULING DAM, WEST JAVA PROVINCE, INDONESIA

Abstract

Dams are structures built across bodies of water to hold the water back. They offer various economic, environmental, and social benefits, including large-scale water storage, hydroelectric power generation, tourism, and recreation. However, in addition to offering benefits, dams are also associated with certain risks. One of the biggest risks is the possibility of a dam breaking, which may occur if the discharge inflow is overly high at the point it enters the reservoir. A very high discharge inflow can result in a probable maximum flood (PMF) discharge. This study investigates the potential of hydrological analysis with regard to mapping the dam break potency of the Saguling Dam in Indonesia. The reservoir system on the Citarum River consists of three reservoirs, namely Juanda (Jatiluhur), Cirata, and Saguling. Together, they comprise a cascade reservoir system. The Saguling Dam is located in the upstream, the Cirata Dam is in the middle stream, and the Juanda Dam is under the Cirata Dam. This study focuses on the Saguling and Cirata Dams. It analyzes the PMF using the Nakayasu, ITB-1, Gama-2, and Snyder methods. Moreover, the rainfall analysis involves the Thiessen polygon and the frequency distribution of the Gumbel, Log Pearson-III, and Log Normal, while the hourly rainfall is analyzed using the PSA-7 currently being investigated in Indonesia. The intensity of the rainfall in the catchment area of a dam is directly related to the level of the discharge inflow that enters the reservoir. The Saguling Dam faces a similar risk, which explains the need to conduct a comprehensive hydrological analysis to assess and map one of the key risk factors for the dam breaking.