Author(s): Cho Thanda Nyunt, Yoshihisa Kawahara
Linked Author(s): Cho Thanda Nyunt
Keywords: Reservoir regulations, climate change impact, CMIP5, Haji dam, water resources management
Abstract: Climate change alters the hydrological cycle in river basins and threatens the future of the surface water resources under the stress of the rapid urbanization and population growth in many cities. Haji dam, located upstream of the Gono river in Chugoku region in Japan, is a very important green energy resource for urban water supply, hydropower generation, irrigation and flood control. Therefore, the assessment of the projected inflow and capacity under the present operating rule is very important for the multi-purpose reservoir. This study shows that the estimated maximum 100-year probable rainfall will be a surplus of at least 5 % of the whole river basin as well as the approximately 35 - 60 mm of rainfall surcharge in July and +5 to +20 mm extra rainfall in September that will fall on the east, west and middle of the basin in near future. The increasing trend in inflow is significant with 50 m3/sec/year in the annual basic and around 100 to 150 m3/sec/month during the wet season. It is necessary to revise the release ratio before and during the flood if the current flood control allocation wants to keep it constant and reservoir water level is continuously retained under the flood alarm level for reservoir safety. However, the present operating rule assures enough capacity after the flood season or from September for the multi-purpose reservoir
Year: 2017