Author(s): Daisuke Nohara; Shunsuke Suzuki; Yoshinobu Sato
Linked Author(s): Yoshinobu Sato, Daisuke Nohara
Keywords: Reservoir operation; Climate change; Drought management; Impact assessment; River streamflow
Abstract: Changes in hydrological systems under changing climate may threaten existing water resources management systems. In order to assess changes in risks of water-related disasters such as floods or droughts, it is important to quantitatively assess river discharge under the future climate condition considering artificial regulation by reservoirs in the river basin. Impact of changes in river streamflow on reservoir operation also need to be estimated to develop a strategy for adaptation. Considering these circumstances, impact assessment of climate change on river streamflow and operation of reservoir systems for water use was conducted. The assessment was conducted for two Japanese river basins with different hydrological characteristics: the Yoshino River basin where droughts often occur, and the Mogami River basin where snow melting water contributes to river discharge significantly. Current (1979-2003) and future (2075-2099) climate data projected by MRI-AGCM3.2S, a high resolution AGCM developed by Meteorological Research Institute, were used as meteorological input for the assessment. River discharges under both the current and future climates were estimated from climate data by use of Hydro-BEAM, a cell concentrate type hydrological model, coupling with reservoir operation models. The assessment with the proposed method showed the potential changes in river streamflow that may increase a risk of drought in the future in the target river basins. The assessment also showed that reservoir operation could be significantly affected by the changes in river streamflow in summer and snow melting season, giving an idea how to change operation of reservoirs for adaptation to climate change.
Year: 2018