SELECTING RESERVOIR OPERATION SCHEME FROM SEASONAL STREAMFLOW PREDICTION: CASE STUDY IN CHAO PHRAYA RIVER BASIN

抄録

 The 2011 unprecedented flooding event in Thailand caused difficulties in water management related to reservoir operation due to heavy rainfall and the lack of information. A prediction at a seasonal scale would be useful information for making policy on water management in such a river basin. There are two large reservoirs in the Chao Phraya basin; a reservoir with an effective operation plan could mitigate floods as well as droughts, and seasonal hydrological predictions could be useful for setting an effective operational plan. Thus, with the utilization of seasonal hydrological predictions, we set the criteria to select a reservoir operation scheme that aims at flood mitigation in 2011. The actually-used reservoir operation scheme and two different reservoir operation schemes proposed in a previous study are considered in this study. We set three criteria to choose an operation scheme out of three operation schemes written above. Seasonal hydrological predictions were carried out by using ECMWF seasonal precipitation prediction with two different bias correction techniques. The results show that seasonal river discharge predictions could mitigate the flooding in 2011 during the peak period, although the current ability of seasonal hydrological prediction was not sufficient. The most effective operation scheme could decrease the peak discharge around 18 percent by releasing water from reservoirs from the beginning of June until August.