Assessment of Water Quality Changes in Reservoirs in Japan Affected by Global Warming

Abstract

 Reservoirs occupy a large portion of water resources in Japan. However, global warming can be a threatening factor of water use in the future through deterioration of water quality. In this study, influence of climate change to reservoirs was investigated in terms of water temperature through the changes of atmospheric temperature and solar radiation. 37 reservoirs were chosen from all over Japan considering their conditions such as location, capacity and hydraulic residence time. Vertical 1-dimensional numerical model was used to project changes of water temperature. Regression analysis was applied to assess the concentration of chlorophyll a from the total phosphorus of inflow and changes in water temperature.