IWRA Proceedings

Reservoirs are important infrastructure in that they occupy a major fraction of water resources in our society. In Japan, more than 50% of domestic water is covered by reservoirs. However, because of their characteristics of closed water body, influences of water quality deterioration tend to accumulate. Therefore, improvement of water quality is generally takes a long time once a reservoir is polluted. In order to project potential influences from climate change on water quality in those water resources reservoirs, we tried to make assessments by the use of a vertical 1-dimensional numerical model. 

Thirty three reservoirs were chosen among multi-purpose reservoirs from all over Japan to make projections of the future conditions of stored water. Stratification intensity of surface layer of reservoirs were used as an index of algal (especially cyanobacteria) growth potential. Future meteorological conditions such as solar radiation and atmospheric temperature were given using the output of several GCMs. Our results predicted that eutrophication potential would be higher in the north part of Japan.