降雨強度の変化が地下ダム水資源に与える影響の評価

-洞窟性パイプフローを考慮した水収支モデルによる検討-

抄録

  A water balance model for a subsurface dam in the Quaternary limestone region in Okinawa, Japan, was developed. Conduit flow through karstic features such as caves and springs in the catchment area was represented by conduit-flow submodel. Fluctuations in groundwater level and conduit flow discharge were simulated, and the results showed that increased conduit flow discharge due to intensified rainfall can cause a decrease in water storage of the subsurface dam; hence occupancy of conduit flow discharge in the water budget should be considered in climate change impact evaluation. As well as improved model parameters and inputs of the water balance model, alternative use of distributed groundwater flow model would lead to better estimation of the amount of conduit flow discharge.