2010 年 16 巻 1 号 p. 1-8
The effect of climatic change of underground dam areas on the dissolution of limestone was observed by using numerical simulation. The examination is related to the sustainable groundwater development from the underground dam constructed in the south islands in Japan. The model includes dispersion/diffusion, advection, ion exchange, formation of complexes in the aqueous phase, and the dissociation of water. The mass action, transport, and the site action equations are expressed in a differential/algebraic form and solved by FEM. As the acidification of the rain water progresses, the dissolution of limestone increases. As a result, calcium ion concentrations increased and finally will block the screen of pumping well and also deteriorated the quality of groundwater. Increase of intensity of rain, which coincides with the increase of velocity of water, caused the increase in the dissolution of limestone. Dissolution of limestone was not favored with increasing temperature. It was found that the areas upstream and relatively distant from the dam body are safer than areas near the body, as regard extraction of groundwater of this underground dam area.
