5:15 PM - 6:30 PM
[HTT21-P03] Monthly monitoring of multiple water-quality to diagnose the linkage between surface water and groundwater in the Saijo plain, Ehime prefecture
Keywords:groundwater, surface water, monitoring, flow rate, water quality diagnosis, recharging area
(1) The concentrations of most elements (Sb, As, V, Rb, Si, Al, Ti) in river water become high in summer and low in winter or spring, whereas those in groundwater at the Ohmachi site are high in winter and low in spring or summer and those in groundwater at the Tokumasu site are high in autumn and low in winter or spring. From the temporal analysis of these water-quality data, we can estimate the flow rate of the shallow groundwater to be about 10 cm per day.
(2) This seasonal variation is not so distinct for most elements in the artesian water at the Uchinuki site; the concentrations of Cl, B, Na, Sb, and As increase, whereas those of Ca and Sr decrease monotonously with weak seasonal change. Other elements (Si, V, Mg, Ti, SO4) show more complex variation. This result indicates that the recharge area and flow rate of the artesian water differ significantly from that of shallow one, and other water source in addition to the Kamo river is involved.
It is concluded that the monthly monitoring of water quality is effective to evaluate the linkage of the surface water and groundwater system, but further continuous monitoring is required especially for elucidating the flow system of artesian water.