Conjecture of Groundwater Level using Tank Model in Kumamoto Area

Abstract

Water supply in Kumamoto area is depended only on groundwater. This urban area spreads for the north and east of Kumamoto city by increasing of houses, roads and factories during the last 25 years. As a results, the impervious area has been increased to 104 km² (about 10% of all the area).
This paper reports relation between rainfall and groundwater level using a tank model which considers recharge of paddy field, lateral flow of groundwater and evapotranspiration. As the results, it is possible to calculate the exchange of groundwater level and quantity of springs using the data of rainfall and temperature.
The parameters using this tank model are calculated from observed data which include effect of rainfall and groundwater flow. So it is necessary that these parameters are determined except the influence of interaction between rainfall and groundwater flow.