Abstract
Sayanokami spring water exists in the new campus of Kyushu University, which is located on the western part of Fukuoka City. This spring water is one of the important water resources for agriculture around the new campus area. The construction of the new campus started last June, 2000. In this study, to understand the hydrological properties of the Sayanokami circumference, 222Rn and tritium were used as tracers, respectively. Consequently, it was found out that the residence time of Sayanokami spring water is 10-20 years. Moreover, the residence time and the catchment area of Sayanokami spring water were estimated using groundwater flow model. As a result, the residence time of Sayanokami spring water was evaluated to be about 25 years at most and the catchment area was specified. It is concluded that the accuracy of estimation of residence time and catchment area of the spring water can be improved by analysis of radioactive isotopes and groundwater flow model.
