17:15 〜 18:30
[AHW23-P03] Isotope and water quality compositions of groundwater in the bedrock and sediment deposits in Kofu basin
Nationwide, Kofu basin in Japan is well renowned for the presence of natural hot water springs. The extraction depth of the hot water in this basin varies while it is also found that the water is being extracted both from the bedrock and sedimentary deposits. However, the exact mechanism of the groundwater recharge process in this basin is yet unknown. Thus, this study is primarily focused in identifying the isotope and water quality compositions of groundwater in the bedrock and sediment deposits and understand the deep groundwater recharge processes in this basin.
For the purpose of the study, 485 borehole data and 307 hot spring water samples were collected from Kofu basin. The lithological analysis using the boreholes estimated bedrock distribution (granite) from surface to 1000+m deep, extending from the north to the central part of Kofu. The distribution of the deep groundwater isotope showed inverse relationship with topography i.e. altitude effect is found prevalent for isotopic variations. Those results suggest the possibility of mountains as the main area for the groundwater recharge to the basin floor. Thus, the presentation will show the isotope and water quality compositions of groundwater in the bedrock and sediment deposits and find the inter-relation between them.
For the purpose of the study, 485 borehole data and 307 hot spring water samples were collected from Kofu basin. The lithological analysis using the boreholes estimated bedrock distribution (granite) from surface to 1000+m deep, extending from the north to the central part of Kofu. The distribution of the deep groundwater isotope showed inverse relationship with topography i.e. altitude effect is found prevalent for isotopic variations. Those results suggest the possibility of mountains as the main area for the groundwater recharge to the basin floor. Thus, the presentation will show the isotope and water quality compositions of groundwater in the bedrock and sediment deposits and find the inter-relation between them.