[A-HW18] 同位体水文学2016

[AHW18-P02] 水文モデルのための甲府盆地の地下水涵養源の推定

*中西 玄樹^1,2、西田 継²、中村 高志²、浅井 和由³ (1.山梨大学大学院医学工学総合教育部国際流域環境科学特別教育プログラム、2.山梨大学国際流域環境研究センター、3.株式会社地球科学研究所)

キーワード：地下水、甲府盆地、水の水素・酸素同位体比

The end member mixing analysis using hydrological tracers have been applied to identify the groundwater recharge sources in local area, such as scale of alluvial fan. However, it is difficult to apply to large scale, due to the wide values of temporal and special for the hydrological tracers. Objective of this study is investigating the groundwater recharge identification using hydrological tracers to adapt for the hydrological model for basin scale.
Groundwater samples were collected once a year from November 2010 to October 2012. Altogether 12 river water samples were collected in 2003, 2004 and 2006 from main rivers in Kofu basin. Rain water samples were collected once a month since 2008. All groundwater samples (n=50) are classified into three types based on recharge sources. Among them 20% of groundwater are mainly recharged by river water. Other 50% samples are river water mixed with local precipitation and 25% are river water mixed with mountain groundwater.