[S-CG59] Crustal fluids and deformation

[SCG59-P03] Effect of active faults on the water quality of the Ado river and neighboring spring waters in Shiga Prefecture from 2018 to 2022

*Naoji Koizumi¹, Shuka Tashiro¹ (1.School of Environmental Science,the University of Shiga Prefecture)

Keywords:Ado river, Water quality, Active fault

The length of the Ado river, which is located in the western part of Shiga Prefecture, is 58km and the second longest in the rivers which flow into Lake Biwa, which is the largest lake in Japan. The catchment area of the Ado river is 300 km² and the third largest in the rivers which flow into Lake Biwa (Shiga Prefecture, 2018). In the part of the upstream and most of the midstream, the Ado river runs along the Hanaore fault. In the downstream the Ado river cross the Biwako-seigan fault (Fig.1). Both of the faults are the main active faults in the western part of the Shiga Prefecture. In addition the ado river basin is not well developped (Biwa basin study group, 2003). Therefore the Ado river is suitable for investigating the effect of active faults on the river water quality. There are some spring waters in the end of the alluvial fan of the Ado river. Hereafter they are called the fan spring waters.
We surveyed the Ado river and the fan spring waters about once every 1-3 months from April, 2018 to May, 2022. We analyzed changes in the water quality of the river water and the spring waters. We also evaluated the effect of the Hanaore fault on the water quality of them.