[A-HW24] Material transportation and cycling at the land-sea interface: from headwaters to the ocean

[AHW24-P19] Estimation of spatial variation of groundwater recharge rate in Asahi River catchment, western Japan using SWAT

*Rendilicha Halake Guyo¹, Yuta Shimizu³, Mitsuyo Saito¹, Shin-ichi Onodera², Yusuke Tomozawa², Sharon Bih Kimbi², Kunyang Wang² (1.Graduate School of Environmental and Life Science, Okayama University, 2.Graduate School of Advanced Science and Engineering, Hiroshima University, 3.National Agriculture and Food Research Organization)

Keywords:Catchment, Groundwater recharge, Sensitivity, SWAT

Groundwater is a critical source of freshwater worldwide. The understanding of natural and spatial rates of groundwater recharge is imperative to the management of groundwater resources and the modeling of contaminant transport within the subsurface. The recharge process helps in the understanding of surface water and groundwater interactions. This study used the quasi-distributed Soil and Water Assessment Tool (SWAT) and three-decade climatic data (1979-2008) to estimate the spatial variation of groundwater recharge rates in the Asahi River catchment, western Japan. The monthly groundwater recharge rates were simulated using weather parameters in the catchment. The model results calibrated and validated against the monthly discharge data from 2000 to 2008 period at the Makiyama gauging station, Okayama prefecture, Japan. From the preliminary results, the calibration and simulation recharge were satisfactory according to statistical indicators and previous studies.

Acknowledgements: This research was supported by JSPS Grant-in-Aid for Scientific Research (B) (No. 21H03650, PI: Mitsuyo Saito) and APN project (No CRRP2019-09MY-Onodera, PI: Shin-ichi Onodera).