Baseflow Recession and Groundwater Recharge Estimation in Pyungchang River Basin

초록

It is not easy to represent the characteristics of the groundwater recession curve in streamflow, but a linear recession model has generally been used. However, some studies have shown that a nonlinear model is more appropriate, and nonlinear analyses have been conducted to describe the relationship between groundwater discharge and storage. The objective of this study is to identify and quantify the main components of the groundwater water balance—namely, discharge, evapotranspiration, storage, and recharge—by applying a nonlinear model to streamflow data from the Pyungchang River basin. In particular, this study proposes a method for separating baseflow using the streamflow hydrograph and peak groundwater stage, and groundwater recharge was also estimated based on unit effective rainfall. The analysis of baseflow revealed that the recession curve shows seasonal variation. Groundwater storage was estimated using a nonlinear model, and groundwater recharge was analyzed in relation to effective rainfall. We found that groundwater recharge continued for up to two days after effective rainfall in the Pyungchang River basin. Using the methodology developed in this study, it is possible to estimate groundwater recharge solely based on effective rainfall.

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