Estimation of layered aquifer diffusivity and river resistance using flood wave response model

SummaryA convolution equation and a discrete ramp kernel equation for the application of the flood wave response were applied to estimate aquifer diffusivity and river resistance using the groundwater levels of a selected well in the Mangyeong-river floodplain. The aquifer diffusivity and river resistance are the key parameters to explain the hydraulic connection between aquifer and river. Groundwater level during a zero rainfall period was used so that the effect of rainfall recharge on groundwater level could be neglected. Selecting an appropriate flood wave and undertaking correction of the preceding recession or trend of the groundwater level and the river stage had to be performed prior to hydrograph matching. The observed and calculated groundwater level responses generated by a flood wave response model to the river stage were matched to each other, and an optimal value of the aquifer diffusivity and river resistance were obtained. The proposed method is an effective and economical means to estimate aquifer diffusivity and river resistance to characterize the hydraulic interaction between groundwater and river.