Evaluation of Riverbank Hydraulic Conductivity: Implications for Groundwater Recharge

Abstract

This study highlights the relationship between the hydraulic conductivity (K) of riverbank deposits and groundwater recharge in an area adjacent to a Chalk river in Hertfordshire, United Kingdom. Three locations were mapped out for In situ permeability measurements based on geological map data indicating changes in superficial deposits along the river Mimram. The study area is predominated by Cretaceous Chalk and overlain by drift deposit such as glacial till and buried channel deposits which include glaciofluvial gravels, sands and silty-clay. Permeability measurements of the riverbank deposits’ field saturated hydraulic conductivity (Ksat) using a constant head permeameter was carried out to determine the coefficient of permeability of the superficial soils along a small stretch of the river Mimram in Hatfield. Preliminary results show a variation in the permeability of the superficial deposits which could have a significant impact on groundwater recharge. It is hoped that this study will provide a better understanding of the role of near surface geological investigation of riverbank hydraulic properties in groundwater recharge.