The influence of riverbank filtration on regional water resources: A case study in the second Songhua river catchment, China

Abstract

Riverbank filtration (RBF) of river water recharging a groundwater system has been identified as a source of water supply that guarantees the quantity of abstracted water and reduces the cost of water treatment. This paper evaluates the safe yield of groundwater in suitable areas using a numerical model of groundwater flow and discusses the influence of RBF on the temporal variation of regional hydraulic heads, groundwater flow, river flow, and groundwater-surface water interaction (GSI) under different precipitation frequencies from 20% to 95% along the Second Songhua River in Northeast China. This study shows that the potential of RBF is enormous and that the total safe yield of groundwater abstraction was 29.56 × 104 m3/day under the precipitation frequency of 95%. The direction of regional groundwater flow was not obviously changed except within the local groundwater flow field under the maximum safe yield pumping conditions. When the precipitation frequencies are higher than 75%, the direction of the GSI might be changed, and the rate of river recharge of groundwater is enhanced. The water quantity that would be captured from the river does not threaten the safety of the river ecology. It is concluded that there were no obvious adverse impacts of the large scale of RBF on regional water resources in the Second Songhua River area.