The researchers studied how much water can effectively recharge karst aquifers in the Yufuhe River area. They used a hydraulic model to simulate river levels and a groundwater model to estimate water seeping into the aquifers. The effective recharge rates were found to be around 65-68%, depending on the depth of the groundwater. Field data confirmed the accuracy of the simulation, showing that most of the recharged water can indeed enter the karst aquifers.