Analysis of groundwater change around Yongding River since ecological water replenishment

In order to evaluate the variation in groundwater around the river course after water replenishment, methods such as spatial analysis were used to analyze the groundwater level and water quality around the Yongding River from 2019 to 2022. The results indicated that during the water compensation period, the groundwater level along the Yongding River exhibited a significant rebound trend, which is more significant among the upstream areas.. Spatially, the closer the area to the river course, the faster the groundwater level response. The groundwater in the study area is weakly alkaline, with Ca²⁺, Na⁺ and HCO₃⁻. as the dominant anions and cations. Under the combined influence of multiple factors such as ecological water replenishment and its water quality, precipitation, hydrogeological conditions, the groundwater quality in the study area has been significantly improved. The total hardness and the nitrate nitrogen concentration of groundwater showed a downward trend, among which the decrease of nitrate nitrogen was more significant.