Interaction between surface water and groundwater in the Alluvial Plain (anqing section) of the lower Yangtze River Basin: environmental isotope evidence

This study aimed to accurately understand the interaction between surface water and groundwater in the alluvial plain (Anqing section) of the lower Yangtze River basin. To this end, the distribution characteristics of hydrogen and oxygen stable isotopes and Rn-222 isotopes in different water bodies were analyzed using the multiple environmental isotope tracing method. The results show that the Yangtze River is generally recharged by groundwater in the alluvial plain (Anqing section), whereas it is stimulated by human activities to recharge groundwater in the urban section of Anqing; the first-order stream of the Yangtze River, the Wan River, receives groundwater recharge in the hilly area and recharges groundwater in the flat area. The main sources of groundwater in the alluvial plain are precipitation and lake water, which account for 45.25% and 54.75%, respectively, of the total recharge. This study provides a reliable scientific basis for quality evaluation, pollution prevention and remediation of the water resources in the alluvial plain (Anqing section) of the lower Yangtze River basin.