The study looked at water samples in Jiyuan Basin to understand how surface water and groundwater are connected. They used chemicals and isotopes to trace the water sources. The main type of water in the area is influenced by rock weathering. Rainfall is the main source of water, with some evaporation happening after. Shallow groundwater and rivers get water from rain, while deep groundwater comes from higher mountain areas. Evaporation is stronger in shallow groundwater and rivers compared to deep groundwater.