The study looked at where water in the Ordos Basin in China comes from and how it moves between surface water and groundwater. They used stable isotopes to track the water sources and connections in 11 river basins. They found that areas with thick layers of soil took longer for surface water and groundwater to connect, while areas with thin soil and human activities had better connections. Summer rain was a common source of water, and groundwater also fed into surface water. The thick soil caused more evaporation of groundwater, but human activities like mining and irrigation helped reduce this impact. Overall, the study gives new insights into managing water resources in areas with thick soil layers.