The study looked at the isotopes in rainwater over the Jiaolai Plain to understand where the water comes from. They found that rain in the area is affected by evaporation before it falls. The East Asian Monsoon brings most of the rain in summer, while Westerlies bring it in winter. Typhoon Lekima also brings heavy rain, changing the isotopes in the water. This information helps us understand how rainwater moves through the environment.