Isotopic characteristics of water within the soil-vegetation-atmosphere system in the Yushenfu mining area

Analyzed the isotopic characteristics of water within the soil-vegetation-atmosphere system in the Yushenfu mining area, and determined the source of water found in typical local plants using stable isotope fractionation techniques and principles. The purpose of the study is to determine if groundwater is used by plants and to provide scientific foundations about water sources essential for vegetation recovery and sustainable development. The results show that there is a significant negative correlation between δD(deuterium), δ18O(oxygen-18) and precipitation, indicating that stable isotopes of hydrogen and oxygen are greatly affected by rainfall in the Yushenfu mining area. Compared to the Global Meteoric Water Line (GMWL), the slope and intercept values of the summer Local Meteoric Water Line (LMWL, δD=7.0δ18O-0.72) are smaller, which indicates that the hydrogen and oxygen isotopic characteristics of precipitation are not well represented by GMWL. The δD values in the xylems of typical plants (-72.49‰~-78.72‰) are close to those in soil water (-68.15‰~-78.00‰) and groundwater (-64.18‰~-67.14‰) and are significantly different from those in precipitation (10.78‰~-94.30‰), reservoirs (-48.945‰) and lakes (-2.65‰), indicating that the main water sources of plants could be soil and groundwater. High rainfall with lower δD values is a major source of groundwater, while low rainfall with higher δD values does not affect the δD values of groundwater.