关键词: 银川平原, 氢、氧同位素, 水化学, 黄河水, 17O盈余

Abstract: Hydrochemical technology and environmental isotopes were used to analyze the hydrogen, oxygen isotopic and hydrochemical characteristics of water in Yinchuan Plain. The research showed that the δD and δ¹⁸O values distribute below the local meteoric water line(LMWL) and δD-δ¹⁸O relationship line of the water in Yellow River. Compared with other surface water, the isotopic composition of lake water was more positive and the d-excess (negative) was far lower than the Global meteoric water line (GMWL) due to strong evaporation. According to the isotopic characteristics, the surface water and groundwater accepted the recharge of the Yellow River. The consistent isotopic composition among the river water, canal water, groundwater indicated that the hydraulic connection between surface water and groundwater was very close. The correlation between δ¹⁷O and δ¹⁸O follows an equation of ln(δ¹⁷O+1)=0.524ln(δ¹⁸O+1)+0.00094, which was similar to the global meteoric water line(ln(δ¹⁷O+1)=0.528ln(δ¹⁸O+1)+0.00033), but the ¹⁷O-excess was larger than seawater. The water bodies of Yinchuan are alkaline. The conductivity of lake water was maximum, the groundwater was medial and the river water is minimum. The water chemical types of water mainly included HCO₃^-Na、HCO₃^-Ca·Mg. The chief cation and anion are Na⁺, HCO₃^- , respectively. The Gibbs plot revealed that the chemical compositions of the water samples were mainly affected by rock weathering and evaporative. The hydrogen and oxygen isotopes and hydrochemical data indicated that the water hydraulic connection between surface water and groundwater was strong. The water management should combine the surface water and groundwater as a complex water resource.

Key words: Yinchuan Plain, hydrogen and oxygen isotope, hydrochemistry, Yellow River water, ¹⁷O-excess