三江平原地表水与地下水氢氧同位素和水化学特征

Hydrogen and Oxygen Isotopic and Hydrochemical Characteristics of Water in Sanjiang Plain

地表水与地下水的相互作用是水循环研究中的重要组成部分,是水资源管理、规划和优化配置的基础。通过野外考察取样和室内测试分析,应用同位素和水化学方法分析了三江平原地表水与地下水的相互作用关系。结果表明:兴凯湖水氢氧同位素最富集,乌苏镇井水同位素最贫化。松花江、黑龙江和乌苏里江沿河流流向,δD都呈现贫化的趋势;δ18O在松花江和黑龙江沿河流流向有富集的趋势,而沿乌苏里江则呈现贫化趋势。在松花江和黑龙江汇合处,黑龙江江水同位素贫化,电导率低。深井的氢氧同位素比浅井贫化,电导率较小。三江平原当地大气降水线(LMWL)为δD=7.4δ18O-3.1。三江平原水化学主要是Ca·Mg-HCO3型,在人类活动较大的地方,水化学类型发生了改变。利用氢氧同位素和水化学分析表明降水是地表水和地下水的补给源,地表水与地下水水力联系较强。地表水与地下水应作为统一体进行水资源管理。

The interaction between surface water and groundwater is not only an important part of the water cycle, but also the foundation of the water assessment and management. The hydraulic connection between surface water and groundwater is strong because of the local climate, geology and topography. The water samples collected from rivers, wells and the Xingkaihu Lake were measured for hydrogen and oxygen isotopes and major cations and anions. The 8D values of the three rivers were depleted along the fiver flow. The stable isotopes of Heilongjiang River were depleted. The lake water stable isotopes were enriched by the evaporation. The stable isotopes of deep wells were depleted than the shallow wells. The precipitation isotopes data of the Sanjiang station of Chinese Network of Isotopes in Precipitation （CHNIP） was used. The local meteoric water line was 8D=7.481sO-3.1. The water type of rivers and wells was Ca＇Mg-HCO3. Human activities effected the water quality and changed the water type in the village. The 8~sO was used to divide the runoff percent. The runoff percent of the Songhuajing River and Heilongjiang River was 1：4. The hydrogen and oxygen isotopes and hydrochemical data indicated that the water hydraulic connection among rivers, shallow wells, deep wells and lake was strong. The water management should combine the surface water and groundwater as a single water resource.