基于原位试验场的融雪水补给地下水过程研究

A Study of Snowmelt Recharging to Groundwater based on in-situ Field Tests

基于原位试验场地,本研究通过对土壤含水率、温度和地下水位、温度、电导率的测量,分析了2017年2月~5月长春市融雪水补给地下水过程,并运用氢氧稳定同位素技术对补给过程进行证明。结果表明,当地大气降水线为δD=7.53δ18O-3.41(R2=0.76)。在δD-δ18O关系图中,地下水各水样点主要分布在当地大气降水线附近,说明地下水主要受融雪水补给。融雪水对地下水的主要补给时间为气温保持在0℃左右的20余天内,地下水位上升幅度能达到0.6 m。在此阶段,地下水位与地下水温度和电导率具有显著相关性,相关系数均在0.9以上。之后由于春季工农业用水增加,水位开始下降。在整个过程中,融雪水对地下水的贡献率为20.1%。黄土地层的田间持水率约为39%。

Based on in-situ field tests,soil water content,soil temperature,and temperature,level and electrical conductivity of groundwater were measured systematically to analyze the recharging process of snowmelt to groundwater during the period of from February to May 2017 in Changchun.The hydrogen oxygen stable isotope technology was applied in describing recharging processes.The results showed that the local meteoric water line wasδD=7.53δ18 O-3.41(R2=0.76).In the diagram ofδD vsδ18 O,the samples of the groundwater distributed mainly near the local meteoric water line,showing that groundwater was recharged mainly by snowmelt.The main recharging time of snowmelt was the twenty days of ambient temperature around 0℃,during this period,the groundwater level rise about 0.6 m and correlated significantly(both correlation coefficients>0.9)with temperature and conductivity of groundwater.In spring,the groundwater level began to decline as the result of industrial and agricultural water usages increasing.In the whole process,recharging contributions of snowmelt and water content in the loess stratum to the groundwater level were about 20.1%and 39%,respectively.