用同位素测井技术确定地下水侧向补给量

Determination of lateral groundwater recharge using single well techniques of a radioactive isotope

采用达西公式计算孔隙地下水系统的侧向补给量有较大的不确定性,当水力梯度不能准确确定时尤为突出。本文在采用单孔放射性同位素(1 31 I)测井技术测定地下水渗透流速、流向的基础上,用流速断面法计算地下水侧向补给量。应用FDC—2 5 0A型地下水参数测试仪测得鹿泉—灵寿断面含水层渗透流速为0 11～1 16m d。根据10个井的测流数据计算得到鹿泉—灵寿46 2km断面的侧向补给量为5 0 73 19万m3 a。结果表明,同位素流速测井技术可以较好地确定山前地下水侧向补给量,并可提供流速、流向、含水层分布等信息。

There is an uncertainty in estimation of lateral groundwater recharge by using Darcy's law, especially when the hydraulic gradients are not determined accurately. In this paper the lateral groundwater recharge through a cross-section is determined on the basis of the seepage velocity (Darcian velocity) and the flow direction which is measured with single well techniques of the radioactive isotope (SWTRI) 131 I. The seepage velocity through the cross-section from Luquan to Lingshou measured by the groundwater parameter FDC-250A is in the range of 0.11～1.16m/d. The total recharge through the 46.2km long cross-section is 50.731*!9 ×10 4m 3/a from the measurements of 10 available wells. The research results indicate that the SWTRI can be used to determine lateral groundwater recharge and to provide information on the Darcian velocity, flow direction and aquifer occurrence.