抽水井单位涌水量的多解性及其应用

Multiple solutions of specific capacity for pumping wells and their application

单位涌水量(q)是水文地质勘察领域的含水层富水性评价参数,在抽水试验中常被用来计算渗透系数。但是,单位涌水量的合理内涵一直存在争议。本文从理论上分析了单位涌水量在动力学上的多解性,给出了几种常见的水文地质条件和抽水条件下单位涌水量的解析公式。讨论了抽水试验中"影响半径"的实际含义。以阿拉善雅布赖山地区的抽水试验为例,提出利用不同流量抽水得到的1/q与Q关系曲线判断抽水试验状态的方法,根据曲线特征以及涌水量公式确定了含水层渗透系数的合理取值范围。单位涌水量并不是与导水系数等效的参数,其实际意义需要根据水文地质条件和抽水条件来判断。

Specific capacity （q） is used to evaluate yield capacity of aquifers in hydrogeological survey and to estimate hydraulic conductivity of aquifer in pumping test. However, what is the real meaning of specific capacity is still a problem with different argues. Based on theoretically analysis on the dynamic behavior, multiple analytical solutions of specific capacity are developed for several possible hydrogeological conditions and pumping conditions. The real meaning of ＂influence radius＂ is discussed. In a case study of pumping testes in the Yabulai Mountain area, in Alxa Plateau, China, it is proposed to determine the type of the aquifer-well system with data curves of 1/q versus Q for different stages of pumping with different flow rates. The reasonable ranges of hydraulic conductivity for the aquifers involved are determined according to the solutions of specific capacity and the characteristics of 1/q-Q curves. Specific capacity is not an equivalent parameter of transmissivity but its real meaning lies on both of the realistic hydrogeologieai situation and pumping conditions.