为能同时分析含水层具有直线隔水边界条件下,抽水试验中抽水一恢复阶段降深数据,提出了一种新的数据分析方法。在建立这种方法时,将表示抽水和恢复阶段水头降深表达式中Theis井函数的级数表达式的前3项作为其近似表达式,经过推导,分别得到抽水和恢复2个阶段的直线方程。2个直线方程的因变量和自变量均为观测数据的函数,而直线常数为待求参数的函数,在进行数据分析时,只要将试验观测数据分别转化为直线方程的因变量和自变量数据,就能够利用一元线性回归法分别计算2个直线方程的常数,而利用直线常数的表达式,能够推导得到计算含水层参数和映射井到观测孔间距离的公式。通过算例说明了方法的具体应用步骤。
In order to determine aquifer parameters and the distance between observation well and imaginary well from the observed drawdown data of both pumping and recovery stage of the test conducted in the aquifer with linear impermeable boundary, a new method is proposed. For deriving the useful formula, the first three terms in expansion series of the Theis' well functions for describing the changes of two stages of pumping and recovery are taken as simplified expresses of the well function respectively. With some suitable transformation, two linear equations for two stages are established, and the constants in these two equations are composed of the parameters to be estimated, and the independent variables and dependent variables of these two linear equations are all the function of the observed data in test. Hence, as soon as the test data are transformed into the data of independent variables and dependent variables in these two linear equations, the linear constants may be calculated by the method of linear regression method, and, then according to values of linear constants, the aquifer parameters and the distance between observation well and imaginary well can be estimated.Finally, an example is given to show in detail the application procedure of the proposed method.