已有的地下水动力学专著和文献,通常用积分变换、分离变量等数学物理的方法来求解地下水径向非稳定运动问题,最终得到用特殊函数表的精确计算公式。无疑这是有理论和实际意义的。但是由于求解的数学方法艰深和计算公式复杂,不易为广大水文地质工作者所掌握,而且在现场使用也不方便。如果能够用简单的数学方法求其近似解并且得到用普通函数如 Existing groundwater hydrodynamics monographs and literature usually solve the problem of unsteady groundwater radial instability by means of mathematical physics such as integral transformation and separation of variables, and finally get the precise calculation formula of special function table. There is no doubt that this is of theoretical and practical significance. However, due to the mathematical method of solving difficult and complicated calculation formula, not easy to grasp for the majority of hydrogeological workers, but also in the field is not convenient to use. If we can use simple mathematical method to find its approximate solution and get using ordinary functions such as