共轭梯度法在新井参数设计中的应用

通常情况下,含水层的参数可分别借助于Dupuit和Theis井流公式,在局部地段利用稳定流和非稳定流抽水试验获得.在新井设计阶段,一般是依据现有参照井数据进行线性或非线性插值计算,但插值受插值表的约束,效率不高.本次研究采用2次优化方法,用网格法确定所求参数最优估计值作为下一步的叠代初值.用共轭梯度法逐步逼近所求参数的精确解,高效地利用参照井的基本数据得到了精度较高的新井参数,为准确地设计新井提供可靠的依据,实地应用效果良好.

THE APPLICATION OF CONJUGATE GRADIENT IN THE CALCULATION OF NEW WELL HYDROGEOLOGICAL PARAMETERS

As we known, hydrogeological parameters play an important role in estimating the water balance in a new well field and building ground water flow model. We often calculate hydrogeological parameters according to formulas of Dupuit and Theis or by the results of pumping test. We usually get new well parameters by method of interpolation. In order to utilize pumping test data of reference wells efficiently, we tries to make full use of GIS and the theory of optimization, known as grid method and Conjugate Gradient in the calculation of new well hydrogeological parameters. The paper concerns the optimum value of net-grid as primary value of Conjugate Gradient, this method not only ensure direction of gradient convergence,but also improve the speed of convergence and parameters?precision. The new method shows its advantages in higher precision and efficiency.