In each optimization design iteration, sensitivity filtration is carried out after objective function sensitivity is obtained bycalculation.
每次优化设计迭代中，计算得到目标函数灵敏度后进行灵敏度过滤。
2
By conservation equation, results will be get by iterative calculation, after each iteration, the parameters will be amendment.
通过守恒方程进行迭代计算，并对参数进行修正，最终得到满意结果。
3
The influential factors of calculation error for groundwater table are discussed by using the iteration method to find solution of numerical model in the mine drainage forecast of deep drawdown.