瞬时单位线的优化估计

瞬时单位线集中反映了流域的汇流特性，便于流域暴雨洪水关系的理论研究和地区综合，在流域防洪兴利工程计算领域具有重要意义。目前常用矩法估计瞬时单位线，据此还原的洪水过程与实测洪水过程之间，特别是洪峰点之间，常具有明显的差别，为此，提出通过用加速遗传算法求解还原洪水过程与同次实测洪水过程加权残差绝对值和最小化问题，来优化估计瞬时单位线的一套数值方法，实测研究的结果表明了该方法的有效性，计算精度高于矩法。

Optimal estimation of instantaneous unit hydrograph

Instantaneous unit hydrograph reflects the main conflux characteristics of drainage basin, favors the theoretic research and regional synthetic analysis of the relation of watershed rainstorm and flood, and occupies a very important station during computations of water resources engineering. The difference is obvious between the computed flood hydrograph according to the traditional method and observed flood hydrograph, especially flood peak. For this reason, a new method of optimal estimation of instantaneous unit hydrograph is presented in this paper, that is equivalent to resloving the problem of minimizing the summation of the weight absolute errors between the computed flood hydrograph and observed flood hydrograph by using the accelerating genetic algorithm developed by the authors. The case study shows that the new method is more efficient with higher computation precision than the traditional methods.