黄河洪水的分期调度与分级调度

根据洪水发生的特点，可以在时间上将其分为前、后期洪水，在量级上将其分为大洪水和中常洪水。在防洪调度中应针对洪水发生的不同特点采用不同的调度方式。通过分期洪水调度，在保证防洪安全的前提下，可以合理处理防洪与水资源的矛盾，使洪水资源化，充分发挥水库的灌溉、供水、发电等综合效益；通过分级洪水调度，可以更加合理地进行防洪工程的优化调度，实现各级洪水调度的相对合理化，减少洪灾损失。

The Yellow River Flood Regulation by Stages and Levels

According to the characteristics of floods occurred in the Yellow River, it could be divided into a flood of earlier stage and later stage in time and a major flood and a dominant flood in quantity. According to the characteristics of floods, it should adopt different mode of regulation during the regulation of flood control. Under the conditions of the safety of flood control, flood regulation by stages can rationally solve the contradiction between floods and water resources, taking floods as water resources and making more rationally the comprehensive benefits of irrigation, water supply and power generation of reservoirs. Flood regulation by levels can make more optimized regulation of engineering works for flood control, realizing relative rationalization of flood regulation at each level and reducing inundation losses.