Secondly,the profitable frequency of wetness-dryness encountering to supply water to Yellow River is 20.9%,it shows that it is possible to supply water to Yellow River in the middle route project.

• 向黄河补水较为有利的丰枯遭遇频率达20.；9%25；这说明中线工程向黄河河道相机补水是可能的