The annual variation of the flooding mainly depends on the annual variation of the rainstorm. Because the annual rainfalls change a lot, the magnitudes of the flooding and annual variation in the northeast rivers also change a lot, and the rangeability is greater than the rivers in the southeast of China.
Besides, the annual variation of flooding also related to the size of the river. If the drainage basin is large so that there are a lot of opportunities for storms, the annual change will tend to uniform. Even under the same condition of flooding, the bigger the river is, the more remarkable the effect of regulating-storing function is, so the less of the rate of flooding is. Therefore, generally, the variation of the flooding is relatively small in big rivers.
The upper source of the West Liaohe Laoha River, the branch in the upper stream of the Liaohe East Liaohe, the main stream of Liaohe, the branches Qing River, Chai River, Fan River in the east side of Liaohe, Hun River, Taizi River, and Ling river, all of these are the rivers whose flooding variation are relatively large in northeasts, and varivation of IQ is between 100-400; the change of K2 is between 6-8; and the variation range of the Cv is between 1.2-1.4. Expecially in the Qing River, Chai River, Fan River, Ling River and the east Liaohe, they are in the high-variation area.
In the main stream of the Nen River, the middle and the down stream of the second Songhua River and the main stream of the Songhua River, the change range of the value of & is between 10-30; K2 is between 3-4.
The annual flooding variation of Tumen River, Yalu River, Mudan River and Tangwang River are relatively small. The change range of & is between 30 and 50; the variation range of K2 is about 4.
Besides, according to the analysis results from the water department of Heilongjiang province, the value of Cv in Muleng River, Suifen River, Naoli River, Woken River, Wuyuer River and Namoer River are between 1.8-2.5, and these rivers are located in the area where have the highest value of Cv.
The information is provided from Disaster Risk Reduction Knowledge Service.
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