Study on encounter rules of floods from Hanjiang River and upper Yangtze River

In the Yangtze River,the encounter of floods from its main stream and branches easily forms big flood.To optimize the operation scheme of TGP and make the best use of its huge flood-control capacity,the encounter rules of floods of different magnitudes from Hanjiang River and upper Yangtze River are studied by the means of hydrological method,from the aspects of encounter frequency,encounter time,encounter magnitude and peak discharge,flood volume.Mid-small flood from upper Yangtze River and Hanjiang River encounters frequently,mainly in July,August and September.The magnitude of flood peak,the maximum flood process of 7 d and 15 d have no obvious corresponding relation,and flood process overlaps greatly when floods encounter.