Research on flood composition and encounter of main streams and tributaries in upper Yangtze River

Through studying the laws of flood composition and encounter of upper Yangtze River,a theoretical basis for developing regulation scheme of the controlling projects(such as TGP) on Yangtze River can be provided.According to the measured data of the representative stations,such as annual maximum flood and its occurrence time,considering the propagation time of the flood,the possibilities of flood encounter of Jinsha River and Minjiang River,Yangtze River and Jialing River,Yangtze River and Wujiang River,are analyzed year by year,so is the probabilities and magnitudes of the encountered floods.The results show that the probabilities of flood encounter of Yangtze River and Minjiang River,Yangtze River and Jialing River are relatively high,and magnitudes of encounter floods are generally small,except individual years.The probability of flood encounter of Yangtze River and Wujiang Rive is low and all encountered floods are small or medium-sized.The probability of flood encounter of all tributaries and main streams in upstream of the Yangtze River at the same time is very low.