Page - 243 - in Book of Full Papers - Symposium Hydro Engineering

The original dispatching rule of the TGP reservoir is designed with the demand in flood control, power generation, shipping, water replenishment etc., based on the historical precipitation characteristics and conditions of water and sediment in the basin. T The design scheduling methods in these periods are as follows: (1) Dispatching rule in flood season The reservoir is operated at the flood control limit level of 145m during the flood season. In the premise of ensuring dam safety, the flood control compensation in the TGP reservoir improves the flood resistance standard of Jingjiang dike. (2) Dispatching rule in storage period The reservoir stores water in the storage period, during which the minimum discharge is not lower than the corresponding flow for smooth downstream shipping, the water level will gradually increase to normal level till the end of October. (3) Dispatching rule in falling period The TGP reservoir gradually drops the water level and carries out water supply, drought resistance, shipping and ecological water replenishment for the downstream in falling period. The outflow in the falling period is not less than the guaranteed power output and the corresponding flow of lowest water level for navigable in the downstream. The water level is gradually dropped to limit water level to make preparation for flood season. 3. CLIMATE CHANGE IN THE UPPER REACHES OF YANGTZE RIVER The mainly influence of climate change on human life is the change of rainfall and temperature. This paper analyzes the climate change in the upper reaches of Yangtze River according to the change of precipitation and temperature, based on 1963~2017 annual climate data. (1) Precipitation The annual average precipitation in the basin has been decreasing since 60s. It was more than average value before 80s and less than average after that, and the drop rate is about 17.4mm/10a. As to the annual distribution, it shows that the rainfall has a decreasing trend in spring, autumn and winter, while the precipitation in summer is increasing due to the strong rainfall. (2) Days and intensity of rainfall The average annual precipitation days (rainfall more than 0.1mm as a rainy day) in the upper reaches of Yangtze River ranged from 132 to 171 days, showing a decline trend with a rate of 2.9d/10a(α=0.001). However, it shows that the average daily precipitation intensity is increasing, which increases the probability of flood. (3) Days and intensity of rainstorm The average annual rainstorm days (rainfall more than 50mm as a rainstorm day) ranged from 13 to 30 days, showing a slight upward trend. Also, the rainstorm intensity is increasing. The average intensity of rainstorm is greater than the annual value after 80s, and mainly concentrated in the flood season, increasing the probability of rainstorm. (4) Temperature The annual average temperature in the Yangtze River basin is on the rise, with an average increase of about 0.14℃ every 10 years. The upward trend in the northwest 243