Analysis of characteristics of inflow and outflow runoff and sediment in Three Gorges Reservoir and its influential factors
The runoff and sediment condition of Three Gorges Reservoir has changed significantly in recent years due to the effects of climate changes and human activities. The Mann-Kendall method and wavelet transform method are applied to analyze the annual runoff and sediment discharge data of the main controlling hydrological stations in recent 60 years. The results show that the runoff has a slight decreasing trend, while the sediment decreases sharply. Both runoff and sediment series of the main stations have an obvious properties of multiple time scale, the dominant period of runoff and sediment are 12-year to 28-year and 15-year to 25-year respectively. The impact of runoff changes on the sediment changes is small, while the soil and water conservation measures, construction of hydraulic engineering projects on upstream and the sand mining are the main causes for the sediment reduction.
runoff and sediment characteristicstrend analysisperiodic lawsinfluential factorsThree Gorges Reservoir