白鹤滩水库运行期非一致性设计洪水估算

Non-Stationary Design Flood Estimation in the Baihetan Reservoir Operation Period

摘要: 水库建设运行改变了下游河流的水文情势，导致水文资料系列无法满足洪水频率分析的一致性假定要求。本文基于GAMLSS模型构，建以水库系数作为协变量的时变P-III型分布模型，分别采用极大似然法和Q-Q图适线法，估计时变P-III型分布模型参数，推求白鹤滩水库运行期设计洪水。结果表明：Q-Q图适线法的拟合效果要优于极大似然法，与原设计值相比白鹤滩水库运行期1000年一遇设计洪峰，3 d、7 d、15 d和30 d洪量，分别削减了26.2%、25.1%、23.8%、22.7%和24.4%。

Abstract: The construction and operation of the reservoir changed the hydrological regime of the downstream river, resulting in the hydrological data series unable to meet the requirements of the consistency assumption of flood frequency analysis. Based on the GAMLSS model, this paper built a time-varying P-III distribution model with reservoir coefficient as a covariable. Maximum likelihood method and Q-Q diagram fitting line method were used respectively to estimate the parameters of the time-varying P-III distribution model. The design flood of Baihetan reservoir during operation is deduced. The results show that the fitting effect of Q-Q map fitting line method is better than that of maximum likelihood method. Compared with the original design value, the design flood peak, 3 d, 7 d, 15 d and 30 d of Baihetan Reservoir during the oper-ation period of 1000 years are reduced by 26.2%, 25.1%, 23.8%, 22.7% and 24.4%, respectively.