气候突变对水库汛期分期及调度的影响

鉴于传统汛期分期方法较少考虑气候变化和极端天气等因素的问题,为更加科学合理地进行汛期分期,以张家庄水库为例,统计分析了研究区降水的时空分布特征,确定了研究区汛期为6～9月,并以1962～2008年介休市降水量(P)、平均气温(T)、日照时数(SD)等气象因子的年数据序列为指标,运用主成分分析法降维得到研究区气候评价综合指标,再采用Mann-Kendall法、滑动T检验法及Yamamoto法对比分析,检测到研究区气候突变年为1988年,以此突变年为分界点,采用PCA-Fisher最优分割法进行汛期分期,并分析了不同主汛期对水库调度的影响。结果表明,气候突变对汛期分期结果有一定影响,气候突变年后较整个时间序列得到的主汛期少11d,在水库调度过程中可有效改善水库下游水资源利用条件,缓解水库供水压力。

Influence of Abrupt Change of Climate on Division of Flood Season and Scheduling

Traditional flood season method is lack of the consideration of factors such as climate change and extreme weather, in order to get the more scientific and reasonable stage of flood season, the spatial and temporal distribution characteristics of precipitation in the Zhangjiazhuan reservoir were analyzed, and the period of June to September was determined as the flood season in this area. Taking the precipitation, average temperature and sunshine duration in the annual sequence of meteorological data in Jiexiu City during 1962 2008 as the indexes, the PCA method was used to get the comprehensive indicator for evaluation of climate in this area. Then Mann Kendall method, sliding T test and Yamamoto method were used to determine the climate sudden change year. As the climate sudden change year 1988 for the boundary point, the PCA Fisher method was adopted to divide the stage of flood season, and the impact of different major flood period on reservoir scheduling was analyzed. The results show that the climate change has a significant impact on the stage results of flood season. The major flood period after the climatic mutant year was shorter 11 d than that of the whole time series. Thus, it can effectively improve the water resources utilization in the lower reaches of reservoir and relieve water supply during reservoir operation.