滹沱河流域汛期气温、降雨及径流变化特征分析

分析汛期水文气象等要素的变化特征对认识流域水资源演变规律非常重要。选取滹沱河流域1958~2004年的水文气象数据,采用线性趋势回归检验法、滑动秩和法及Morlet小波分析法分别对汛期水文气象要素序列的趋势、突变及周期性进行分析,并基于Surfer 9软件分析了降雨变异前后空间分布的变化情况。结果表明,滹沱河流域汛期月平均气温呈升高趋势,而降雨及洪量则呈下降趋势;气温、降雨和洪量序列均存在突变现象,变异点大致出现在1980年前后;变异后流域平均降雨量明显减少,且变异前后降雨空间分布也存在明显差异,变异前降雨在流域空间上更为集中,更易形成洪水过程,变异后滹沱河流域洪涝灾害发生可能性有所降低。

Variation Characteristics Analysis of Air Temperature, Rainfall and Streamflow in Flood Season of Hutuohe Basin

Analyzing the variations of hydro meteorological elements in flood seasons is very important for understanding the evolution of watershed water resources. The hydro meteorological data of Hutuohe Basin from 1958 to 2004 was selected in this paper. The tendency, sudden change points and periodicity of hydro meteorological data series in flood seasons were identified based on linear trend regression test, sliding rank sum method and Morlet wavelet analysis. Meanwhile, the spatial patterns of precipitation before and after change points were examined by using software Surfer 9. The results show that the monthly average air temperature in flood season appears upward trend while precipitation and flood volume decrease; there have the abrupt changes in the air temperature, precipitation and flood volume series, and the change points approximately appeared in the year 1980; the spatial patterns of precipitation before and after change point were considerably changed with decreasing basin average rainfall; before 1980, the concentrated rainfall event resulted in large floods more easily; after 1980, therefore, the possibility of floods disaster in Hutuohe Basin may be reduced.