青藏高原大通河流域气候干湿状况时空分布研究

Research on temporal and spatial distribution of climate dry-wet status in Datong river basin

利用气候倾向率法、反距离加权插值、Mann-Kendall法、小波分析等对大通河干燥指数演变特性进行了分析,以期为流域农业发展布局、生态环境保护以及梯级水电站调度运行提供科学依据。结果表明:大通河流域地表有不显著变湿趋势,干燥指数减小率0.05/10a,但这种湿化表现为反持续性;流域气候空间上为南干北湿,东干西湿,干湿状况在流域上呈现出比较明显的带状交替格局;流域四季与全年一样表现出变湿趋势,其中以春季和冬季湿化较为明显,干燥指数减小率分别0.049/10a、3.79/10a,但只有冬季通过显著性检验,且冬季湿化趋势具有反持续性;季干燥指数空间分布不均,表明流域季节气候干湿变化存在着明显的地域差异性;干湿周期分析显示,流域存在7、17及29a的周期,春季存在4、13和28a的周期,夏季存在8、17及30a的周期,秋季周期对应5、17及26a;冬季气候对应5、9及29a的周期。

The paper used climatic trend rate,inverse distance weighted,and Mann-Kendall and wavelet analysis method to analyze the evolution of dry index so as to provide scientific basis for the agricultural development,protection of ecological environment and dispatch operation of cascade hydropower in Datong River basin. The results showed that: there is unremarkable trend of becoming humid in surface of the basin,the annual aridity index is decreased by 0. 05 per ten years with,but there is anti-persistence.The climate of the basin is dry in south and wet in north,and dry in east and wet in west on spatial distribution. The status of dry and wet presents more clear pattern of banded alternation; the climate of four seasons also shows the tendency of wet. The humidified trend is more obvious in spring and winter. The aridity indexes in spring and winter are decreased by 0. 049 and 3. 79 per ten years respectively. However,only the trend in winter passed significant test,and the wet trend has anti-durative. The temporal distribution of season dry index is uneven. There is obvious regional differences in the dry and wet change of season climate; the periods of annual aridity index are 7,17 and 29 years; the cycles of aridity index in spring are 4,13 and 28 years,and that in summer are 8,17 and 30 years,that in. autumn are 5,17 and 26 years while that in winter are 5,9 and 29 years.