近50a来黄河源区降水、气温及径流变化分析

Analysis of Change of Precipitation,Temperature and Streamflow in Source Region of the Yellow River in Recent 50 Years

基于1961—2010年气象、径流资料,采用M-K趋势检验法分析了黄河源区近50 a来降水量、气温和径流量的变化规律及三者间的内在关系,探讨了气温、降水量对黄河源区径流量季节性变化的影响。结果显示,近50 a来黄河源区降水量、气温变化具有明显的时空差异;黄河源区春季降水量显著增加,年降水量呈微弱减小趋势但不显著,东南部高值区降水量呈下降趋势而西北部低值区的降水量呈增加趋势;各季节均显著升温,东南部气温高值区的升温幅度要低于西北部气温低值区的;近50 a来黄河源区径流量呈显著下降趋势,其夏季径流量主要受夏季季风降水量的影响,而春季径流主要受春季降雨/降雪和上一年冬季降雪的影响。

The changing characteristics of temperature,precipitation and discharge in the source region of the Yellow River were analyzed by using hydrological and meteorological data from 1961 to 2010 based on the Mann Kendall trend test. Based on this,this paper also analyzed the inner relationship between runoff,precipitation,and temperature,and further discussed the effect of meteorological change on the stream flow in the source region of the Yellow River. The results indicate that there is a large temporal and spatial variation for temperature and pre cipitation change. The annual precipitation has a minor decreasing trend,but not dramatically,with a significant increasing trend for spring precipitation. The mean seasonal temperature shows a significant increasing trend. In southeast of the source region of the Yellow River,with wetter and warmer climate,precipitation/temperature have a decreasing/smaller amplitude trend,which is opposite to that of the northwest of the source region of the Yellow River,belong to drier and cooler climate. The discharge of the studied basin shows a significant decreasing trend in the past 50 years. Summer runoff is affected by monsoon rainfall and spring streamflow is influenced by winter snow accumulation and spring melt process or rainfall.