近60a黄河流域地表径流变化特征及其与气候变化的关系

利用气温、降水量和NCEP/NCAR地表径流资料,运用线性趋势系数、相关系数和不规则区域网格化方法,研究了近60a来黄河流域地表径流的变化及其与气候因素的相关关系。结果表明:1951-2010年整个黄河流域均为升温趋势,北部升温幅度高于南部;降水量正趋势主要位于黄河源区,中、下游地区为负趋势;地表径流变化在黄河源区(处于青藏高原)和河套北部(阴山南麓)呈现为增加趋势,其余广大的地区呈现为减少趋势;从不同年代的地表径流来看,不论是黄河源区还是广大的中、下游地区,上世纪60年代的径流量均是最高的,而二十一世纪10年代径流量是最低的;从整个流域来看,径流量与气温和降水均有较好的相关性。在黄河源区以外的流域内,降水与径流的关系好于气温,而在黄河源区则相反,不同区域差异的原因有待进一步研究。

The spatial and temporal structure of runoff variation and the climate background in the Yellow River basin during the past 60 years

On the basis of NCEP/NCAR reanalyzed 2.5°×2.5° monthly mean runoff data and monthly climate data(temperature and rainfall) of 160 stations in China from National Climate Centre for period of 1951-2010,the spatial patterns and temporal variation of runoff in the Yellow River basin,and the relationships between temperature,rainfall and runoff were investigated by use of trend coefficient,correlation coefficient and irregular domain gridding.Results showed that the temperature presented a warming trend,and the value in northern part was higher than southern part.Rainfall in the source region showed an increasing trend while a falling trend in the extensive middle and lower reaches.The spatial pattern of runoff variability was similar with the rainfall,and the highest value appearred in 1960s while the lowest in 2010s.From a whole perspective,the negative correlation relationship between temperature and runoff was significant while the positive correlation relationship between rainfall and runoff was relatively insignificant.