气候变暖背景下陕甘宁蒙接壤区1961-2015年降水变化响应特征

Response Characteristics of Precipitation Change in Contiguous Areas of Shaanxi,Gansu,Ningxia and Inner Mongolia Under Global Warming From 1961 to 2015

[目的]探讨全球变暖背景下陕甘宁蒙接壤区降水量的变化响应特征,为该区自然生态系统和社会经济系统可持续发展提供科学理论依据。[方法]利用陕甘宁蒙接壤区40个气象站点1961—2015年降水量数据资料,采用趋势线拟合,线性倾向估计,普通Kriging插值等数理分析方法,对陕甘宁蒙接壤区54a的降水量时空变化特征进行分析。[结果](1)随着全球变暖,陕甘宁蒙接壤区在54a间降水量总体略微减少,但近十几年降水量呈现明显上升趋势;(2)该区年均降水量空间变化大致是沿东南—西北方向呈现由多到少的过渡,年均降水量倾向率空间变化则大致沿东南—西北方向呈现由减少到增加逐步过渡;(3)54a间四季降水距平变化趋势为春、夏、冬3季的降水量呈增加趋势,秋季降水量呈减少趋势,变化速率为:夏季>冬季>春季>秋季。四季降水量的空间差异明显,大致都沿东南—西北方向呈现由多到少的逐步过渡趋势。[结论]全球变暖下陕甘宁蒙接壤区54a来降水量总体略微减少的趋势表明该区域气候具暖干化发展趋势,且季节差异显著。但就2000年以来该区的降水量又呈现明显增加趋势来看,是否该区气候具有由暖干向暖湿转型的大趋势,还需深入研究。

[Objective]To explore the response characteristics of precipitation change in the Shaanxi,Gansu,Ningxia and Inner Mongolia bordering area under global warming in order to provide scientific theoretical basis for the sustainable development of natural ecosystem and social economy in this area.[Methods]Precipitation data was collected from 40 national meteorological stations during the period from 1961 to 2015.The spatial-temporal variation of precipitation in the past 54 years was analyzed,using linear trend estimation,Mann-Kendall mutation test and ordinary Kriging interpolation mathematical analysis methods.[Results]（1） With the global warming,the precipitation decreased in the study areas during the past 54 years.（2） Spatially,the annual precipitation reduced roughly from the southeast to northwest,and the tendency rate showed a decreasing trend initially and then increased from the southeast to northwest.（3） The changes in precipitation anomaly showed that the precipitation increased in spring,summer and winter,but reduced in autumn,and the rate of precipitation change ranked as：winter〉spring〉autumn〉summer.The spatial differences ofprecipitation in four different seasons were obvious,which reduced gradually from the southeast to northwest.[Conclusion]A warm-drying trend is expected in the Northern Shaanxi,Gansu,Ningxia and Inner Mongolia contiguous area,and it is obvious in four different seaons.Further studies are needed to confirm whether the climate will transferred from the warm-dry to warm-wet since the precipitation in the region has shown an obvious increasing trend since 2000.