全球气候变暖背景下陕甘宁地区风速时空变化特征

Wind Speed Change Characteristics of Shaanxi-Gansu-Ningxia Area in 1960-2014

风速是影响沙尘天气最重要因素,认识温度对风速的影响有助于环境保护实践。运用Mann-Kendall突变检验法、线性趋势法、Spearman秩相关分析对陕甘宁地区1960—2014年风速和气温日平均值数据进行年尺度及季尺度时空变化特征分析。结果表明:(1)陕甘宁地区气温呈上升趋势,冬季气温上升最快,年平均气温在1994年发生突变。(2)陕甘宁地区年平均风速呈显著下降趋势(P<0.01),且以0.07 m·s^(-1)·(10a)^(-1)的速率下降,春季下降速度最快,气温突变后下降趋势更明显。(3)从空间尺度上看,年平均风速呈现以环县、延安、西吉、河曲为中心向四周逐渐增加的趋势,且区域平均风速呈整体下降趋势。四季平均风速在气温突变后以陕甘宁中部地区为减少中心。(4)气候变化背景下陕甘宁地区风速变化与气温存在负相关关系。

Wind is one of the most important factors that influence the sand and dust weather. So under- standing the impact of wind speed change caused by global warming can play a guiding role in environmental protection. In this paper, the wind speed, air temperature daily data of Shaanxi-Gansu-Ningxia area in 1960 -2014 were analyzed with Mann-Kendall method, linear regression method and Spearman correlation analy- sis method. The following conclusions are drawn： （1） The air temperature in Shaanxi-Gansu-Ningxia area showed an upward trend. The winter air temperature increased most quickly, and a abrupt change occurred in 1994. （2） In recent 55 years, the annual average wind speed rate showed a downward trend with 0.07 m · s-1 · （ 10a）-1 in Shaanxi-Gansu-Ningxia area. The wind speed decreased more obvious after the temperature abrupt change. The average wind speed in spring declined the fastest, followed by the winter, the slowest in summer and autumn; （3） The wind speed gradually increased from the center of Huanxian, Yan＇an, Xiji, Hequ; and the regional average wind speed had an overall downward trend. After the temperature abrupt change, the wind speed decreased in middle Shaanxi-Gansu-Ningxia area. （4） Under the background of cli- mate change, there is a negative correlation between air temperature and wind speed.