辽西北地区近60 a气候变化趋势及空间分异特征

Climate Change Trend and Spatial Differentiation Characteristics for Northwest Liaoningin in Recent 60 Years

了解辽西北半干旱生态脆弱区的气候变化规律,对科学指导农业生产具有重要意义。基于1961—2020年辽西北地区23个气象站点的数据,利用Theil-SenMedian斜率估算、Mann-Kendall趋势分析及突变检验,在辽西北区域尺度,探讨1961—2020年的气温、降水量、风速、日照时间、潜在蒸散量、湿润指数、相对湿度、大气压等要素的变化趋势,在辽西北地区行政区的局域尺度上,探讨不同气象要素的空间分异特征。结果表明:辽西北地区年均气温以0.027℃·a^(-1)倾向率呈显著增加(p<0.01),降水量以0.686 mm·a^(-1)倾向率下降。风速、气压、日照时间呈显著下降(p<0.01),但潜在蒸散量、湿润指数的下降趋势及相对湿度的增加趋势均不显著。春季、冬季的增温倾向率(0.040、0.039℃·a^(-1)),明显高于夏季、秋季的增温倾向率(0.016、0.018℃·a^(-1))。夏季降水、日照时间倾向率降幅分别达到-0.949 mm·a^(-1)、-1.814 h·a^(-1)。辽西北地区气候变化呈现出,中部局域强暖干化趋势明显,而东北、西南局域暖干化趋势逐渐减弱的空间分异特征。日照时间下降倾向率呈现出由东北向西南逐渐递减的空间格局,其极显著下降趋势会给昌图、康平、彰武、阜蒙、朝阳等生态脆弱区的农业生产具有更大的负面影响。

With the daily data of 23 meteorological stations in northwest Liaoning from 1961 to 2020,by using Theil-Sen Median slope estimation and Mann-Kendall trend analysis and mutation test,we discussed the trend slope of temperature,precipitation,velocity,sunshine hour,potential evapotranspiration,humid index,humidity and air pressure at the regional scale of northwest Liaoning,and also discussed the spatial differentiation characteristics of different meteorological elements at the local scale of the administrative region in northwest Liaoning.The results showed that average annual temperature increased significantly with 0.027℃·a^(-1) slope(p<0.01),while precipitation changed in multiple years and then showed insignificantly decreased by-0.686 mm·a^(-1) slope(p>0.05).Velocity,sunshine hour and air pressure all decreased significantly(p<0.01),but the downward slope of evapotranspiration and humid index and the upward slope of relative humidity all were not significant(p>0.05).The increasing slope for temperature in spring and winter were 0.040 and 0.039℃·a^(-1),which is obviously higher than that 0.026 and 0.018℃·a^(-1) in summer and autumn.The decreasing tendency slope for precipitation and sunshine hour was the highest in summer,reaching-0.949 mm·a^(-1) and-1.814 h·a^(-1),respectively.The climate change in northwestern Liaoning shows the spatial differentiation characteristics of strong warm-drying in central part and weak warm-drying in northeastern and southwestern parts.The decreasing tendency rate of sunshine hour showed a spatial pattern of gradually decrease from northeast to southwest,and the extremely significant decreasing trend maybe bring greater negative impacts on agricultural production in ecologically fragile areas including Changtu,Kangping,Zhangwu,Fumeng and Chaoyang,etc.