山西地区近55年参考作物蒸散量的变化特征及其主要影响因素分析

利用1955—2009年山西地区5个站点(大同、阳泉、太原、吕梁和临汾)逐日气象资料,采用FAO推荐的Penman-Monteith公式计算参考作物蒸散量(ET0),分析了不同地区的气象要素(温度、相对湿度、日照时数和风速)和年ET0随时间变化特征,并采用敏感性分析方法对影响ET0变化的主要气候因子进行了探讨。结果表明,5个站点平均温度和平均相对湿度从低纬度到高纬度逐渐增大;而平均风速和平均日照时数则逐渐减小。5站点的多年平均温度随时间有平缓上升趋势。大同和阳泉的年ET0高于其他站点,其他站差异不明显。4气象要素中对大同、太原和吕梁站ET0影响最大的要素为相对湿度,对临汾站ET0影响最大的要素为日照时数,温度变化对各站点ET0的影响作用最小。

Changing Trend of Reference Crop Evapotranspiration and Its Dominated Meteorological Variables in Shanxi Province in the Past 55 Years

Changing trends of meteorological variables(temperature,relative humidity,sunshine hours and wind speed) and reference crop evapotranspirations(ET0) from 1955—2009 at five meteorological stations,Datong station,Yangquan station,Taiyuan station,Lvliang and Linfen stations,in Shanxi Province were analyzed.Daily ET0 was calculated with FAO Penman-Monteith equation(PM).The dominated meteorological variables causing great changes of ET0 were found using a sensitivity analysis method.Results showed that average air temperature and average relative humidity of the five weather stations in Shanxi Province gradually increased from north to south,while the average wind speed and average sunshine hours gradually decreased from north to south.The average air temperature at the five meteorological stations rose over time with gentle.ET0 of Datong and Yangquan were higher than the others;the difference of average wind speed of the other stations was not significant.Sensitivity analysis on annual ET0 indicated that the relative humidity was the dominated meteorological element to ET0 in Datong,Taiyuan,Lvliang,Yangquan stations,sunshine hours was the dominated element to ET0 in Linfen.The effect of average air temperature on ET0 was not significant.