东北地区参考作物蒸散量对主要气象要素的敏感性分析

Sensitive Analysis on Reference Evapotranspiration to Key Meteorological Factors in Northeast China

利用国家气象局提供的地面气候资料日值数据集,通过FAO推荐的Penman-Monteith公式计算了东北地区1961-2008年生长季(5-9月)逐日的参考作物蒸散量(ET0),分析了ET0及主要气象要素的变化趋势,并通过响应曲线、敏感矩阵、敏感系数等方法分析了ET0对气温、日照时数、平均风速、平均相对湿度的敏感性。结果表明:(1)近50a来,东北地区的气温呈极显著上升趋势(P<0.01),日照时数、平均风速、平均相对湿度呈极显著下降趋势(P<0.01);东北地区生长季平均日ET0在以3.60mm.d-1为平均值、±0.3mm.d-1的范围内波动,总体上比较稳定,最大值出现在2001年(3.87mm.d-1),最小值出现在1990年(3.28mm.d-1);(2)当气温、日照时数、平均风速的变化量从-20%变化到20%时,ET0表现为逐渐增加的趋势,当平均相对湿度的变化量从-20%增加到20%时,ET0则逐渐减小;(3)气温、日照时数、平均风速、平均相对湿度的生长季平均日敏感系数均具有较强的空间分异特性,其中气温变化对ET0的影响最为明显,其次是平均相对湿度,日照时数、平均风速对ET0的影响较小。

Daily reference evapotranspiration （ ET0 ） in growing season （ May to September） during 1961 - 2008 was calculated by using Penman-Monteith equation recommended by FAO, based on daily meteorological data provided bv China Meteorological Administer. Temporal variation of ET0 and key meteorological factors were analyzed. Sensitivity of daily ET0 to key climate factors, such as temperature, sunshine hours, average wind speed and average relative humanity, was analyzed by using the methods of response curves, sensitivity matrixes and sensitivity coefficients. The results showed that temperature increased significantly （P 〈0.01 ） during 1961 to 2008, while sunshine hours, average wind speed and average relative humidity decreased significantly （P 〈0.01 ） in same time. The average daily ETo u- ring growing season did not extended ＋ 0.3mm per day at the point of 3.60ram per day, and it was steady in these years and got maximum value in 2001 （3.87mm per day） and minimum value in 1990 （3.28mm per day）. Daily ET0 also increased with temperature, sunshine hours and mean wind speed changed from -20% to 20% , while daily ET0 decreased with average relative humidity changed from - 20% to 20% . Average daily sensitivity coefficients of meteorologieal factors during the growing season varied in region, of which temperature was the most sensitive to ET0, followed by average relative humidity, sunshine hours and mean wind speed.