参考作物蒸散量对气象要素的敏感性分析

为了研究参考作物蒸散量(ET_0)对气象要素的敏感性,利用新乡地区1951―2003年逐日气象资料,由Penman-Manteith公式计算参考作物蒸散量,采用敏感曲线和敏感系数方法分析了参考作物蒸散量对气象要素的敏感性。结果表明,温度、风速和日照时间3种气象要素与ET_0正相关,相对湿度与ET_0负相关。1―12月,相对湿度和风速的敏感系数表现为"先减小后增大"趋势,而日照时间和温度敏感系数表现为"先增大后减小"趋势。在全年中,ET_0对气象要素的敏感程度表现为相对湿度风速日照时间温度;第一、四季度各气象要素在季尺度中的敏感性均为相对湿度风速日照时间温度,第二季度表现为相对湿度日照时间风速温度,第三季度表现为相对湿度日照时间温度风速;冬小麦生育期典型时段内各气象要素敏感性在1、3、10月份均表现为相对湿度风速日照时间温度,5月则表现为相对湿度日照时间风速温度。

Sensitivity Analysis of the Reference Crop Evapotranspiration to Meteorological Factors

Calculating the reference crop evapotranspiration (ET0) from the Penman-Monteith formula needs a number of meteorological data and we analyzed the sensitivity of the ET0 to different meteorological factors using weather data measured daily in Xinxiang from 1951 to 2003. We firstly calculated the ET0 using these measured data and the Penman-Monteith formula, and then analyzed its sensitivities to different meteorological factors based on the sensitivity curves and sensitivity coefficients. The results showed that the ET0 was correlated posi-tively with temperature (T), wind speed (U2) and sunshine hours (n), and negatively with the relative humidity (RH). From January to December, the sensitive coefficients of ET0 to RH and WS decreased first and then in-creased, but its sensitive coefficients to SH and T increased first and then decreased. The sensitivity of annual ET0 to meteorological factors was in the order of RH>U2>n>T. Seasonally, the sensitivity of ET0 to meteorological fac-tors was in the order of RH>U2>n>T in the first and fourth quarters, RH>n>U2>T in the second quarter, and RH>n>T>U2 in the third quarter. In critical growing season, the sensitivity of ET0 to meteorological factors was in RH>U2>n>T in January, March and October, and RH>n>U2>T in May.