根据1998年FAO修正彭曼-蒙特斯公式,利用宁夏引黄灌区8个气象站近50多年的气象资料,计算了各气象站逐月的参考作物蒸发蒸腾量ET0、各气象因子的长期变化趋势和各气象因子与ET0的相关东数。分析了ET0空间分布特征、年内分布特征和年际变化特征。分析结果表明:黄河以东各站的ET0值均大于黄河以西各站的ET0值;除石嘴山站外,各站5—7月份的ET0占全年比例在20世纪80年代后比80年代前有所下降;除石嘴山站外,各站的ET0均表现为逐年增加的趋势,尤其在1990年后更为明显;气温呈递增趋势、相对湿度呈减少趋势、温差在逐渐减小;相对湿度和重高/重低气温以及平均风速对ET0的影响比较显著。
Based on the meteorological data collected from 8 meteorological observation stations in more than 50 years in the Yellow River irrigation area of Ningxia Region, The monthly crop reference evapotraspirations were calculated with the Peman-Monteith equation recommended by the FAO in 1992. The characteristics of the spatial distribution and the change of annual and monthly of the ETo was analyzed. The ETo of the east-Yellow River was more than the west-Yellow River. The proportions of the ETo in the months from May to July accounting for the whole year were decreasing year by year except the Shi Zui Shan station . And the ETo was increasing except the Shi Zui Shan station. In addition, the coefficients of correlation of ETo with the meteorological variables were also analyzed. The coefficient of ETo with the relative humidity and average wind speed were great.