中文摘要：

根据黄土地区1951—2000年14个站点的日气象资料以及FAO56 Penman-Monteith公式,计算各站逐月替在蒸散量,分析近50 a各站年平均气温、降水量、日照时数、风速和相对湿度等气候要素以及年潜在蒸散量的变化趋势和变化特征,并据此分析ET0变化的气候成因.结果表明：（1）近50 a来黄土地区基本都表现为显著的增温趋势,增温速率为0.039～0.396℃/10a,与全国平均水平0.22℃/10a相当；降雨量、风速、日照时数和相对湿度总体上均呈下降趋势；（2）潜在蒸散量年际间除驻马店和介休显著下降外,其他大部分站点呈显著上升趋势；（3）敏感性分析表明黄土地区潜在蒸散量的主要影响因素是相对湿度,其次是太阳辐射（日照时数）和气温,风速变化的影响最弱.

英文摘要：

Based on the climatic data of 14 meteorological stations in the Loess area in 1951 -2000, the temporal and spatial variation of the climatic variables and potential evapotranspiration were analyzed, and then the influence factors of ETo were also analyzed. The results showed that ： （1） There was a temperature warming trend in Loess area in the last 50 years. The annual mean temperature had a warming rate of about 0. 039 - 0. 396℃/10a, which increased by about 0.195 - 1.98℃. The annual mean precipitation, wind speed, sunshine duration and relative humidity had a trend to decrease as a whole. （2） The reference crop evapotranspiration had a significant trend to increase except in Jiexiu and Zhumadian. （3） All in all, relative humidity was the most sensitive factor in the Loess area, followed by net shortwave radiation and air temperature, while wind speed had the least impact.