滇中地区参考作物蒸散量时空变化特征

Spatiotemporal Variations of Reference Crop Evapotranspiration in Central Yunnan

参考作物蒸散量是灌溉设计、灌溉计划等的基础数据,利用滇中地区19个气象台站的观测数据,计算了滇中地区的参考作物蒸散量(ET0),分析了ET0时间和空间的变化特征及气象要素对其的影响。结果表明:研究区的ET0于1982年发生突变,1960—1982年变化趋势不明显,1982—2002年呈现下降的趋势,2003—2012年ET0呈现增加的趋势,多年平均ET0约为1 223.7mm。ET0的空间特征表现为中部高,东西低,春季最大,夏季高于秋季,冬季最小,高值区出现在元谋地区。ET0与风速、气温和日照时数呈现显著的正相关关系,与相对湿度呈现极显著的负相关关系。偏相关分析和逐步回归分析显示在年尺度上,风速、相对湿度和日照时数的组合可以预测ET0的年际变化。

The ET0 is the basis of irrigation and irrigation scheme. This paper, based on the meteorological measurement of meteorological stations in central Yunnan, the yearly reference evapotranspiration （ET0） was estimated. The spatiotemporal characteristics and the influence of meteorological elements were also ana- lyzed. The results showed that the abrupt change of ETohappened in 1982 approximately, the downward trend happened from 1982 to 2002, the increased trend happened from 2003 to 2012, the regional average ET0was 1 223.7 mm. the main space characteristics of ETo is high in central and low in east and west, the maximum value appeared in Yuanmou area in the seasons, the maximum value of ET0 occurred in spring, and the value of ET0 in summer was higher than that in autumn, the minimum value of ET0occurred in spring. The ET0 increased with wind velocity, temperature and sunshine duration significantly and decreased with the relative humidity significantly. Partial correlative analysis and multiple regression analysis indicated that wind velocity, relative humidity and sunshine duration were the most significant predictors of the annual ET0.