中国参考作物腾发量时空变化特性分析

分析参考作物腾发量的时空变化特征，有助于了解中国农业及生态需水的分布与演变规律。基于全国范围200多个气象站测站逐日气象观测资料，应用FAO-Penman-Monteith公式，计算得出各站历年逐日参照作物腾发量ET₀。利用GIS的空间分析功能，采用反距离空间插值方法得到全国参考腾发量的分布图，统计分析了不同分区不同时段ET₀的变化情况。结果表明：西北河西走廊地区和南方岭南地区的参考作物腾发量较大，最大值超过1500 mm。而东北黑龙江一带和四川盆地附近，参考作物腾发量较小，在600～700 mm之间。此外，夏季ET₀的分布特征决定了全年ET₀的分布特征。选取4个代表气象站，对其ET₀的历年变化及其与气象因素的关系进行了分析。分析表明，受风速减小和气温增加的共同影响，干旱地区、半干旱地区和半湿润地区的参考作物腾发量呈现减少趋势，湿润地区则相对稳定。

Temporal and spatial characteristics of reference evapotranspiration in China

The analysis of the temporal and spatial characteristics of reference evapotranspiration is helpful to understand the distribution and variability of the agricultural and ecological water requirement. Based on the daily meteorological data of more than 200 stations all over China, daily reference evapotranspiration(ET₀) was estimated by using the FAO Penman-Monteith equation. The spatial distribution of ET₀ was obtained by GIS and IDW method was used for spatial interpolation. In China, the largest ET₀ was found to be more than 1500 mm in northwest and south region, and the smallest is found to be 600 mm to 700 mm in the northeast region and Sichuan Basin. In addition, the ET₀ in summer contributes most of a year. Then four representative stations were selected to analyze the temporal variation of ET₀ values and the effects of meteorological data on ET₀. It is concluded that in recent years ET₀ in arid areas tends to become smaller because of the decreases of solar radiation and wind speed, while in humid areas ET₀ is relatively stable.