东北地区参考作物蒸散确定方法研究

Study on Calculating Methods for Reference Crop Evapotranspiration in Northeastern China

运用FAO Penman monteith方法和Hargreaves方法对中国东北地区4个气候大区16个气象台站的参考作物蒸散(ET0)进行了研究,并对FAO Penman monteith方法和Hargreaves方法的计算结果进行分析。发现:Hargreaves方法可适用于东北地区,尤其是亚湿润地区,但是相对于FAO Penman monteith方法,该方法还存在偏差,特别是半干旱地区。为了进一步提高Hargreaves方法的精度,对其进行了修正,得出比Hargreaves方法精度更高的适于东北地区参考作物蒸散计算的方程,为精确、实用地确定作物需水量和合理的灌溉制度提供了科学依据,有利于水资源的合理利用,尤其是水资源缺乏的半干旱地区。

Based on FAO-Penman-monteith method and Hargreaves method, the paper studied the reference crop evapotranspiration (ET_0) of sixteen meteorological observatories in four climate zones of the northeastern China, and analyzed the results of the two methods. The results indicated that in the northeastern China the ET_0 computed by the FAO-Penman-monteith method and that by Hargreaves method showed the same tendency in the crop growth stage. From the beginning of April to the beginning of June the ET_0 increased, and then began to decrease, but a small peak was inserted in the last ten days of August. The tendency proved the lineal relationship between the two methods. The degree of fitness between the results of the two methods indicated that the Hargreaves method was suitable for the northeastern China, especially for the semi-humid area. But compared with the FAO-Penman-monteith method, the Hargreaves method still had deviation on the result, especially in the semi-arid area of the middle temperate zone. So the Hargreaves method needed to be adjusted. In order to improve the precision of the Hargreaves method, the equation acquired by the regressive analysis was recommended in the paper.