Hargreaves法在滇中地区的应用及改进

The Application and Improvement of Hargreaves Method in Middle of Yunnan

参考作物需水量是作物需水量的计算基础,是灌排工程规划、设计、管理和水资源合理开发利用的基本依据。为提高Hargreaves法计算参考作物需水量(ET0)的计算精度,在传统回归法的基础上,利用主成分分析法,以滇中地区7个气象站56年(1958-2013年)的逐日气象资料作为数据基础,引入相对湿度气象因子改进H-S法,以P-M法计算的ET0为标准评价改进H-S法的计算精度与适应性。结果表明:与P-M法计算结果相比,改进H-S法和P-M法的ET0计算结果相关性得到提高,逐日ET0值绝对偏差和偏差率得到降低,引入相对湿度气象因子后的改进H-S法改善了传统H-S法4-5月后计算值偏大的缺点,具有较高的计算精度,可作为滇中地区参考作物需水量(ET0)的计算方法。

Reference crop evapotranspiration is the basis of computing the crop water requirement, the planning, designing and management for irrigation and drainage and rational utilization of water resources. In order to improve the calculation accuracy, the traditional method is used as the foundation and the principal component analysis method is applied based on the daily data from seven stations during 1958 to 2013. To further enhance the appropriateness and calculation accuracy of the improve Hargreaves method, the humidity factor is introduced and the Penman-Monteith is taken as criteria. The result shows that the improved methods present a higher correlation than Penman-Monteith ; the absolute deviation and deviation rate of the average daily ETo value are reduced; the modified Hargreaves model by introducing the humidity overcomes the shortcomings and is more adaptive and accurate than traditional method, and it can be used as a method for the calculation of ET0 in the middle of Yunnan.