宁夏引黄灌区几种参考作物蒸散量计算方法适用性及修正研究

The Applicability and Correction of Calculation Methods for Several Reference Crop Evapotranspiration in Ningxia Yellow River Irrigation Districts

为了提高宁夏引黄灌区参考作物蒸散量(ET0)简化公式的精度,基于宁夏引黄灌区5个国家级基本气象站点1962-2017年逐日气象资料,分别使用Priestley-Taylor(P-T)、FAO-24 Radiation(FAO-24)、1948 Penman-Monteith(1948P-M)、Hargreave-Samani(H-S)和Makkink(M-A)五种简化计算方法计算多年日均ET0,以Penman-Monteith(P-M)公式计算为标准,通过使用1962-2000年P-M公式所得日值,分别对五种简化计算方法进行线性拟合,用最小二乘法确定出斜率k和经验系数c,并用2001-2017年计算数据对拟合公式进行验证,使用平均绝对误差(MAE)、平均相对百分误差(MRPE)和Nash-Sutcliff系数(NS)对宁夏引黄灌区各个站点的精度进行评价。结果表明:修订前,各简化计算方法对宁夏引黄灌区各个站点适用性及精度较差,经过修正后,其拟合效果和精度均有不同程度的提高。因此,经过修正后的五种简化计算方法在宁夏引黄灌区有较高的适用前景。

In order to improve reference crop evapotranspiration in Ningxia Yellow River Irrigation District(reference crop evapotranspiration, ET0), This paper simplifies the accuracy of the formula, based on the daily meteorological data of the 5 national-level basic meteorological stations in Ningxia Yellow River Irrigation District from 1962 to 2017 by using Priestley-Taylor(P-T), FAO-24 Radiation(FAO-24), and 1948 Penman respectively. Monteith(1948 P-M), Hargreave-Samani(HS) and Makkink(MA) five simplify calculation methods to calculate the multi-year average ET0, using the Penman-Monteith(PM) formula as the standard. The obtained daily values are linearly fitted to the five simplified calculation methods, the slope k and the empirical coefficient c are determined by the least squares method, and the fitting formula is verified by the calculated data from 2001 to 2017 by using the mean absolute error(MAE). The average relative percentage error(MRPE) and Nash-Sutcliff coefficient(NS) are used to evaluate the accuracy of each site in Ningxia Yellow River Irrigation District. The results show that before the revision, the simplified calculation methods have poor applicability and accuracy for each site in Ningxia Yellow River Irrigation District. After modification, the fitting effect and accuracy are improved to different extents. Therefore, the five simplified calculation methods have a high application prospect in Ningxia Yellow River Irrigation District.