基于气象资料的日辐射模型在中国西北地区适用性评价

地表总辐射(Rs)是作物生长模型率定、蒸散量估算、灌溉制度制定和太阳能资源利用的重要基础数据。为有效提高辐射资源利用率,该文基于中国西北地区10个气象站点1993-2016年气象数据对9种不同日辐射模型进行适用性评价。采用非线性回归分析法对Bristow-Campbell(B-C)模型进行参数属地化修正,得到B-C校正模型。模型适用性评价结果表明:9种模型在西北地区的辐射模拟值和实测值均呈极显著相关(P0.01);基于日照时数的日辐射模型(?ngstr?m-Prescott、Ogelman、Bahel、Louche、Almorox-Hontoria、Glower-Mc Culloch,其R2介于0.875~0.954)计算精度高于基于温度的模型(Hargreaves-Samani、Annandale、Bristow-Campbell,其R2介于0.652~0.813);其中基于日照时数的模型中Bahel模型精度最高,其次是Ogelman和Glower-Mc Culloch模型,其RMSE分别为2.282、2.309和2.313 MJ/(m~2·d),n RMSE分别为14.0%、14.2%和14.2%,MAE分别为1.666、1.701和1.697 MJ/(m~2·d),Nash-Sutcliffe系数(NS)分别为0.905、0.903和0.902;基于温度的日辐射模型中B-C校正模型精度最高,其RMSE为3.819 MJ/(m~2·d),n RMSE为23.3%,MAE为2.680 MJ/(m~2·d),NS为0.741。因此,西北地区日辐射计算当仅有日照时数资料时推荐使用Bahel模型,当仅有温度资料时推荐使用Bristow-Campbell校正模型。

Evaluation on applicability of daily solar radiation model in Northwest China based on meteorological data

Abstract: Complete and accurate global solar radiation data at a specific region are highly crucial to regional crop modeling, evapotranspiration estimation, irrigation system development and utilization of solar energy resources. In order to improve the utilization efficiency of facility agriculture technology on radiation resources, daily climatic data in 10 meteorological stations in Northwest China from 1993 to 2016 were used to calculate daily global solar radiation. The applicability of 6 solar radiation models based on sunshine (?ngstr?m-Prescott, Ogelman, Bahel, Louche, Almorox-Hontoria and Glower-McCulloch model) and 3 solar radiation models based on temperature (Hargreaves-Samani, Annandale and Bristow-Campbell model) was evaluated using the coefficient of determination (R2), root mean square error (RMSE), normalized root mean square error (nRMSE), Nash-Sutcliffe coefficient (NS), mean absolute error (MAE) and relative error (RE). In addition, the parameters of Bristow-Campbell (B-C) model were calibrated based on least square method using the daily meteorological data from 1993 to 2010, and the daily meteorological data from 2001 to 2016 were adopted to evaluate the applicability of B-C model. The results showed that the estimated and measured daily global solar radiation had statistically significant correlations (P<0.01) for all the 9 models at the 10 stations. Generally, the models based on sunshine (with R2 ranging from 0.875 to 0.954 for the 10 stations) were more accurate to estimate daily global solar radiation than the models based on temperature (with R2 from 0.652 to 0.813). In Northwest China, the Bahel model showed the best performance for daily global solar radiation estimation among the 6 models based on sunshine, followed by Ogelman model and Glower-McCulloch model, with average RMSE of 2.282, 2.309 and 2.313 MJ/(m2·d), average nRMSE of 14.0%, 14.2% and 14.2%, average MAE of 1.666, 1.701 and 1.697 MJ/(m2·d), and average NS of 0.905, 0.903 and 0.902, respectively. The best model based on temperature for estimation of daily global solar radiation was B-C model, followed by Hargreaves-Samani model and Annandale model, with average RMSE of 3.819, 4.167 and 4.368 MJ/(m2·d), average nRMSE of 23.3%, 25.5% and 26.6%, average MAE of 2.680, 3.068 and 3.378 MJ/(m2·d), and average NS of 0.741, 0.688 and 0.656 respectively. On the monthly scale, the estimated and measured monthly average daily global solar radiation had good agreement, and the monthly average daily global solar radiation all increased from January to June and decreased from July to December. The Bahel model also showed the best performance for monthly average daily global solar radiation estimation among the 6 models based on sunshine, followed by Ogelman model and Glower-McCulloch model, with average RE of 5.350%, 5.375% and 5.679%, respectively. The B-C model had the best estimation accuracy among the models based on temperature, with average RE of 4.254%. It meant that the B-C model was more accurate than the Bahel model for global solar radiation estimation in monthly scale. Overall, the Bahel model is recommended to estimate daily global solar radiation when the sunshine hours are available, and the calibrated B-C model is recommended to estimate daily global solar radiation in Northwest China when only temperature data are available. This paper provides valuable information for global solar radiation estimation method in Northwest China, and also provides the theoretical basis and technical support for accurate estimation of daily global solar radiation.