| Cite this article: | 夏兴生,朱秀芳,潘耀忠,等.中国大陆地区Angstrom公式参数校正与优选:年内尺度[J].灌溉排水学报,0,():-. |
| Xia Xingsheng,zhu xiufang,Pan Yaozhong,et al.中国大陆地区Angstrom公式参数校正与优选:年内尺度[J].灌溉排水学报,0,():-. |
|
| |
|
|
| This article has been：Browse 1725Times Download 0Times |
|
|
|
| DOI： |
|
| Parameter Calibration and Optimization of Angstrom Equation in China Mai-land for a year scale |
|
Xia Xingsheng, zhu xiufang, Pan Yaozhong, Zhang Jinshui
|
|
Beijing Normal University
|
| Abstract: |
| The Food and Agriculture Organization (FAO) of the United Nations recommended Angstrom Equation as the pro-posed algorithm for the total solar radiation (Rs) parameters in the calculation process of reference crop evapotran-spiration. Therefore, the value of as and bs coefficients of this equation is crucial for the accurate calculation of Rs.【Objective】In order to discuss the spatial characteristics of the two empirical coefficients in Angstrom Equation within the land area of China, and to give the correction values of each agricultural area, 【Method】this study, using the least-squares regression, acquired as and bs coefficients of 38 agricultural areas in China within a year based on daily mean effective observation records of solar radiation (Rs) and sunshine percentage from 121 stations monthly data in Dataset of Monthly Values of Radiation Data and Climate Data from Chinese Surface Stations in 1957 to 2010, and with the Rs observation data in 2011 to 2016 as the true value, compared the relative precision of Rs calculated by as, bs coefficient from regression value and FAO recommended value respectively. Lastly, the optimal values of as and bs coefficients for agricultural areas were selected month by month.【Result】The correlation coefficients between n/N and Rs/Ra of the most stations is above 0.8; The Angstrom formula coefficient as obtained by linear regression analysis maintains in the range of 0.1-0.2 in most regions, and its value is stable in space, while the coefficient bs fluctuates and changes greatly in the range of 0.4~0.8 in most regions; The Rs calculated by the regression coefficient is better than the FAO recommended value on the whole, but in the specific application, some Rs calculated by the FAO recom-mended value are better than that by the regression coefficient.【Conclusion】In China, based on the correlation between n/N and Rs/Ra, the as and bs coefficients of Angstrom formula can be obtained by regression analysis directly; The coefficients as and bs obtained by regression in each agricultural area were significantly different from the sug-gested values of FAO 56; And the relative size of the two shows the rule of one is smaller, and the other is larger; Under the condition of existing data and methods, combined using the regression value and recommended value of as and bs coefficients is the best scheme. This study enriches the case study of parameter calibration of Angstrom Equation, and the results can improve the accuracy of Rs calculation in China, which has certain reference value for more refined radiation parameter research in different agricultural areas of China. |
| Key words: Solar Radiation；Angstrom Equation；Calibration；Reference Crop Evapotranspiration；China |
|
|
|
|
|
|
