中国寧夏地域における日照時間から日積算日射量の推定 Estimation of daily solar radiation from sunshine durationin Ningxia region, China
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For the estimation of daily solar radiation from sunshine duration, observation data of Yinchuan station in Ningxia, China was used. Using a linear relationship between solar radiation and extraterrestrial radiation including relative sunshine duration and daylength, we obtained local coefficients s a =0.18, s b =0.62 from past five years data(1981-1985). Using the same method, coefficients for Guyuan region were confirmed too as a representative of south part of Ningxia province. Applying the localcoefficients and calculation formula of solar radiation, we validated daily solar radiation of two years(1986-1987) of Yinchuan station and four years(1991-1994) of Guyuan station. The results showed high correlation coefficients of R2=0.94 in Yinchuan and R2=0.85 in Guyuan. Error analysis was applied using mean bias error(MBE), mean absolute bias error(MABE), root mean square error(RMSE)，mean absolute percentage error(MAPE) on solar radiation of Yinchuan(1973-2006) and Guyuan(1986-2006) stations.Results showed that mean absolute bias error(MABE) was less than 13% and 17% in Yinchuan station and Guyuan stationrespectively. Then we have applied this method to the estimation of daily solar radiation at 'Yongning' station(near Yinchan) with the sunshine duration data at 'Yongning'. The estimated values were compared with observed daily solar radiation at Yinchuan as past twelveyears data(1989-2000). The results showed good linear relationship with high correlation coefficient of R2= 0.88.
- Okayama University Earth Science Report
Okayama University Earth Science Report 15(1), 79-86, 2009-03-31