作物模擬模式的開發或驗證常需要日射量此項氣象資料,但受限於感測器較昂貴及自動紀錄等因素,日射量的累積資料或各測站點的分布均不如溫度密集,因此,本研究探討利用日最高溫及最低溫的溫差推估日射量的可行性。以農業試驗所氣象站資料分析溫差及輻射量在不同年際及季節問的差異,發現降雨狀態會影響溫差估算日射量的準確度,尤其是每年6月至10月較多雨的季節,但若將降雨量納入迴歸式可降低誤差值。依據不同氣候狀態及海拔高度分別選取6個測站的資料作分析,利用迴歸式估算日射量,在均值平方根偏差的範圍為1.02-6.08 MJ m^(-2)day^(-1),均值偏差為2.33 MJ m^(-2)day^(-1)。
Solar radiation is an important input parameter for crop simulation model. Because the sensor of solar radiation is expensive, to measure solar radiation are not popular as air temperature. Therefore, the objective for this study is to develop the algorithms for calculating solar radiation from daily maximum and minimum temperature. With a 10-year data set from weather station of Taiwan Agricultural Research Institute, we found the rainfall condition highly effect the estimation of solar radiation based on daily temperature, especially during the high rain-month period (June to October). A newly combined formula that included the temperature and rainfall could provide the estimation with less error than single factor. This study evaluated the accuracy for using daily temperature to estimate daily solar radiation at 6 weather stations in Taiwan area, the root mean square error (RMSE) range between calculated values from developed model and measured data in 1995 was 1.02-6.08 MJ m^(-2) day^(-1) with a standard deviation of 2.33 MJ m^(-2) day^(-1).