考虑地形遮蔽的日照时数精细化推算模型  

Refine Project Model of Sunshine Resources in China Considering Terrain Masking

作　　者：王怀清[1,2] 殷剑敏[1] 占明锦[1] 黄明凤 

机构地区：[1]江西省气候中心,南昌330046 [2]江西省彭泽县气象局,彭泽332700

出　　处：《中国农业气象》2011年第2期273-278,共6页Chinese Journal of Agrometeorology

基　　金：2007年度科技部公益性行业(气象)科研专项"精细化农业气候区划及其应用系统研究"(GYHY200706007)

摘　　要：日照时数是农业气候资源中光照资源的重要衡量指标,实际地形下地形遮蔽是不可忽略的因素,为了获取实际地形下全国日照时数的精细化资料,推算模型必须精确计算遮蔽量。本文基于全国1∶25万数字高程模型(DEM)资料,构建了实际地形下天文可照时数自动计算模型,通过模型可以精确地计算出地形遮蔽量。采用1971-2000年全国2346个具有完整资料的国家气象站日照时数资料,用各时间尺度的格点实际地形下天文可照时数量与格点日照百分率乘积,作为相应尺度的日照时数,得到了各时间尺度全国实际地形下日照时数格点数据集,格点距为0.01°×0.01°。采用了全国2346个台站日照时数实测值,与推算值进行对比分析,结果表明,考虑了地形遮蔽的年日照时数推算值普遍稍小于实测值,年日照时数推算平均绝对误差(MAE)约为61.6h,均方根误差(RMSIE)约为78.7h,平均相对误差约为2.9%;地形起伏越剧烈,推算误差越大;太阳高度角越大,则推算误差越小。Sunshine duration was an important indicator for light resource in agricultural climate resources.In fact,terrain masking should be considered in the extrapolated model in order to acquire the refine national sunshine duration data in the actual terrain.The model which could automatically calculate astronomical sunshine duration in the actual terrain was established based on the 1∶250000 Digital Elevation Model（DEM） data.The sunshine grid data sets of the national actual terrain of each ten days,monthly,quarterly and annual time scale were got respectively,based on the sunshine duration data from 2346 national weather stations from 1971-2000.The calculated values and measured data from 2346 stations were compared.The results showed that the annual sunshine duration value,considering terrain masking,was slightly smaller than the measured value.The MAE of the extrapolated annual sunshine time was 61.6h,the RMSIE was 78.7h,and the average relative error was 2.9%.The calculated error was higher with the terrain more intense,the calculated error was smaller with the solar elevation angle larger.

关 键 词：地形遮蔽 日照时数 推算 

分 类 号：S161.1[农业科学—农业气象学]