摘要
基于DEM模型,探讨了在受到自身地形遮挡和周围地形遮挡综合影响下北京西部山区太阳实际直接辐射分布的计算问题,并对研究区的太阳直接辐射分布进行了分析。分析结果认为,复杂地形条件下山区太阳直接辐射分布受多种地形因素共同影响。随着坡向由阴坡转为阳坡、坡度由小变大,太阳直接辐射量最大值逐渐增大,但在15°~20°坡度处,太阳直接辐射量开始下降。在1275~1475m海拔间太阳直接辐射的平均值最小,之后随海拔的升高和降低,其平均值向两边均逐渐增大,海拔在1075m以下,平均值差异不明显。研究区直接辐射量的最大值出现在坡度为10°~15°、坡向为-67.5°~67.5°的坡面上,低值区出现在坡度为35°~40°、坡向为112.5°~247.5°的坡面上。该试验采用的方法通用性较好,原则上适用于一切复杂地形太阳直接辐射计算。
The algorithm to calculate actual solar direct radiation over rugged terrain was designed and tested based on digital elevation model(DEM), and the spatial distribution of solar direct radiation in West Beijing was also analyzed. In the algorithm, all of terrain shading, not only from research points themselves, but also from the near terrain were calculated. The result shows that the spatial distribution of solar direct radiation over rugged terrain is a compositive result by many terrain factors. At the altitude of 1275~1475 meter, the mean of solar direct radiation was the least, then with altitude rising or falling down from that altitude on, the mean begins increasing. Below 1075 meter, the difference of means was not remarkable. The maxima of solar direct radiation at the different radiation quantity groups appear constantly rising with the aspect turning from north to south, and they increase with the slope angle enlarging until 10°~15°, then decrease with the slope angle increasing. The largest values of solar direct radiation occurs at the region with slope 10°~15° and aspect -67.5°~67.5°, while the least values are located at the region with slope 35°~40° and aspect 112.5°~247.5°. Generally, the method in this paper could be adopted in calculating solar direct radiation over all kinds of rugged terrain.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2006年第9期154-158,共5页
Transactions of the Chinese Society of Agricultural Engineering
关键词
DEM模型
山区
地形遮挡
太阳直接辐射
辐射分布
DEM
mountain area
terrain shading
solar direct radiation
solar radiation distribution