Direct distribution of solar radiation in complex terrain base on GIS

Xu Zongwen;Luo Han;Zhao Tingning;Ma Huan;Zhang Hua;Gao Jun;College of Soil and Water Conseration,Beijing Forestry University;Beijing General Research Institute of Mining & Metallurgy;Pearl River Water Resources Research Institute;

imaging total station;;topographic survey;;ViewGIS3.0;;solar radiation;;variation

In order to study the direct distribution of solar radiation in complex terrain,imaging total station technology and ViewGIS3.0 were integrated to calculate the solar radiation in the quarry of Huangyuan village,Fangshan District,Beijing,which is a typical representative area.Meanwhile,the accuracy of direct radiation model was confirmed through the fieldwork observation(error only 4.1%),and impacts of slope and aspect on direct solar radiation were investigated.Results are shown as follows.1) Errors of each observation point during the daytime have shown the same trend that there are big errors in the morning and evening and small errors at the noon,indicating that the model can reflect the real value of direct solar radiation more accurately when the solar elevation angle is large.2) On the sunny slope,the amount of solar direct radiation increases first and then decreases with the increase of slope.The critical point is consistent with complementary angle of the solar elevation angle.On the shady slope,the amount of solar direct radiation decreases with the increase of slope.3) In different seasons,impacts of aspect on the amount of solar direct radiation differ.The amount of solar direct radiation in winter is affected the most by aspect,followed by that of fall and spring,and the amount of solar direct radiation in summer is affected the least.