Distributed Simulation Of Hebei Solar Radiation Over Real Topography

Based on DEM (digital elevation model) data and meteorological observations, Geographic Information System (GIS) as the data processing platform, using the distributed models for calculating solar radiation, the temporal and spatial distribution of solar radiation in Hebei was simulated and studied. Normals of astronomical, direct, diffuse, topography reflect and global solar radiation quantity with the resolution of 100m×100m in Hebei was calculated. Characteristics of solar radiation quantity influenced by geographic, topography, astronomical and meteorological factors over rugged terrains were analyzed. The main achievements were concluded as follows:(1) The astronomical radiation quantity is followed by July>April>October>January. The space distribution has a obvious latitudinal character and presents a descendent trend from south to north; (2) The direct radiation quantity is followed by April>July>October>January. The space distribution has a obvious latitudinal character and presents a increasing trend from south to north; (3) The diffuse radiation quantity is followed by July>April>October>January. The space distribution has a obvious latitudinal character and presents a descendent trend from south to north; (4) The topography reflect radiation of altiplano, basin, plain is very less and has not a obvious difference. The mountain reflect radiation is larger than plain; (5) The global radiation quantity is followed by July>April>October>January. The space distribution has a obvious latitudinal character and presents a increasing trend from south to north; (6) As the solar altitude becomes smaller, the solar radiation quantity becomes less and the difference between south and north becomes larger and vice versa; (7) The more the terrain becomes flatter, the more the terrain openness becomes larger and the less the terrain influences the solar radiation and vice versa; (8) The solar radiation of southern slope is larger than that of flat, but northern slope is smaller than flat. Especially when the solar altitude is small, this difference is very obvious. The influences of eastern and western slope to the solar radiation distribution is very small; (9) In January, April, July and October, it was followed by the direct radiation quantity>the diffuse radiation quantity>the reflect radiation. The proportion of the reflect radiation in global radiation is under 1%. The proportion of the direct radiation in global radiation is followed by October>January>April>July because it has less cloud, relative humidity and higher atmosphere transparence in January and October than April and July.