起伏地形下黄河流域太阳直接辐射分布式模拟

Distributed Modelling of Direct Solar Radiation of Rugged Terrain over the Yellow River Basin

基于数字高程模型(DEM)数据和气象站观测资料建立了起伏地形下太阳直接辐射分布式计算模型,模型充分考虑了地形因子(坡向、坡度、地形相互遮蔽)对起伏地形下太阳直接辐射空间分布的影响;以1km×1km分辨率的DEM数据作为地形的综合反映,计算了起伏地形下黄河流域1km×1km分辨率太阳直接辐射的空间分布;深入分析了起伏地形下太阳直接辐射受地理、地形因子影响的变化规律。结果表明:受地形起伏和坡向、坡度等局地地形因子的影响,山区年太阳直接辐射量的空间差异比较明显,向阳山坡(偏南坡)的年直接辐射量明显高于背阴山坡(偏北坡)

Due to the influences of local topographical factors and terrain inter-shielding, calculation of DSR quantity over rugged terrains is very complex. Based on DEM （digital elevation model） data and meteorological observations, a distributed model for calculating direct solar radiation over rugged terrains is developed. This model gives an all-sided consideration on factors influencing DSR. Using the selected model, normals of annual DSR quantity with a resolution of 1 km × 1 km for the Yellow River Basin was generated, with DEM data as the general characterization of the terrains. Characteristics of DSR quantity influenced by geographic and topographic factors over rugged terrains were analyzed thoroughly. The results suggest that influenced by local topographic factors, i.e. azimuth, slope and so on, the annual DSR quantity over mountainous area has a clear spatial difference; and the annual DSR quantity of sunny slope （or southern slope） of mountains is obviously larger than that of shady slope （or northern slope）. The calculated DSR quantity of the Yellow River Basin is provided in the same way as other kinds of spatial information and can be employed as basic geographic data for relevant studies as well.