复杂地形下长江流域太阳总辐射的分布式模拟

利用长江流域气象站1960-2005年的观测资料(包括常规气象站点资料和辐射站点资料)、NOAA-AVHRR遥感数据(反演地表反照率),以1km×1km的数字高程模型(DEM)反映地形状况的主要数据,通过基于DEM数据的起伏地形下天文辐射模型和地形开阔度模型,分别建立了长江流域太阳直接辐射、散射辐射和地形反射辐射分布式模型,实现了长江流域太阳总辐射模拟,并对总辐射模拟结果进行了时空分布规律分析和对其受季节、纬度、地形因子(高度、坡度和坡向等)影响的局部规律分析,以及模拟结果的误差分析和站点验证分析。结果显示:太阳总辐射在季节上受影响的程度依次是春季>冬季>夏季>秋季;随着高度、坡度、纬度的增加,太阳总辐射受坡向影响的程度呈增强趋势,从坡向上看,向阳山坡(偏南坡)对太阳总辐射量明显高于背阴坡(偏北坡)。模拟的平均绝对误差为13.04177MJm^-2,相对误差平均值3.655%,用站点验证方法显示:模拟绝对误差为22.667MJm^-2,相对误差为4.867%。

Distributed Modeling of Global Solar Radiation of Rugged Terrain of the Yangtze River Basin

Based on the distributed model for calculating astronomical solar radiation of the rugged topography and the terrain shield model, by using meteorological observation data of the Yangtze River Basin (including the routine meteorological data and the solar radiation data), NOAA-AVHRR of remote sensing data (offering surface Aledo) and the digital elevation model (DEM) data with a resolution of 1 km × 1 km as a terrain response of the main data, a distributed direct solar radiation model, a distributed diffuse radiation model and a distributed terrain reflectance radiation model of the Yangtze River Basin are set up separately, and a distributed model for calculating global solar radiation over rugged terrains is developed for the Yangtze River basin. This paper deeply analyzes simulation results errors and variations of global solar radiation due to locality and terrains. The results suggest that the global solar radiation to be affected, owing to different seasons, is followed by spring > winter > summer > autumn and the impact degree was enhanced owing to increases of altitude, slope, latitude, trend, from the aspect perspective, the global solar radiation quantity over mountainous areas for the Yangtze Rive Basin influenced by local topographic factors has a clear spatial difference and subsists sunny slope (or southern slope) obviously larger than shady slope (or northern slope). Simulation error analysis shows that average absolute error of simulation is 13.04177 MJm^-2, average relative error 3.655%, and in site authentication method shows an absolute error of simulation of 22.667 MJ m^-2, while relative error of 4.867%.