永定河流域太阳辐射逐时过程模拟

针对太阳辐射在不同区域地形条件下的差异,通过建立任意倾角和坡面方位角下的太阳辐射逐时模型,模拟了永定河流域1951—2018年的太阳辐射,并分析了该流域太阳辐射在不同倾角和坡面方位角下的变化特征.结果 表明:永定河流域1951—2018年逐年太阳辐射总体呈现减小趋势.任意倾角下,同一站点太阳辐射时变化形态基本一致,均呈抛物线型,不同站点太阳辐射峰值受地理纬度及海拔影响较大.任意坡面方位角下,太阳辐射沿流域中心向东西两向逐渐减少并呈对称分布.太阳辐射年内具有明显的月度变化特征,1—3月、10—12月太阳辐射受倾角和坡面方位角影响较4—9月大.该研究成果对量化太阳辐射、研究流域能量收支及分析陆面蒸发过程等方面具有一定的参考意义.

Simulation on hourly process of solar radiation in Yongding River Basin

Focusing on the difference of solar radiation in different regions and topographical conditions, an hourly calculation model of solar radiation at arbitrary direction and inclination angle is established. Using the solar radiation model, the total radiation of 1951-2018 in Yongding River Basin is calculated, and its hourly variation characteristics at arbitrary inclination and direction angles are analyzed. The results show that the annual solar radiation decreased in the Yongding river basin from 1951 to 2018. The changing pattern of daily solar radiation is similar at any inclination angle with a parabolic pattern, and the peak value is mainly affected by geographical latitude and altitude. The distribution of solar radiation is symmetrical and decreasing along the east and west directions at arbitrary slope azimuth, taking the center of the basin. Obvious monthly variations at arbitrary inclination azimuth is shown in the solar radiation which has larger fluctuation in the period of January to March and October to December than in April to September. This paper can provide basic reference for quantifying energy budget, utilizing solar energy and analyzing evaporation process in land surface.