【摘要】 根据辐射传输方程的近似解方法和光照传输的累加原理,建立了包括水面风浪效应、水中悬浮粒多次散射和底泥反射的垂直分层水体的光照传输数值模式。利用该模式和太湖悬浮粒实测资料,计算和讨论了太湖水体中光照随水深的变化以及悬浮粒浓度、风浪和太阳高度的影响。结果表明,悬浮粒的多次散射所形成的漫射光是湖水中光照不可忽视的重要部分。在水体的下层,漫射光甚至是光照的主要构成部分。风浪对水中光照的影响则主要在天顶角大于70°时才明显地表现出来,此时风浪水体对太阳直接辐射和全辐射的反射率比平静水面都有明显的减小。更多还原

【Abstract】 Based on the two-stream approximation method and the adding method of irradiance transfer, a numerical model of irradiance transfer for vertically stratified water body is established in which al1 effects such as surface waves, multis cattering of suspended particles in the water and reflection of lake bottom are included. Utilizing this model and measured data of suspended particles in Lake Taihu and considering Cox-form distribution as orientation of the wave surface, the irradiance as function of depth and the effects of concentration of particles, waves and the sun’s altitude are calculated and discussed. The results show that for shallow lakes such as Taihu, as a result of wind disturbance, there is an abundance of suspended particles in the water; hence, the irradiance in the lake attenuates rapidly with increase in water depth. Its direct light contributes to the irradiance only in the upper water layer, while the diffused light brought about by multi-scattering of suspended particles may be an important part of the irradiance of the lake water which must not be overlooked: In the deeper layer of the water body, the diffused light may even be a cardinal part of the irradiance. However, it should be pointed out that the contribution of the diffused light to the irradiance varies with the concentration of particles and wavelength of light. As for the effect of wind waves on irradiance, it mainly occurs when the zenith angle of the sun is higher than 70°. Under this condition, the albedo of water for both direct and total radiation is evidently reduced in comparison with calm water surface.更多还原