博斯腾湖夏季水下光场特征分析及影响因素探讨

2011年8月,在新疆博斯腾湖17个站点进行水样采集,同步对11个站点进行水下光场原位测定.结果发现,博斯腾湖夏季总颗粒物吸收系数光谱表现出明显的浮游植物吸收特征,而浮游植物光谱曲线有明显的硅藻吸收光谱特征.在光合有效辐射波段,有色可溶性有机物（CDOM）吸收系数与浮游植物吸收系数对总吸收的贡献相当,而非色素颗粒物对总吸收的贡献最低.水下光谱衰减系数的最小值出现在580nm左右的绿光波段,PAR漫射衰减系数平均值为0.53m-1,平均真光层深度约为9.69m,大于湖水平均深度.在博斯腾湖虽然纯水和CDOM在总吸收中占有很重要的部分,但主导漫射衰减的因子仍为颗粒物.通过本文研究,以期能为干旱地区湖泊环境保护和水质遥感监测提供数据和理论基础.

Characterization of the underwater light field and the affecting factors in Bosten Lake in summer

The underwater irradiance was measured and water samples were collected in August 2011 in Bosten Lake of Xinjiang Province. The total particulate absorption coefficient spectra showed significant absorption features of phytoplankton, and phytoplankton absorption spectral curve had a spectral signature of diatom in Bosten Lake in summer. The relative contributions of CDOM and phytoplankton absorption to the total absorption were close, and the non-pigment particles had the lowest relative contribution to the total absorption during the waveband of photosynthetically active radiation (PAR). The minimum underwater spectral diffuse attenuation coefficient appeared in the green range around 580 nm with an average PAR diffuse attenuation coefficient of 0.53 m^-1. The average euphotic depth was 9.69 m, which was higher than the mean water depth in the lake. The pure water and CDOM were important parts of the total absorption, but the suspended solid was the dominant affecting factor of PAR attenuation in Bosten Lake. This study may provide data and theoretical basis for the environment protection and lake water quality remote sensing in arid areas.