基于ASD光谱仪的悬浮泥沙光学衰减系数研究

Diffuse Attenuation Coefficient of Suspended Sediment based on ASD Spectrometer

设计了基于ASD光谱仪的玻璃水槽实验,测量人工光源穿透不同水深、不同质量浓度含沙水体的辐亮度,以纯水为参照,得出了某一粒径组成下不同质量浓度悬浮泥沙在350-920 nm波段范围内的光学衰减系数。实验泥沙样本的光学衰减系数光谱特征单一,随着波长的增大逐渐减小,表现为一条略倾的曲线,且正比于泥沙质量浓度。在0-0.15 m深度范围内的,相同质量浓度的泥沙光学衰减系数随水深的变化可以忽略不计。从350-920 nm,实验泥沙样本的单位质量浓度光学衰减系数从0.084缓慢减小至0.069 m^2/g。

In this paper,a study was carried out to calculate the diffuse attenuation coefficient of suspended sediment by using the ASD F3.The experiment is based on measuring the radiance of an artificial light source penetrating through the water with different concentrations of suspended sediment in different water depths.Compared with pure water,the diffuse attenuation coefficients of suspended sediment with similar grain sizes were calculated for different concentrations with wavelength from 350 to 920 nm.The results show that the spectral characteristics of the diffuse attenuation coefficient of suspended sediment are simplex,and it decreases as the wavelength increases.Furthermore,it shows a positive correlation between the diffuse attenuation coefficients and the concentrations of suspended sediment,with the exception of the water depth from 0~0.15 m,where the diffuse attenuation coefficients of suspended sediment are almost invariant.The diffuse attenuation coefficient of per unit concentration of suspended sediment used in the experiment gradually decreases from 0.084 to 0.069 m2/g with wavelength from 350 to 920 nm.