目前水体重金属遥感反演相关研究仍比较薄弱。 自然界中重金属污染水体的光谱特征研究是重要的基础性工作, 是将来实现卫星遥感反演时波段选择的重要理论依据, 也是遥感反演模型所必须的基础参数。 首先利用Analytical Spectral Devices(ASD)光谱仪, 测量获得以大宝山尾矿水为例的典型重金属污染水体在两种水深和两种光照条件下的离水反射率光谱曲线, 发现在600~700 nm(红波段)均有稳定的反射峰, 然后进一步与自然界常见的两类水体(浑浊水体和富营养化水体)的反射峰位置进行对比, 发现: 以长湖水库石英砂厂附近为例的浑浊水体反射峰在550~700 nm(绿、 红波段), 以北江韶关冶炼厂附近为例的富营养化水体反射峰在550~600 nm(绿波段), 3种水体的反射峰位置各异, 说明该重金属污染水体反射率光谱与这两类水体具有很好的可分性。 然后在测量水体反射率基础上, 结合水质遥感模型和进行室内消光系数测量, 反演得到大宝山尾矿水体的总散射系数和总吸收系数光谱, 并进一步分离水分子吸收作用, 最终得到水中成分的综合吸收系数光谱曲线, 结果表明: 在紫光波段吸收最强, 在红光波段吸收最弱; 具体表现为: 从400 nm开始, 吸收系数快速递减, 在蓝绿光波段递减速度变缓, 从黄光波段又开始快速递减, 到676 nm达到极小值, 然后又快速增强至750 nm, 随后变化减缓。 最后结合水样的水质化验结果, 对该重金属污染水体的光谱成因进行分析, 发现现场水色和水中成分的综合吸收系数光谱特征皆与作者前期研究测量获得的硫酸铁溶液颜色及其吸收系数光谱特征吻合, 因此认为水中成分的光谱特征是由硫酸铁及其水解产物所引起。 以上说明该重金属污染水体的光谱特征明显, 反射峰和强吸收波长位置明确, 这是将来利用卫星遥感手段反演水中重金属浓度的重要特征波段。 该研究获得了以大宝山尾矿水为例的典型重金属污染水体反射率、 消光系数、 散射系数和吸收系数的光谱结果, 为日后推广至其他种类重金属矿的尾矿水体及水中成分光学参数反演提供方法依据, 也为将来利用卫星遥感技术对水中重金属浓度进行定量提取打下良好的理论基础。

At present, the research on remote sensing inversion of heavy metal in water is still relatively weak, therefore the study on the spectral characteristic of heavy metal polluted water in nature is an important basic work, which is an important theoretical basis for the band selection when realizing the remote sensing inversion, and the measuring results are also the important parameters necessary for the remote sensing inversion model in the future. Firstly, using Analytical Spectral Devices (ASD) spectrometer, measuring the water-leaving reflectance spectrum curve of mine drainage of Dabaoshan Mountain as an example of typical heavy metal polluted water under two different water depths and light conditions, we found that there was a stable reflection peak in 600~700 nm (red light). Then further comparing the reflection peak position of mine drainage of Dabaoshan Mountain with two types of water (turbid water and eutrophication of water) which are common in nature, we found that the reflection peak position of Changhu Reservoir near the Quartz Factory as an example of turbid water was in 550~700 nm (green and red band) and that of Beijiang River near the Shaoguan Smelter as an example of eutrophication of water was in 550~600 nm (green band), and the position of the reflection peak of these three kinds of water was different, which means that the reflection spectrum of this heavy metal polluted water has a good separability with these two common types of water. On this basis, through a combination of water quality remote sensing model and the indoor water extinction coefficient measurements, we obtained the scattering coefficient and absorption coefficient spectrum of the mine drainage of Dabaoshan Mountain, and further eliminated water molecules absorb effect, finally got the absorption spectrum curve of compositions in this heavy metal polluted water, with the results showing that: it absorbed the strongest in purple band, while the weakest in red band; Starting from 400nm, the absorption coefficient decreased rapidly, then slowdown in the blue and green light band; arrived at the yellow light band, it decreased rapidly again until 676 nm, which reached the minimum; then it increased rapidly to 750nm, and then the change slowed down. Finally, combined with the water quality test results of water samples, the causes of the spectrum of the heavy metal polluted water were analyzed, and we found that the water color in-situ and its absorption coefficient spectrum characteristics were consistent with the color and absorption coefficient of ferric sulfate solution measured in our previous study, therefore we considered that the spectral characteristic of this water sample was caused by the ferric sulfate and its hydrolysate. The results above showed that the absorption spectrum of the mine drainage of Dabaoshan Mountain had obvious characteristics, and the position of the reflection peak and strongest absorption wavelength was clear, which were the important characteristic bands for future extraction of heavy metal concentration in water using satellite remote sensing technique. In this paper, the reflectance spectrum, extinction coefficient spectrum, scattering coefficient spectrum and absorption coefficient spectrum of the mine drainage of Dabaoshan Mountain as an example of typical heavy metal polluted water were obtained for the first time, which provides a method basis for the optical parameters inversion of drainage in other heavy metal mines and also lays a good theoretical foundation for the quantitative extraction of heavy metal concentration in water using remote sensing technology in the future.