典型海洋溢油污染的高光谱响应机理研究

Marine oil spill pollution is the major monitoring object in ocean environment. Different oil spill pollution types, such as oil slicks, oil-water mixture and black floating oil, could be produced in the oil transport and weathering processes and brought more damage to ocean environment. Identifying and estimating these marine oil spill types would help to oil spill recovery processing method selection, valuation of loss and claim indemnity. The light reflection, transmission, refraction and scattering effects of oil slick, oil-water mixture and black floating oil are difference. Therefore, the spectral response characteristics of these oil spill pollution types are difference. Hyperspectral remote sensing technology has the advantage of fine spectrum feature recognition, and played an important role in marine oil spill remote sensing research. However, the researches of hyperspectral response mechanism of these pollution types are still not perfect. In this project, marine diesel oil and crude oil would be used to simulate the oil slick with different thickness, the oil-water mixture with different concentration and the black floating oil with different viscosity in experiments. The spectral reflectance, physical and chemical parameters and some optics parameters of these samples should be collected and used to analyze the hyperspectral response characteristics, mechanism and changing rules of different oil spill pollution types. Based on optical radiation transmission analysis, some quantitative hyperspectral remote sensing models should be built by us for oil spill volume estimating. This research will improve oil spill optical remote sensing and provide more theory and method reference for future research.

海洋溢油污染是海洋环境监测的重点对象。溢油在迁移转化过程中，会形成海面油膜、油水混合物与黑色浮油等污染类型，危害会进一步扩散并加剧。识别与估算这些溢油污染具有重要的意义，有助于溢油回收处理方法的选取，损失评估与索赔。不同厚度海面油膜、不同浓度油水混合物与不同粘稠度黑色浮油对入射光的反射、折射、透射与散射作用各不相同，因此这些典型溢油污染的光谱响应特征差异明显。高光谱遥感技术具有识别地物精细光谱的优势，已经在海洋溢油遥感研究中发挥了重要作用，但典型溢油污染的光谱响应机理研究尚不完善。本项目选取典型原油与船用重柴油，设计海面油膜、油水混合物与黑色浮油的高光谱遥感实验，测量相关理化与光学参数，着重分析典型溢油污染的精细光谱响应特征及其变化规律，研究典型溢油污染的反射光谱响应机理，并基于辐射传输理论，构建典型溢油污染的定量遥感反演模型，为海洋溢油污染的高光谱遥感研究与应用奠定方法与理论基础。

进入海洋的石油在风化作用下，会形成多种不同的污染类型，快速准确的识别这些溢油污染类型，能为海洋溢油事故的监测与评估、油气资源勘探等提供有力的技术支撑；故其遥感探测、分类与量化一直是海洋资源与环境遥感研究领域的重点、难点与热点。申请人在本项目的支持下，在如下几个方面取得一定的研究成果：（1）阐明海洋溢油光学遥感的分类目标，即溢油污染形成的海面油膜、黑色浮油与油水混合物；基于模拟实验获取了上述典型溢油污染的反射光谱曲线，分析了其对入射光的光学作用过程（如反射、吸收、散射、干涉等），及其产生的光学响应特征，这是光学遥感识别、分类与定量估算的理论基础。（2）基于油膜的亮温控制与模拟实验，定量厘定了油膜厚度、表面亮温、观测时间、传感器参数（温度等效噪声，NE∆T）等要素之间的多维度协同关系，推导出MODIS、Landsat、ASTER等不同星载热红外传感器探测海面油膜厚度的增益系数与效能。（3）针对美国中等分辨率成像光谱仪（MODIS）影像，完善了近红外波段海面油膜归一化耀斑反射率的计算方法，消除了重大误差来源，可用于准确计算海面油膜表面粗糙度和折射率系数。（4）基于偏振模拟实验和偏振卫星观测数据，阐明了海洋溢油耀光反射的偏振遥感机理与优势，能克服光学临界角与表面粗糙度差异产生的不确定性影响。（5）国际上第一次阐明水体遥感反射率峰值（以761 nm为中心）的叶绿素荧光填充效应，发现了荧光遥感有效探测海洋藻类的新途径。在项目支持下，已经发表SCI论文12篇，其中Remote Sensing of Environment，Journal of Geophysical Research: Oceans，Optics Letters等高水平期刊论文5篇；培养/协助培养博士/硕士研究生6人；开展了广泛的国内外交流与合作研究，取得明显效果，合作研究正深入推进。研究成果进一步丰富了海洋溢油光学遥感的理论基础，能为海洋溢油的实时监测、识别分类与定量评估提供更好的解决方案。