黄浦江上游遥感监测溶解氧模型与时空变化

Monitoring Model and Temporal-Spatial Changes of Dissolved Oxygen Based on Remote Sensing:a Case Study in Huangpu River

溶解氧含量是反映水体有机污染的重要水质指标。文章选择黄浦江上游水源中的典型水质参数——溶解氧为研究对象,利用地面高光谱遥感数据、多光谱遥感数据和现场水质监测数据来研究水体反射光谱特征与水质参数浓度之间的关系,发现溶解氧含量与641 nm波段的光谱反射率相关性最高,由Landsat5 TM第3和4波段的遥感反射率比值变量所建立的对数模型相关性最高,达到0.829。在此基础上,基于多时相遥感影像对溶解氧模型的通用性和准确性进行验证,并探讨了溶解氧的时空变化规律。结果表明,该模型具有较高精度,估测值与地面实测值在时间变化规律上保持一致,同时根据该模型得出的黄浦江上游溶解氧含量空间分布规律与该区域的有机污染实际分布情况是相互吻合的。

The concentration of dissolved oxygen （DO） is one of the most important quality indicators to reflect the water organic pollution. In the present paper, the typical water quality parameter in Huangpu River upper region, namely dissolved oxygen （DO）, is chosen as the research object. Using ground hyperspectral remote sensing data, multispectral remote sensing data and in situ water quality monitoring data, the relation between the characteristic of water spectral reflectance and the concentration of DO is first analyzed. The result generated with the given monitoring methods indicates that the correlation between DO concentration and spectral reflectance at band 641 nm is the highest, while the logarithmic model using the ratio of Landsat5 TM band 3 to 4 as an independent variable has the highest correlation coefficient （0. 829）. The accuracy and the generality of the derived model are then tested, and the temporal-spatial changes of dissolved oxygen based on multi-temporal remote sensing imageries are further studied. The result shows that the DO model has a high accuracy, the temporal change characteristic of estimated DO is in consistency with that of measured ground data, and the DO concentration distribution derived from this model is also in accordance with the practical organic pollution distribution characters in this region.