昆承湖水质状况遥感监测与空间特征分析

Remote sensing monitoring and spatial character analysis for water quality of Kuncheng lake

针对镇域水资源常规的监测方法不能满足对水质适时、大尺度的监测评价要求等问题,该文以江苏常熟辛庄镇昆承湖为例,分析叶绿素a(Chl-a)和悬浮物(SS)浓度值与水体归一化反射光谱、一阶微分反射光谱特征的关系,运用PEARSON法分析两者之间的相关性,确定Chl-a和SS的敏感波段,利用Chl-a和SS敏感波段归一化光谱反射值和实测浓度数据建立了水质参数反演模型。采用同时相ETM遥感数据对水质参数(叶绿素a和悬浮物)浓度进行遥感定量反演,并根据反演结果分析镇域水体污染空间分布特征。结果表明,对水质参数几个最大正(负)相关的光谱值进行波段组合处理可以提高反演精度,并且模型反演值和实测浓度值之间误差较低。通过对叶绿素、悬浮物等水质参数反演实现了对昆承湖水体污染状况的快速、准确和动态的信息获取和评价,有效地实时监测镇域水体在空间和时间上的变化状况和特性。

The article proposed an inversion model of water quality parameters based on the experiments results acquired in Kuncheng Lake of Xinzhuang town,Changshu city,Jiangsu province.The research analyzed the relationship of the concentration values of Chl-a and SS and the characteristics of water normalized reflectance spectrum and the first derivative reflectance spectrum,respectively.The relationship parameter R based on PEARSON method was applied to analyze the corresponding correlation of the four parameters separately,and optimizing sensitive bands for Chl-a and SS are determined.The water parameters were inversed quantitatively with the same temporal serial ETM images,and the spatial distribution of water pollution for the town region was analyzed.The results showed that the combination and processing for several maximum positive（negative）correlation values could improve the inversion accuracy,and the measured value and the inverted value had small relative errors.A fast,accurate and dynamic information acquisition and evaluation for the water pollution,and real-time monitor spatial and temporal change trend and characteristic of town region water could be achieved through the inversion of the water pollution parameters（Chl-a and SS）.