基于ASTER数据的混合像元分解技术在水质监测与评价中的应用

Decomposition Technique of Mixed Pixel Used in Monitoring and Evaluation of Water Quality Based on ASTER

以ASTER数据为数据源对湖北省钟祥市胡集虎山尾矿库水质状况进行了监测与评价。文中运用FLAASH模型对ASTER数据进行了大气辐射纠正,并对数据进行了几何纠正。因ASTER数据空间分辨不能很好地满足水质监测的精度要求,故而文中使用波谱沙漏分析对ASTER数据进行混合像元分解,提取到研究区的水体信息,同时在获得基于ASTER数据的纯净像元指数基础上,利用反距离权重算法对野外采样点处混合像元的光谱反射率值进行计算。通过对比试验结果,利用数学统计方法建立了实测污染物数据与水体反射率比值间显著相关的反演模型,并对模型进行显著性检验,最后利用建立的模型对水体反射率进行运算处理,得到研究区水体相应污染物浓度分布,完成了对研究区水体的水质状况的监测与评价。

This paper has made use of ASTER data to monitor and evaluate water quality of Hushan tailings,Zhongxiang city,Hubei province.FLAASH was used to atmospheric radiation correction,and geometric correction was done to the results further.Because the spatial resolution of ASTER data does not meet the precision requirement of water quality monitoring,this paper exert spectral hourglass analysis to decomposed mixed pixel of ASTER data,and finally got PPI.Then according to the theory of spatial autocorrelation,the reflectance of mixed pixel was computed.By comparing test results,the model was build that the relationship between the measured data of contamination and reflectance was clearly correlative,and it passed correlative test.At last,the model was used to calculate and create distributed graph of contamination of the water,so this paper has achieved monitoring and calculation of water quality research.