Remote Sensing Based Water Quality Evaluation Index Research

With the rapid economic development and industrialization, water pollution becomes increasingly serious, which affects not only national production but also people's living water, in some areas which has become an important factor to restraint economic development. Therefore, we must strengthen the water quality evaluation index monitoring and make a comprehensive evaluation of the degree of water pollution , in order to establish and actualize the correct management,decision and control of program.Based-on the analysis result of surface water monitoring data and MODIS image data, this paper systematically studied the issues related to the lake water, Set up a system of evaluation criteria ,especially analysis the spectral characteristics, monitoring principles and research methods of the indicators of remote monitoring (including chlorophyll a, suspended solids and chemical oxygen). Through the use of correlation analysis and Partial correlation analysis theory, we researched the correlation among the system of evaluation criteria. And we can see that there is a strong correlation between chlorophyll a and chemical oxygen demand.Based on the region of research for MODIS image , regression models and GA based Spectral mixture analysis model were separately used to construct the corresponding inversion model of suspended. solid,chlorophyll a and chemical oxygen demand and so on. Based on the integrated features of water spectral characteristics, the paper attempts to study the integrated index; According to the water quality evaluation model, using ENVI Software to produce the concentration level map of Taihu Lake .As an applied instance, this paper use the gray clustering and TSI method to evaluate the water quality of Taihu Lake region, according to the established evaluation system, We can see that the water quality of Taihu are from mesotrophy to middle mesotrophy.