Correlations Between Water Quality Indexes and Reflectance Spectra of Huangpujiang River
黄浦江水质指标与反射光谱特征的关系分析

This study was conducted to establish correlations between reflectance spectra and water quality indexes of the Huangpujiang River of Shanghai, sampled in August and November of 2002.31 typical stations were selected to measure the spectral reflectance and 9 water quality parameters were analyzed for every measured stations,including Total Phosphorous(TP),Total Nitrogen(TN),Chemical Demand Oxygen with potassium permanganate(COD_(Mn)) and with chromate (COD_(Cr)),Dissolved Oxygen(DO),Biological Demand Oxygen(BOD_5),Suspended Sediments and Turbidity.With significant correlation between the nine water quality indexes,TN and suspended sediment concentration were selected,then the paper mainly analyzed the correlations between the two water quality indexes and the normalized reflectance,its logarithm,derivative spectrum,and the ratio of spectral reflectance at different bands.The characterized bands were analyzed for the two water quality parameters with single band normalized spectral reflectance and the first derivative reflectance,and the linear models were built between the water quality parameters and the spectral reflectance ratios of different band,all these models had the good correlation coefficient of more than 0.75 between the two parameters and the spectra reflectance.