Evaluation of Lake Eutrophication Based on the HJ-1 Satellite Multispectral Data

Abstract

Chinese domestic satellite HJ-1 was launched in 2008, now it has become a significant resource for environment monitoring because its Multispectral data are characterized by 2-day temporal resolution, 30 m spatial resolution and 700 km breadth. A study case was made that HJ-1 multispectral data were used for retrieving aggregative trophic level index (TLI()) of water body of lakes in Wuhan, China. The aim of this study is to evaluate the probability of HJ-1 Multispectral data on estimating the eutrophic level of inland water. At first, the TLI() of sampling spots of some lakes in Wuhan were calculated using the monitoring water quality data. In the mean time, the NDVI of corresponding spots were calculated from the HJ-1 multispectral data which had been taken radiometric calibration and geometric correction beforehand. After that, a remote sensing inversion model for TLI() had been built through linear regression using the NDVI as independent variables. Finally, the TLI() of all water bodies of Wuhan lakes were inversed with this model and a map for its spatial distribution was drawn up. Results demonstrated that there were good linear correlation relationships between the TLI() and NDVI of HJ-1 Multispectral data, and the distribution of inversed TLI() of the lakes accorded with the reality quite well. According to the above, an inference can be made that the methods to evaluate lakes eutrofication based on the HJ-1 satellite multispectral data may provide a cheap and rapid way for real-time monitoring and evaluation of lakes eutrophication.