| Eutrophication of water body has already become a global difficult problem in controlling water pollution, and was one of the most important environmental problems. At present, eutrophication of inland water caused by water pollution was very serious in China. It was one of the main environmental problems limiting economic development of China. Protection and prevention from water pollution in three lakes, namely Taihu lake, Dianchi lake and Chaohu lake, has been listed among the most important projects in the Ninth Five-Year Plan of national environmental protection.Qiandao lake lies in the west of Zhejiang Province, China. It is a large reservoir formed after the artificial dam of hydropower station of Xin'an river was built in 1959. The whole area above the basin is 10442km2. Qiandao lake has been used for many purposes such as electricity generation, flood control, tourism, fishery, shipping and so on , which has a great influence on entironment and sustainable development of Zhejiang Province. Qiandao lake has always been famous for excellent water quality, while in recent years, along with the development of regional economy, the sign of trophism appears. Strengthening the dynamic monitoring , control the dynamic states of water quality of the reservoir, especially the main tributary of the upper reaches in time and set up the dynamic monitoring of water quality of large area using remote sensing technology ,will have great values for research and application .This research was based on the water quality parameters data and spectra reflection data which were collected in Qiandao lake in 2001,10, and satellite remote sensing data of different date. The main objectives of this study involved the following: the hyper-spectral reflection features of different trophic states of water and the correlation between alga chlorophyll-a content and spectral reflection of Qiandao lake ; the spectral reflection features of suspended sediment of different contents in lab ; structuring a series of multi-spectral and hyper-spectral variables and models for simulating or prospecting the content of chlorophyll-a and suspended sediment of the water body; some qualitative and quantitative research was done on the water quality of Qiandao lake using satellite remote sensing data.Results of this research were summarized as following: (1) The essential feature of spectra reflection of different trophic states water body isshown as: with the chlorophyll-a content increasing , the peak and valley of spectra reflection curve become more remarkable, and the position of reflecting peak near 700nm of chlorophyll-a moves toward long wave band gradually, locates at between 690nm and 730nm.The spectral curve of the most eutrophied water body has two obvious reflecting peaks at about 550 nm and 700 nm. The Peak value was maximal and closer to the long wave band . The more eutrophied water body formed the reflecting peak at the same location , but the height was declined and the position of the peak near the short wave band. The spectral curve of the least eutrophied water body was similar to the spectra of clean water ,the trend was very flat and there was no obvious peak existing.(2) Spectral features of different contents of suspended sediment: in the range of 340nm to 2500nm, two reflecting peaks are found locating at about 815nm and 1070nm respectively, while the spectra shows flat between 560nm and 720nm . The high-reflection appears at visible light wave band and behind 1160nm, the reflecting rate of the spectra decline to about zero gradually. When the depth of water body was fixed , with suspended sediment content increasing, the reflecting rate of the spectra increases . The spectral curve shows remarkable changes at some bands, such as 650nm,760nm and 820nm and the position of reflecting peak moves toward long wave band . Between 490nm and ISOOnm, the correlation between suspended sediment content and reflecting rate are positive.(3) Structuring a series of spectra variables and corresponding models, simulating t...
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