Three Gorges Reservoir Water Quality Parameters Of Hyperspectral Inversion Of The Data Processing And Analysis

The contents of Chlorophyll a, dissolved carbon and suspended substance in the inland water are the indicator of water eutrophic state, water color remote sensing can do much contribution to the aiding of water monitoring using classical measures and now become one of the hot research field. The Three Gorges dam is the biggest water conservancy in the world, which plays a big role in the political and economical aspects of China, meanwhile, the water quality changing of the Three Gorges reservoir affects the life of people by the side of the reservoir, all of the reasons mentioned above entails important meaning of water quality monitoring in the Three Gorges reservoir.In this research the water color remote sensing data CHRIS/PROBA is adopted, combining the in situ measured water spectrum, chlorophyll a and dissolved organic carbon concentration, retrieval algorithms based on semi-empirical statistic mode are explored for the Three Gorges reservoir.Correlative analysis between in situ measured hyperspectral data and chlorophyll a, dissolved organic carbon concentration are taken as the start to explore the regression relationship, using model tuning techniques to seek the sensitive band or band combination. According to the band combination selected by the model tuning technique, appropriate channels are picked out in the CHRIS bands settings and the algorithms are validated on the CHRIS images. Model simulated values and space distribution maps of Chlorophyll a and dissolved organic carbon are achieved as the results.The in situ measured water quality data show that the Three Gorges reservoir shares almost no common characteristics with other inland lakes such as Tailake, Chaolake, etc, which invalidates the classical algorithms drawn by the other scholars engaging in other water bodies. Using the experience of other scientists for reference, the author broke up the formula using several typical features such as 680nm absorption peak and 700nm fluorescence peak, as well as the blue to green ratio proposed by Gordon, a new form of multi-band ratio algorithms is built, compared to the in situ measured chlorophyll a and dissolved organic carbon values, the result derived from the new algorithms show pretty accordance.