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标题：Monitoring of Suspended Substance Concentration in Three Gorges Dam Based on the Semi- Analytical Model
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作者：GAI Li-Ya ; LIU Zheng-Jun ; ZHANG Ji-Xian 等
期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2008
卷号：XXXVII-B8
页码：779-786
出版社：Copernicus Publications
摘要：Chlorophyll a (chla) concentration is an important index of water quality evaluation. It is significant to build a quantitative remote sensing retrieval algorithm to inverse the chla concentration. With focus on the problems that empirical method is lack of the support of the physical theory and not robust in quantitative remote sensing monitor of SS concentration in inland water, the feasibility of spectrum and inherent optical properties analysis with clear physical meaning is discussed. Based on the experiment taken on 17th, November 2007, the characteristic spectrum, absorption coefficient and chla concentration are taken on 30 samples distributed along the reservoir where is far away from the dam above 3 kilometers. The absorption characteristic of the chlorophyll a and the contribution of the main constituents of the water (chlorophyll a, suspended substance, DOC) to the total absorption are analyzed. Based on the achievements we have acquired, two semi-analytical models using Gordon model is built to inverse the chla concentration. With the chla concentration on samples, the precision of the inversion models are tested. The results show that the no more than 30% of the inversion data whose estimation precision were over 70%.Further, the inversion method is applied on the multi-temporal image CHRIS to check the prison of the model, and the mean retrieval error is 50.17%.In despite of the low retrieval precision, the chlorophyll a concentration retrieval model is valuable in the remote sensing monitoring of the inland water quality. Many empirical/semi-analytical/analysis algorithms of inversing chlorophyll a concentration have been developed since the CZCS (costal zone color scanner) operates. The empirical statistic algorithms based on the "band ratio /combination" , the precision of which are higher in caseⅠwater, become the main algorithms on business(Ren Jing-ping,2002). For case Ⅱ water, the inversion precision can increased by choosing the appropriate bands and increasing the spectrum bands. These algorithms not only apply simply, but also calculate speedy. But there is a drawback that the applicability of them is worse. Semi-analytical algorithms which are based on the water color principle, integrate the empirical or subjective hypothesis values in the bio-optical model, using the bio-optical model to interpret or model the remote sensing data, then inverse the water component concentration from the remote sensing data by AOP band ratio and mathematics methods (Liu Chan-de, 2005). Semi-analytical algorithms are suitable for inland water color remote sensing monitoring due to its less dependency of the ground in-situ data. Especially with the development of the highspectral sensor technology and the optical instrument in ocean and lake, Semi-analytical algorithms play an important role in inland water color remote sensing monitoring. In this paper, we established the Semi-analytical algorithm of the Three Gorges Dam water using the Gordon model, then inversed the water components concentration with t he CHRIS data
关键词：Chlorophyll a; Semi-analytical model; Retrieval; Three Gorges Dam