HJ CCD Remote Sensing Monitoring Temporal And Spatial Variation Of Total Suspended Matter Concentration In Poyang Lake

Poyang Lake is the largest freshwater lake in china, where the inundation area shows great inter-annual variability and the Total suspended matter (TSM) has significant tempo-spatial distribution. Being a new technique in acquiring the large-scale data, remote sensing could play a critical role in monitoring the water dynamics, while the traditional filed measurement is impossible to fulfill this task. High frequent remote sensing data is particularly suitable in monitoring TSM concentration. This study choose the high temporal and spatial resolution data-HJ-1A/1B satellite Charge Coupled Device (CCD) data to investigate the change of TSM variations in Poyang Lake, the main achievements are as follows:1. A novel index for TSM retrieval was proposed, namely Total Suspended Matter Index (TMSI). Considering the dynamic nature of its inundation area, HJ-1A/IB CCD, with high temporal and spatial resolution, was selected as the main data source to monitor the total suspended matter concentration of Poyang Lake. A novel approach index was developed to retrieve the total suspended matter (TSM) concentration. For turbid waters, standard atmospheric correction method often failed in removing the molecule-aerosol multiple scattering from the satellite imagery, while the TSMI was proven to be more effective in detecting total suspended matter than other methods, which is primarily due to that most of the aerosol effects are removed by the baseline subtraction, and TSMI is insensitive to changes in solar/viewing geometry. The TSM estimates showed a satisfied accuracy, and this method could improve the potential of land-oriented sensors in water color applications.2. Considering the particle size distribution when using TSMI method to retrieve TSM concentration. Particle size distribution measurements of LISST (Laser In-Situ Scattering and Transmissomentry) were collected from three cruises in2008,2009and2011. The different contribution to the reflectance and the quality concentration of total suspended matter is partly due to different particle sizes. A remote sensing inversion model was presented using the empirical relationship between the LISST total suspended concentration data and HJ-1A/1B CCD total suspended matter index. Validation of various methods showed that the TSMI method is particularly suitable for monitoring turbid waters in Poyang Lake.3. The spatial and temporal distribution of total suspended matter in Poyang Lake. In total,151cloud-free HJ-1A/1B CCD images were selected from September2008to December2011, which has a spatial resolution of30m and temporal resolution of2days. Diurnal and seasonal variations of TSM in Poyang Lake were analyzed. Then, the change frequency of the TSM concentration was also studied to discuss the possible wet season and dry season seasonal changes in Poyang Lake, and the human interference to the TSM changes was also indentified. The most important finding is that the total suspended matter concentration in North Lake of Poyang Lake was higher than South Lake, which was due to the sand dredging activities from2009-2011.4. Dredging area delineation with HJ-1A/1B CCD imagery. With the TSM estimates using remote sensing data, the changes in annual TSM distributions were obtained, from which the sand dredging area in Poyang Lake was delineated during each year from2009to2011. Results showed that the total dredged sand close to the Songmen Mountain of Poyang Lake were more than60million tons from2009-2011, and the dredging activities appeared an increasing trend.