Study on spatial distribution of total suspended matter of Poyang Lake and its effect on the water quality

摘要

Suspended matters have a significant role on the overlying water. Nutrients and heavy metal released from sediments were an important source for lake eutrophication and pollution, especially for the shallow lakes. In this paper, HJ-1A/1B charge Coupled Device (CCD) data was collected to generate the Total suspended matter (TSM) concentration map of Poyang lake. Gaseous absorption and Rayleigh scattering effects was removed to get the reflectance of the lake and a TSM retrieve method called total suspended matter index (TSMI) at 660um wss used to retrieve the TSM concentration map from the HJ-1A/1B CCD images. During 15th to 23rd. Jul, 2011, A cruise survey was to get the in-situ data which was arranged to get the water samples to analyze the field TSM concentration of the lake, as well as the nutrients, Chemical Oxygen Demand (COD) and heavy metal concentration data. Results showed that it was a high TSM concentration in Northern part of the lake while it is a low TSM concentration in the southern part of the lake. Spatial Correlation analysis was used to find the relationship between the TSM and the nutrients data, as well as the heavy metal data and the COD data. Total phosphorus (TP) had a higher relationship (R2=0.756 and Sig.<=0.01) with the TSM concentration data along the main course of the lake while the Total nitrogen has no relationship to it. The COD concentration varied with the TSM concentration changed. The heavy metal concentration (Cu, Pb, Zn) were in a low level in the lake and only Pb was related to the TSM concentration at the 0.05 confidence level.