Remote Estimation of Suspended Matter Concentration in Hongze Lake, China Using the Experimental Tiangong-II Moderate-resolution Wide-wavelength Imager

Abstract

Total suspended particulate matter (TSPM) is an important indicator of water quality. Remote sensing has advantages of wide range and high time efficiency. The use of satellites to monitor TSPM concentration is of great significance for the study of water quality and eutrophication. Using the measured data on the ground and taking Hongze Lake as the research area, we compared and analyzed seven types of suspended particulate matter concentration estimation model based on Tiangong-II wide-band moderate-resolution widewavelength images (MWI), selected the TSPM concentration estimation model suitable for the MWI data of Hongze Lake, and verified the accuracy and applicability of MWI data products. The results show that the linear model constructed by using the band ratio combination of B5/B9 MWI data as a variable has a high estimation accuracy, with a determination coefficient of 0.94, an average absolute error percentage of 12.27%, and a root mean square error of 2.97 mg/L. Compared with the TSPM estimation results from the moderate-resolution imaging spectroradiometer data obtained on the same day, the two estimation results were similar, and the change trend of TSPM concentration is basically consistent. The TSPM concentration in Hongze Lake has an obvious spatial difference. Huaihe River Bay is affected by its inflow into the lake, and its TSPM concentration is the highest. The concentration in the east of the gulf of Lihe Bay was also affected by Huaihe River Bay. Owing to eutrophication, the TSPM concentration of Chengzi Bay is relatively high in some areas.