Publications

Yu, ZY; Yang, K; Luo, Y; Yang, YL (2021). Secchi depth inversion and its temporal and spatial variation analysis-A case study of nine plateau lakes in Yunnan Province of China. INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION, 100, 102344.

Abstract
Secchi depth (SD) can directly reflect the state of lake water quality, and it is the key to control and improve the lake environment at mastering long-term and large-scale. In this research, deep neural networks algorithm was used to derive SD of 9 major plateau lakes in Yunnan Province from January 2001 to December 2018 based on MODIS remote sensing images, and explored the spatial-temporal variation characteristics with SD by geospatial analysis. The results showed that: (1) The inversion model proposed in this paper had a good performance (RMSE = 0.1359, MAE = 0.1134), which can objectively reflect SD status in the lake. (2) The temporal variation characteristics showed that SD of all lakes has a downward trend with a mean comprehensive change rate of -0.25 m/decade. (3) The spatial variation characteristics showed that the region of higher SD has a larger decline rate, and the trend in the region with lower SD was relatively stable. SD near urban and residential areas was relatively low, and declined fast. (4) Human activities would become an important factor to affect SD changes in the plateau lakes of Yunnan Province, and it was also the main factor causing lake pollution in the Yunnan-Guizhou Plateau.

DOI:
10.1016/j.jag.2021.102344

ISSN:
1569-8432