%I ELSEVIER
%K Science & Technology, Technology, Remote Sensing, Water transparency, Chinese lakes, Spatio-temporal variation, Water depth, Vegetation restoration, LONG-TERM MODIS, INLAND WATERS, LANDSAT IMAGERY, CLIMATE-CHANGE, SHALLOW LAKES, CLARITY, PHYTOPLANKTON, CARBON, RIVER, RESUSPENSION
%J International Journal of Applied Earth Observation and Geoinformation
%L discovery10107313
%X Water transparency, usually denoted by Secchi disk depth (SSD), represents the first-order description of water
quality and has important implications for the diversity and productivity of aquatic life. In China, lakes supply
freshwater and ecosystem services to nearly a billion people. Therefore, real time monitoring of lake transparency
is of great significance. Moreover, understanding how and why transparency varies in space and time in
response to different driving forces is needed to understand, manage, and predict lake water quality. Based on
the time-saving and low-cost Google Earth Engine cloud platform, this study developed a new algorithm for
quickly mapping SDDs in Chinese lakes. SDDs were retrieved for 412 Chinese lakes (> 20 km2) for the period
2000–2018. Results demonstrated that lake water depth spatially differentiated transparency. Deep lakes usually
had high transparency and water depth explained 88.81 % of the spatial variations. With increasing catchment
vegetation coverage and lake water depth, 70.15 % of lakes witnessed increasing transparency during
2000–2018. Of these 42.72 % were significant (p<0.05). Transparency of deep lakes was generally determined
by phytoplankton density not sediment resuspension. Minimum transparency occurred in summer. Future increases
in lake water levels in response to factors such as climate change may contribute to further improvements
in transparency. Management should focus on controlling eutrophication and increasing vegetation cover in
catchments.
%O This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/BY-NC-ND/4.0/).
%T Observations of water transparency in China's lakes from space
%V 92
%A D Liu
%A H Duan
%A S Loiselle
%A C Hu
%A G Zhang
%A J Li
%A H Yang
%A JR Thompson
%A Z Cao
%A M Shen
%A R Ma
%A M Zhang
%A W Han
%D 2020