Abstract
China faces increasingly serious water scarcity due to the uneven distribution of available water resources, rapid economic development, and water pollution. The current war on water pollution by the Chinese government requires nationwide water quality information at high spatiotemporal resolution that can be obtained by only remote sensing (RS) methods. However, it is challenging to remotely retrieve such information from turbid Case-2 waters. This paper reviews four aspects of the major achievements in remotely sensed coastal and inland water quality in China. Specifically, achievements in atmospheric correction prior to water quality retrieval, progress in water-related sensor design, developments (improvements) to existing Case-2 water algorithms, and advances in oil spill and harmful algal bloom monitoring. Major challenges are identified, including: 1) a large mismatch exists between the water quality information required and RS datasets due to a lack of professional inland water sensors; 2) planned monitoring and field experiments for studying the optical properties of inland waters are scarce; and 3) RS of urban black odorous waters and international rivers is of great urgency. This review may provide scientific guidelines for obtaining information about coastal and inland waters and assist water resource managers and aquatic ecologists in controlling water pollution.
Acknowledgments
We gratefully acknowledge the financial support from the National Key R&D Program of China (2017YFB0503905), the Major Projects of High Resolution Earth Observation Systems of National Science and Technology (05-Y30B01-9001-19/20-1), and the National Natural Science Foundation of China (41671416). We also thank the USGS for providing Landsat, MODIS, and EO datasets. We are grateful to the editors and reviewers for their insightful and constructive comments.
Disclosure statement
No potential conflict of interest was reported by the authors.