Abstract: The numbers of manual monitoring section and fixed automatic monitoring station are limited and the spacing of monitoring section is large. Shipborne automatic monitoring of water quality is a new technical approach to study the transmission and distribution law of water pollutants as it can accomplish automatic monitoring with high density and multiple parameters. However, this technology needs to be further verified in applications. In this study, the "China Environmental Monitoring 008" monitoring ship was equipped with the automatic monitoring devicesto monitor the water quality in the mainstream of the Yangtze River (from Chongqing to Wuhan) and the Three Gorges Reservoir area. The spatial distribution characteristics of pollutants along the Yangtze River from Chongqing to Wuhan was obtained. Correlation was found between the distribution of some pollutants and pollution load produced by regional production and life. The feasibility and effectiveness of the automatic monitoring technology was evaluated through quality control and comparison between automatic monitoring and manual monitoring. The research finding provides technical support for large-scale, rapid, dynamic and continuous automatic monitoring of the Yangtze River and investigations on water quality characteristics and environmental risks.

Key words: water quality monitoring, distribution characteristics of pollutants, automatic monitoring, monitoring ship, Yangtze River