[Characteristics of Phosphorus Speciation and Genesis in Typical Tributaries of the Three Gorges Reservoir].

A comparative analysis of phosphate occurrence and its genesis during different dispatching periods of representative level I tributaries of the Three Gorges Reservoir was conducted. For this, water quality, hydrodynamic force, and environmental data were examined for backwater areas of the Xiangxi River and Shennong River during the low-water-level period (June), storage period (September) and high-water-level period (December) in 2018. The results suggest that the mass concentration of total phosphorus (TP) in the water body of the coves of Xiangxi River and Shennong River range from 0.

[Vertical Distribution Characteristics of Dissolved Oxygen and Chlorophyll a in Typical Tributaries During the Impoundment Period of the Three Gorges Reservoir].

The water quality of the backwater areas in the Xiangxi River and Shennong River, which are typical tributaries of the Three Gorges Reservoir, was monitored in September 2018. The vertical distribution characteristics of dissolved oxygen, chlorophyll a, and other indicators in the two rivers were analyzed and compared, and the environmental factors affecting their vertical distribution were discussed. The results showed that the dissolved oxygen concentration 0-10 m and 0-12 m from the surface of the Xiangxi River and Shennong River, respectively, showed significant stratification and decreased with increasing water depth.

[Distribution Characteristics and Influencing Factors of Phosphorus in the Dongting Lake at Different Water Periods].

To study the distribution characteristics and influencing factors of phosphorus in the Dongting Lake at different water periods, water samples were collected from 18 representative monitoring sections located in the Dongting Lake and its upper rivers from January to December 2016. Various forms of phosphorus concentration in the samples were analyzed. The results showed that, overall, the average concentrations (range) of total phosphorus (TP), total dissolved phosphorus (DTP), and phosphate (DPO) in the Dongting Lake were 0.