[Assessment of Physico-chemical Properties and Phosphorus Fraction Distribution Characteristics in Sediments after Impounding of the Three Gorges Reservoir to 175 m].

In order to understand the characteristics of the distribution of sediment total phosphorus (TP) and phosphorus fractions in the mainstream sediments in the Three Gorges Reservoir (TGR) after impounding the water level to 175 m, 13 surface sediment samples were collected from the Wujiang to Maoping sections in October 2010. The physico-chemical properties, including organic matter content, particle grain size distribution, and major mineral analysis, as well as total phosphorus and its fractions in the sediment, were determined. Moreover, the relationships among phosphorus fractions, organic matter contents, and particle grain size were discussed, and the effect of the impoundment on sediment phosphorus accumulation and bioavailability was also evaluated.