Phosphorus distribution characteristics in sediments of Three Gorges Reservoir Area during the exposed period
三峡库区出露期消落带沉积物磷分布特征

In order to reveal the source-sink alternation of phosphorous based on the entire anti-seasonal dry-wet cycle in the fluctuating zone, we analyzed the distribution characteristics and content changes of phosphate in sediments of Three Gorges Reservoir Area (TGRA) during the exposed period. The result indicated that macroscopically, total phosphorous (TP) accumulated in sediments in the fluctuating zone which experienced the entire anti-seasonal dry-wet cycle for the first time. However, the TP in submerged sediment was bigger than TP in exposed sediment. It indicated the upper layer of exposed sediments was eroded because of abundant rainfall and water and sand discharge in summer. Anti-seasonal wet-dry alternation is helpful to discharging relatively stable occlude phosphorus (O-P) and calcium bounded phosphorus (Ca-P) and promotes the accumulation of active phosphorus (Ac-P) and organic phosphorus (Or-P) in sediments.