三峡库区消落带干湿交替表层沉积物磷分布特征

通过研究分析经历完整反季节干湿交替周期的三峡库区消落带沉积物中磷的赋存形态及含量变化,揭示了消落带沉积物磷的源/汇转化趋势。结果表明:三峡库区消落带本底土壤、覆水沉积物以及落干沉积物无机形态磷分布均呈现一致规律,即钙磷>闭蓄态磷>铝磷>铁磷>可交换态磷,反映出三峡库区短期反季节干湿交替对无机形态磷分布规律影响不大。消落带反季节干湿交替有利于表层沉积物中活性较高的有机磷、活性磷累积,有利于相对稳定的闭蓄态磷、钙磷释放。

Phosphorus Distribution Characteristics in Dry-wet Alteration Sediment of Fluctuation Zone in Three Gorges Reservoir Area

Analyses of content changes of phosphorus were made on sediments of Three Gorges Reservoir Area(TGRA) based on the time period of an entire anti-seasonal dry-wet cycle,in order to reveal the source-sink alternation of phosphorous in the fluctuating zone.The results show that the inorganic phosphorus distribution exhibited the same pattern in soils,submerged sediment and exposed sediment in TGRA,which means the content of different forms of phosphorous ranks as follows:calcium bounded phosphorus(Ca-P)> occlude phosphorus(O-P)> aluminum bounded phosphorus(Al-P)> iron bounded phosphorus(Fe-P)> exchangeable phosphorus(Ex-P).It also signifies that short-term anti-seasonal wet-dry alternation in TGRA has little impact on the inorganic phosphorus distribution.Besides,it is found that the anti-seasonal dry-wet alternation is conductive to accumulate relatively active formations,for instance,Ac-P and Or-P,while to discharge relatively stable formations such as O-P and Ca-P.