• 关键词：磷  颗粒态磷  富集系数  沉积物  团聚体  地表径流

• 基金项目：国家自然科学基金(批准号49801019);国家“九五”重大基金(批准号39790100)

• 晏维金
• 中国科学院地理研究所环境质量室, 北京 100101

• 章申
• 中国科学院地理研究所环境质量室, 北京 100101

• 唐以剑
• 中国科学院地理研究所环境质量室, 北京 100101

• 摘要：通过模拟降雨径流实验,在72mm/h的大暴雨条件下,研究侵蚀性颗粒从土壤中的径流流失过程及其对磷的富集作用和机理.结果表明,沉积物中不同粒径团聚体的组成和原来土壤中的组成有很大差异.径流流失的沉积物主要以0.25mm以下的团聚体为主.径流中80%以上的磷以颗粒态形式流失,而颗粒态磷的60%—90%随0.1mm以下的团聚体流失.不同粒径团聚体对磷的富集作用和富集系数不同.模拟实验建立了沉积物富集系数与其累积流失量之间相关关系的经验模型:ln(ER)=1.15—0.22ln[SL],来预测颗粒态磷的流失.

• Abstract：The study on mechanisms of soil aggregates detachment by rainfall and loss by runoff was conducted to seek explanation for the enrichment of PP in eroded sediment and original soil (Meadow Drab Soil) in a rainfall simulation experiment with a constant rainfall rate of 72mmh^-1. The results showed that the aggregate size distribution of the eroded sediment was drastically different to that of the original soil. More than 80% of total P transported by runoff was in the particulate form, whereas 60%—90% of PP lost with finer aggregates smaller than 0 1mm. The study demonstrated that both the PP enrichment mechanism and enrichment ratio (ER) are different for different aggregate sizes. The ER for both larger aggregates (>0.1mm) and finer aggregates (<0.045mm) is higher than that of intermediate one (0.1—0.045mm). The enrichment mechanism of larger aggregates is due to the higher proportion of organic matter, while the higher content of clay in finer sediment is responsible for that of finer aggregates. A simple enrichment equation is proposed to predict the loss of PP: ln ER=1.15—0.22ln[soil loss].

• Key words：sediment, phosphorus (P)  particulate phosphorus (PP)  aggregate  enrichment ratio (ER)  runoff

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