| 西苕溪流域不同土地类型下磷素随暴雨径流的迁移特征 |
| 摘要点击 2330 全文点击 2105 投稿时间：2002-04-01 修订日期：2002-06-26 |
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| 中文关键词 土地利用类型 暴雨径流 磷素流失 人工降雨 |
| 英文关键词 land use types surface runoff phosphorous loss artificial rainstorm |
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| 中文摘要 |
| 选择太湖上游西苕溪流域最具代表性的5种土地类型,利用野外人工降雨装置(3m2),模拟天然大暴雨(降雨强度2 nm·min-1),研究了不同形态磷素随暴雨径流水相及沉积物相的迁移过程,对比了流域内不同土地利用/土地覆被条件下磷素的迁移特征并估算流失速率.3次平行实验结果表明,在相同的降雨条件下,地表径流中总磷的流失量桑林最大,高出水田和松林的5倍.地表径流水相中的悬浮颗粒态磷占水相总磷的绝大部分,溶解态磷的流失量菜地和桑林接近,高于松林,且远大于水田和竹林;地表径流水相溶解态磷主要以溶解态无机磷的形式流失,松林的流失量和流失速率远高于其他4种土地类型.各土地类型的地表径流沉积物相总磷流失量都随时间段的推移呈近似线性的下降趋势,桑林、菜地和竹林的流失量相对较大,松林最小.单位面积、表层10cm土壤的总磷流失量界于2.57～4.89g·m-2.地表径流水相总磷流失速率为0.45～4.11mg·(m2·min)-1,沉积物相高达72.82～135.96 mg·(m2·min)-1,桑林流失速率最大,松林最小. |
| 英文摘要 |
| Five typical land covers in West Tiaoxi catchment were studied on phosphorous loss in artificial rainstorm runoff. Triple duplication experiments were carried out under the artificial rain condition with intensity of 2 mm·min-1 lasting 32 minutes in 3m2 plot. Transportation and flux of various species of phosphorous in runoff and sediments were investigated. The results showed that phosphorous losses amount and rate were different among five types of land covers. The loss of total phosphorous in runoff of mulberry garden was the largest, which was five times higher than that of paddy and pinery field. The majority of total phosphorous in runoff was particulate phosphorous. Losses of dissolved phosphorous in vegetable plots and mulberry gardens were much higher than bamboo plot and paddy field. Loss of dissolved inorganic phosphorous in runoff was the main part of dissolved phosphorus, which pinery was much higher than others. Total amounts of phosphorous loss from top 10cm layer of 5 kinds of soils were estimated as high as 2.57～4.89g·m-2, of which phosphorous loss through sediment of runoff accounted for more than 97%. The rate of total phosphorous losses were ranged in 0.45～4.11 mg·(m2·min)-1 in runoff, which was much lower than that of 72.82～135.96 mg·(m2·min)-1 in sediment of runoff. |
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