放水冲刷对红壤坡面侵蚀过程及溶质迁移特征的影响

发布时间：2018-01-05 23:22

本文关键词：放水冲刷对红壤坡面侵蚀过程及溶质迁移特征的影响　出处：《土壤学报》2016年02期 　论文类型：期刊论文

【摘要】：坡面薄层水流侵蚀不仅造成土壤养分流失,土壤质量恶化,同时对水体污染等环境问题造成一定影响。为了分析上方来水流量对红壤坡面径流侵蚀过程中泥沙的迁移规律及土壤溶质运移特征的影响,本试验利用室内放水冲刷试验,采用3个不同上方来水流量(10 L min-1、15 L min-1、20 L min-1)对第四纪黏土发育红壤坡面径流侵蚀过程中坡面径流泥沙和径流中非吸附性离子(Br-)迁移过程进行了研究。结果表明:不同上方来水条件下,放水初期产流量迅速增大,后期趋于稳定,累积径流量与产流时间成显著的线性关系,10 L min-1、15 L min-1、20 L min-1三种上方来水流量下累积径流量分别为263.2 L、295.1 L、291.04 L;上方来水流量越大,薄层径流冲刷作用越强烈,径流含沙量随时间变化波动越剧烈,累积泥沙量随产流时间呈幂函数变化,15 L min-1、20 L min-1流量下累积泥沙量分别为10 L min-1流量下累积泥沙量的1.42倍、4.25倍;径流Br-浓度随产流时间呈幂函数衰减,反映了土壤溶质随径流迁移量变化主要受水流与土壤接触时间和作用程度的影响。研究表明放水冲刷对土壤侵蚀及溶质运移有重要作用,试验结果对有效预测与控制红壤坡面侵蚀及养分流失具有重要实际意义。
[Abstract]:Overland flow erosion not only caused the loss of soil nutrients, soil quality deterioration, also caused some impact on the environmental problems such as water pollution. In order to analyze the above inflow of migration and soil solute transport characteristics during sediment erosion red soil slope runoff influence, this experiment use indoor scouring test, using 3 different upslope flow rate (10 L min-1,15 L min-1,20 L min-1) on ion adsorption of Quaternary clay soil runoff erosion processes in runoff sediment and runoff in the non (Br-) migration process were studied. The results showed that different upslope conditions on the initial stage of runoff increased rapidly, but later stabilized. Cumulative runoff and production a significant linear relationship between flow time, 10 L min-1,15 L min-1,20 L min-1 three above the water flow under the cumulative runoff were 263.2 L, 295.1 L, 29 1.04 L; above the water flow is larger, the more intense the action layer of runoff erosion, sediment concentration change with time fluctuating, the cumulative amount of sediment runoff time was power function, 15 L min-1,20 L min-1 flow sediment accumulation were 1.42 times, the cumulative amount of sediment discharge of the min-1 10 L 4.25 times; the Br- concentration of runoff with runoff time exponentially decay, reflects the soil solute transfer with runoff volume change is mainly affected by water and soil contact time and degree. The results indicate that the scouring has important effect on soil erosion and solute transport, the test results has important practical significance for effective prediction and control of soil erosion and nutrient loss.

【作者单位】：华中农业大学水土保持研究中心;
【基金】：国家自然科学基金项目(41401303)资助~~
【分类号】：S157.1
【正文快照】： 我国红壤丘陵区地处热带、亚热带,包括长江流域的大部分及其南部,该地区水热资源丰富,是我国重要的农业生产区域。随着人们对土地资源长期的不合理开发与利用,该地区土壤遭到严重破坏,土壤侵蚀造成土壤肥力急剧下降,阻碍本区农业生产发展[1-2]。坡面是土壤侵蚀发生的基本单元,

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