流域磷素面源污染产生与输移空间分异特征

发布时间：2018-02-10 23:30

本文关键词： 流域面源磷河道迁移过程空间分布 SWAT模型　出处：《中国环境科学》2017年02期 　论文类型：期刊论文

【摘要】：u6于面源污染物从坡面产生后至向流域出口输出过程会发生一系列变化,如在河道迁移过程发生的沉降衰减,基于污染物产生与输出空间分布识别关键区会存在一定的差异.因此,本研究选取面源污染较为严重的高原湖泊洱海典型小流域,以子流域为空间分析单元,采用经实测数据验证后的定量模拟工具-SWAT模型和数学统计方法,分析流域面源磷产生与输出的空间分布及差异,评估河道迁移过程对两者空间分布差异的影响.结果表明:流域面源流失磷产生强度存在明显的空间分异特征,不同子流域流失磷的产生强度在1.52~1.82kg/hm~2之间变化,高强度区主要集中在有坡耕地分布的水文敏感区和植被覆盖度差的土壤侵蚀敏感区;不同子流域流失的磷经河道迁移后发生了-25.6%~21.6%的变化,导致流失磷的输出与产生空间分布出现差异,较高产生强度区,磷流失高输出强度区缩小为土壤侵蚀敏感区;不同子流域流失磷经河道迁移后发生的不同变化受流失磷产生强度与径流迁移时间的综合影响.
[Abstract]:U6, a series of changes will take place in the process of non-point source pollutants output from the slope to the outlet of the river basin, such as the subsidence attenuation in the course of river course migration. Based on the difference between the spatial distribution of pollutant generation and output, there are some differences in the identification of the key areas. Therefore, in this study, the typical small watershed of Erhai Lake, a plateau lake with serious non-point source pollution, is selected as the spatial analysis unit, and the sub-watershed is used as the spatial analysis unit. The spatial distribution and difference of the generation and output of non-point phosphorus in the watershed were analyzed by using the quantitative simulation tool -SWAT model and mathematical statistical method, which were verified by the measured data. The effects of channel migration on the spatial distribution of phosphorus loss were evaluated. The results showed that the intensity of phosphorus loss from non-point source was significantly different, and the intensity of phosphorus loss varied from 1.52 to 1.82 kg / hm ~ (-2) in different subbasins. The high intensity areas are mainly concentrated in hydrological sensitive areas with sloping cultivated land distribution and soil erosion sensitive areas with poor vegetation coverage, and the phosphorus loss in different subbasins has changed by -25.6% after the river course migration. As a result, the spatial distribution between the output and the generation of phosphorus loss is different, and the high output intensity area of phosphorus loss is reduced to the sensitive area of soil erosion. The changes of phosphorus loss in different subbasins were affected by the intensity of phosphorus loss and the time of runoff migration.
【作者单位】：农业部面源污染控制重点实验室;中国农业科学院农业资源与农业区划研究所;中国科学院测量与地球物理研究所;农业部环境保护科研监测所;云南省农业科学院农业环境资源研究所;
【基金】：公益性行业(农业)科研专项(201303089) 国家标准委科研项目《农村生态环境重要标准前期研究》
【分类号】：X52

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