摘要
为控制水体污染,改善水质,最大效率地降低磷素污染,迫切需要寻找非点源磷素流失的关键源区。采用半定量、经验性的流域尺度磷素流失危险分级方案,通过分析确定以土地利用类型为源因子,以坡度和区域至河流的距离为迁移因子,最大限度地识别缺资料小流域非点源磷素输出关键源区,并以辽宁社河农业小流域为例,通过GIS技术探索小流域磷素流失的关键源区。结果表明,社河流域大部分区域地表径流磷素流失风险等级为低,该部分区域面积占流域总面积的80%;河流两侧大部分农田非点源磷素流失风险等级属于中,该部分区域面积占流域总面积的13%;非点源磷素输出高风险等级的区域占流域总面积的7%,主要分布在流域内坡度较大、与河流距离较近的山区旱地和丘陵旱地等区域。需要对磷素输出关键源区域加强土地管理,降低非点源磷素负荷输出。
To control water pollution, improve water quality and largely reduce phosphorus pollution, it is essential and urgent to define critical source areas of non-point source phosphorus output loss. By using the semi-quantitative empirical catchment scale phosphorus loss risk grading scheme, landuse type as source factor and slope and distance from a river as transfer factors, critical source areas of non-point source phosphorus loss in data-deficient small watershed can be identified as definite as possible. Shehe agricultural watershed was used as an example for the work by means of GIS technology. Results show that about 80% of the Shehe watershed was sorted into the category of “low risk” of phosphorus loss with surface runoff, while 13% of the watershed, consisting mainly of farmlands alongside the river was in the category of “moderate risk”, and 7% of the watershed, consisting of upland areas high in slope gradient and close to the river, in the category of ＂high risk” . It is, therefore, necessary to intensify land management in this critical source area in the watershed in order to reduce non-point source phosphorus output.
出处
《生态与农村环境学报》
CAS
CSCD
北大核心
2014年第3期403-408,共6页
Journal of Ecology and Rural Environment
基金
水利部公益性行业科研专项(201101031
201201026)
关键词
小流域
非点源
磷素
关键源区
small watershed
non-point source
phosphorus
critical source area
