摘要
为探讨不同降雨和坡面类型的产流产沙及地表径流污染状况，选取北京延庆上辛庄3种坡面小区（灌草坡面、鱼鳞坑坡面、水平条坡面）、112场侵蚀降雨资料，对径流泥沙、氮磷流失量及化学需氧量（COD）值数据进行统计分析。结果表明：降雨量、最大30min和最大60min雨强是影响坡面产流产沙及水质的主要降雨指标，据此划分为Ⅰ型（大雨量、高雨强）、Ⅱ型（中等雨量、高雨强）、Ⅲ型（中等雨量、低雨强）、Ⅳ型（小雨量、低雨强）4种降雨类型；Ⅰ、Ⅱ雨型易引发坡面水土流失，流失量约占所有降雨总水沙量的90％；Ⅱ型暴雨更易引起水质污染，其产生的污染物可占总量的45％-50％，Ⅰ、Ⅲ、Ⅳ雨型下径流污染程度相似；水平条坡面在Ⅱ雨型下产沙能力大于另外2种坡面，灌草坡面在Ⅲ、Ⅳ雨型下产水产沙能力高于另外2种坡面；与灌草坡面相比，鱼鳞坑和水平条坡面氮素流失量增加，磷素流失量减少，COD值更低。
In order to explore the runoff and sediment yields and water quality characteristics un- der varying rainfall types, three types of slope plots （grass slope, fish-scale pit slope, and hori- zontal strip slope） in Yanqing County in Beijing and 112 erosive rainfall events were selected to analyze the losses of runoff-sediment, nitrogen and phosphorus, and chemical oxygen demand （COD）. The results showed that the precipitation and maximal 30 and 60 minutes rainfall inten- sities were the critical factors affecting runoff, sediment and water quality. Accordingly, four rainfall types were classified, i.e. Ⅰ （heavy rainfall, high rainfall intensity）, Ⅱ （medium rain- fall, high rainfall intensity）, Ⅲ （ medium rainfall, low rainfall intensity） and IV （ small rainfall, low rainfall intensity）. Types Ⅰ and Ⅱ were easier to cause water and soil loss, and accounted for 90% of total water and soil loss amounts. Type Ⅱ was easier to cause water pollution, and the resultant contaminants accounted for 45%-50% of the total amount. The water pollution level was similar among types Ⅰ ,Ⅲ and Ⅳ. Under type Ⅱ rainfall, the ability of runoff-sediment yield of horizontal strip slope was higher than that of the other two slopes, while under types Ⅲ and Ⅳ rainfall, the runoff-sediment yield of grass slope was the highest. Compared with the grass slope, N loss increased, P loss decreased, and COD amount was lower on fish-scale pit slope and hori- zontal strip slope.
出处
《生态学杂志》
CAS
CSCD
北大核心
2015年第12期3509-3517,共9页
Chinese Journal of Ecology
基金
国家林业公益性行业科研专项(201404209)资助
关键词
降雨类型
坡面径流小区
聚类分析
产流产沙
水质
rainfall type
slope runoff plot
clustering analysis
runoff and sediment yields
water quality.
