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• 研究报告 • 上一篇    下一篇

北京延庆县雨型和坡面措施对水沙及污染物的影响

朱楠1,张会兰1,2**,马超1,2,歌丽巴1   

  1. 1北京林业大学水土保持与荒漠化防治教育部重点实验室, 北京 100083; 2北京林业大学北京市水土保持工程技术研究中心, 北京 100083)
  • 出版日期:2015-12-10 发布日期:2015-12-10

Runoff/sediment yield and pollutant characteristics under varying rainfall types and slope measures in Yanqing County in Beijing.

ZHU Nan1, ZHANG Hui-lan1,2**, MA Chao1,2, GE Li-ba1   

  1. (1Key Laboratory of Soil and Water Conservation and Combating Desertification, Ministry of Education, Beijing Forestry University, Beijing 100083, China; 2Soil and Water Conservation Engineering Research Centre of Beijing, Beijing Forestry University, Beijing 100083, China)
  • Online:2015-12-10 Published:2015-12-10

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30 min和最大60 min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。

关键词: 15N标记法, 幼苗富集, 种子传播, 稳定性氮同位素

Abstract: In order to explore the runoff and sediment yields and water quality characteristics under varying rainfall types, three types of slope plots (grass slope, fishscale pit slope, and horizontal 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 intensities 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 rainfall, 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 horizontal strip slope.

Key words: seedling accumulation, stable nitrogen isotope, 15N labeling method, seed dispersal.