川中丘陵区小尺度范围非点源氮素流失特征分析  

Characteristics of non-point nitrogen exported from small scale hilly area in middle Sichuan Province

作　　者：刘泉[1,2] 朱波[2] 杨小林[3] 黄文军[1] 任三强 LIU Quan ZHU Bo YANG Xiaolin HUANG WenjunI REN Sanqiang(Mianyang Normal University, Mianyang 621000, China Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China Henan Polytechnic University, Jiaozuo 454000, China Water Resources Bureau of Shiquan County, Shiquan 725200, China)

机构地区：[1]绵阳师范学院,四川绵阳621000 [2]中国科学院水利部成都山地灾害研究所,四川成都610041 [3]河南理工大学,河南焦作454000 [4]石泉县水利局,陕西石泉725200

出　　处：《人民长江》2017年第5期21-25,共5页Yangtze River

基　　金：国家重点基础研究发展计划"973"项目(2012CB417101);中国博士后科学基金项目(2014M562338);绵阳师范学院博士科研启动项目(QD2014A002);四川省教育厅项目(16ZB0311)

摘　　要：为研究自然降雨条件下紫色土地块-小流域尺度农业非点源氮素随径流流失的特征,采用野外径流观测法,对2011年川中某紫色土丘陵区12次典型降雨产流事件进行了监测,测定径流量及径流中氮素浓度与负荷变化情况。结果表明:旱地流失负荷值远大于林地流失负荷值,且旱地氮素流失主要集中在施肥后的初期降水事件中,占流失总量的76.1%;壤中流氮素平均浓度为0.98~54.1mg/L;旱地氮素迁移有显著月变化特征,明显受到当地施肥习惯和汛期降雨量影响。陈家湾农林复合小流域氮素迁移特点分析表明,该小流域受到多种土地利用类型影响,径流氮素浓度波动范围不大;但在大雨降雨事件中,浓度在降雨后期有所升高,体现了"末期冲刷效应"。研究结果可为调控长江上游紫色土丘陵区氮素流失提供参考。In order to study the characteristics of agricultural non - point nitrogen loss in runoff from small purple plot - catch- ment of Sichuan, 12 rainfall events in the study area were selected to monitor the runoff yielding, nitrogen concentration and cal- culate the exported nitrogen load by runoff. The results showed that the exported nitrogen load from upland field was much greater than that from forest land and the amount of exported nitrogen from the upland field in the early rainfall accounted for 76.1% of the total loss after fertilization. The average concentration of nitrogen in subsurface flow was 0.98 - 54.1 mg/L ; the nitrogen ex- ported from upland field varied monthly, which was apparently influenced by local fertilization and precipitation in rainy season. The nitrogen export characteristics in Chenjiawan agroforestry small catchment showed that the nitrogen concentration in runoff was stable because of the multiple land uses. However, the nitrogen concentration increased in the later stage of the heavy rainfall e- vents, which exhibited a strong ＂ end flush＂ effect of the total nitrogen （TN）. The exported nitrogen load showed a significant monthly variation characteristics. This research can provide a feb＇fence for the regulation and control of non - point nitrogen loss in the hilly area of purple soil in upper Yangtze River.

关 键 词：非点源氮 径流 流失负荷 地块-小流域尺度 

分 类 号：TV121[水利工程—水文学及水资源]