亚热带农业小流域暴雨过程硝态氮迁移特征及水文示踪研究

发布时间：2018-02-27 13:17

  本文关键词： 农业小流域 硝态氮 暴雨径流 紫色土丘陵区 水文示踪　出处：《水利学报》2016年08期 　论文类型：期刊论文

【摘要】：为揭示亚热带丘陵区农业小流域暴雨过程中硝态氮迁移规律及其主要水文输送途径,本研究通过对紫色土丘陵区典型农业小流域典型暴雨过程跨尺度(从3~1 236 hm2)连续监测,分析径流硝态氮迁移动态特征及其尺度效应,并对比δ18O和硝态氮作为示踪剂的端元混合分析(EMMA)解析结果,探讨硝态氮作为暴雨过程水文示踪剂的可行性。结果表明:(1)两场暴雨事件中源头小流域苏荣小流域(含集镇污水)径流中硝态氮浓度最高,而到达梯级小流域出口处(万安小流域)硝态氮浓度最低,林地来水的贡献是较大尺度小流域径流硝态氮浓度降低的主要原因,坡耕地壤中流补给可能是径流消退过程中硝态氮出现浓度峰值的主要原因。(2)EMMA模型解析结果显示:δ18O与硝态氮均能示踪农业小流域径流消退期间壤中流补给过程;但硝态氮在受人居活动强烈影响子流域的示踪应用需谨慎。以农业为主的亚热带丘陵区小流域中,硝态氮具有同时作为环境效应指示剂和水文示踪剂的潜力,但其应用效果仍有待于进一步验证。
[Abstract]:Transportation of migration of nitrate nitrogen in subtropical hilly region revealed small agricultural watershed in the rainstorm process and main hydrology, through the study of typical rainstorm process in purple hilly area of typical agricultural watershed scale span (from 3~1 to 236 hm2) continuous monitoring, analysis of runoff nitrate migration dynamic characteristics and scale effect, and compared 18O. And nitrate as endmember tracer mixture analysis (EMMA) to investigate the analytical results, the nitrate nitrogen as the feasibility of rainstorm process of tracer hydrology. The results showed that: (1) two rainstorm events in small watershed source Su Rong small flow domain (sewage containing town) the concentration of nitrate nitrogen in runoff is highest, and arrived at the small watershed cascade exit (small watershed Wanan) the concentration of nitrate nitrogen was lowest, woodland runoff contribution is the main reason of large scale watershed runoff nitrate concentration decreased, slope cropland interflow recharge may be runoff recession process The main reason of nitrate nitrogen concentration peak. (2) analysis results of EMMA model showed that delta 18O and nitrate nitrogen were small watershed runoff agriculture tracer interflow dissipated during the recharge process; but the nitrate in the human activities are strongly influenced by the sub basin tracer applications need to be cautious. The agricultural small watershed subtropical hilly region, nitrate nitrogen has at the same time as the environmental effect indicator and hydrological tracer potential, but the effect still needs to be further verified.

【作者单位】： 中国科学院水利部成都山地灾害与环境研究所;中国科学院大学;
【基金】：国家自然科学基金项目(41371241) 科技部973课题(2012CB417101)
【分类号】：X52
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本文编号：1542820