我国南方红壤区氮磷湿沉降对森林流域氮磷输出及水质的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 我国南方红壤区氮磷湿沉降对森林流域氮磷输出及水质的影响 DOI: 10.5846/stxb201503030415 作者: 作者单位: 西南林业大学环境科学与工程学院,中国科学院地理科学与资源研究所,西南林业大学环境科学与工程学院,中国科学院地理科学与资源研究所,中国科学院地理科学与资源研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31570465）；中国科学院青年创新促进会资助项目 Impact of atmospheric nitrogen and phosphorus wet deposition on nitrogen and phosphorus export and associated water quality: a case study of forest watershed in the red soil area, Southern China Author: Affiliation: College of Forestry, Southwest University of environmental science and engineering,Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:持续高通量的氮、磷输入导致水体富营养化的问题已引起广泛关注。通过对江西省千烟洲香溪流域水样（常规水样，降雨后的地表径流以及雨水水样）的季节性监测，研究大气氮、磷湿沉降对森林流域氮、磷输出动态及水质的影响。结果表明：从2013年6月至2014年5月，香溪流域内氮、磷湿沉降通量分别为11.86 kg/hm2和0.38 kg/hm2，其中氮湿沉降主要集中在夏秋两季，占全年输入量的64%，而磷沉降主要集中在夏季，占全年输入量的43%，表现出明显的季节性差异；水体pH值（6.22-8.89）的变化范围较大，而且氮、磷的输出受土地管理（施肥方式）及降雨事件的影响较为明显，尤其在耕作期，总氮的输出量占全年氮输出总量的96.2%，而总磷的输出量占全年磷输出总量的61.4%；对4场不同强度降雨（按降雨强度从大到小）的氮、磷输出动态过程分析，发现不同强度的降雨对水体氮、磷的输出过程影响不同，在径流未形成前以及降雨强度达到暴雨级别时，降雨对流域水体氮、磷的稀释作用明显，而在大雨强度下水体磷的输出量明显高于其他降雨；研究期间，香溪流域内氮湿沉降对水体的贡献量为101.97 kg，磷湿沉降的贡献量为0.60 kg，4场降雨氮对流域水体的贡献量为4.46kg，占流域氮输出负荷的15.22%，磷对水体的贡献量为0.032kg，占流域磷输出负荷的0.85%。同时，根据营养状态指数（EI），发现流域水体全年处于中至富营养状态，而且研究期间水体氮、磷浓度均超过水体富营养化阈值（氮1.5 mg/L，磷0.15 mg/L），存在爆发水体富营养化的威胁。 Abstract:Continuously high flux of nitrogen (N) and phosphorus (P) input into rivers leading to water eutrophication has attracted public concern. The aim of the study was to determine the impact of N and P wet deposition on N and P transport in the forest watershed in Qianyanzhou, Jiangxi Province, China, based on the monitoring data from long-term sample and analysis. The results showed that from June 2013 to May 2014, the N and P wet deposition flux for the monitored watershed reached 11.86 kg/hm2 and 0.38 kg/hm2, respectively. There was a seasonal difference in deposition rates, wherein the N wet deposition mainly focus on the summer and autumn, accounting for 64% of total N wet deposition, whereas the P deposition mainly occurred in summer, accounting for 43% of total P wet deposition input. The pH fluctuation for watershed was large and the impact of land management (e.g., fertilizing) and rainfall events on N and P output were pronounced. The output of N and P mainly focus on the cultivation period, accounting for 96.2% and 61.4% of the total output from June 2013 to May 2014, respectively, which is because exogenous input of N and P from chemical fertilizers was large in this period. By analyzing the dynamic processes of N and P output during four rainfall events, we found that the impact of different intensities of rain events on the output process was different. The dilution effect on N and P output during rainfall process was significant before becoming runoff or rain intensity reached the storm level. Under heavy rain, P output was higher than that under other rainfall intensities. The contribution of N and P wet deposition to water were 101.97 kg and 0.60 kg, respectively. The N and P wet deposition in four rain events reached 4.46 kg and 0.032 kg, respectively, accounting for 15.22% of total N and 0.85% of total P output. According to the Eutrophication Index for the Xiangxi watershed, the water quality of the Xiangxi watershed is at moderate to severe degree of eutrophication state, especially during the cultivation period. We also analyzed that the N and P concentration in water during study period all exceeded the eutrophication threshold (N 1.5 mg/L, P 0.15 mg/L), which have the potential risk of water eutrophication. 参考文献 相似文献 引证文献