Determining the sources of nutrient flux to water in headwater catchments: Examining the speciation balance to inform the targeting of mitigation measures
Determining the sources of nutrient flux to water in headwater catchments: Examining the speciation balance to inform the targeting of mitigation measures
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DOI：
10.1016/j.scitotenv.2018.08.190
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发表时间：
2019-01-15
影响因子：
9.8
通讯作者：
Collins, A. L.
中科院分区：
文献类型：
--
作者：
Lloyd, C. E. M.;Johnes, P. J.;Collins, A. L.
农业水污染（DWPA）是一个主要的环境问题，对人类和生态系统健康产生重大不利影响。然而，如果对影响水的多种因素没有适当的了解，缓解措施就无法有针对性。因此，本文解决了这一理解上的差距，报告了从英国政府示范测试集水区 (DTC) 计划收集的水化学监测证据，包括对比白垩和粘土/泥岩集水区。我们使用在多个地点每天和次日收集的数据来解决：(1) 全系列氮 (N) 物种和磷 (P) 组分的行为有何变化？ (2) N 形态和 P 分数在年际和年内有何变化？ （3）这些数据说明了哪些主要污染源？ (4)哪些扩散污染缓解措施适合我们的研究景观？根据流域特征，确定了养分通量速率的主要差异。完整的氮形态和磷分馏以及溶解有机碳 (DOC) 能够识别每个流域中最可能的贡献源。硝酸盐（NO3-N）是白垩中的主要氮成分，而有机氮和颗粒氮构成了粘土/泥岩流域中的大部分负荷。尽管有现行立法，但在任何监测的流域中，均未发现正磷酸盐 (PO4-P) 是磷的主要形式。白垩子流域的无机/溶解有机磷（DOP）比例最大，同时伴有颗粒磷（PP）的间歇性输送。相比之下，粘土/泥岩子流域负荷以 PP 和 DOP 为主。因此，我们的结果表明，通过监测无机和有机部分，可以更全面地确定流域养分通量，并查明污染源。最终，只有采用多重压力源方法，控制营养影响的政策和管理才会成功。 (C) 2018 作者。由 Elsevier B.V. 出版
Diffuse water pollution from agriculture (DWPA) is a major environmental concern, with significant adverse impacts on both human and ecosystem health. However, without an appropriate understanding of the multiple factors impacting on water, mitigation measures cannot be targeted. Therefore, this paper addresses this gap in understanding, reporting the hydrochemical monitoring evidence collected from the UK Government's Demonstration Test Catchments (DTC) programme including contrasting chalk and clay/mudstone catchments. We use data collected at daily and sub-daily frequency over multiple sites to address: (1) How does the behaviour of the full range of nitrogen (N) species and phosphorus (P) fractions vary? (2) How do N species and P fractions vary inter- and intra-annually? (3) What do these data indicate about the primary pollution sources? And (4) which diffuse pollution mitigation measures are appropriate in our study landscapes?Key differences in the rates of flux of nutrients were identified, dependent on catchment characteristics. Full N speciation and P fractionation, together with dissolved organic carbon (DOC) enabled identification of the most likely contributing sources in each catchment. Nitrate (NO3-N) was the dominant N fraction in the chalk whereas organic and particulate N comprised the majority of the load in the clay/mudstone catchments. Despite current legislation, orthophosphate (PO4-P) was not found to be the dominant form of P in any of the catchments monitored. The chalk sub-catchments had the largest proportion of inorganic/dissolved organic P (DOP), accompanied by episodic delivery of particulate P (PP). Contrastingly, the clay/mudstone sub-catchments loads were dominated by PP and DOP. Thus, our results show that by monitoring both the inorganic and organic fractions a more complete picture of catchment nutrient fluxes can be determined, and sources of pollution pin-pointed. Ultimately, policy and management to bring nutrient impacts under control will only be successful if a multistressor approach is adopted. (C) 2018 The Authors. Published by Elsevier B.V.