Phosphorus dynamics in groundwater-fed rivers

地下水供给河流中的磷动态

基本信息

批准号：
NE/G001707/1
负责人：
Ann Louise Heathwaite
金额：
$ 73.83万
依托单位：
Lancaster University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2008
资助国家：
英国
起止时间：
2008 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FG001707%2F1
关键词：
Phosphorus dynamics groundwater fed rivers

项目摘要

Reducing diffuse nutrient pollution is a prime focus of measures to improve the environmental status of UK rivers. In groundwater-fed rivers, processes operating in the hyporheic zone (HZ) and its interchange with surface waters (SW) are key drivers of the ecological health of the river. The HZ is the subsurface region beneath, or adjacent to, a SW body where mixing occurs with groundwater (GW). This zone is hydrologically, geochemically and microbiologically complex. Large redox-driven concentration gradients exist across the sediment-water interface. The resulting potential for complete consumption of dissolved oxygen in hyporheic flowpaths 10-100 cm into the streambed creates areas where anaerobic microorganisms dominate microbial activity, which in turn control the bioavailability of redox-sensitive elements such as nitrogen (N) and, indirectly, phosphorus (P). The retention/release of P through interaction between HZ flows and in-river (SW) processes may be particularly important because elevated P concentrations have been linked to increased rates of plant growth, changes in species composition and proliferation of planktonic and epiphytic and epibenthic algae in rivers. Such rivers often fail to meet the standards of the EU Water Framework Directive necessitating the introduction of expensive mitigation measures. These measures can only succeed if we understand the processes controlling the ecological health of the river. This project seeks to unravel these controls in relation to P dynamics in groundwater-fed rivers.The focus in on understanding of the temporal variation in nutrient processes in groundwater-fed rivers.

减少扩散营养物污染是改善英国河流环境状况措施的首要重点。在地下水补给的河流中，潜流带 (HZ) 及其与地表水 (SW) 的交换过程是河流生态健康的关键驱动因素。 HZ 是 SW 体下方或附近的地下区域，在此与地下水 (GW) 发生混合。该区域的水文、地球化学和微生物学都很复杂。沉积物-水界面上存在较大的氧化还原驱动浓度梯度。由此产生的潜在可能会完全消耗河床 10-100 厘米的潜流流道中的溶解氧，从而形成厌氧微生物主导微生物活动的区域，进而控制氮 (N) 等氧化还原敏感元素的生物利用度，并间接控制磷（P）。通过 HZ 流和河内 (SW) 过程之间的相互作用保留/释放磷可能特别重要，因为磷浓度升高与植物生长速度加快、物种组成变化以及浮游、附生和表栖藻类的增殖有关在河流中。此类河流往往无法达到欧盟水框架指令的标准，因此需要采取昂贵的缓解措施。只有了解控制河流生态健康的过程，这些措施才能取得成功。该项目旨在阐明与地下水供水河流中磷动态相关的这些控制。重点是了解地下水供水河流中营养物过程的时间变化。