Identification of groundwater nitrogen point source contribution through combined distribute temperature sensing and in-situ UV photometry

通过组合分布式温度传感和原位紫外光度测定识别地下水氮点源贡献

• 批准号: 208194744
• 负责人: Professor Dr. Lutz Breuer
• 金额: --
• 依托单位: Professur für Landschafts-, Wasser- und Stoffhaushalt
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/208194744?language=en
• 关键词: Identification; groundwater; nitrogen; point; source

Agriculture is the major contributor of nitrogen to ecosystems, both by organic and inorganic fertilizers. Percolation of nitrate to groundwater and further transport to surface waters is assumed to be one of the major pathways in the fate of this nitrogen. The quantification of groundwater and associated nitrate flux to streams is still challenging. In particular because we lack understanding of the spatial distribution and temporal variability of groundwater and associated NO3- fluxes. In this preliminary study we will focus on the identification and quantification of groundwater and associated nitrate fluxes by combining high resolution distributed fiber-optic temperature sensing (DTS) with in situ UV photometry (ProPS). DTS is a new technique that is capable to measure temperature over distances of km with a spatial resolution of ~1 m and an accuracy of 0.01 K. It has been applied successfully to identify and quantify sources of groundwater discharge to streams. ProPS is a submersible UV process photometer, which uses high precision spectral analyses to provide single substance concentrations, in our case NO3-, at minute intervals and a detection limit of less than 0.05 mg l-1 (≈0.01 mg NO3--Nl-1). We will conduct field experiments using artificial point sources of lateral inflow to test DTS and ProPS based quantification approaches and estimate their uncertainty. The selected study area is the Schwingbach catchment in Hessen, Germany, which has a good monitoring infrastructure. Preliminary research on hydrological fluxes and field observations indicate that the catchment favors the intended study.

农业是生态系统氮的主要贡献者，包括有机和无机肥料。硝酸盐渗透到地下水和进一步运输到地表沃茨被认为是这种氮的命运的主要途径之一。地下水和相关的流硝酸盐通量的量化仍然具有挑战性。特别是因为我们缺乏了解的空间分布和地下水和相关的NO3-通量的时间变化。在这项初步研究中，我们将集中在地下水和相关的硝酸盐通量的识别和量化相结合的高分辨率分布式光纤温度传感（ECOMS）与原位紫外光度法（ProPS）。温度测量是一项新技术，能够测量公里距离上的温度，空间分辨率约为1米，精度为0.01 K。它已成功地应用于确定和量化地下水排放到河流的来源。ProPS是一种潜水紫外过程光度计，它使用高精度光谱分析，以分钟为间隔提供单一物质浓度，在我们的情况下，NO3-，检测限小于0.05 mg l-1（≤ 0.01 mg NO3--Nl-1）。我们将进行现场实验，使用人工点源的横向流入，以测试基于量化方法和估计其不确定性的反渗透和ProPS。选定的研究区域是德国黑森州的Schwingbach集水区，该集水区具有良好的监测基础设施。水文通量的初步研究和实地观测表明，流域有利于预期的研究。