Evaluating Streamwater Dissolved Organic Carbon Dynamics in Context of Variable Flowpath Contributions With a Tracer‐Based Mixing Model
Evaluating Streamwater Dissolved Organic Carbon Dynamics in Context of Variable Flowpath Contributions With a Tracer‐Based Mixing Model
复制标题
使用基于示踪剂的混合模型评估可变流路贡献背景下的溪水溶解有机碳动力学
DOI：
--
复制
发表时间：
2021
影响因子：
5.4
通讯作者：
P. Raymond
中科院分区：
文献类型：
--
作者：
J. Saiers;J. Fair;J. Shanley;J. Hosen;S. Matt;K. Ryan;P. Raymond
本研究的重点是表征关键的陆地途径，提供溶解有机碳（DOC）流在水文事件和阐明这些途径的水和DOC通量的变化因素的贡献。我们在佛蒙特州（美国）四个流域（面积从0.4平方公里到139平方公里）的221个事件中记录了放电，电导率（SC）和荧光溶解有机物（FDOM）的高频测量。使用SC测量，以及流量的统计信息，我们将事件过程线分为三个陆地路径的贡献，我们称之为河岸快速流动，地下快速流动和缓慢流动的地下水。通道排放被用作混合模型的输入，该模型非常接近FDOM传感器测量的亚小时径流DOC浓度。地下急流，包括事件前的水，是主要的贡献者，河水DOC通量，而河岸急流，包括事件的水，是第二大贡献者，河水DOC通量，尽管包括最小比例的三个端元路径之间的径流产量。固定效应回归分析表明，DOC通量从端元途径和事件的大小之间的关系是一致的，在四个流域。该分析还表明，DOC通量的快速流动途径增加显着的温度和变化相反，但弱，与集水区前期湿度。我们认为，我们的方法，利用流中传感器，使高频测量在较长的时间内，可能适用于评估控制DOC输出从其他流域内外我们的研究区域。
This study focuses on characterizing the contributions of key terrestrial pathways that deliver dissolved organic carbon (DOC) to streams during hydrological events and on elucidating factors governing variation in water and DOC fluxes from these pathways. We made high‐frequency measurements of discharge, specific conductance (SC), and fluorescent dissolved organic matter (FDOM) during 221 events recorded over 2 years within four Vermont (USA) watersheds that range in area from 0.4 to 139 km2. Using the SC measurements, together with statistical information on discharge, we separated the event hydrographs into contributions from three terrestrial pathways, which we refer to as riparian quickflow, subsurface quickflow, and slow‐flow groundwater. The pathway discharges were used as input to a mixing model that closely approximated sub‐hourly streamwater DOC concentrations as measured with the FDOM sensors. Subsurface quickflow, comprised of pre‐event water, was the leading contributor to streamwater DOC fluxes, while riparian quickflow, comprised of event water, was the second‐leading contributor to streamwater DOC fluxes, despite comprising the smallest proportion of streamflow yield among the three end‐member pathways. Fixed‐effects regression analysis revealed that the relationship between DOC fluxes from the end‐member pathways and event magnitude was consistent across the four watersheds. This analysis also showed that DOC fluxes from the quickflow pathways increased significantly with temperature and varied inversely, but weakly, with catchment antecedent wetness. We believe that our approach, which leverages in‐stream sensors that enable high‐frequency measurements over extended periods, may be applicable for evaluating controls on DOC export from other watersheds within and beyond our study region.
影响因子：
4
作者：
J. Dick;D. Tetzlaff;C. Birkel;C. Soulsby
通讯作者：
J. Dick;D. Tetzlaff;C. Birkel;C. Soulsby
影响因子：
5.2
作者：
J. Zarnetske;M. Bouda;Benjamin W. Abbott;J. Saiers;P. Raymond
通讯作者：
J. Zarnetske;M. Bouda;Benjamin W. Abbott;J. Saiers;P. Raymond