Washington Brittany N, Groffman Peter M, Duncan Jonathan M, Band Lawrence E, Miller Andrew J
Department of Earth and Environmental Sciences, Brooklyn College of the City University of New York, Brooklyn, New York, USA.
Advanced Science Research Center, Graduate Center of the City University of New York, New York, New York, USA.
J Environ Qual. 2025 Jan-Feb;54(1):257-274. doi: 10.1002/jeq2.20654. Epub 2024 Dec 8.
Hydrologic alterations associated with urbanization can weaken connections between riparian zones, streams, and uplands, leading to negative effects on the ability of riparian zones to intercept pollutants carried by surface water runoff and groundwater flow such as nitrate (NO ) and phosphate (PO ). We analyzed the monthly water table as an indicator of riparian connectivity, along with groundwater NO and PO concentrations, at four riparian sites within and near the Gwynns Falls Watershed in Baltimore, MD, from 1998 to 2018. The sites included one forested reference site (Oregon Ridge), two suburban riparian sites (Glyndon and Gwynnbrook), and one urban riparian site (Cahill) with at least two locations and four monitoring wells, located 5 m from the center of the stream, at each site. Results show an increase in connectivity as indicated by shallower water tables at two of the four sites studied: Glyndon and Cahill. This change in connectivity was associated with decreases in NO at Glyndon and increases in PO at Glyndon, Gwynnbrook, and Cahill. These changes are consistent with previous studies showing that shallower water table depths increase anaerobic conditions, which increase NO consumption by denitrification and decrease PO retention. The absence of change in the forested reference site, where climate would be expected to be the key driver, suggests that other drivers, including best management practices and stream restoration projects, could be affecting riparian water tables at the two suburban sites and the one urban site. Further research into the mechanisms behind these changes and site-specific dynamics is needed.
与城市化相关的水文变化会削弱河岸带、溪流和高地之间的联系，从而对河岸带拦截地表水径流和地下水流携带的污染物（如硝酸盐（NO ）和磷酸盐（PO ））的能力产生负面影响。我们分析了1998年至2018年期间，马里兰州巴尔的摩市格温斯瀑布流域内及附近四个河岸带站点的月地下水位，将其作为河岸带连通性的指标，同时分析了地下水中NO 和PO 的浓度。这些站点包括一个森林参考站点（俄勒冈岭）、两个郊区河岸带站点（格林登和格温布鲁克）以及一个城市河岸带站点（卡希尔），每个站点至少有两个位置和四个监测井，位于距离溪流中心5米处。结果显示，在所研究的四个站点中的两个站点（格林登和卡希尔），地下水位变浅表明连通性增加。这种连通性的变化与格林登的NO 减少以及格林登、格温布鲁克和卡希尔的PO 增加有关。这些变化与之前的研究一致，之前的研究表明，较浅的地下水位深度会增加厌氧条件，从而增加反硝化作用对NO 的消耗并减少PO 的滞留。在预计气候是关键驱动因素的森林参考站点没有变化，这表明包括最佳管理实践和溪流恢复项目在内的其他驱动因素可能正在影响两个郊区站点和一个城市站点的河岸带地下水位。需要进一步研究这些变化背后的机制以及特定地点的动态。
