Impacts of Novel Stormwater Management on Groundwater Recharge

Aditi S.博士Bhaskar已被授予NSF地球科学博士后奖学金，在美国地质调查局开展研究和教育计划。 城市发展的新形式旨在设计复制自然水文功能的系统。 这包括通过在产生雨水的不透水表面附近渗透雨水，保持近自然的地下水补给。 美国马里兰州皮埃蒙特省的一个小流域是最近开发的第一个仪表化流域，完全与新的，分布式雨水管理技术，并作为一个案例研究的工作。 本研究旨在了解这些对自然景观的改变如何影响地下水流系统和地下水-地表水相互作用。 将使用一个实地观察网络，包括测量径流、降水、水头、雨水控制措施的渗透和规格以及水力传导率。 现场数据将为三维分布式水文模型的应用提供信息，该模型建立在将相同的建模系统应用于其他城市地区的经验基础上。 这项工作将促进我们对城市发展如何改变水文功能的理解。 缓解战略，如分布式雨水管理，可能会以前所未有的方式改变水循环。 雨水的分布式渗透可能导致地下水补给超过开发前的水平。 这意味着，在自然系统中可能被植物蒸发或蒸腾的水，或者在传统开发的城市系统中产生的暴雨流，都被重新引导到地下水通道。 这些潜在的重大水循环变化的影响是未知的，但可能包括河岸生态和生物地球化学循环的方式，还没有很好地理解的显着变化。 了解这些缓解策略在模拟自然水文功能方面的有效性，将为自然水文系统的驱动因素和自然系统最敏感的景观变化提供一个窗口。 Bhaskar博士将与学生研究人员合作，并将在发达流域地区的高中开展教育推广活动，以实践介绍地球科学，水文学，地下水以及与该研究项目的联系。

Dr. Aditi S. Bhaskar has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at the United States Geological Survey. Novel forms of urban development aim to engineer systems that replicate natural hydrologic functioning. This includes preservation of near-natural groundwater recharge through infiltration of stormwater close to impervious surfaces where stormwater is generated. A small watershed in the Piedmont province of Maryland, USA is one of the first instrumented watersheds that was recently developed entirely with novel, distributed stormwater management techniques and is used as a case study for the work. This study seeks to understand how these alterations to the natural landscape impact subsurface flow systems and groundwater - surface water interactions. A network of field observations will be used, including measurements of streamflow, precipitation, hydraulic head, infiltration from and specifications of stormwater control measures, and hydraulic conductivity. The field data will inform the application of a three-dimensional, distributed hydrologic model, building on experience applying the same modeling system to other urban areas. The work will advance our understanding of how urban development alters hydrologic functioning. Mitigation strategies, such as distributed stormwater management, may transform the water cycle in previously unseen ways. Distributed infiltration of stormwater may result in groundwater recharge above pre-development levels. This means that water that might have evaporated or been transpired by plants in a natural system, or generated stormflow in a conventionally developed urban system, is instead redirected to groundwater pathways. The implications of these potentially major water cycle alterations are as yet unknown but may include significant changes to riparian ecology and biogeochemical cycling in ways that are not well understood. Understanding the effectiveness of these mitigation strategies in mimicking natural hydrologic functioning will provide a window into both the drivers of the natural hydrologic system and the landscape changes to which the natural system is most sensitive. Dr. Bhaskar will work with student researchers and will carry out education outreach to high schools in the area of the developed watershed for hands-on presentations about earth science, hydrology, groundwater, and connections to this research project.