LTREB Renewal: Baltimore Urban Watershed Studies

Urban, suburban and exurban ecosystems are increasing in the U.S. This long-term study uses the watershed approach, which systematically tracks the inputs and outputs of water and associated substances from hydrologically defined basins. This approach has been central to advances in ecosystem ecology and watershed management for over 50 years. This project continues unique long-term observations, experiments, and modeling of watersheds across a gradient of human uses and urbanization in the Baltimore region. The project produces valuable datasets on urban hydrology, nutrients (nitrogen, phosphorus), salt (chloride), pathogens and contaminants such as metals and pharmaceutical compounds and contributes novel understanding of changes in water quantity and quality that are essential to urban water resource management. The project advances biotechnology with novel data and analyses to understand and improve the implementation of green infrastructure to cost-effectively manage stormwater. Such data and analyses are rare at the spatial and temporal scale of this project. This Long-term Research in Environmental Biology (LTREB) project on urbanizing watersheds continues an experimental design initiated by the Baltimore urban ecosystem Long Term Ecological Research project in 1998. Continuous data on stream stage and discharge as well as weekly water samples for nitrate, phosphate, total nitrogen, total phosphorus, chloride, sulfate, turbidity, temperature, dissolved oxygen, and pH are collected from eight long-term stream stations along an urban-rural gradient. The experimental design captures the integrated influence of the biological, physical, built, and social aspects of urban ecosystem structure on watershed dynamics. The Core Data comprise more than 25 years of continuous streamflow and multiple measurements from over 14,000 water samples, a physical archive of collected samples, and long-term data that provide mechanistic support for the watershed studies. This renewal project will test decadal-scale hypotheses about stream responses to urbanization (flashiness, nutrient/salt export) that account for interactions between precipitation changes, watershed characteristics and efforts to mitigate and manage watersheds with biotechnology and conventional approaches. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.