3rd UF Water Institute Symposium Abstract

Submitter's Name Lawrence Band
Session Name Opening Plenary - Day 1
Category Plenary Session
Author(s) Lawrence Band,  University of North Carolina (Presenting Author)
  Sources, Cycling and Coupling of Water, Carbon and Nutrients in Urban
  Urban watersheds include a complex mixture of land use, including natural and built ecosystem components. Alteration of nutrient sources, reduction in carbon assimilation and cycling, and increased hydrologic flashiness with increased impervious surfaces and drainage infrastructure have contributed to significant changes in the magnitude and timing of nutrient loading to aquatic systems. Channelization of streams and the drainage and filling of wetlands to satisfy demand for additional land has reduced ecosystem retention of nutrients, exacerbating increased stormwater and nutrient loading. Drainage networks have been repeatedly altered over the last century to support evolving goals and paradigms in public health, flood mitigation and stormwater pollution control. Changes in land use and infrastructure are accompanied by changes in human and institutional behavior in terms of direct addition, abstraction and redistribution of water, carbon and nutrients across terrestrial and aquatic ecosystems. The Baltimore Ecosystem Study has developed a long observational record of spatially distributed hydrologic and ecosystem processes across a gradient of rural through dense urban catchments. Observations of biogeochemical and socioeconomic components of these ecosystems have been used to construct conceptual and operational models to scale ecological patch-scale dynamics through heterogeneous watersheds. In this region, a reduction in nitrogen and phosphorus export to the Chesapeake Bay is having an important influence on new urban development and urban redevelopment. However, new measures taken to control nutrient export are combined with and interact with existing and historical practices prioritizing upland drainage, flood control, GHG reduction and urban climate controls. In this talk, I explore how coupled water, carbon and nutrient cycling and export interact along the rural to urban gradient, and how sources of nutrients shift from storm event through seasonal, interannual and decadal time frames. Strong coupling of hydrologic and biogeochemical cycling and transport, and direct and indirect individual and institutional behavior are evident in the empirical record, and have important implications for the management of urban hydrological and ecosystem form and pattern designed to minimize watershed stormwater and nutrient export.