Hydroecological Organization and Dynamics in Urbanizing Watersheds

点击翻译按钮获取中文摘要

The linkages between the mechanisms and pathways of water movement through landscape, and the human/ecosystem processes controlling terrestrial-aquatic nutrient loading, have not been clearly understood. This area of research has been cited as a priority need in geographic, hydrologic, and ecosystem sciences. This project specifically assesses and quantifies the role played by the spatial organization and connectivity of watershed hydrologic and ecosystem form and process on the dynamics of nitrogen cycling and export in urbanizing watersheds. The work will include both natural and human modified landscapes, focussing on areas we are currently monitoring as part of the Baltimore Ecosystem Study, an NSF funded Long Term Ecological Research site. The project includes field sampling of soil moisture, stream discharge, and nutrient concentration patterns. An integrated spatial hydroecological data and simulation system (i.e., a geographic information system GIS) and a set of indices will be developed to predict and explain the sensitivity of ecosystem and catchment export of nitrogen to alterations in surface cover and hydrologic flowpaths.The project will develop important data, theory, and techniques assessing the impacts of human modification of integrated hydrologic and ecosystem processes at the landscape level (e.g., small catchments or neighborhoods). The GIS/modeling system represents and simulates the pattern of ecosystem, water, carbon, and nutrient storage and cycling along drainage flowpaths at the hillslope scale (ridge to stream). These drainage sequences in turn influence catchment export efficiency of nutrients at the scale of typical subdivisions in urbanizing watersheds. This project augments and complements the long term monitoring components of the Baltimore Ecosystem Study by providing higher spatial and temporal resolution information focussing on hydrologic and ecosystem processes within small watersheds that are amenable to design and restoration efforts. The research will generate a better understanding of the role of natural and designed landscape patterns on cumulative watershed impacts, a capability to evaluate alternative watershed development and restoration scenarios, and tools to rapidly screen existing development patterns for nutrient export potential.