PARENT SESSION
Symposium 9: Spatial heterogeneity in urban ecosystems: Integration and scaling in coupled natural-human systems
Organized by: ML Cadenasso, M Grove, and STA Pickett
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 517 C, Level 5, Palais des congrès de Montréal
Hydrological heterogeneity in urban ecosystems: Integrating the built, modified, and relict hydrologies with social and ecological processes.
Tague, Christina*,1, Pohl, Molly1, 1 San Diego State University, San Diego, CA
ABSTRACT- Urban ecosystems modify watershed hydrologic processes by altering the inputs of water, the residence times in different stores and the pathways that water takes as it moves through the landscape. Hydrologic models often represent these impacts through lumped coefficients that aggregate the multiple and interacting impacts of human and ecological processes. Alternatively, more bottom-up approaches can disentangle the roles played by specific processes and their spatial-temporal structure and can lead to new insights into the link between watershed hydrology, ecology and human systems. By using several case study watersheds in San Diego, California and Baltimore, Maryland, we illustrate the potential contribution of physically based models as a technique to evolve conceptual understanding of geographic pattern and process. We use the RHESSys (Regional Hydro-Ecologic Simulation System) to examine the internal watershed processes that control lateral soil moisture redistribution and terrestrial biogeochemical cycling and illustrate situations where the conclusions about the effects of urbanization on streamflow and nitrogen export are a function of within watershed spatial patterns. In particular, we explore how changes in drainage network organization associated with different patterns of suburban development result in a range of different hydrologic and ecosystem response. Through these examples, we address the issue of how the connection between urban design and pre-existing landscape patterns sets the stage for the resulting urban hydro-ecology.
Key words: urban, hydrology, nitrogen cycling