You are here:
Urban watershed modeling in Seattle, Washington, to simulate hydrologic impacts of green infrastructure
Citation:
Barnhart, B., P. Pettus, Bob Mckane, J. Halama, P. Mayer, A. Brookes, AND K. Djang. Urban watershed modeling in Seattle, Washington, to simulate hydrologic impacts of green infrastructure. American Geophysical Union Fall Meeting, Washington, D.C, December 10 - 14, 2018.
Impact/Purpose:
This abstract and poster will be presented at the American Geophysical Union in Washington, DC on December 10-14, 2018. The conference will host scholars from academia as well as industry professionals from a variety of fields. In particular, this work will showcase EPA ORD WED’s modeling abilities using the VELMA watershed model and will highlight green roof scenarios in Seattle, WA to better understand the hydrologic impacts of large-scale implementations of green infrastructure. Therefore, academics will benefit from the insights into urban watershed modeling, and industry professionals may learn about the hydrologic impacts of targeting large quantities of green infrastructure in urban environments.
Description:
U.S. EPA’s Visualizing Ecosystem Land Management Assessments (VELMA) is a spatially explicit (i.e., gridded) watershed model that has recently been improved to simulate green infrastructure management in urban watersheds. We utilize the model to simulate watershed-scale hydrologic discharge for several urban stream systems in Seattle, Washington, including Thornton Creek, Piper’s Creek, Longfellow Creek, and Taylor Creek. A 1-meter land use classification is used to distinguish four cover types, including roads, buildings, trees, and grass. After model calibration and validation, we construct scenarios of hypothetical green roof implementations and simulate their impacts on watershed-scale discharge. The results show that approximately 30% annual flow reductions are possible when 100% of rooftops are converted to green roofs. We emphasize the utility of spatially explicit models for targeting green infrastructure in urban watersheds and the development of decision-support tools to aid in city planning.