Modeling urban hydrology and green infrastructure using the AGWA urban tool and the KINEROS2 model

Authors: KORGAONKAR, Y. - University Of Arizona; GUERTIN, D.P. - University Of Arizona; Goodrich, David - Dave; Unkrich, Carl; KEPNER, W.G. - Us Environmental Protection Agency (EPA); BURNS, I.S. - University Of Arizona

Submitted to: Frontiers in the Built Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2018
Publication Date: 10/23/2019
Citation: Korgaonkar, Y., Guertin, D., Goodrich, D.C., Unkrich, C.L., Kepner, W., Burns, I. 2019. Modeling urban hydrology and green infrastructure using the AGWA urban tool and the KINEROS2 model. Frontiers in the Built Environment. 4:58. https://doi.org/10.3389/fbuil.2018.00058.
DOI: https://doi.org/10.3389/fbuil.2018.00058

Interpretive Summary: Urbanization has a profound influence on watershed hydrology by increasing runoff volumes and peak runoff rates. Incorporation of green infrastructure (GI) into developments such as infiltration gardens, rainwater harvesting cisterns, and permeable pavement is gaining acceptance as a measure to reduce post-urbanization runoff. The Automated Geospatial Watershed Assessment (AGWA) Urban tool was developed to simulate the hydrologic behavior of the built environments and GI using the Kinematic Runoff and Erosion (KINEROS2) model. The KINEROS2 model provides an urban modeling element that can be used to represent various land cover types and GI while treating runoff-runon and infiltration between and within the components in a physically based manner. The AGWA Urban tool provides a Geographic Information System (GIS) framework to prepare parameters required for KINEROS2, execute the model, and import results for visualization in the GIS. The AGWA Urban tool was validated against observed runoff with high confidence for runoff volume and peak runoff rate on the La Terraza subdivision in the city of Sierra Vista, Arizona. A roof runoff analysis was simulated for 787 events to analyze the water availability from roof runoff capture. Simulation results indicated a 15% capture of the average monthly rainfall volume on the watershed. Additionally, rainwater captured from roofs has the potential to provide for up to 70% of the domestic annual per capita water use in this region.

Technical Abstract: Urban hydrology and green infrastructure (GI) can be modeled using the Automated Geospatial Watershed Assessment (AGWA) Urban tool and the Kinematic Runoff and Erosion (KINEROS2) model. The KINEROS2 model provides an urban modeling element that can be used to represent various land cover types commonly found in the built environment while treating runoff-runon and infiltration between and within the components in a physically based manner. The AGWA Urban tool provides a Geographic Information System (GIS) framework to prepare parameters required for KINEROS2, executes the model, and imports results for visualization in the GIS. The AGWA Urban tool was validated against observed runoff with high confidence for runoff volume and peak runoff rate on the La Terraza subdivision in the city of Sierra Vista, Arizona. A roof runoff analysis was simulated for 787 events to analyze the water availability from roof runoff capture. Simulation results indicated a 15% capture of the average monthly rainfall volume on the watershed. Additionally, rainwater captured from roofs has the potential to provide for up to 70% of the domestic annual per capita water use in this region. Five different scenarios were simulated to compare the effectiveness of GI implementation at the lot level on runoff and peak flows at the watershed outlet. Results indicate a higher runoff volume reduction by retention basins as compared to permeable driveways or rainwater harvesting cisterns.