Modeling Urban Hydrology and Green Infrastructure Using the AGWA Urban Tool and the KINEROS2 Model

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 with nine overland flow components that can be used to represent various land cover types commonly found in the built environment while treating runoff-runon and infiltration processes in a physically based manner. The AGWA Urban tool utilizes 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 on a residential subdivision in Arizona, USA, using 47 rainfall events (June 2005 to September 2006) to compare observed runoff volumes and peak flow rates with simulated results. Comparison of simulated and observed runoff volumes resulted in a slope of 1.00 for the regression equation with an R2 value of 0.80. Comparison of observed and simulated peak flows had a slope of 1.12 with an R2 value of 0.83. A roof runoff analysis was simulated for 787 events, from January 2006 through December 2015, 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 (S1 - base, S2 - with retention basins, S3 - with permeable driveways, S4 - with rainwater harvesting cisterns, and S5 - all GI practices from S2, S3, and S4) were simulated over the same period to compare the effectiveness of GI implementation at the parcel level on runoff and peak flows at the watershed outlet. Simulation results indicate a higher runoff volume reduction for S2 (53.41 m3 average capacity, average 30% reduction) as compared to S3 (average 14% reduction), or S4 (3.78 m3 capacity, average 6% reduction). Analysis of peak flows reveal larger peak flow reduction for S2. S3 showed more reduction of smaller peak flows as compared to S4.

Integrating Urban Planning and Water Management Through Green Infrastructure in the United States-Mexico Border

“…In addition to spatial variation of inputs (land use, slope, soils and rainfall), the spatial variation of outputs (infiltration, runoff, and erosion) can be accommodated (Goodrich et al, 2012). KINEROS has been used to determine the effects of various artificial features such as small detention reservoirs, green infrastructure, and gabion rock detention structures on flood hydrographs and sediment yield (Kennedy et al, 2013;Korgaonkar et al, 2018). In AGWA 3.x the Nogales Watershed was delineated and discretized using a mosaiced 0.6 m digital elevation model (DEM modified from the Santa Cruz County LiDAR dataset).…”

“…This land-use reclassification allows for a rapid evaluation of the different hydrologic responses to landscape changes and an assessment of maximum benefits to target mitigation activities (Norman et al, 2010a). The implementation of UGI in KINEROS with AGWA 3.x was highly simplified in order to model a large spatial area efficiently using existing model tools (Korgaonkar et al, 2018). While modeling UGI as wetlands has been previously vetted as an appropriate approach, there are important site-specific characteristics that are not captured.…”

“…Geospatial watershed models address the spatial variation that might occur in a landscape including variations in geology, soils, vegetation, land use/land cover, and precipitation patterns. Best management practices, such as stormwater control, can be input to models to determine the optimal placement for making desired improvements (Avellaneda et al, 2017;Korgaonkar et al, 2018), including for flood mitigation (Zellner et al, 2016), water quality (Korgaonkar et al, 2021) and equity (Garcia-Cuerva et al, 2018). Watershed models of Ambos Nogales have been used to predict impacts of best management practices , identify hotspots of erosion , and situate large rock detention structures (gabions) for optimal flood detention (Norman et al, 2010a,b).…”

Flood resilience in paired US–Mexico border cities: a study of binational risk perceptions

“…Green infrastructure has been proposed, and plans have been developed, for the twin city area over the past 10-20 years (Norman 2005;Norman et al 2008aNorman et al , b, 2010aViani 2019). The use of green infrastructure as a stormwater mitigation tool has been demonstrated to have significant hydrological impacts in other watersheds, and modeling in this region indicates that it could have potential to reduce runoff from flooding events (Norman et al 2008a(Norman et al , b, 2010aKorgaonkar et al 2018;Pennino et al 2016). In 2020, a proposal to develop "Sustainable Strategies for Stormwater and Combined Sewer Overflows Control in Ambos Nogales" was selected for funding by the North American Development Bank (NADBANK), a binational financial institution run by the Federal Governments of the USA and Mexico.…”

Integrated water management recommendations in practice: coexistence of old and new ways in Arizona

“…Apart from water demands, the characteristics of the built environment also co-determine flood risk. Installation of low impact development practices, such as rain gardens, permeable pavement, and riparian buffers, decrease surface runoff and peak flows (Korgaonkar et al, 2018;Hoghooghi et al, 2018).…”