Assessing Variability and Uncertainty in Green Infrastructure Planning Using a High-Resolution Surface-Subsurface Hydrological Model and Site-Monitored Flow Data

Lim, Theodore; Welty, Claire

doi:10.3389/fbuil.2018.00071

Cited by 17 publications

(12 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, the fact that changes in some metrics lacked statistical significance is partly a consequence of model uncertainty: Small relative changes might be observed if such levels of stormwater management were implemented in reality. Conversely, observation of SCM effects are limited by measurement uncertainty, climatic noise, and confounding effects of other human activities (Lim & Welty, 2018; Roy et al, 2014).…”

Section: Discussionmentioning

confidence: 99%

Sensitivity of Streamflow Metrics to Infiltration‐Based Stormwater Management Networks

Avellaneda

Jefferson

2020

Water Resources Research

View full text Add to dashboard Cite

As stormwater control measures (SCMs) capture surface runoff from impervious areas, a shift in the water balance and flow regime components may emerge in urban watersheds, but the amount of SCM treatment needed to detectably shift these components may vary. We used the Soil and Water Assessment Tool (SWAT) hydrologic model to assess the sensitivity of 16 hydrologic metrics as an increasingly dense rain garden SCM network was applied across the West Creek watershed, near Cleveland, Ohio (USA). As the area treated by SCMs increased, annual baseflow increases matched decreases in surface runoff, while water yield and evapotranspiration changes remained small. The stream's peak response to rainfall decreased with SCM implementation across storm sizes, ranging from the threshold rainfall depth (4.8 mm) to values higher than the design storm of a single rain garden (19 mm). SCM networks draining >20% of directly connected impervious area (DCIA) significantly decreased the magnitude of discharges with a return period of less than 1 year, the percentage of time above mean flow, and flashiness. Recession slopes and annual 1‐ and 7‐day low flows exhibited a slight response that fell within uncertainty limits of the model. Water balance and rainfall response metrics exhibited the greatest sensitivity to different intensities of stormwater management, while infrequent high and low flows were resistant to detectable change even at high levels of SCM treatment when model uncertainty was included.

show abstract

Section: Discussionmentioning

confidence: 99%

Sensitivity of Streamflow Metrics to Infiltration‐Based Stormwater Management Networks

Avellaneda

Jefferson

2020

Water Resources Research

View full text Add to dashboard Cite

show abstract

“…Besides the future directions discussed above, our immediate future work on improving this theoretical framework includes the development of methods and tools for characterizing within‐storm intensity patterns, network travel time, adjustment of the CSO separation lines and the CSO envelope, optimizing the design and siting of GI for CSO control, and applications in real sewersheds. Another future direction is to incorporate groundwater into the framework, guided by the work of Lim and Welty (2017, 2018) who pointed out that the locational effects can be amplified by the presence of substantial subsurface stormflow in the rainfall‐runoff response in the urban watershed.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, there are several assumptions made in our analysis that can have a substantial impact on the assessment of the CSO metrics (volume and frequency) and the GI's ability to control CSOs. These factors include sewer baseflow, leaking pipes (groundwater infiltration and exfiltration into sewer systems), soil permeability, groundwater level, evapotranspiration, and other GI types (e.g., detention GI with outlet control and stormwater disconnection) (Lim & Welty, 2018; Lucas & Sample, 2015; Pennino et al, 2016). The framework can provide insights into the first‐order controls of CSOs but to address these complications, detailed models, (e.g., SWMM and SWAT) are needed.…”

Section: Discussionmentioning

confidence: 99%

Assessment of Climate, Sizing, and Location Controls on Green Infrastructure Efficacy: A Timescale Framework

Hung

Harman

Hobbs

et al. 2020

Water Resources Research

View full text Add to dashboard Cite

We investigate how the effectiveness of green infrastructure (GI) to mitigate the frequency and magnitude of significant discharge events and combined sewer overflows (CSOs) depend on both climate and sewershed characteristics and propose a theoretical framework for a holistic assessment of GI's efficacy. The framework is based on the comparison of three characteristic timescales that control the production of peak discharge: rainfall duration (t r ), travel time in the sewer network (t n ), and the duration of rain that would be required to fill the GI's storage (t GI ). Storm events can then be characterized by two ratios of these timescales: T n = t n /t GI and T r = t r /t GI . A third dimensionless number characterizes critical storms during which adverse events (such as CSOs) occur and allows us to identify the combinations of T n and T r for which GI may substantially mitigate those events. The results of numerical experiments with the model demonstrate that the storms for which GI can substantially reduce peak discharge and CSO volume typically occur in a narrow band of T n and T r . Within that band, the efficacy of GI may depend on the location of GI within the sewershed if network routing substantially affects the timing and magnitude of flood peaks. The proposed framework is applied to examine the efficacy of GI using historical precipitation data from two major U.S. cities: Philadelphia, PA, and Seattle, WA, and the results of this comparative analysis suggest that GI location is an important control on catchment-scale GI efficacy in Philadelphia, but less so in Seattle.Plain Language Summary Combined sewer overflows (CSO) occur when storm rainfall exceeds the capacity of the sewer system to drain it. Green infrastructure (GI) is intended to mitigate the occurrence and severity of CSOs. But how effective will it be in helping to manage CSOs? Here we present a theoretical framework to address this question, by focusing on the major physical controls on the efficacy of GI for managing CSOs, including the relative roles of climate, the size of the sewershed, and the location of the GI within it. The framework is based on three characteristic timescales: storm duration, travel time to the overflow location, and time required to fill GI storage. We use the framework to explore how GI might work differently in different places. The results show that GI is most effective under certain combinations of climate and sewershed conditions, and that the location of GI within the sewershed can be very critical. The latter effect was found to be more evident, for example, in Philadelphia, PA, than in Seattle, WA, due to differences in storm duration and intensity between these two places. In these ways, the proposed framework can support green infrastructure planning by providing insights on location-effectiveness tradeoffs.

show abstract

“…The presence of trees and other plants that are part of the design can help to reduce volumes via evapotranspiration. Examples of this approach are wet detention ponds and stormwater wetlands (Jefferson et al, 2017; Lim & Welty, 2018).…”

Section: Green Infrastructurementioning

confidence: 99%

“…Examples of stormwater, infiltration‐based GI include bioretention cells, rain gardens, bioswales, permeable pavement, and green roofs. Other retention‐based stormwater treatment practices, such as wet detention ponds and stormwater wetlands are also designed to flatten the peak flow curve (Burns, Fletcher, Walsh, Ladson, & Hatt, 2012; Lim & Welty, 2018). The effect of GI and other stormwater treatment practices on stormflow and baseflow dynamics is difficult to assess and model (Hamel, Daly, & Fletcher, 2013).…”

Section: Introductionmentioning

confidence: 99%

Swimming through the urban heat island: Can thermal mitigation practices reduce the stress?

Timm

Ouellet

Daniels

2020

River Research & Apps

View full text Add to dashboard Cite

Green infrastructure (GI) and other stormwater management practices are commonly designed to reduce stormflow volume and pollutant loads by using infiltration, retention, and evapotranspiration to capture stormwater. Although these methods are be designed to reduce impacts of stormwater volumes and pollutant loads, they may not be designed to mitigate thermal load from stormwater runoff in urban areas. This review of literature identifies key drivers of stream temperature in urban streams, including heat transference from stormflow and effects of pipe networks and evapotranspiration on baseflow. Recent simulation studies indicate the need for more than bioretention, increased infiltration, and tree canopy mitigation practices to reduce heat stress in urban streams. These studies show greatest reductions in thermal load by applying cool surfaces as a single thermal mitigation practice (TMP) and comprehensive applications of TMPs to all available areas at the watershed scale. This review of available literature suggests that incorporating TMPs into current and future GI designs will help maintain water resources, water quality, aquatic ecosystems, and coldwater stream species across the landscape. Further research is needed on the most effective ways to implement TMPs as part of our current and future GI designs for stormwater and how to best incorporate these measures into urban design concepts at larger spatial scales. K E Y W O R D S bioretention, coldwater fish, cool surfaces, effective impervious, forest canopy, thermal load, urban stormwater 1 | INTRODUCTION Urbanization is known to impact stream fish communities, with previous research relating percent impervious surface in watersheds to changes in fish species diversity and tolerance to pollution (Roy et al., 2005). Specific stormwater hydrology processes related to impervious surfaces that drive temperature and thermal habitat characteristics for coldwater fish have not been explored extensively by the literature. Fish require specific ranges of temperatures to survive, successfully spawn, and recruit all life stages into the next generation, and thermal habitat connectivity throughout stream networks needs to be maintained (Al-Chokhachy, Wenger, Isaak, & Kershner, 2013). While stream water temperature increases have been documented throughout the United States, rates of increase are the greatest for urban streams (Kaushal et al., 2010). With urban land use in the United States projected to increase by 79% from 39.5 million hectares in 1997 to 70.5 million hectares by 2025, it is vital to understand the magnitude and mechanisms of thermal impacts to urban streams (Alig, Kline, & Lichtenstein, 2004) both from traditional and "green" urban infrastructure. Green infrastructure (GI) to treat stormwater is commonly designed to reduce stormflow volume and pollutant loads by using infiltration, retention, and evapotranspiration to capture stormwater. Examples of stormwater, infiltration-based GI include bioretention

show abstract

Assessing Variability and Uncertainty in Green Infrastructure Planning Using a High-Resolution Surface-Subsurface Hydrological Model and Site-Monitored Flow Data

Cited by 17 publications

References 68 publications

Sensitivity of Streamflow Metrics to Infiltration‐Based Stormwater Management Networks

Sensitivity of Streamflow Metrics to Infiltration‐Based Stormwater Management Networks

Assessment of Climate, Sizing, and Location Controls on Green Infrastructure Efficacy: A Timescale Framework

Swimming through the urban heat island: Can thermal mitigation practices reduce the stress?

Contact Info

Product

Resources

About