scholarly journals Modeling a Bioretention Basin and Vegetated Swale with a Trapezoidal Cross Section using SWMM LID Controls

Author(s):  
Julia Bond ◽  
◽  
Essoyeke Batchabani ◽  
Musandji Fuamba ◽  
David Courchesne ◽  
...  

The Low Impact Development (LID) Control module is utilized in the United States Environmental Protection Agency’s Stormwater Management Model (USEPA SWMM) to predict the hydraulic performance of a variety of sustainable stormwater technologies. Data collected in 2019 from the monitoring of a pilot project in Montreal was used to verify the ability of the Bioretention LID Control (which assumes a rectangular cross-section) to accurately simulate outflow from a structure with a trapezoidal cross-section. Two types of LID facility were modeled: one releases captured inflow through a perforated underdrain below the soil layer (bioretention basin; BB); and the other is drained at the surface of the soil layer (vegetated swale; VS). Initially, the modeled LID structures were sized identically to the field surface areas. However, it was necessary to change their model representation to account for the non-rectangular shape of the soil layer. In addition, a sensitivity analysis was completed, and the most influential parameters were identified as the conductivity slope and seepage rate. Both the alteration of the LID structure representation and the parametric calibration greatly improved the simulated outflows from the vegetated swale resulting in an increase of the Nash–Sutcliffe efficiency (NSE) coefficient from −0.6 to 0.64 (NSE >0.5 is acceptable for hydrologic models according to the literature). The bioretention basin calibration did not prove as successful. The evaluated LID Control module presented better predictive capabilities for the basin with a simpler overall design (VS).

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2119
Author(s):  
Luís Mesquita David ◽  
Rita Fernandes de Carvalho

Designing for exceedance events consists in designing a continuous route for overland flow to deal with flows exceeding the sewer system’s capacity and to mitigate flooding risk. A review is carried out here on flood safety/hazard criteria, which generally establish thresholds for the water depth and flood velocity, or a relationship between them. The effects of the cross-section shape, roughness and slope of streets in meeting the criteria are evaluated based on equations, graphical results and one case study. An expedited method for the verification of safety criteria based solely on flow is presented, saving efforts in detailing models and increasing confidence in the results from simplified models. The method is valid for 0.1 m2/s 0.5 m2/s. The results showed that a street with a 1.8% slope, 75 m1/3s−1 and a rectangular cross-section complies with the threshold 0.3 m2/s for twice the flow of a street with the same width but with a conventional cross-section shape. The flow will be four times greater for a 15% street slope. The results also highlighted that the flood flows can vary significantly along the streets depending on the sewers’ roughness and the flow transfers between the major and minor systems, such that the effort detailing a street’s cross-section must be balanced with all of the other sources of uncertainty.


2021 ◽  
pp. 155982762110078
Author(s):  
Jennifer M. Drost ◽  
Pauline H. Lucas ◽  
David C. Patchett ◽  
Melissa R. Hatley ◽  
Daniel C. Johnson ◽  
...  

Purpose: High-value care is becoming increasingly important as the United States shifts toward a more sustainable health care system. Lifestyle medicine (LM) may be the highest-value model of care. Surprisingly, however, it is taught in a minority of medical schools. In this article, we describe a pilot project of introducing a brief LM course taught within the Mayo Clinic Alix School of Medicine in Arizona. The main purpose of the course was to introduce the students to LM as a specialty practice and to provide students with foundational knowledge of the pillars of LM. Results: Students reported improved personal health habits and increased confidence in LM competencies.


2001 ◽  
Vol 68 (6) ◽  
pp. 865-868 ◽  
Author(s):  
P. Ladeve`ze ◽  
J. G. Simmonds

The exact theory of linearly elastic beams developed by Ladeve`ze and Ladeve`ze and Simmonds is illustrated using the equations of plane stress for a fully anisotropic elastic body of rectangular shape. Explicit formulas are given for the cross-sectional material operators that appear in the special Saint-Venant solutions of Ladeve`ze and Simmonds and in the overall beamlike stress-strain relations between forces and a moment (the generalized stress) and derivatives of certain one-dimensional displacements and a rotation (the generalized displacement). A new definition is proposed for built-in boundary conditions in which the generalized displacement vanishes rather than pointwise displacements or geometric averages.


Children ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 261
Author(s):  
Priya Patel ◽  
Andrew Houck ◽  
Daniel Fuentes

Variability in neonatal clinical practice is well recognized. Respiratory management involves interdisciplinary care and often is protocol driven. The most recent published guidelines for management of respiratory distress syndrome and surfactant administration were published in 2014 and may not reflect current clinical practice in the United States. The goal of this project was to better understand variability in surfactant administration through conduct of health care provider (HCP) interviews. Questions focused on known practice variations included: use of premedication, decisions to treat, technique of surfactant administration and use of guidelines. Data were analyzed for trends and results were communicated with participants. A total of 54 HCPs participated from June to September 2020. In almost all settings, neonatologists or nurse practitioners intubated the infant and respiratory therapists administered surfactant. The INSURE (INtubation-SURrfactant-Extubation) technique was practiced by 83% of participants. Premedication prior to intubation was used by 76% of HCPs. An FiO2 ≥ 30% was the most common threshold for surfactant administration (48%). In conclusion, clinical practice variations exist in respiratory management and surfactant administration and do not seem to be specific to NICU level or institution type. It is unknown what effects the variability in clinical practice might have on clinical outcomes.


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