scholarly journals Development of an empirical formula for estimation of bioretention outflow rate

Water SA ◽  
2019 ◽  
Vol 45 (2 April) ◽  
Author(s):  
Sezar Gulbaz ◽  
Cevza Melek Kazezyılmaz-Alhan ◽  
Rasim Temür
Keyword(s):  
Empirical Formula ◽  
Peak Flow ◽  
Groundwater Resources ◽  
Low Impact Development ◽  
Initial Moisture Content ◽  
Peak Flow Rate ◽  
Impervious Area ◽  
Outflow Rate ◽  
Cent Error ◽  
Peak Value

Urbanization of a watershed affects both surface water and groundwater resources. When impervious area increases, the excess runoff and volume of water collected at the downstream end of the watershed also increases, due to the decrease in groundwater recharge, depression storage, infiltration and evapotranspiration. Low-impact development (LID) methods have been developed in order to diminish adverse effects of excess stormwater runoff. Bioretention is one of the LID types which is used to prevent flooding by decreasing runoff volume and peak flow rate, and to manage storm-water by improving water quality. In this study, an empirical formula is derived to predict the peak outflow out of a bioretention column as a function of the ponding depth on bioretention, hydraulic conductivity, porosity, suction head, initial moisture content and height of the soil mixture used in the bioretention column. Coefficients of the empirical formula are determined by using metaheuristic algorithms. For analyses, the experimental data obtained from rainfall-watershed-bioretention (RWB) system are used. The reliability of the empirical formula is evaluated by calculating the absolute per cent error between the peak value ofthe measured outflow and the calculated outflow of the bioretention columns. The results show that the performance of the empirical formula is satisfactory.

Large-Scale Application of Biofiltration Swale Runoff Management Practices

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
William C. Lucas
Keyword(s):  
Large Scale ◽  
Management Practices ◽  
Peak Flow ◽  
Low Impact Development ◽  
Urban Runoff ◽  
Management Model ◽  
Check Dams ◽  
Runoff Reduction ◽  
Impervious Area ◽  
Hydrologic Responses

Retaining rainfall where it lands is a fundamental benefit of Low Impact Development (LID). The Delaware Urban Runoff Management Model (DURMM) was developed to address the benefits of LID design. DURMM explicitly addresses the benefits of impervious area disconnection as well as swale flow routing that responds to flow retardance changes. Biofiltration swales are an effective LID BMP for treating urban runoff. By adding check dams, the detention storage provided can also reduce peak rates. This presentation explores how the DURMM runoff reduction approach can be integrated with detention routing procedures to project runoff volume and peak flow reductions provided by BMP facilities. This approach has been applied to a 1,200 unit project on 360 hectares located in Delaware, USA. Over 5 km of biofiltration swales have been designed, many of which have stone check dams placed every 30 to 35 meters to provide detention storage. The engineering involved in the design of such facilities uses hydrologic modeling based upon TR-20 routines, as adapted by the DURMM model. The hydraulic approach includes routing of flows through the check dams. This presentation summarizes the hydrological network, presents the hydrologic responses, along with selected hydrographs to demonstrate the potential of design approach.

scholarly journals INVESTIGATING THE EFFECTS OF LOW IMPACT DEVELOPMENT (LID) ON SURFACE RUNOFF AND TSS IN A CALIBRATED HYDRODYNAMIC MODEL

2016 ◽  
Vol 9 (2) ◽  
pp. 091-096 ◽  
Author(s):  
Sezar Gülbaz ◽  
Cevza Melek Kazezyilmaz-Alhan
Keyword(s):  
Water Quality ◽  
Flow Rate ◽  
Hydrodynamic Model ◽  
Surface Runoff ◽  
Peak Flow ◽  
Low Impact Development ◽  
Sediment Accumulation ◽  
Suspended Solid ◽  
Storm Water ◽  
Peak Flow Rate

The land development and increase in urbanization in a watershed affect water quantity and water quality. On one hand, urbanization provokes the adjustment of geomorphic structure of the streams, ultimately raises peak flow rate which causes flood; on the other hand, it diminishes water quality which results in an increase in Total Suspended Solid (TSS). Consequently, sediment accumulation in downstream of urban areas is observed which is not preferred for longer life of dams. In order to overcome the sediment accumulation problem in dams, the amount of TSS in streams and in watersheds should be taken under control. Low Impact Development (LID) is a Best Management Practice (BMP) which may be used for this purpose. It is a land planning and engineering design method which is applied in managing storm water runoff in order to reduce flooding as well as simultaneously improve water quality. LID includes techniques to predict suspended solid loads in surface runoff generated over impervious urban surfaces. In this study, the impact of LID-BMPs on surface runoff and TSS is investigated by employing a calibrated hydrodynamic model for Sazlıdere Watershed which is located in Istanbul, Turkey. For this purpose, a calibrated hydrodynamic model was developed by using Environmental Protection Agency Storm Water Management Model (EPA SWMM). For model calibration and validation, we set up a rain gauge and a flow meter into the field and obtain rainfall and flow rate data. And then, we select several LID types such as retention basins, vegetative swales and permeable pavement and we obtain their influence on peak flow rate and pollutant buildup and washoff for TSS. Consequently, we observe the possible effects of LID on surface runoff and TSS in Sazlıdere Watershed.

scholarly journals INVESTIGATING THE EFFECTS OF LOW IMPACT DEVELOPMENT (LID) ON SURFACE RUNOFF AND TSS IN A CALIBRATED HYDRODYNAMIC MODEL

2016 ◽  
Vol 9 (2) ◽  
pp. 091-096
Author(s):  
Sezar Gülbaz ◽  
Cevza Melek Kazezyilmaz-Alhan
Keyword(s):  
Water Quality ◽  
Flow Rate ◽  
Hydrodynamic Model ◽  
Surface Runoff ◽  
Peak Flow ◽  
Low Impact Development ◽  
Sediment Accumulation ◽  
Suspended Solid ◽  
Storm Water ◽  
Peak Flow Rate

The land development and increase in urbanization in a watershed affect water quantity and water quality. On one hand, urbanization provokes the adjustment of geomorphic structure of the streams, ultimately raises peak flow rate which causes flood; on the other hand, it diminishes water quality which results in an increase in Total Suspended Solid (TSS). Consequently, sediment accumulation in downstream of urban areas is observed which is not preferred for longer life of dams. In order to overcome the sediment accumulation problem in dams, the amount of TSS in streams and in watersheds should be taken under control. Low Impact Development (LID) is a Best Management Practice (BMP) which may be used for this purpose. It is a land planning and engineering design method which is applied in managing storm water runoff in order to reduce flooding as well as simultaneously improve water quality. LID includes techniques to predict suspended solid loads in surface runoff generated over impervious urban surfaces. In this study, the impact of LID-BMPs on surface runoff and TSS is investigated by employing a calibrated hydrodynamic model for Sazlıdere Watershed which is located in Istanbul, Turkey. For this purpose, a calibrated hydrodynamic model was developed by using Environmental Protection Agency Storm Water Management Model (EPA SWMM). For model calibration and validation, we set up a rain gauge and a flow meter into the field and obtain rainfall and flow rate data. And then, we select several LID types such as retention basins, vegetative swales and permeable pavement and we obtain their influence on peak flow rate and pollutant buildup and washoff for TSS. Consequently, we observe the possible effects of LID on surface runoff and TSS in Sazlıdere Watershed.

scholarly journals The model and simulation of low impact development of the sponge airport, China

2019 ◽  
Vol 20 (2) ◽  
pp. 383-394 ◽  
Author(s):  
Jing Peng ◽  
Jiayi Ouyang ◽  
Lei Yu ◽  
Xinchen Wu
Keyword(s):  
Flood Control ◽  
Low Impact Development ◽  
Water Environment ◽  
Drainage System ◽  
Practical Significance ◽  
International Airport ◽  
Model And Simulation ◽  
Impervious Area ◽  
Before And After ◽  
Airport Runway

Abstract Recently urban waterlogging problems have become more and more serious, and the construction of an airport runway makes the impervious area of the airport high, which leads to the deterioration of the water environment and frequent waterlogging disasters. It is of great significance to design and construct the sponge airport with low impact development (LID) facilities. In this paper, we take catchment N1 of Beijing Daxing International Airport as a case study. The LID facilities are designed and the runoff process of a heavy rainfall in catchment N1 is simulated before and after the implementation of LID facilities. The results show that the total amount of surface runoff, the number of overflow junctions and full-flow conduits of the rainwater drainage system in catchment N1 of Beijing Daxing International Airport are significantly reduced after the implementation of the LID facilities. Therefore, the application of LID facilities has greatly improved the ability of the airport to remove rainwater and effectively alleviated the risk of waterlogging in the airport flight area. This study provides theoretical support for airport designers and managers to solve flood control and rainwater drainage problems and has vital practical significance.

scholarly journals Correlation of intravesical prostatic protrusion with severity of lower urinary symptoms among patients with benign prostatic hyperplasia

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Babatunde K. Hamza ◽  
Muhammed Ahmed ◽  
Ahmad Bello ◽  
Musliu Adetola Tolani ◽  
Mudi Awaisu ◽  
...  
Keyword(s):  
Flow Rate ◽  
Bladder Outlet Obstruction ◽  
Peak Flow ◽  
Prostate Volume ◽  
Outlet Obstruction ◽  
Peak Flow Rate ◽  
The Mean ◽  
Benign Prostate ◽  
Intravesical Prostatic Protrusion ◽  
Lower Urinary

Abstract Background Benign prostate hyperplasia (BPH) is characterized by an increase in the number of epithelial and stromal cells in the periurethral area of the prostate. Lower urinary tract symptoms (LUTS) often develop as a manifestation of bladder outlet obstruction (BOO) due to benign prostate enlargement. When the prostate enlarges, protrusion into the bladder often occurs as a result of morphological changes of the gland. Prostatic protrusion into the bladder can be measured with ultrasound as intravesical prostatic protrusion (IPP). There are studies that have shown IPP as a reliable predictor of bladder obstruction index (BOOI) as measured by pressure flow studies. IPP is thereby reliable in assessing the severity of BOO in patients with BPH. The severity of symptoms in patients with BPH can be assessed through several scoring systems. The most widely used symptoms scoring system is the International Prostate Symptoms Score (IPSS). The aim of this study is to determine the correlation of IPP with IPSS in men with BPH at our facility. Methods The study was a cross-sectional observational study that was conducted at the Division of Urology, Department of Surgery, in our facility. The study was conducted on patients greater than 50 years LUTS and an enlarged prostate on digital rectal examination and/or ultrasound. All consenting patients were assessed with the International Prostate Symptoms Score (IPSS) questionnaire, following which an abdominal ultrasound was done to measure the intravesical prostatic protrusion (IPP), prostate volume (PV) and post-void residual (PVR) urine. All the patients had uroflowmetry, and the peak flow rate was determined. The data obtained were entered into a proforma. The results were analyzed using Statistical Package for Social Sciences (SPSS) software package version 20. Results A total of 167 patients were seen during the study period. The mean age was 63.7 ± 8.9 years, with a range of 45–90 years. The mean IPSS was 18.24 ± 6.93, with a range of 5–35. There were severe symptoms in 49.1%, while 43.1% had moderate symptoms and 7.8% had mild symptoms. The overall mean IPP was 10.3 ± 8 mm. Sixty-two patients (37.1%) had grade I IPP, 21 patients (12.6%) had grade II IPP and 84 patients (50.3%) had grade III IPP. The mean prostate volume and peak flow rate were 64 g ± 34.7 and 11.6 ml/s ± 5.4, respectively. The median PVR was 45 ml with a range of 0–400 ml. There was a significant positive correlation between the IPP and IPSS (P = 0.001). IPP also had a significant positive correlation with prostate volume and post-void residual and a significant negative correlation with the peak flow rate (P < 0.01). Conclusion Intravesical prostatic protrusion is a reliable predictor of severity of LUTS as measured by IPSS, and it also shows good correlation with other surrogates of bladder outlet obstruction.

scholarly journals New Patterns of Temporal and Spatial Variation in Water Quality of a Highly Artificialized Urban River-Course—a Case Study in the Tongzhou Section of the Beiyun River

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1446 ◽  
Author(s):  
Juanhui Ren ◽  
Ji Liang ◽  
Bo Ren ◽  
Xiuqing Zheng ◽  
Chaofan Guo
Keyword(s):  
Water Quality ◽  
Management Practices ◽  
Low Impact Development ◽  
Urban River ◽  
Quality Data ◽  
Dominant Factor ◽  
Water Runoff ◽  
Reclaimed Wastewater ◽  
Water Quality Data ◽  
Impervious Area

This paper aims to gain a better understanding of urban river pollution through evaluation of water quality. Data for 10 parameters at eight sites of the Tongzhou Section of the Beiyun River (TSBR) are analyzed. Hierarchical cluster analysis, fuzzy comprehensive assessment, discriminant analysis and Spearman’s correlation analysis were used to estimate the water situation of each cluster and analyze its spatial-temporal variations. Principal component analysis/factor analysis were applied to extract and recognize the sources responsible for water-quality variations. The results showed that temporal variation is greater than spatial and sewage discharge is the dominant factor of the seasonal distribution. Moreover, during the rapid-flow period, water quality is polluted by a combination of organic matter, phosphorus, bio-chemical pollutants and nitrogen; during the gentle-flow period, water quality is influenced by domestic and industrial waste, the activities of algae, aquatic plants and phosphorus pollution. In regard to future improvement of water quality in TSBR, the control of reclaimed wastewater from adjacent factories should first be put in place, as well as other techniques, for example, an increase of the impervious area, low-impact development, and integrated management practices should also be proposed in managing storm water runoff.

Decreasing peak flow rate with a new bag-valve-mask device: effects on respiratory mechanics, and gas distribution in a bench model of an unprotected airway

Resuscitation ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 193-199 ◽  
Author(s):  
Horst G. Wagner-Berger ◽  
Volker Wenzel ◽  
Angelika Stallinger ◽  
Wolfgang G. Voelckel ◽  
Klaus Rheinberger ◽  
...  
Keyword(s):  
Flow Rate ◽  
Respiratory Mechanics ◽  
Peak Flow ◽  
Peak Flow Rate ◽  
Gas Distribution ◽  
Unprotected Airway ◽  
Bench Model

scholarly journals The improvement on Respiratory Muscle, Trunk Stability, and health status after Abdominal Drawing-in Maneuver in COPD Patients

2017 ◽  
Vol 6 (02) ◽  
pp. 9
Author(s):  
Winny W ◽  
Siti Chandra Widjanantie ◽  
Maryastuti M ◽  
Nury Nusdwinuringtyas
Keyword(s):  
Health Status ◽  
Respiratory Muscle ◽  
Peak Flow ◽  
Chronic Obstructive ◽  
Peak Flow Rate ◽  
Obstructive Pulmonary Disease ◽  
Trunk Stability ◽  
Functional Reach ◽  
Copd Patients ◽  
Functional Reach Test

Background: Chronic Obstructive Pulmonary Disease (COPD) patients experienced respiratory muscledysfunction, postural instability, and decreasing in health status. Abdominal drawing-in maneuver (ADIM) hasbeen studied in many cases of low back pain for lumbar stabilization, moreover this maneuver is also designedto activate the transversus abdominalis (TA) muscle that involved in expiration. But this exercise has not beenconsidered as a respiration exercise in COPD patients. The purpose of this study was to determine whether theapplication of ADIM to COPD patients would affect the strength of respiratory muscle, improve core musclestability, and health status of COPD patients.Methods:All clinically stable COPD patients who visited PMR clinic at Persahabatan General Hospital wererecruited in the study. They received exercise interventions 2 times a week for 4 weeks. ADIM as a mainprogram is using pressure transducer (Chattanooga, Australia). Each exercise was held 10 repetitions, 10 setswith 2 minutes rest. Strength of respiratory muscle measured by peak cough flow (PCF) and peak flow rate(PFR). Core muscle stability measured by functional reach test (FRT) and the health status measured with CATscore. The measurements were done before and immediately after intervention.Results: Subjects were 8 patients with mean age 62 years old, consisted of 7 men and 1 woman, with 1 patienteach with COPD grade A, B, and C, and 5 patients with COPD grade D. There were increasing of PCF (268.75± 59.146 L/min to 285.00 ±59.522 L/min; p=0.061), PFR (251.3±96.3 L/min to 286.3±92 L/min; p=0.028),FRT (20.2±3.8 cm to 22±3.9 cm; p=0.011), and decreasing of CAT score (14 ±8.685 to 11.50 ±8.848; p=0.027)after ADIM.Conclusion: There were an improvement in respiratory muscle, trunk stability, and CAT after ADIM, so themaneuver is effective for COPD management.Keywords: Abdominal drawing-in maneuver (ADIM), Chronic Obstructive Pulmonary Disease (COPD),COPD Assessment Test (CAT), Functional reach test (FRT), Peak cough flow (PCF), Peak flow rate (PFR)

A Method of Measuring the Peak Flow-Rate and the Regurgitant Volume of Regurgitation

1990 ◽  
pp. 125-129
Author(s):  
Motoaki Sugawara ◽  
Akio Hirai ◽  
Yasutsugu Seo ◽  
Yasuo Miyajima ◽  
Takanobu Uchibori
Keyword(s):  
Flow Rate ◽  
Peak Flow ◽  
Peak Flow Rate ◽  
Regurgitant Volume
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