Analytical Derivation of Urban Runoff-Volume Frequency Models

Author(s):  
Sonia Hassini ◽  
Yiping Guo
2012 ◽  
Vol 16 (12) ◽  
pp. 4531-4542 ◽  
Author(s):  
S. Oraei Zare ◽  
B. Saghafian ◽  
A. Shamsai

Abstract. Urban development affects the quantity and quality of urban surface runoff. In recent years, the best management practices (BMPs) concept has been widely promoted for control of both quality and quantity of urban floods. However, means to optimize the BMPs in a conjunctive quantity/quality framework are still under research. In this paper, three objective functions were considered: (1) minimization of the total flood damages, cost of BMP implementation and cost of land-use development; (2) reducing the amount of TSS (total suspended solid) and BOD5 (biological oxygen demand), representing the pollution characteristics, to below the threshold level; and (3) minimizing the total runoff volume. The biological oxygen demand and total suspended solid values were employed as two measures of urban runoff quality. The total surface runoff volume produced by sub-basins was representative of the runoff quantity. The construction and maintenance costs of the BMPs were also estimated based on the local price standards. Urban runoff quantity and quality in the case study watershed were simulated with the Storm Water Management Model (SWMM). The NSGA-II (Non-dominated Sorting Genetic Algorithm II) optimization technique was applied to derive the optimal trade off curve between various objectives. In the proposed structure for the NSGA-II algorithm, a continuous structure and intermediate crossover were used because they perform better as far as the optimization efficiency is concerned. Finally, urban runoff management scenarios were presented based on the optimal trade-off curve using the k-means method. Subsequently, a specific runoff control scenario was proposed to the urban managers.


1992 ◽  
Vol 25 (8) ◽  
pp. 225-232 ◽  
Author(s):  
A. Saget ◽  
G. Chebbo ◽  
A. Bachoc

The purpose of this study was to estimate the volume of urban stormwater which must be treated in order to achieve a given efficiency in terms of pollutant retention in a storm basin. The data used for this were those from the French national programme (1980-82), collected in four separately sewered catchments whose area is less than 100 hectares. The intercepted loads for one year and for the most polluted events have been calculated for interception volumes varying between 0 and 300 m3 per impervious hectare. It was concluded that 100 m3/imp ha can intercept about 80% of the annual load of SS, BOD5 and COD. But for the most polluted events, to achieve the same efficiency (80% of the produced load), a reservoir volume of 200 m3/imp ha is needed. The reduction of frequency of the most polluted events was also studied: for the events of which the load is in excess of 5% of the annual load produced, even a storage volume of 200 m3/imp ha is insufficient to entirely prevent these occurring.


2020 ◽  
Vol 29 (1) ◽  
pp. 67-87 ◽  
Author(s):  
Christian Hunold

City-scale urban greening is expanding wildlife habitat in previously less hospitable urban areas. Does this transformation also prompt a reckoning with the longstanding idea that cities are places intended to satisfy primarily human needs? I pose this question in the context of one of North America's most ambitious green infrastructure programmes to manage urban runoff: Philadelphia's Green City, Clean Waters. Given that the city's green infrastructure plans have little to say about wildlife, I investigate how wild animals fit into urban greening professionals' conceptions of the urban. I argue that practitioners relate to urban wildlife via three distinctive frames: 1) animal control, 2) public health and 3) biodiversity, and explore the implications of each for peaceful human-wildlife coexistence in 'greened' cities.


2007 ◽  
Vol 2 (2) ◽  
Author(s):  
William C. Lucas

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.


1995 ◽  
Vol 30 (2) ◽  
pp. 243-246 ◽  
Author(s):  
Heather Culbert ◽  
Robert France

Abstract In urban centres, leaves are customarily gathered and temporarily stored in large roadside piles prior to their transport to disposal sites. To simulate the release of total phosphorus to urban runoff, birch and trembling aspen leaves were leached with distilled water in laboratory flasks. There was no difference in rate of total phosphorus release between oven-dried and non-dried leaves. An empirical equation developed from these data and knowledge of the litterfall rates for southern Canada indicated that leaves yielded from 11 to 45 mg TP m−2 of forested watershed. This amount represents up to 5% of the total export of total phosphorus from urban catchments and has the potential to exacerbate eutrophication of municipal waters if leaf pickup is not promptly enforced.


1996 ◽  
Vol 33 (2) ◽  
pp. 79-90 ◽  
Author(s):  
Jian Hua Lei ◽  
Wolfgang Schilling

Physically-based urban rainfall-runoff models are mostly applied without parameter calibration. Given some preliminary estimates of the uncertainty of the model parameters the associated model output uncertainty can be calculated. Monte-Carlo simulation followed by multi-linear regression is used for this analysis. The calculated model output uncertainty can be compared to the uncertainty estimated by comparing model output and observed data. Based on this comparison systematic or spurious errors can be detected in the observation data, the validity of the model structure can be confirmed, and the most sensitive parameters can be identified. If the calculated model output uncertainty is unacceptably large the most sensitive parameters should be calibrated to reduce the uncertainty. Observation data for which systematic and/or spurious errors have been detected should be discarded from the calibration data. This procedure is referred to as preliminary uncertainty analysis; it is illustrated with an example. The HYSTEM program is applied to predict the runoff volume from an experimental catchment with a total area of 68 ha and an impervious area of 20 ha. Based on the preliminary uncertainty analysis, for 7 of 10 events the measured runoff volume is within the calculated uncertainty range, i.e. less than or equal to the calculated model predictive uncertainty. The remaining 3 events include most likely systematic or spurious errors in the observation data (either in the rainfall or the runoff measurements). These events are then discarded from further analysis. After calibrating the model the predictive uncertainty of the model is estimated.


1998 ◽  
Vol 37 (1) ◽  
pp. 179-185
Author(s):  
Morten Grum

On evaluating the present or future state of integrated urban water systems, sewer drainage models, with rainfall as primary input, are often used to calculate the expected return periods of given detrimental acute pollution events and the uncertainty thereof. The model studied in the present paper incorporates notions of physical theory in a stochastic model of water level and particulate chemical oxygen demand (COD) at the overflow point of a Dutch combined sewer system. A stochastic model based on physical mechanisms has been formulated in continuous time. The extended Kalman filter has been used in conjunction with a maximum likelihood criteria and a non-linear state space formulation to decompose the error term into system noise terms and measurement errors. The bias generally obtained in deterministic modelling, by invariably and often inappropriately assuming all error to result from measurement inaccuracies, is thus avoided. Continuous time stochastic modelling incorporating physical, chemical and biological theory presents a possible modelling alternative. These preliminary results suggest that further work is needed in order to fully appreciate the method's potential and limitations in the field of urban runoff pollution modelling.


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