scholarly journals Investigation of Appropriate Model Structures for Modelling Small Urban Catchments

2021 ◽  
Author(s):  
Naglaa Ahmed

Although the hydrologic modelling of small urban catchments has been practised for several decades, guidance on the development of models is still needed. This research evaluates and compares several modelling structures of small residential areas with and without low impact development implementation using distributed and lumped models. Hypothetical small areas were modelled to examine several grid based models with different grid sizes. The results were used to test the ability of uncalibrated models to predict runoff using three model configurations: 1) single catchment, 2) grid, and 3) homogenous areas, where every building, backyard, and street was modelled separately as a single catchment. The results of the models were compared and evaluated based on the total runoff volume, peak flow rate, and infiltration volume. The results of a real case study show that the grid model is an appropriate model structure for modelling small urban catchments.

2021 ◽  
Author(s):  
Naglaa Ahmed

Although the hydrologic modelling of small urban catchments has been practised for several decades, guidance on the development of models is still needed. This research evaluates and compares several modelling structures of small residential areas with and without low impact development implementation using distributed and lumped models. Hypothetical small areas were modelled to examine several grid based models with different grid sizes. The results were used to test the ability of uncalibrated models to predict runoff using three model configurations: 1) single catchment, 2) grid, and 3) homogenous areas, where every building, backyard, and street was modelled separately as a single catchment. The results of the models were compared and evaluated based on the total runoff volume, peak flow rate, and infiltration volume. The results of a real case study show that the grid model is an appropriate model structure for modelling small urban catchments.


2019 ◽  
Vol 80 (8) ◽  
pp. 1591-1600 ◽  
Author(s):  
Maryam Movahedinia ◽  
Jamal Mohammad Vali Samani ◽  
Fakhreddin Barakhasi ◽  
Saleh Taghvaeian ◽  
Raffi Stepanian

Abstract Low impact development (LID) methods have been shown to be efficient in reducing the peak flow and total volume of urban stormwater, which is a top priority for effective urban stormwater management in many municipalities. However, decision-makers need information on the effects of LIDs and their associated costs before allocating limited resources. In this study, the Storm Water Management Model (SWMM) was used to investigate the effects of five different LID scenarios on urban flooding in a district in Tehran, Iran. The LID scenarios included rain barrel (RB) at two sizes, bio-retention cell (BRC), and combinations of the two structures. The results showed that significant node flooding and overflow volume would occur in the study area under the existing conditions, especially for rainfall events with longer return periods. BRC and combinations of BRC and RBs were the most effective options in reducing flooding, while the smaller-size RB was the cheapest alternative. However, normalized cost, obtained through dividing the total cost by the percent reduction in node flooding and/or overflow volume, was smallest for BRC. The results of this study demonstrate how hydraulic modeling can be combined with economic analysis to identify the most efficient and affordable LID practices for urban areas.


2020 ◽  
Vol 28 (3) ◽  
pp. 105-115
Author(s):  
Ireneusz Nowogoński

Uncontrolled urbanization causes local flooding and deterioration of the water quality of receivers as a result of an increase in peak flow rate and increased washing out of contaminants from the catchment area. Currently, classic storage tanks are most often used. An alternative solution may be the use of Low Impact Development (LID), i.e. the preservation and restoration of natural landscape elements, minimizing the imperviousness of the catchment in the form of rain barrels, permeable walkways or bio-retention reservoirs. The comparison of both techniques was carried out using the Environmental Protection Agency Storm Water Management Model (EPA SWMM). The influence of several solutions on a selected urbanized catchment located in Gorzów Wielkopolski was tested.


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.


2021 ◽  
Vol 167 ◽  
pp. 105381
Author(s):  
X. Cuong Nguyen ◽  
T. Thanh Huyen Nguyen ◽  
D. Duong La ◽  
Gopalakrishnan Kumar ◽  
Eldon R. Rene ◽  
...  

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