scholarly journals Evaluating the Impact of Urban Growth on the Design of Storm Water Drainage Systems

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1572 ◽  
Author(s):  
Hany F. Abd-Elhamid ◽  
Martina Zeleňáková ◽  
Zuzana Vranayová ◽  
Ismail Fathy

Urban growth is one of the major causes of flooding in urban areas. This affects the runoff coefficients, which is among the most important factors that affect the design of storm water drainage systems. Changing the runoff coefficient will affect the design parameters of the drainage network, including outfall discharge, velocity, lag time and cost of construction. This study aims to assess the effect of changing the runoff coefficient due to urban growth on the design of a storm water drainage system. The hydrological models Hyfran, StormCAD and GIS are used to analyze different runoff coefficients. This study examines three zones in Dammam in the Kingdom of Saudi Arabia (KSA). The data developed from the models for the current case studies are used to develop an empirical equation to predict the max discharge for other catchments. The discharge is a function of the return period, runoff coefficient, drainage density, longest path, rainfall intensity and catchment area. To validate the developed equation, we use it to estimate the discharge in a real case study in South Korea. A comparison between the measured discharge and estimated discharge shows that the empirical equation is capable of predicting the maximum discharge for different catchments with high accuracy. Then, the validation of the models is carried out to determine the effect of the runoff coefficient on the design of a storm water drainage system in a case study in KSA. The results show that an increasing runoff coefficient due to urban growth increases the outfall discharge and velocity of storm water drainage systems, as well as affecting the cost of construction and decreasing the lag time. The cost increases by two to three times with increasing urbanization. This study provides a new perspective on the hydrologic impact of urban growth on the design of storm water drainage systems, which are essential for flood management. Moreover, the relationship between urban growth and the cost of storm drainage networks is explored, which could help decision makers to make appropriate judgements.

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 514
Author(s):  
Leonardo Bayas-Jiménez ◽  
F. Javier Martínez-Solano ◽  
Pedro L. Iglesias-Rey ◽  
Daniel Mora-Melia ◽  
Vicente S. Fuertes-Miquel

A problem for drainage systems managers is the increase in extreme rain events that are increasing in various parts of the world. Their occurrence produces hydraulic overload in the drainage system and consequently floods. Adapting the existing infrastructure to be able to receive extreme rains without generating consequences for cities’ inhabitants has become a necessity. This research shows a new way to improve drainage systems with minimal investment costs, using for this purpose a novel methodology that considers the inclusion of hydraulic control elements in the network, the installation of storm tanks and the replacement of pipes. The presented methodology uses the Storm Water Management Model for the hydraulic analysis of the network and a modified Genetic Algorithm to optimize the network. In this algorithm, called the Pseudo-Genetic Algorithm, the coding of the chromosomes is integral and has been used in previous studies of hydraulic optimization. This work evaluates the cost of the required infrastructure and the damage caused by floods to find the optimal solution. The main conclusion of this study is that the inclusion of hydraulic controls can reduce the cost of network rehabilitation and decrease flood levels.


2018 ◽  
Vol 44 ◽  
pp. 00129
Author(s):  
Monika Nowakowska

In the paper were made the verification of the operation of a rainwater drainage system in the residential communities of Gaj and Tarnogaj in Wrocław, carried out in the hydrodynamic model using SWMM software. There were used two criterial precipitation: Euler’s model (with a frequency of C = 3 years) and the actual precipitation (C = 5 years). The criteria of overloading the system was the specific flood volume (SFV). For both cases of precipitation load of catchment, the simulated calculations showed the occurrence of outflows from the channels. Due to the value of SFV indicator (respectively: 19 m3/ha and 42,9 m3/ha), it was found that the tested system needs modernization, therefor acceptable instantaneous water level above the maximum water impoundment were more often than 1 per 3 years, which leads to overflows from channels for residential areas more often than allowed once every 20 years.


2018 ◽  
Author(s):  
Thomas Lelandais ◽  
Édouard Ravier ◽  
Stéphane Pochat ◽  
Olivier Bourgeois ◽  
Christopher D. Clark ◽  
...  

Abstract. Ice streams are corridors of fast-flowing ice that control mass transfers from continental ice sheets to oceans. Their flow speeds are known to accelerate and decelerate, their activity to switch on and off, and even their locations to shift entirely. Our analogue physical experiments reveal that a lifecycle incorporating evolving subglacial meltwater routing and bed erosion can govern this complex transitory behaviour. The model ice streams switch on when subglacial water pockets drain as marginal outburst floods. Then they decelerate as basal coupling increases as a consequence of the lubricating water drainage system spontaneously organising itself into channels that erode tunnel valleys. They surge or jump in location when these water drainage systems maintain low discharge but they ultimately switch off when tunnel valleys have expanded to develop efficient drainage systems. Beyond reconciling previously disconnected observations of modern and ancient ice streams into a single lifecycle, the modelling suggests that tunnel valley development may be crucial in stabilising portions of ice sheets during periods of climate change.


2019 ◽  
Vol 32 (02) ◽  
pp. 126-138
Author(s):  
B. Beiranvand ◽  
A. Mohammadzade ◽  
M. Komasi

The drainage system is used to guide the flow of water in the earth dams. Construction of drainage in the dam body to collect and direct the drainage formed in the dam body to keep the slope dry and prevent the increase of pore water pressure in the body. One of the main goals of the designers is to find the minimum factor of safety and, consequently, reduce the cost of construction. In this study, the Marvak dam is modeled with the actual characteristics of the materials in the Geostudio software, and with the change in the dimensions of the drain, the material and the slope of the dam body, the minimum Factor of safety of the dam is obtained. In order to predict the minimum Factor of safety, a two-layer neural network has been used. With the training of the neural network based on the data obtained from heterogeneous dams, a minimum Factor of safety has been extracted for optimization of drainage. Finally, it was determined that the internal friction angle of the body material and the slope of the dam have the greatest effect on the dam factor of safety.


2021 ◽  
Author(s):  
M. Guo ◽  
◽  
Argaw Gurmu ◽  
L. Tivendale ◽  
◽  
...  

A large portion of infrastructure was flooded by water running off pavements or overflowing from the drainage systems in Fiji. The main objectives of this study are to identify the most suitable drainage management solution to reduce the overflow of the drainage system in Fiji, and to develop a framework of drainage management systems. The literature review was conducted to identify various drainage systems used to mitigate flooding around the world. After the review, the characteristics of Fiji such as climate pattern, location and soil type were analysed in the case study section. Secondary data which was obtained from Australia, Norway, the Netherlands, the U.S., Korea, and China were used in the research. The characteristics of Fiji were then mapped to other countries and a scoring system was created to analyse the suitability of different flood mitigation techniques in Fiji. Finally, multiple flood management strategies were proposed, and a drainage management framework for flood mitigation was developed.


Author(s):  
Vidyapriya V. ◽  
Ramalingam M.

Mostly populous city like Chennai is subjected to frequent flooding due to its complex nature of natural and man-made activities. From the analysis of the past records of flood events of 1943,1976,1985,2005 and 2008,it has been observed Adayar watershed is subjected to cataclysmic flooding in low-lying areas of the city and its suburbs because of inoperativeness of the local drainage system, rainfall associated with cyclonic activity, topography of the terrain, encroachments along the floodplain, hugh upstream flow discharge into the river and the highly impervious area which blocked the runoff to flow into the storm water drainage. After looking into these problems of flooding, a study have been conducted on Adayar watershed to develop a 2D hydrodynamic model for the two scenarios of existing condition of storm water drainage network and revised conditions of storm water drainage network using high resolution Lidar DEM to assess the volume of runoff with respect to time and duration on flood peaks for the two flood events of 2005 and 2015.Secondly to develop a 1D flood model to predict the river stages during peak floods using MIKE 11 for the Adayar watershed. Thirdly to integrate the coupled 1D and 2D model using MIKEFLOOD for assessing the extent of inundation in the floodplain area of Adayar river. Finally results from the integrated model have been validated and the results found satisfactory. As a part of mitigation measures, two flood mitigation measures have been adopted. One measure such as revised storm water drainage system which enhances the flood carrying capacity of the drains and results in less inundated area which solves the problem of urban flooding and second measure such as regrading the river bed which reduces the floodplain inundation around the adjacent area of the river. After adopting these measures, the river is free to flow into the sea without any blockades.


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