scholarly journals The applicability of LID facilities as an adaptation strategy of urban CSOs management for climate change

Author(s):  
Kyungmin Kim ◽  
Ryoungeun Kim ◽  
Jeonghyeon Choi ◽  
Sangdan Kim

Abstract The magnitude and frequency of extreme rainfall due to climate change is increasing. Increasing rainfall causes serious hydrological problems in cities. Rainfall does not infiltrate the soil, but mostly flows through the sewer pipes into the stream. Most old urban watersheds have combined sewer pipes. When rainfall exceeds the capacity of the combined sewer pipes, sewage mixed with stormwater overflows the sewer pipes and flows directly into the stream. This is called Combined Sewer Overflows (CSOs). CSOs enter the stream with non-point source pollutants accumulated on the surface and pollute the stream. CSOs are one of the major water quality problems in older urban watersheds. This can be solved by replacing the combined sewer pipes with separated sewer pipes, but in reality it requires astronomical costs. As an alternative, the Low Impact Development (LID) technique has recently been introduced. In this study, we analyzed the effects of climate change on CSOs in urban watersheds and applied LID techniques to offset the effects. The LID facility was applied with the most commonly used Bio-Retention cells.

1998 ◽  
Vol 38 (10) ◽  
pp. 23-30
Author(s):  
Sarah Jubb ◽  
Philip Hulme ◽  
Ian Guymer ◽  
John Martin

This paper describes a preliminary investigation that identified factors important in the prediction of river water quality, especially regarding dissolved oxygen (DO) concentration. Intermittent discharges from combined sewer overflows (CSOs) within the sewerage, and overflows at water reclamation works (WRW) cause dynamic conditions with respect to both river hydraulics and water quality. The impact of such discharges has been investigated under both wet and dry weather flow conditions. Data collected from the River Maun, UK, has shown that an immediate, transient oxygen demand exists downstream of an outfall during storm conditions. The presence of a delayed oxygen demand has also been identified. With regard to modelling, initial investigations used a simplified channel and the Streeter-Phelps (1925) dissolved oxygen sag curve equation. Later, a model taking into account hydrodynamic, transport and dispersion processes was used. This suggested that processes other than water phase degradation of organic matter significantly affect the dissolved oxygen concentration downstream of the location of an intermittent discharge. It is proposed that the dynamic rate of reaeration and the sediment oxygen demand should be the focus of further investigation.


2011 ◽  
Vol 2 (4) ◽  
pp. 260-271 ◽  
Author(s):  
V. Nilsen ◽  
J. A. Lier ◽  
J. T. Bjerkholt ◽  
O. G. Lindholm

Climate change is expected to lead to an increased frequency and intensity of extreme precipitation events. For urban drainage, the primary adverse effects are more frequent and severe sewer overloading and flooding in urban areas, and higher discharges through combined sewer overflows (CSO). For assessing the possible effects of climate change, urban drainage models are run with climate-change-adjusted input data. However, current climate models are run on a spatial–temporal scale that is too coarse to resolve processes relevant to urban drainage modelling, in particular convective precipitation events. In the work reported here the delta-change method was used to develop a high-resolution time series of precipitation for the period 2071–2100 based on a recently produced climate model precipitation time series for Oslo. The present and future performance of the sewer networks was determined using MOUSE software. The simulations indicated future increases in annual CSO discharge of 33% when comparing years of maximum annual runoff. There is also an 83% increase in annual CSO discharge when comparing years of maximum annual precipitation. In addition, there are increases in the flooding of manholes and increased levels of backwater in pipes, which translates into more flooding of basements.


2019 ◽  
Author(s):  
◽  
Ali Shallal

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Modeling rainfall runoff can help to understand what is happening throughout the system, how can control of water to prevent flood, and how much the quality of runoff can change in urban area. Modeling sewer system help decision maker to indicate best strategy to prevent flooding, reduce runoff pollution, reduce cost of wastewater treatment and determine best suitable LID to an urban area. This dissertation first starting with analysis the complexity of model necessary to get accepted result in term peak flow, runoff volume, numbers of flooding nodes and time to peak. Modeling requirements may lead to system simplification, as in limiting the size of the pipes included in the analyses. Researchers analyzed the combined sewer system of the urbanized Town Fork Creek catchment in Kansas City, Missouri using PCSWMM to assess the potential impact of the simplifications on hydraulic results.


2010 ◽  
Vol 61 (1) ◽  
pp. 207-215 ◽  
Author(s):  
A. Casadio ◽  
M. Maglionico ◽  
A. Bolognesi ◽  
S. Artina

The Navile Channel (Bologna, Italy) is an ancient artificial water course derived from the Reno river. It is the main receiving water body for the urban catchment of Bologna sewer systems and also for the Waste Water Treatment Plant (WWTP) main outlet. The aim of this work is to evaluate the Combined Sewer Overflows (CSOs) impact on Navile Channel's water quality. In order to collect Navile flow and water quality data in both dry and wet weather conditions, two measuring and sampling stations were installed, right upstream and downstream the WWTP outflow. The study shows that even in case of low intensity rain events, CSOs have a significant effect on both water quantity and quality, spilling a considerable amount of pollutants into the Navile Channel and presenting also acute toxicity effects. The collected data shown a good correlations between the concentrations of TSS and of chemical compounds analyzed, suggesting that the most part of such substances is attached to suspended solids. Resulting toxicity values are fairly high in both measuring points and seem to confirm synergistic interactions between heavy metals.


2020 ◽  
Vol 20 (5) ◽  
pp. 1219-1232 ◽  
Author(s):  
Luca Locatelli ◽  
Beniamino Russo ◽  
Alejandro Acero Oliete ◽  
Juan Carlos Sánchez Catalán ◽  
Eduardo Martínez-Gomariz ◽  
...  

Abstract. Combined sewer overflows (CSOs) affect bathing water quality of receiving water bodies by bacterial pollution. The aim of this study is to assess the health hazard of bathing waters affected by CSOs. This is useful for bathing water managers, for risk assessment purposes, and for further impact and economic assessments. Pollutant hazard was evaluated based on two novel indicators proposed in this study: the mean duration of insufficient bathing water quality (1) over a period of time (i.e., several years) and (2) after single CSO/rain events. In particular, a novel correlation between the duration of seawater pollution and the event rainfall volume was developed. Pollutant hazard was assessed through a coupled urban drainage and seawater quality model that was developed, calibrated and validated based on local observations. Furthermore, hazard assessment was based on a novel statistical analysis of continuous simulations over a 9-year period using the coupled model. Finally, a validation of the estimated hazard is also shown. The health hazard was evaluated for the case study of Badalona (Spain) even though the methodology presented can be considered generally applicable to other urban areas and related receiving bathing water bodies. The case study presented is part of the EU-funded H2020 project BINGO (Bringing INnovation to OnGOing water management – a better future under climate change).


2014 ◽  
Vol 522-524 ◽  
pp. 979-982
Author(s):  
Chuan Bao Wu ◽  
Xiang Hui Zeng

Water quality of Poyang Lake is facing serious threats with the quick development of Jiangxi Province. Water quality control and pollution prevention of Poyang Lake have become important problems set before Jiangxi Province. To keep good water quality of Poyang Lake, a series of pollution-preventing strategies were studied. In order to prevent point source (PS) pollution, industrial types and layout, management measures and production technique should be improved. Strategies to prevent non-point source (NPS) pollution include four aspects. First is to transform part of NPS pollution to PS pollution by rationally laying out industry system. Second is to construct spatially harmonious and reasonable landscape pattern. Third is to reform conventional agricultural production by using advanced chemical and biological technologies. Fourth is to carry out Best Management Practices (BMPs) and Low-impact Development (LID) by learning and innovation.


2014 ◽  
Vol 45 (6) ◽  
pp. 774-787 ◽  
Author(s):  
Oana Iacob ◽  
John S. Rowan ◽  
Iain Brown ◽  
Chris Ellis

Climate change is projected to alter river flows and the magnitude/frequency characteristics of floods and droughts. Ecosystem-based adaptation highlights the interdependence of human and natural systems, and the potential to buffer the impacts of climate change by maintaining functioning ecosystems that continue to provide multiple societal benefits. Natural flood management (NFM), emphasising the restoration of innate hydrological pathways, provides important regulating services in relation to both runoff rates and water quality and is heralded as a potentially important climate change adaptation strategy. This paper draws together 25 NFM schemes, providing a meta-analysis of hydrological performance along with a wider consideration of their net (dis) benefits. Increasing woodland coverage, whilst positively linked to peak flow reduction (more pronounced for low magnitude events), biodiversity and carbon storage, can adversely impact other provisioning service – especially food production. Similarly, reversing historical land drainage operations appears to have mixed impacts on flood alleviation, carbon sequestration and water quality depending on landscape setting and local catchment characteristics. Wetlands and floodplain restoration strategies typically have fewer disbenefits and provide improvements for regulating and supporting services. It is concluded that future NFM proposals should be framed as ecosystem-based assessments, with trade-offs considered on a case-by-case basis.


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