| 1. |
- Adamsson, Åsa, 1970, et al.
(författare)
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Measurement and three-dimensional simulation of flow in a rectangular detention tank
- 2005
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Ingår i: Urban Water Journal. - 1744-9006 .- 1573-062X. ; 2:4, s. 277-287
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Tidskriftsartikel (refereegranskat)abstract
- There are two main ways to obtain better knowledge of the hydraulics of ponds, namelymeasurements and simulations. In this study, the applicability of using three-dimensionalsimulations as an engineering tool in stormwater pond design was investigated. To dothis, three-dimensional simulations were compared with measurements of flow patternand residence time in a large physical model of a detention tank (13 x 9x 1 m). Theagreement between measurements and simulations concerning both flow pattern andresidence time distribution curves was found to be good for high flow rates.
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| 2. |
- Al-Rubaei, Ahmed, et al.
(författare)
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Long-term hydraulic performance of stormwater infiltration systems
- 2015
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Ingår i: Urban Water Journal. - 1573-062X. ; 12:8, s. 660-671
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Tidskriftsartikel (refereegranskat)abstract
- Despite the common use of stormwater infiltration systems, there is still only limited data available evaluating the long-term hydraulic function of such systems. The hydraulic performance of twelve stormwater infiltration systems (vegetated and unvegetated concrete grid pavers, unvegetated interlocking concrete pavers and grassed swales) was therefore investigated in field and laboratory environments in Växjö, Sweden. The systems investigated had not been subjected to regular maintenance to sustain infiltration capacity. Due to this, and the fact that, for most systems, an inappropriate joint filling material was used and (at the swales) there was severe compaction, most systems showed a reduced infiltration capacity. Despite this, especially the older vegetated systems, were still capable of infiltrating intense design rainfalls. This study showed the influence of some factors (type and age of the system, the type of joint filling material (grass and macadam) and the distance from the edge of the pavement) on the long-term behaviour of the infiltration capacity. In conclusion, there is a significant risk that existing stormwater infiltration systems are not working adequately in praxis. Proper implementation of construction and regular control by the inspecting authority has to be ensured.
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| 3. |
- Bengtsson, Lars
(författare)
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Wetland systems to control urban runoff
- 2007
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Ingår i: Urban Water Journal. - : Informa UK Limited. - 1744-9006 .- 1573-062X. ; 4:2, s. 133-133
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Recension (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Berggren, Karolina, et al.
(författare)
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Climate changed rainfalls for urban drainage capacity assessment
- 2014
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Ingår i: Urban Water Journal. - 1573-062X. ; 11:7, s. 543-556
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Tidskriftsartikel (refereegranskat)abstract
- Guidance on what type of rainfall to use when assessing hydraulic capacity of urban drainage systems under climate change is unclear; focus is mainly on what climate factors to use. Based on a case study in Kalmar, Sweden, this paper compares system performance using two design rainfalls, Block rainfalls and Chicago Design Storm (CDS), and selected observed rainfalls, with two methods of addressing future climate: a constant factor and Delta Change (DC) factors that depend on rainfall intensity. The use of CDS rainfalls presents the maximum hydraulic response, whereas Block rainfalls give lower responses but identify critical durations in the system, which may be useful addressing adaptation actions. Observed rainfalls of target return periods gave similar responses to CDS rainfalls, and can be applied with DC factors to address future changes in both intensity and volume. Differences between the two methods indicate a high dependence related to the maximum factors applied on the rainfalls
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| 5. |
- Blecken, Godecke-Tobias, et al.
(författare)
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Stormwater control measure (SCM) maintenance considerations to ensure designed functionality
- 2017
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Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X. ; 14:3, s. 278-290
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Tidskriftsartikel (refereegranskat)abstract
- Great investment is made in the design and installation of stormwater control measures (SCMs). Substantial research investment, too, is made to optimise the performance of SCMs. However, once installed, SCMs often suffer from lack of maintenance or even outright neglect. Key maintenance needs for wet ponds, constructed stormwater wetlands, bioretention, infiltration practices, permeable pavement, swales, and rainwater harvesting systems are reviewed with many tasks, such as the cleaning of pre-treatment areas and the preservation of infiltration surfaces, being common maintenance themes among SCMs. Consequences of lacking maintenance are illustrated (mainly insufficient function or failure). Probable reasons for neglect include insufficient communication, unclear responsibilities, lack of knowledge, financial barriers, and decentralised measures. In future designs and research, maintenance (and lack thereof) should be considered. Assessing the performance of SCMs conservatively and including safety factors may prevent consequences of under-maintenance; and requiring regular inspection may help to enforce sufficient maintenance.
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| 6. |
- Borris, Matthias, et al.
(författare)
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Snow pollution management in urban areas: an idea whose time has come?
- 2021
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Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X .- 1744-9006. ; 18:10, s. 840-849
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Tidskriftsartikel (refereegranskat)abstract
- Needs for extending the principles of a sustainable urban drainage approach to the winter season with snow and pollutant accumulations have been so far unanswered. One of the first steps to remedy this situation is to make available a prototype snow management tool (PSMT) described herein. It is a simple empirical spreadsheet tool, as yet untested, which uses generally available input data to simulate accumulation of snow (as snow water equivalent) and pollutants in an urban catchment, intermittent snowmelt episodes, and snow management options including in situ melting, removal from the catchment, treatment of snowmelt by settling, and snow disposal in the receiving waters. The tool output comprises snow and the selected pollutant mass balances, and pollutant concentrations in snowmelt from individual snow deposits. Such data provide decision support for choosing the methods of disposal for individual snow deposits. The testing and refinement of the tool is planned.
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| 7. |
- Broekhuizen, Ico, et al.
(författare)
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Reducing uncertainties in urban drainage models by explicitly accounting for timing errors in objective functions
- 2021
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Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X .- 1744-9006. ; 18:9, s. 740-749
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Tidskriftsartikel (refereegranskat)abstract
- Traditional hydrological objective functions may penalize models that reproduce hydrograph shapes well, but with some shift in time; especially for urban catchments with a fast hydrological response. Hydrograph timing is not always critical, so this paper investigates alternative objective functions (based on the Hydrograph Matching Algorithm) that try to mimic visual hydrograph comparison. A modified version of the Generalized Likelihood Uncertainty Estimation is proposed to compare regular objective functions with those that account for timing errors. This is applied to 2-year calibration and validation data sets from an urban catchment. Results show that such objective functions provide equally reliable model predictions (they envelop the same fraction of observations), but with more precision, i.e. smaller estimated uncertainty of model predictions. Additionally, identifiability of some model parameters improved. Therefore objective functions based on the Hydrograph Matching Algorithm can be useful to reduce uncertainties in urban drainage modelling.
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| 8. |
- Bäckström, Magnus, et al.
(författare)
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Transport of stormwater pollutants through a roadside grassed swale
- 2006
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Ingår i: Urban Water Journal. - : Informa UK Limited. - 1573-062X .- 1744-9006. ; 3:2, s. 55-67
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Tidskriftsartikel (refereegranskat)abstract
- Investigations of the pollutant trapping capability of a grassed swale receiving runoff from a road with a traffic intensity of 8,000 vehicles/day were carried out in central Luleå, Sweden. Transport and retention of suspended solids, particles and heavy metals (copper, lead and zinc) were analysed. The sampling was carried out during seven rain events. The results show that once pollutants are trapped in a grassed swale they are not permanently bound to vegetation or soil. A roadside grassed swale may be regarded as a stormwater treatment facility that attenuates the peaks in pollutant loads, without being capable of producing consistently high removal rates.
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| 9. |
- Cettner, Annicka, et al.
(författare)
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Sustainable development and urban stormwater practice
- 2014
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Ingår i: Urban Water Journal. - 1573-062X. ; 11:3, s. 185-197
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Tidskriftsartikel (refereegranskat)abstract
- The traditional use of piped systems for stormwater management is increasingly criticized as being ‘unsustainable’. These systems are part of the water domain where much research has focused on sustainable development indicators to support decision-makers in selecting systems that are more sustainable. However, the interest in sustainable development indicators is low. This paper identifies conditions to engage the practitioners to inform their actions in regard to sustainable stormwater management. Empirical evidence has been obtained from interviews with water professionals from Swedish municipalities. The environmental-technical discourse of sustainable stormwater development is a strong barrier in the change process, to the neglect of the social aspects. In the interviews, reframing the discourse was possible in visions of future sustainable stormwater systems embracing green infrastructure. In action, primary conditions can support sustainable pathways in realizing this vision. The paper suggests further incentives for increased implementation of non-structural measures by developing the identified conditions.
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| 10. |
- Chowdhury, Rezaul K., et al.
(författare)
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Selection of the optimal alternative : rehabilitation of a regional drainage channel in Bangladesh
- 2009
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Ingår i: URBAN WATER JOURNAL. - : Informa UK Limited. - 1573-062X .- 1744-9006. ; 6:5, s. 395-405
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Tidskriftsartikel (refereegranskat)abstract
- Due to the dynamic inter-relationship between human society and water resources, decision-making is a tricky task in water management sectors. In this study, multi-criteria analysis has been used as a decision support tool for the selection of a sustainable option in a regional channel improvement in Bangladesh. The Malnichara channel flows across the north-eastern divisional city of the country, and is responsible for storm water conveyance to the downstream Surma River. The channel was observed to be at risk due to anthropogenic activities such as encroachment, sewage and solid waste disposal and the filling up of natural depression basins. Using the multi-criteria analysis, three alternatives for channel improvement (sodding natural channel, lined natural channel and concrete box culvert) were evaluated with respect to ten indicators, grouped into four sustainability criteria (technical, economic, environmental and social). Sodding natural channel was found to be the optimal alternative, though the selection was sensitive to social criteria. Such a straightforward tool can efficiently be used to ensure sustainability of the channel through stakeholders' involvement in decision-making.
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| 11. |
- Davy, Jonathan, et al.
(författare)
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Designing a greywater treatment system in a highly adaptive urban environment: an ergonomics and human factors observational analysis
- 2023
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Ingår i: Urban Water Journal. - : TAYLOR & FRANCIS LTD. - 1573-062X .- 1744-9006. ; 20:5, s. 624-637
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Tidskriftsartikel (refereegranskat)abstract
- Unplanned, high-density settlements in low-middle income countries often lack functional wastewater management systems. Nature-based solutions, such as constructed wetlands, are an option for the treatment of greywater, provided they are used by and useful to the community. We explored the effectiveness of iterative design for two pilot constructed wetlands in an informal settlement in Johannesburg, South Africa. Using ergonomics and human factors (E/HF) design approaches, this study evaluated the usability and postural risks associated with interactions with the constructed wetlands to motivate (and evaluate) design changes to increase use and reduce the risk of musculoskeletal pain. An elevated work area reduced musculoskeletal risks and a larger work area allowed more users at one time. The raised work areas provided other benefits such as stormwater and sewerage protection. The value of E/HF as part of a broader transdisciplinary team was demonstrated by embedding the design in the activities of the community.
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| 12. |
- Ellerbæk Nielsen, J., et al.
(författare)
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GLUE based marine X-band weather radar data calibration and uncertainty estimation
- 2015
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Ingår i: Urban Water Journal. - 1573-062X. ; 12:4, s. 283-294
-
Tidskriftsartikel (refereegranskat)abstract
- The Generalized Likelihood Uncertainty Estimation methodology (GLUE) is investigated for radar rainfall calibration and uncertainty assessment. The method is used to calibrate radar data collected by a Local Area Weather Radar (LAWR).In contrast to other LAWR data calibrations, the method combines calibration with uncertainty estimation. Instead of searching for a single set of calibration parameters, the method uses the observations to construct distributions of the calibration parameters. These parameter sets provide valuable knowledge of parameter sensitivity and the uncertainty.Two approaches are analyzed; the static calibration approach, where the LAWR is calibrated once for a long period and the dynamic approach, where the estimate is continuously adjusted based on ground observations.The analysis illustrates that the static calibration performs insufficiently, whereas the dynamic adjustment improves the performance significantly.It is found that even if the dynamic adjustment method is used the uncertainty of rainfall estimates can still be significant.
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| 13. |
- Eriksson, Eva, 1973-, et al.
(författare)
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Phytotoxicity of grey wastewater evaluated by toxicity tests
- 2006
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Ingår i: Urban Water Journal. - : Informa UK Limited. - 1573-062X .- 1744-9006. ; 3:1, s. 13-20
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Tidskriftsartikel (refereegranskat)abstract
- An algal growth inhibition test and a short-term acute assay for willows were used in order to evaluate the phytotoxicity of grey wastewater from different sources. Bathroom grey wastewaters were toxic towards algae (EC10 = 36 – 375 mL/L), whereas kitchen and laundry wastewaters were found to be toxic to both organisms (EC10 = 55 – 198 mL/L). The investigation showed that untreated grey wastewater could pose an environmental hazard if discharged into small-size receiving waters. Discharge to willow evaporation beds is problematic and toxic effects may be encountered, but, compared to direct discharge to surface water, the risks of toxic effects are much less pronounced.
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| 14. |
- Fletcher, Tim D., et al.
(författare)
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SUDS, LID, BMPs, WSUD and more : The evolution and application of terminology surrounding urban drainage
- 2015
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Ingår i: Urban Water Journal. - 1573-062X. ; 12:7, s. 525-542
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Tidskriftsartikel (refereegranskat)abstract
- The management of urban stormwater has become increasingly complex over recent decades. Consequently, terminology describing the principles and practices of urban drainage has become increasingly diverse, increasing the potential for confusion and miscommunication. This paper documents the history, scope, application and underlying principles of terms used in urban drainage and provides recommendations for clear communication of these principles. Terminology evolves locally and thus has an important role in establishing awareness and credibility of new approaches and contains nuanced understandings of the principles that are applied locally to address specific problems. Despite the understandable desire to have a 'uniform set of terminology', such a concept is flawed, ignoring the fact that terms reflect locally shared understanding. The local development of terminology thus has an important role in advancing the profession, but authors should facilitate communication between disciplines and between regions of the world, by being explicit and accurate in their application. © 2014 © The work of Tim D. Fletcher is Crown copyright in the Commonwealth of Australia 2014, University of Melbourne. The work of Danielle Dagenais is Copyright of the Crown in Canada 2014, University of Montreal. The work of William Shuster was authored as part of his official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 USC. 105, no copyright protection is available for such works under US Law. William F. Hunt, Richard Ashley, David Butler, Scott Arthur, Sam Trowsdale, Sylvie Barraud, Annette Semadeni-Davies, Jean-Luc Bertrand-Krajewski, Peter Steen Mikkelsen, Gilles Rivard, Mathias Uhl and Maria Viklander hereby waive their right to assert copyright, but not their right to be named as co-authors in the article.
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| 15. |
- Glaas, Erik, 1981-, et al.
(författare)
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Development and user testing of the ICT-platform Visual Water supporting sustainable municipal stormwater planning
- 2022
-
Ingår i: Urban Water Journal. - : Taylor & Francis Ltd. - 1573-062X .- 1744-9006. ; 19:9, s. 962-974
-
Tidskriftsartikel (refereegranskat)abstract
- The need to develop sustainable stormwater management is intensifying due to climate impacts and urban densification. Such complex planning processes require insights into disparate issues, connecting heterogeneous actors. While many decision-support tools are developed to facilitate such planning, research assessing their usefulness is requested. This study introduces and assesses one such ICT-tool; the Visual Water platform, aiming to support sustainable stormwater planning in Swedish municipalities. The study aims to identify critical points to consider for developers of related decision-support tools and to detangle requirements and tradeoffs in making them relevant and user-friendly, building on test-sessions with Swedish practitioners. Results show that the platform responds to challenges within municipal planning as outlined by Swedish practitioners. However, though the platform content is considered relevant, its application in real-world planning is perceived as somewhat unclear. The paper discusses ideas for how sustainability-related decision-support tools better can respond to user demands.
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| 16. |
- Govindarajan, Venkatesh, 1972-, et al.
(författare)
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Analysis of chemicals and energy consumption in water and wastewater treatment, as cost components : Case study of Oslo, Norway
- 2011
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Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X. ; 8:3, s. 189-202
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Tidskriftsartikel (refereegranskat)abstract
- Adopting a systems-approach to an urban water and wastewater system, while applying a triple bottom line strategy to management, entails a careful analysis of all the sub-systems and components thereof with a view to improving service levels, optimising expenditure, augmenting investments, and also reducing the life-cycle environmental impacts associated with setting up, maintaining and operating the system. The scope for optimising expenses is system-wide, though it varies from one sub-system to another, depending on inherent lock-ins and external factors beyond the direct control of the water and wastewater utility. Optimising the consumption of energy and chemicals and improving the cost-efficiency thereof, is always on the agenda of water treatment plants (WTPs) and wastewater treatment plants (WWTPs). This paper analyses the consumption of and the expenditure on chemicals and energy at Oslo's WTPs and WWTPs over time. Energy and chemicals for water and wastewater treatment, on an average account for 10.8% of the total operational expenses in the water supply sub-system and 13.7% for the wastewater handling sub-system. There is a perceptible increase in this share from 5.2% in 2004 to 14.9% in 2009 for water and 12.3% to 14.2% for wastewater. Chemicals cost more than energy for the WWTPs, while it was the other way round for the WTPs. The total real cost of energy and chemicals per cubic metre, in year-2007 currency, was between 4 and 5.2 Euro cents for the WTPs, and between 1 and 4.5 Euro cents for the WTPs. The total (WTP + WWTP) per-capita real costs of energy and chemicals, expressed in year-2007 currency, rose from around 10 Euros in year 2000 to about 12.2 Euros in year 2007.
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| 17. |
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| 18. |
- Govindarajan, Venkatesh, 1972-, et al.
(författare)
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Metabolism-modelling approaches to long-term sustainability assessment of urban water services
- 2017
-
Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X .- 1744-9006. ; 14:1, s. 11-22
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Tidskriftsartikel (refereegranskat)abstract
- There is a discernible need for a holistic, long-term and sustainability approach in decision-making in water and wastewater utilities around the world. Metabolism-based modelling, which can quantify various flows within an urban water system (UWS), has shown its effective usability for a more comprehensive understanding of the impacts of intervention strategies and can be used by any water utility for future planning of UWS. This study presents the main principles of a holistic Sustainability Assessment Framework which can be simulated by using two analytical, conceptual, mass-balance-based models to quantify relevant key performance indicators (KPIs) associated with the metabolic flows of the urban water cycle. These two models are WaterMet2 (WM2) and dynamic metabolism model (DMM), developed recently under the aegis of the EU TRUST (Transitions to the Urban Water Services of Tomorrow) project. There are clear differences between the two models which make them useful in different contexts and circumstantial situations. DMM is a mass-balance consistent model which quantifies and presents annually-aggregated performance values for system wide energy consumption, emissions, environmental impacts and costs for the entire UWS though it is also possible to derive corresponding indicators for individual sub-systems (e.g. water distribution and wastewater transport). WM2 is the opposite of this, it is a distributed metabolism model which simulates water related and other resource flows throughout the UWS components with a higher resolution both spatially (e.g. multiple water resources and service reservoirs) and temporally (e.g. daily and monthly), and thereby is useful in contexts where utilities would like to focus on further details of the UWS metabolism with the aim to understand and solve specific problems. Overall, these two complementary metabolism-based approaches enable any water utility to quantitatively explore and understand the influences of different external drivers and intervention strategies on future performance profiles linked to any physical, environmental and economic criteria.
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| 19. |
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| 20. |
- Jang, Nicole, et al.
(författare)
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Increasing knowledge and trust to overcome barriers to green infrastructure implementation : a Vancouver case study
- 2024
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Ingår i: Urban Water Journal. - 1573-062X .- 1744-9006.
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a case study of the obstacles to green infrastructure implementation in the City of Vancouver. This case study has two aims, 1) to better understand the planning and decision-making processes hindering the widespread implementation of green infrastructure across the City of Vancouver, and 2) propose solutions to facilitate the uptake of GI. This paper begins by reviewing existing literature on barriers to green infrastructure implementation. Then, it investigates current perceptions of GI in the City of Vancouver, and what barriers exist to its implementation through document analysis and semi-structured interviews. Proposed solutions to green infrastructure implementation are reviewed and recommendations are provided for the City of Vancouver. It ends with a short discussion on the applicability of lessons learned from the study of Vancouver for other municipalities seeking to overcome barriers to green infrastructure implementation.
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| 21. |
- Kaykhaii, Saida, 1989-, et al.
(författare)
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Stormwater treatment using an ultrafiltration membrane and pulsatile fluid flow
- 2023
-
Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X .- 1744-9006.
-
Tidskriftsartikel (refereegranskat)abstract
- A polymeric ultrafiltration (UF) membrane was used for stormwater treatment, with the focus on evaluating the increase in the membrane process productivity by adding pulsatile fluid flow to UF membrane treatment. Sedimentation and sieving were used as pre-treatment. The result showed that increasing the pulse frequency from 0 to 4 Hz increased productivity from -6.6 to 82 LMH. UF membrane removed suspended solids, oil and turbidity below detection limit. The UF membrane also separated total coliforms, E. coli and P. aeruginosa below detection limit. Total organic carbon (TOC) was reduced by between 70 and 91%. In addition, the UF membrane was able to reduce BOD7 and COD to below 7 mg/L in the permeate. According to the US EPA, WHO, and national regulations in Canada, Japan, and South Korea, treated stormwater can be used for flushing toilets and streets irrigation and agricultural use.
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| 22. |
- McConville, J. R., et al.
(författare)
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Infrastructure investments and operating costs for fecal sludge and sewage treatment systems in Kampala, Uganda
- 2019
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Ingår i: Urban Water Journal. - : Taylor and Francis Ltd.. - 1573-062X. ; 16:8, s. 584-593
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Tidskriftsartikel (refereegranskat)abstract
- Like many low-income countries, Uganda is struggling to provide sanitation to its inhabitants. Meeting the Sustainable Development Goal related to sanitation (SDG6) will require major investments in sanitation. This study uses the concept of service regimes to analyze existing sanitation infrastructure and services and their respective costs. The service regimes investigated are the sewage regime and the fecal sludge (FS) regime. The results show that approximately 56% of the fecal flow in Kampala is estimated as ‘safely managed’. The results also show that the annual per capita costs for the sewage regime (USD 186) are more than 13-fold those for the FS regime (USD 14). Additionally, there are large differences in subsidies between the regimes. When allocating public funds, decision-makers are advised to consider (i) number of customers within regimes, (ii) total capital and operating costs of services, (iii) cost allocation between stakeholders, and (iv) infrastructure performance. © 2019, © 2019 The Author(s).
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| 23. |
- Milovanovic, Ivan, 1990-, et al.
(författare)
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Performance of a Zeolite Filter treating Copper Roof Runoff
- 2022
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Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X .- 1744-9006. ; 19:5, s. 499-508
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Tidskriftsartikel (refereegranskat)abstract
- Copper is a common roofing material used in urban environments, yet it poses a threat to the ecosystem. Space requirements for stormwater treatment in urban areas are often problematic. This study investigated the treatment efficiency of a filter system containing zeolite as filter medium and treatment of copper roof runoff in field conditions. Emphasis was placed on copper and zinc treatment, while the release of sodium and aluminium was also evaluated. The filter system was monitored over a period of 16 months (7 sampling events). The filter reduced the total and dissolved copper by 52–82% and 48–85%, respectively. Although the average observed treatment efficiency of copper and zinc was high, considerable decline in filter efficiency was noticed, indicating potential saturation of the filter medium. Moreover, the copper concentrations in the outlet were still high, 350–600 μg/l, and significantly higher than the concentrations recommended by the relevant authorities.
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| 24. |
- Moghadas, Shahab, et al.
(författare)
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Review of models and procedures for modelling urban snowmelt
- 2016
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Ingår i: Urban Water Journal. - 1573-062X .- 1744-9006. ; 13:4, s. 396-411
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Tidskriftsartikel (refereegranskat)abstract
- A literature review of selected snowmelt models or algorithms was undertaken to identify which of these tools could be readily used, or easily modified, for simulating urban snowmelt. In this context, the urban factors influencing snowmelt were classified into three categories: human activities, land use, and the origin of deposited snow; and served to develop a classification of urban snow covers with characteristic properties influencing snowmelt. Finally, the assessment of capabilities of the surveyed models or algorithms to simulate snowmelt for these covers indicated that: (i) only two of the tools addressed the critical characteristics of urban snow covers (for specific cases only), (ii) urban runoff models with snowmelt subroutines offered best operational flexibility, though modifications and/or guidance on input values would be required for satisfactory simulations, and (iii) the review findings should help modellers in choosing a snowmelt simulation tool best serving their task with respect to urban conditions.
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| 25. |
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| 26. |
- Saagi, Ramesh, et al.
(författare)
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Key control handles in integrated urban wastewater systems for improving receiving water quality
- 2018
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Ingår i: Urban Water Journal. - 1573-062X. ; 15:8, s. 790-800
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Tidskriftsartikel (refereegranskat)abstract
- There is an increasing interest in modelling and control of integrated urban wastewater systems (UWS). Nevertheless, given the multiple interactions between the sub-systems–catchment, sewer system, wastewater treatment plant (WWTP) and receiving water system–the selection of effective control handles for improving receiving water quality is a major challenge. In this paper, a systematic study to identify the most important control handles in an UWS is presented. The Benchmark Simulation Model for Urban Wastewater Systems (BSM-UWS) is selected as a virtual case-study. Morris screening is used to perform global sensitivity analysis. Results indicate that, for the BSM-UWS layout, while river dissolved oxygen quality (Texc,DO) is influenced by multiple control handles both in the sewer system and WWTP, river un-ionized ammonia quality (Texc,NH3) is mainly influenced by WWTP control handles. The study highlights the need to perform simulations for at least 1 year when determining key control handles for UWS.
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| 27. |
- Sjömander-Magnusson, Therese, et al.
(författare)
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Context driven policy design in urban water management : A case study of Windhoek, Namibia
- 2005
-
Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X .- 1744-9006. ; 2:3, s. 151-160
-
Tidskriftsartikel (refereegranskat)abstract
- Urban water management in the southern cities of Namibia is composed through both a formal and an informal system. In the formal system, controlling demand is the key issue, and in the informal system, an improved accessibility to water is fundamental. The main issue raised in this paper is how authorities can support an ever-increasing poor population with water and at the same time keep demand among households with private water connections at a reasonable level. To decrease the demand for water in Windhoek, a thorough water demand management strategy (WDM) was launched in 1994. Water managers showed a high level of adaptability to the alarming water situation. One of the lessons learned from the implementation in Windhoek is that dedicated people with active involvement and vision are important for successful WDM. The budget must be allocated on a continuous basis for the implementation of certain WDM measures and a degree of flexibility among water users is important for the strategy to be successful. The dual situation experienced in cities in the South where both a need to expand services, and at the same time control demand, calls for a new approach in urban water management. Strategies need to be socially specific and flexible to changing pre-conditions. Therefore, a context driven policy design is advocated.
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| 28. |
- Søberg, Laila, et al.
(författare)
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Bioaccumulation of heavy metals in two wet retention ponds
- 2016
-
Ingår i: Urban Water Journal. - 1573-062X. ; 13:7, s. 697-709
-
Tidskriftsartikel (refereegranskat)abstract
- Metal accumulation in stormwater ponds may contaminate the inhabiting fauna, thus jeopardizing their ecosystem services function. We evaluated bioaccumulation of metals in natural fauna and caged mussel indicator organisms in two wet retention ponds. Mussel cages were distributed throughout the ponds to detect bioaccumulation gradients and obtain a time-integrated measure of metal bioavailability. We further investigated if sediment metal concentrations correlate with those in the fauna and mussels. Metal concentrations in the fauna tended to be higher in the ponds than in a reference lake, but statistical significance was only shown for Cu. Positive correlations were found for some metals in fauna and sediment. Sediment metal concentrations in one pond decreased from inlet to outlet while no gradients were observed in the mussels in either pond. These findings indicate that metal accumulation in the examined ponds currently does not pose a threat to their habitat function.
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| 29. |
- Ugarelli, Rita, et al.
(författare)
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Historical analysis of blockages in wastewater pipelines in Oslo and diagnosis of causative pipeline characteristics.
- 2010
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Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X. ; 7:6, s. 335-343
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Tidskriftsartikel (refereegranskat)abstract
- The city of Oslo is evaluating strategies for the selection of appropriate materials for the pipelines and manholes of its wastewater network. The overarching motive is to minimise construction-related failures over the system lifetime and also ensure that it is able to avert flooding events. This paper analyses the blockage records of the last 16 years (1991-2006) in the wastewater pipeline network of Oslo. For the purpose of the analysis, the pipeline stock is categorised on the basis of pipe diameter, material of fabrication, slope and age. Proneness to blockages is studied and attempts are made to correlate the same to the size, material, slope and age. The analyses performed confirm that older and small diameter sewage pipelines made of concrete, laid almost horizontal to the ground surface are the high-priority candidates, and more importantly enables one to compare among the different categories and classes of pipelines.
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| 30. |
- Vergeles, Yuriy, et al.
(författare)
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Formation and properties of sediments in constructed wetlands for treatment of domestic wastewater
- 2016
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Ingår i: Urban Water Journal. - 1573-062X. ; 13:3, s. 293-301
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Tidskriftsartikel (refereegranskat)abstract
- Sediments formation and biogeochemical properties were studied in an experimental constructed wetland site in Ukraine (Bioplato) for treatment of domestic effluents. The wetland, with a capacity of 50m(3) d(-1) of wastewater, consists of vertical and horizontal filtrations units with fine gravel, middle and coarse sand, a subsurface flow unit with natural wetland soil applied, and a septic tank and sludge-drying field. Macrophytes, reed (Phragmites australis), cattail (Typha latifolia) and a number of sedge species (Carex spp.) were planted in the area and dominate the average cover of 85-90%. Treatment efficiency for BOD5 and suspended solids was 93-96%, for COD - 82%, for nutrients - 27-50%, and for pathogenic microorganisms 99.3-99.6%. Sludge was sampled at each unit followed by standard laboratory analyses of its main characteristics: total organic carbon (TOC), total nutrients (N, P), contents of trace elements, abundance of pathogenic microorganisms, and general toxicity. Results confirmed that the top layer of sludge from each unit of wetland could be used as a source of fertilizers for grain and leguminous crops.
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| 31. |
- Vinnerås, B., et al.
(författare)
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The characteristics of household wastewater and biodegradable solid waste : a proposal for new Swedish design values
- 2006
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Ingår i: Urban Water Journal. - : Informa UK Limited. - 1573-062X .- 1744-9006. ; 3:1, s. 3-11
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Tidskriftsartikel (refereegranskat)abstract
- The present Swedish design values (DV) for urine, faeces, greywater and biodegradable solid waste were scrutinised and compared to the composition of these fractions in two blocks of flats, Gebers and Ekoporten. For evaluation of the greywater composition, two additional areas were included: the housing area Vibyåsen and a calculation based upon the composition of the sewage sludge in Ryaverken sewage treatment plant in Gothenburg. The parameters scrutinised were dry mass, wet mass, BOD7, COD, N, P, K, Cu, Cr, Ni, Zn, Cd, Hg and Pb. Based on the results, new updated Swedish DV were proposed for these parameters in the fractions urine, faeces, greywater and biodegradable solid waste
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| 32. |
- Wu, Jiechen, Postdoctoral position, et al.
(författare)
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Uncertainty inherent to a conceptual model StormTac Web simulating urban runoff quantity, quality and control
- 2021
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Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X .- 1744-9006. ; 18:5, s. 300-309
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Tidskriftsartikel (refereegranskat)abstract
- Assessing uncertainties of urban drainage models is important for their applications. While most attention in the literature was paid to large comprehensive models, little has been published about Low-Complexity Conceptual Models (LCCMs). This paper explores the uncertainties inherent to a conceptual, data-based proprietary model StormTac Web, simulating annual urban runoff quantity and quality, and serving here as an example of a LCCM. The analyses were demonstrated for a small urban catchment, Sätra in Stockholm, Sweden, using the Law of Propagation of Uncertainties and Morris screening methods. The results indicate that the uncertainty of the modelled annual runoff quality (about 30%) is greater than that of annual runoff volumes (about 24%), and the latter uncertainties can significantly contribute to the uncertainty in runoff quality. In computations of pollutant loads, the most sensitive inputs were land-use specific parameters, including the annual volumetric runoff coefficients and default pollutant concentrations for various land uses.
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