| 1. |
- 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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| 2. |
- 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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| 3. |
- 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
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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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| 4. |
- 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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| 5. |
- Govindarajan, Venkatesh, 1972-, et al.
(författare)
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Metabolism-modelling approaches to long-term sustainability assessment of urban water services
- 2015
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Ingår i: Urban Water Journal. - : Taylor & Francis. - 1573-062X. ; , s. 1-12
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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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| 6. |
- 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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| 7. |
- 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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| 8. |
- 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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| 9. |
- Søberg, Laila, et al.
(författare)
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Bioaccumulation of heavy metals in two wet retention ponds
- 2016
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Ingår i: Urban Water Journal. - 1573-062X. ; 13:7, s. 697-709
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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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| 10. |
- 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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