Existing Water Infrastructure Research Articles

Climate change impact on short-duration extreme precipitation and intensity–duration–frequency curves over Europe

To build future climate-proof water systems and to reduce the failure risk of infrastructure, short-duration extreme precipitation design storms must be updated. However, a robust future projection of such storms on a continental scale has not been presented due to the scarcity of long, high quality sub-daily data both for observations and model simulations. To address this need, we develop current and future precipitation intensity–duration–frequency (IDF) curves for Europe for 0.5-, 1-, 3-, 6-, 12- and 24-hour durations and for different return periods ranging between 1 and 100 years derived from a Generalized Pareto Distribution (GPD). Future IDF curves are developed in the framework of the quantile perturbation downscaling method by applying climate change signals from the EURO-CORDEX RCMs on current IDF curves obtained from high-resolution remote sensing based products. Here we show that rarer sub-daily extreme precipitation events will intensify more than less rare events and that changes may depend on precipitation duration. The frequency of sub-daily extreme precipitation events of 50- and 100-year return periods will be tripled under the high-end RCP8.5 scenario. Such intensification will lead to a substantial uplift (16–27% depending on duration and return period) and steepening (17–25% depending on return period) of the IDF curves under future climate change, calling attention to the vulnerability of the existing water infrastructure systems.

Analysis of sediment load under combined effect of rainfall and flow

An increase in sediment load resulting from extreme weather event can affect the capacity of existing water infrastructure, for example, decreasing reservoir capacities, creating obstacles and reducing the navigation depth, or eroding bridge piers by scouring actions. A number of studies have been carried out on factors affecting sediment yield and transport but only a few studies being done on the combination of both rainfall and flow on the sediment load. Therefore, the aim of this study is to identify the impact on sediment load comprising of well-graded silica sand due to combined effect of flow and rainfall. This research has two objectives; firstly, to study the relationship between flow, rainfall, and sediment load and secondly to devise an experiment to investigate how combination of flow and rainfall could affect sediment load with the help of Advanced Environmental Hydrology System. Thirty-six sets of experiments were conducted on a 2 m long, 0.2 m wide and 0.15 m deep channel, moulded in the Armfield S12 MKII on a 1% constant slope with six different readings of rainfall ranging from 6 to 72 mm/hr and by varying the flow ranging from 0.5 to 3.0 L/min to observe the different trends and changes to sediment load when rainfall and flow varies. This experimental study demonstrates a combination of both rainfall and flow resulted in a stronger linear correlation with sediment load.

Development of a design and implementation process for the integration of hydrokinetic devices into existing infrastructure in South Africa

In South Africa there is currently no notable use of modern small-scale hydrokinetic (HK) energy systems, mainly due to formerly low-cost coal-powered electricity. This renewable energy option makes use of the kinetic energy from flowing water, rather than potential energy, which is more often used in conventional hydropower. Updated refined versions of this technology are now being investigated and manufactured due to the global drive towards reducing carbon emissions and increasing energy efficiency. These modular units allow for installation of HK turbines into existing water infrastructure with very little civil works. The study’s objective was to develop a simplified design and implementation process for HK devices within the South African legislative and regulatory environment. Approximately 66% of South Africa’s water supply is used by the agricultural sector with more than 6 500 km of canal systems running through many areas which could benefit from alternative energy sources. The recent electricity crisis in the country allowed for problem resolution through funding opportunities and thereby an introduction of an innovative and sustainable technology to provide renewable electricity where otherwise not feasible. A pilot HK project was implemented in an applicable section on the Boegoeberg irrigation canal in the Northern Cape Province and tested for optimum functionality and correct application. This process allowed evolution of a development process for the implementation of HK devices in existing water infrastructure.

In-Between Waters /Intercepting Wetness: Inventing Rain in the Mining Landscape of Shanxi Province, China

Under the background of imposing engineered structures, including reservoirs and inter-basin water transfer infrastructures, being applied to solve drought caused by coal mining in Shanxi Province of China and floods caused by mineral mining in Western Ghats of India, the author reviews the intrinsic reason of water problems and recommends a water management solution that is design on “rain before floods” and “fields of wetness before flows of water.” Most magnificent engineered infrastructures are designed upon an idea of separating water from its milieu, thus becoming contained flows in pipes, channels, and reservoirs to solve water problems. To compensate for the shortage of existing water infrastructures, the author suggests gathering a regional-level landscape capacity for building “wetness” of resilience when facing problems of “water” in extremities. This is a radical shift compared with a problem-solving approach, as engineering does, to one that is grounded in landscape and uncovers opportunities. The landscape research and design project introduced in this article aims to provide an alternative future for Shanxi Province, China, which seems arid and is challenged by monodevelopment mode. The research and design within the project are across four nested scales. A landscape infrastructure of intercepting wetness is taken as an underlying thread which initiates intertwined ecological, programmatic, temporal and material trajectories. On the other hand, the project demonstrates research, representation, design, and planning can actually inform one another, and the design remains open and adaptive to its changing environments.

Urban Landscape Design Adaption to Flood Risk: A Case Study in Can Tho City, Vietnam

Located in the centre of the Mekong Delta (MD), Can Tho City (CTC), with a development history of more than three centuries, has affirmed its strategic position as an interregional centre. The city on Hau river is blessed by nature with the identity of a delta landscape associated with riverine dynamics. First, this article presents the development history of CTC, and the correlation between its urbanization history and the existing characteristics of the urban landscape. Then, this study further analyses challenges in urban development, assessing existing water infrastructure and opportunities of current urban and rural landscapes. Finally, urban landscape design strategies have been discussed to suggest improved resilience of the city with flood management in the context of climate change.

Sustainability Strategies at the Water–Energy Nexus: Renewable Energy and Decentralized Infrastructure

AbstractWith a global focus on incorporating renewable energies into existing water infrastructure, the water industry has established important strategies to conserve water and energy for future sustainability.

Importance of scenario analysis in urban development for urban water infrastructure planning and management

Sealing of surfaces and land use change induced by population change puts pressure on urban water networks. Changes in paved areas can also increase the risk of pluvial flooding at places that have not been endangered before. For an anticipatory planning and adaptation of the existing water infrastructure to a dynamic and evolving system like a growing or shrinking city, a comprehensive urban development scenario analysis is essential. This work presents an urban development model designed especially for simplistic simulation of multiple predefined population and spatial scenarios and allowing for an integration with successive urban water network models.Results show that an analysis of different development scenarios can help to increase a city's resilience to unexpected changes. Hence it is crucial to simulate a variety of scenarios to cover as many future outcomes of city development as possible for a systematic and rigorous inquiry for problematic situations in the future.

Survival Analysis of US Water Service Lines Utilizing a Nationwide Failure Data Set

Research into leakage in water distribution systems in the United States has shown that substantial amounts of real water loss can occur in service lines. The current research therefore sought to, first, describe trends in US service line failures on the basis of nearly 10 years of national‐level historical failure data; second, develop a structured survival analysis for various service line materials that have failed; and third, provide evidence to demonstrate to water industry stakeholders the importance of proactive water service line maintenance practices and strategies. Given that the condition of the existing water infrastructure in the United States continues to deteriorate, it is essential to ensure that service lines on private property be diligently maintained. This research on service lines will help shape safer design criteria, not only within individual residences, but also to support dependable maintenance procedures within water distribution systems.

Awa: Using water distribution systems to transmit data

AbstractThis article presents Awa, a real‐time wireless monitoring solution for urban water distribution systems (WDSs). The Awa system is composed of a distributed network of low‐cost sensor nodes that can be quickly installed on water pipes. Rather than using conventional radio signals, which are attenuated in underground environments, the nodes use the actual water‐filled pipe as the transmission medium to communicate with one another. This permits the use of an already existing water infrastructure in the deployment of large wireless sensor networks. We describe the development and evaluation of novel and battery‐powered sensor nodes that can be magnetically clipped to valves and hard‐to‐access points in WDSs without requiring digging or cutting of pipes. A channel characterization is carried out and a number of data modulation schemes are evaluated across a 110‐m section of pipe in an operational WDSs. We identify a near‐optimal frequency (near 500 Hz) for transmitting data. We demonstrate communication at 100 bps across a real‐world water pipe using amplitude modulation. Not unlike radio‐frequency wireless, we also measure the highly nonstationary effects of multipath fading. The article also contains an in‐depth discussion about the opportunities that this emerging communication technology offers in the context of city‐wide leak detection and flow monitoring.

The Limits of Water Pricing in a Developing Country Metropolis: Empirical Lessons from an Industrial City of Pakistan

This paper seeks to question the effectiveness of water pricing as a means of consumer behavioural change in urban centres of the Global South by analysing the domestic usage for water in a major industrial city of Pakistan. Using survey data of 1100 households from Faisalabad city, we estimate the price and income elasticities of water demand. Instrumental variable methods are applied to overcome the endogeneity issues of water pricing. The findings reflect that price and income elasticities vary across different groups. Price elasticities range from −0.43 to −0.71, and income elasticities vary between 0.01 and 0.12. These findings suggest that pricing policies may have limited scope to drive households’ water consumption patterns. However, these empirics may suggest that policy makers should design an appropriate tariff structure to increase revenues that can be invested to further improve the existing water infrastructure. The study findings also suggest that non-pricing instruments, such as water saving campaigns, may be helpful in driving an efficient use of water in rapidly growing cities in the developing world.

Bringing Future Climatic Change into Water Resources Management Practice Today

The global climate is changing and altering the hydrologic cycle that results in (i) reduction of water supply; (ii) increase in frequency and magnitude of flood and drought events; (iii) damage to the shoreline areas; (iv) increase in irrigation water use; (v) decrease in quality of all freshwater sources; and (vi) increase in functional and operational requirements for the existing water infrastructure. The paper provides the review of water resources management challenges posed by the climate change. In order to provide guidance for including climate change impacts into water management studies, a generic approach is detailed for potential implementation in practice. Methods for selecting global climate models and emission scenarios, followed by bias correction and downscaling are discussed. The paper ends with the description of one practical example, IDF_CC, a web based tool for updating intensity duration frequency curves under changing climate. The tool is designed in response to real needs of water engineering practice and has been in use in Canada since early 2015.

Maximizing the impact of mining investment in water infrastructure for local communities

Mining activities requiring the development of new or expansion of existing water infrastructure provide an opportunity to benefit local communities with limited access to clean water. Mining companies have commonly assisted water service provision to communities as part of their mining concession or through corporate social responsibility programs. In addition to the water infrastructure provided to local communities, the accompanying capacity building, infrastructure governance, and the consultation process all have notable impacts not only on the sustainability of the water infrastructure, but also the level of benefit to communities. Using recent Australian Government funded water and sanitation interventions along the Nacala Economic Corridor (Mozambique) as a case study, we provide an examination of how mining companies can most effectively ensure the delivery of sustainable water infrastructure to local communities.

Evaluation of Water Permeability in Fibre Reinforced Hydraulic Lime Mortar Intended for Conservation

Much of the existing water infrastructure across the world was constructed using masonry in the last 200 years and many of these structures were built with pre-Portland cement binders. Although these mortars exhibit good workability and high water retention in the plastic state, the water tightness deteriorates over the years resulting in a pressing need for suitable repair materials. The addition of polypropylene micorfibre in cement-based systems was found to be effective in reducing water permeability. But the effect of polymeric fibres on the permeability coefficient of hydraulic lime mortar (HLM) is unknown. Therefore, this paper focuses on measuring water permeability in fibre reinforced HLM. Besides, this study examined the application of nanolime onto the aforementioned mortars and its effect on their water permeability. Accordingly, a permeability cell was setup to monitor the onset of the steady state condition in fluid flow. Companion data was generated for the mechanical performance of these mortars. The results show that in hydraulic lime mortar, there is likely an optimal fibre dosage in order to reduce the permeability coefficient. Unlike with Portland cement mortar, this dosage is significantly lower. As well, applying nanolime was most beneficial in limiting water permeability in the natural hydraulic lime mortars.

The potential of water infrastructure to accommodate solar PV systems in Mediterranean islands

Electricity production in Mediterranean islands currently depends heavily on imported fossil fuels. This strategy has several disadvantages and has been accused of hindering the islands’ sustainable development. In the present research an integrated approach to increase solar photovoltaic (PV) systems’ (SPVS) share in the energy mix of Mediterranean islands is presented, through installations on the available surface near existing water infrastructure. Accordingly, we have analyzed the potential of existing dams to accommodate SPVS on their downstream face as well as the option of SPVS over irrigation canals. We processed databases of water infrastructure in five big islands and developed a methodology to identify favorable locations. Using geographic information system (GIS) we processed the technical characteristics of each location and calculated the potential power capacity and the corresponding electricity production. Eleven dams were identified as “first-rate” locations with a total generating capacity of 63MWp, producing 97GWh of electricity annually, while additional 10 dams with less optimal conditions would add 30MW of capacity and 33GWh of annual production. We also identified an additional advantage of placing SPVS over irrigation canals, proposing additional 60MWp capacity, namely the significant water savings through reduced evaporation.

Time-varying land subsidence detected by radar altimetry: California, Taiwan and north China.

Contemporary applications of radar altimetry include sea-level rise, ocean circulation, marine gravity, and icesheet elevation change. Unlike InSAR and GNSS, which are widely used to map surface deformation, altimetry is neither reliant on highly temporally-correlated ground features nor as limited by the available spatial coverage, and can provide long-term temporal subsidence monitoring capability. Here we use multi-mission radar altimetry with an approximately 23 year data-span to quantify land subsidence in cropland areas. Subsidence rates from TOPEX/POSEIDON, JASON-1, ENVISAT, and JASON-2 during 1992–2015 show time-varying trends with respect to displacement over time in California’s San Joaquin Valley and central Taiwan, possibly related to changes in land use, climatic conditions (drought) and regulatory measures affecting groundwater use. Near Hanford, California, subsidence rates reach 18 cm yr−1 with a cumulative subsidence of 206 cm, which potentially could adversely affect operations of the planned California High-Speed Rail. The maximum subsidence rate in central Taiwan is 8 cm yr−1. Radar altimetry also reveals time-varying subsidence in the North China Plain consistent with the declines of groundwater storage and existing water infrastructure detected by the Gravity Recovery And Climate Experiment (GRACE) satellites, with rates reaching 20 cm yr−1 and cumulative subsidence as much as 155 cm.

Potential roles of past, present, and future urbanization characteristics in producing varied stream responses

AbstractStormwater drainage and wastewater disposal are primary pathways through which urbanization degrades streams. These technologies and management practices change over time, reshaping the urban template and affecting the environmental challenges a city will face in the following decades to centuries. Spatial and temporal asynchrony in the implementation and replacement of these technologies and the adoption of new management approaches means that the mechanisms of the urban stream syndrome will be heterogeneous. Thus, promoting ‘one size fits all’ global panaceas for urban streams may be less effective than local solutions based on the unique urban templates and socioeconomic factors governing streams. Understanding the cumulative effects of spatiotemporal changes in urban templates on streams is critical to protecting and managing them because: 1) existing water infrastructure in many countries (especially high-income countries) is aging and requires replacement, 2) urbanization in rapidly developi...

Time scale effect and uncertainty in reconstruction of paleo‐hydrology

AbstractTree‐ring‐based reconstructions of paleo‐hydrology have proved useful for better understanding the irregularities and extent of past climate changes, and therefore, for more effective water resources management. Despite considerable advances in the field, there still exist challenges that introduce significant uncertainties into paleo‐reconstructions. This study outlines these challenges and address them by developing two themes: (1) the effect of temporal scaling on the strength of the relationship between the hydrologic variables, streamflow in this study, and tree growth rates and (2) the reconstruction uncertainty of streamflow due to the dissimilarity or inconsistency in the pool of tree‐ring chronologies (predictors in reconstruction) in a basin. Based on the insight gained, a methodology is developed to move beyond only relying on the annual hydrology‐growth correlations, and to utilize additional information embedded in the annual time series at longer time scales (e.g. multi‐year to decadal time scales). This methodology also generates an ensemble of streamflow reconstructions to formally account for uncertainty in the pool of chronology sites. The major headwater tributaries of the Saskatchewan River Basin, the main source of surface water in the Canadian Prairie Provinces, are used as the case study. It is shown that the developed methodology explains the variance of streamflows to a larger extent than the conventional approach and better preserves the persistence and variability of streamflows across time scales (Hurst‐type behaviour). The resulting ensemble of paleo‐hydrologic time series is able to more credibly pinpoint the timing and extent of past dry and wet periods and provides a dynamic range of uncertainty in reconstruction. This range varies with time over the course of the reconstruction period, indicating that the utility of tree‐ring chronologies for paleo‐reconstruction differs for different time periods over the past several centuries in the history of the region. The proposed ensemble approach provides a credible range of multiple‐century‐long water availability scenarios that can be used for vulnerability assessment of the existing water infrastructure and improving water resources management. Copyright © 2015 John Wiley & Sons, Ltd.

Factors Affecting Water Supply in Owah-Abbi, Delta State

This study aims at examining the factors that influence inadequate water supply in Owah-Abbi. The research was conducted by applying the survey research design and data relevant to the topic of study were generated via direct field measurement and administration of questionnaire. Findings include: major sources of water in Owah Abbi Community including Borehole (57.33%), hand dug well (21.33%) and River/Stream water (12%), and those who depend on rain water are 9.33%. It was also revealed that in Owah-Abbi Community water is provided by Government (42.66%); Community (20.67%); Individual efforts (10.67%) and other bodies (26%). Similarly, causes of the water shortage in Owah-Abbi Community included corruption (37.33%); unfavourable Government policies (25.33%); while 17.33% blamed it on the theft and vandalization of Owah-Abbi water supply facilities. Others were the poor management culture of the facilities (8.67%), Erratic Power supply in the community (6.67%), Faulty Hydraulic equipment (2.67%) and carelessness (2%). The study recommended that the government should provide water for the people of Owah-Abbi as a matter of urgency; protection of the existing water infrastructures was also required; the people of Owah-Abbi should be advised on the need to purify water; enlightenment programs should be carried out in the area.

Assessment of future water availability under the changing climate: case study of Klang River Basin, Malaysia

ABSTRACTThis study aims to assess future water deficit and availability in Klang valley in the context of climate change. A surface water budget model for Klang river basin was developed using MIKE BASIN. The parameters for the Nedbør‐Afrstrømnings (NAM) model were determined and examined by trial-and-error approach and evaluated based on correlation coefficient (R), Nash–Sutcliffe efficiency (RNS), and overall water balance error (WBer). The climate change scenario assessment used downscaled projected future rainfall data from 18 Global Circulation Models for the period 2046–2065. The assessment of water availability was carried out for Klang Gates Dam. The calibration and validation results for NAM model were satisfactory. The reservoir model verification result showed that the observed and simulated dam level were slightly dissimilar, which may be due to insufficient input data, particularly rainfall data as rainfall stations were very sparse upstream of the dam. The water deficit analysis for 2046–2065 showed that there will be water shortage in most of the months. The results of this assessment will help decision-makers evaluate the water availability and existing water infrastructure capacity in the vicinity of Klang river basin, particularly with respect to future raw and treated water yield.

Synergistic co-digestion of solid-organic-waste and municipal-sewage-sludge: 1 plus 1 equals more than 2 in terms of biogas production and solids reduction

Making good use of existing water infrastructure by adding organic wastes to anaerobic digesters improves the energy balance of a wastewater treatment plant (WWTP) substantially. This paper explores co-digestion load limits targeting a good trade-off for boosting methane production, and limiting process-drawbacks on nitrogen-return loads, cake-production, solids-viscosity and polymer demand. Bio-methane potential tests using whey as a model co-substrate showed diversification and intensification of the anaerobic digestion process resulting in a synergistical enhancement in sewage sludge methanization. Full-scale case-studies demonstrate organic co-substrate addition of up to 94% of the organic sludge load resulted in tripling of the biogas production. At organic co-substrate addition of up to 25% no significant increase in cake production and only a minor increase in ammonia release of ca. 20% have been observed. Similar impacts were measured at a high-solids digester pilot with up-stream thermal hydrolyses where the organic loading rate was increased by 25% using co-substrate. Dynamic simulations were used to validate the synergistic impact of co-substrate addition on sludge methanization, and an increase in hydrolysis rate from 1.5 d−1 to 2.5 d−1 was identified for simulating measured gas production rate. This study demonstrates co-digestion for maximizing synergy as a step towards energy efficiency and ultimately towards carbon neutrality.