City Water System Research Articles

Assessing the water metabolism of coastal urban areas based on the water mass balance framework across time periods: A case study of Cape Town, South Africa

The status of water resources in many coastal cities has become increasingly fragile. In a changing climate, the amount and intensity of rainfall have continued to decline, causing some coastal regions to experience severe drought and deteriorated water supply situation. This article presents a comprehensive study of the urban water metabolism of Cape Town, South Africa. A water mass balance framework was utilized to examine the city's water system across four distinct periods. In addition, the water-energy nexus before and after the drought crisis was evaluated. The key findings include a large amount of surface runoff in the Cape Town area that was not utilized before the drought crisis, resulting in a natural loss potential of water supply that is 2.54 times greater than water used for supply systems. During the drought, per capita water consumption dropped by a substantial 25%; at the same time, the total rate of water loss experienced a substantial decrease of approximately 21%. Since the pandemic, Cape Town's water resources policy has shifted to diversifying water sources, and the use of wastewater and natural water losses will be optimized by more than 32% in 2040 to achieve a water-sensitive city. Future research should explore the temporal and spatial dynamics of urban water flows, the impact of socioeconomic factors, and the integration of water system optimization models for enhanced urban water management.

Fatigue crack growth and slow crack growth of HDPE pipes under internal pressure and flat plate compression

High-Density Polyethylene (HDPE) pipes are widely used in city gas and water systems as buried pipelines for their excellent performance. However, in addition to the internal pressure, it also suffers loads from traffic vehicles, foundation settlements, and illegal buildings. In this paper, fatigue crack propagation of HDPE pipes with a longitudinal external crack was experimentally studied under different load ratios in two cases. Pulsatile internal pressure was implemented in the first case. In the other one, pulsatile flat plate compression and constant internal pressure were applied. The crack mouth opening displacements were recorded by the digital image correction technique. The crack depth was obtained with compliance calibration. It shows that the fatigue crack growth rate decreases as the load ratio increases. In both cases, the slow crack growth kinetics were gained by extrapolating the load ratio to 1.0, representing constant internal pressure or flat plate compression.

Pollution of Water’s direct effect in Iraq on the Public Health & Safety

The devastating effects of pollution of Water are significant, affecting human life, animal life and vegetation at the same time. Recently, Iraq has experienced the effects of pollution of Water, destroying an abundance of plants and many animals. Pollution of Water is one of the mostly deadly and severe problems facing humankind currently. This study analysed the effects of heavy metals Pb, like Cr, Zn and Fe in water for drinking. The findings revealed an upsurge in the number of cholesterol, urea, and white blood cells among people in Basra, Baghdad, and other urban areas. It was also found that these individuals were more likely to have fever, diarrhea, kidneys, and respiratory problems. Recent studies have revealed that pollution of Water in Iraq is caused by a variety of factors, i.e., solid pollutants, chemicals, and microorganisms. Unfortunately, due to the current state of war, there is not much concentration on water treatment plants (WTPs) resulting in a decrease in the quality of the supplied water. Due to the lack of wastewater treatment facilities in most Iraqi cities, sewage is simply discharged into the river. In addition, supply of water and sanitation systems in some major cities have been damaged and the two networks are jointly linked.

Preface

The 10th International Conference on Environmental and Engineering Geophysics (ICEEG) is hosted by China University of Geosciences, Beijing, China, from June 07-12, 2023. Held biennially since 2004, the ICEEG Conference is one of the most important events for geophysical research and applications in environmental and engineering. Drawing together scientists, engineers, industrial delegates and end-users, the conference is a place to see all of the advanced developments, ranging from fundamental achievement in geophysical methods to the most interesting case studies. Traditionally, the proceedings “Engineering Environmental Geophysics and Intelligent Detection Technology” of the 10th International Conference on Environment and Engineering geophysics is published for the readers from the near-surface geophysics communityShallow surface geophysics refers to the exploration theory and application research on the surface of the earth using physical principles and methods. The shallow surface supports the needs of human survival and development. On the one hand, human beings obtain water and minerals from it, and build the necessary underground space to contain water, electricity, gas, communication, transportation and other pipe network systems in modern cities. On the other hand, various kinds of waste generated by human activities is discharged and buried in it, forming a unique geological layer of the Anthropocene. Whether from the technical level (physics) or non-technical level (politics, society, law), shallow surface geophysics is becoming more and more important. Artificial intelligence technology has been widely used in various fields in recent years, and the construction of smart cities cannot be separated from the support of shallow surface geophysical exploration and monitoring methods and technologies. Due to the integration of urbanization and the development of geophysical technology in China, geophysicists have more opportunities for scientific research. In order to promote exchanges, improve the level of environmental and engineering geophysical exploration, and provide a first-class platform for extensive exchanges among workers engaged in scientific research, technology development and production applications in this field, the 10th International Conference on Environment and Engineering Geophysics will be held in China University of Geosciences (Beijing), a famous university of geosciences. We warmly welcome experts and scholars to contribute and participate in the conferenceIn the proceedings of 10th ICEEG, 160 peer-reviewed research expended abstracts are published according to the following topics: geophysical exploration of urban underground space, high frequency surface wave theory and application, ground penetrating radar technology and application, advances in shallow surface geophysics, engineering geophysics, hydrology and environmental geophysics, disaster geophysical survey, archaeological geophysics, unmanned aerial vehicle detection, smart city geophysics, intelligent detection technology, geophysical monitoring technique, geophysical instruments and software, shallow active source and passive source seismic detection, and young scientists forum.We are deeply grateful to the members of the scientific committee and institutional scientific partners of ICEEG: Chinese Geophysical Society, China University of Geosciences (Beijing), Shallow Surface Geophysical Committee of Chinese Geophysical Society, Professional Committee of Environmental Geophysics, Chinese Geophysical Society, Department of Earth Sciences, National Natural Science Foundation of China, China University of Geosciences (Wuhan), Central South University, Chengdu University of Technology, Chang’ An University, Institute of Geology and Geophysics, Chinese Academy of Sciences, China University of Mining and Technology (Beijing), Zhejiang University and Jilin UniversityWe would like to thank all reviewers for their great efforts to achieve the high quality of published articles.We would also like to extend our gratitude to all participants of 10th ICEEG for their interests and great contributions. Our special thanks go to the invited speakers for their significant contributions to the conference and the proceedings.We would also like to thank all the sponsors. It is your years’ support that makes the ICEEG conference a success.We would also extend our thanks to all committee members and student volunteers for their great efforts in organizing this wonderful event.We hope the proceedings show the challenges and the latest developments in the application of Engineering Environmental Geophysics and Intelligent Detection Technology.

A thorough examination of smart city applications: Exploring challenges and solutions throughout the life cycle with emphasis on safeguarding citizen privacy

With the increasing use of artificial intelligence (AI) and the Internet of Things (IoTs), it is crucial to acknowledge the potential security and privacy issues that arise from these advanced technologies in smart cities. This article provides overview of these concerns, highlighting the various ways in which smart city technologies can be vulnerable to cyber-attacks and other security threats. Additionally, the paper examines the privacy risks associated with the collection and use of personal data in smart cities. Effective security measures and privacy protection policies are crucial in ensuring the safety and security of smart cities. Cooperation between governments, private companies and citizens is essential to implement such measures and policies, allowing smart cities to continue developing while guaranteeing the security and privacy of their citizens. Likewise, smart city public safety systems that utilize AI-powered surveillance technologies may be predisposed to hacking, leading to privacy breaches and data misuse. Moreover, smart city energy systems, which rely on IoT devices to regulate power grids, are susceptible to cyber-attacks that can result in power outages or significant damage to vital infrastructure. The adoption of information and communication technology for smart city development has increased the risk of cyber threats, emphasizing the need for a review cybersecurity governance model. In addition, smart city water systems that rely on AI-powered sensors to monitor water quality may also be at risk of hacking, which could result in the contamination of the water supply. Further research is required to better understand the potential risks associated with smart city technologies and develop new solutions to address them. This article shows as a valuable resource for city administrators, policymakers and researchers interested in the security and privacy concerns of smart cities.

Geospatial analysis of patients' social determinants of health for health systems science and disparity research.

Geospatial analysis of patients' social determinants of health for health systems science and disparity research.

Carbon peaks of water systems in Chinese cities under varying water demand dynamics and energy transition pathways

Decarbonization of urban water systems has been increasingly important for addressing the target of climate change mitigation. Yet, little insight has been derived regarding how water use and energy transition policies jointly alter climate impact of water systems in cities. In this study, using 21 cities in Guangdong Province (China) as a case study, we account for the carbon dioxide emissions related to energy use in urban water systems (UWSs) over 2006–2035. By constructing a city-scale water-carbon nexus model, we project future trajectories of electricity-related CO2 emissions in UWSs by considering dynamics of water demand and varying pathways of energy transition. We show that increasing need of tap water purification is a main contributor to electricity-related CO2 emissions, followed by tap water distribution and wastewater treatment. The electricity-related CO2 emissions in most cities could peak before 2030 under a fast-decarbonization energy transition pathway, despite the rise of urban water demand. Fast-urbanizing cities like Foshan, Shantou and Qingyuan may witness a 4–23% increase of emissions between 2020 and 2035. With a more rapid increase of proportion of cleaner energies in electricity mix, the fast-decarbonization pathway could end up with 21% more reduction of emissions on average during 2020–2035, compared to currently-planned energy transition pathway. Under the stringent climate goal of China, cities should foster a joint mechanism between water system and grid companies that leads to a more effective low-carbon governance of water systems.

Improving suitability of urban canals and canalized rivers for transportation, thermal energy extraction and recreation in two European delta cities

Canals and canalized rivers form a major part of surface water systems in European delta cities and societal ambitions to use these waters increase. This is the first assessment of how suitability of these waters can improve for three important uses: transportation, thermal energy extraction (TEE) and recreation. We assess suitability with Suitability Indices (SIs) and identify which alterations in the water system are needed to improve SI scores in Amsterdam, The Netherlands, and Ghent, Belgium. The results show spatial variability in suitability scores. Current suitability for transportation is low (SI score = 1) to excellent (SI score = 4), for TEE fair (SI score = 2) to excellent (SI score = 4), and suitability for recreation is low (SI score = 1). Suitability could improve by enlarging specific waterway dimensions, increasing discharge and clarity, and by enhancing microbiological water quality. The same methodology can be applied to optimize designs for new water bodies and for more water uses.

Daily Precipitation Data for the Mexico City Metropolitan Area from 1930 to 2015

The Metropolitan Zone of Mexico City, as well as the associated basin, includes the territories of Mexico City, some municipalities of the State of Mexico and the state of Hidalgo. In addition, this area is the most densely populated in Mexico. The region is influenced by mid-latitude and tropical weather systems and is vulnerable to extreme hydrometeorological events. In this context, we developed a dataset from the records of 136 geolocated sites that includes daily precipitation data from the CLImate COMputing (CLICOM) project and the Mexico City Water System. The data spans the period from 1930 to 2015 for the rainy months (June–October) from stations with records of 20 or more years. In each recording site, automatic and manual data quality control were performed to verify the consistency of the daily precipitation data. We believe that our highly dense precipitation dataset will be useful for climate, trend and extreme events analysis. Additionally, the data will allow validating simulations of numerical atmospheric models. The dataset is public, and it was previously used in other research to determine areas susceptible to flooding due to heavy rain events and to develop a web mapping application of daily precipitation data.

Study on Key Technologies of Ecological Civilization of Lishui Ancient City Water System

Starting from the historical dimension, this paper studies the historical documents and engineering cases of ancient water conservancy projects in Lishui, explores the transformation law of urban water system in Lishui, and summarizes the key technologies of water ecology contained in ancient water control practice. It was found that Chuzhou took advantage of geographical, geological and climatic conditions, followed the overall balanced water control strategy, planned the ancient city water system network, and completed the task of water distribution. Among them, guided by planning technology, supplemented by canal system network, water and sediment regulation, flood control, interchange diversion and other technologies, a perfect water system is finally formed, which can provide reference for modern water conservancy projects construction.

Multifaceted intra-city water system arrangements in California: Influences and implications for residents

Some cities directly provide drinking water and other utility services to their residents, whereas others contract out these responsibilities in full or in part, with considerable implications for service and non-service outcomes. There is a robust literature considering reasons for city-private provider binaries, as well as a growing number of studies assessing the rise in special district service provision, mixed service delivery arrangements, and inter-municipal service delivery within metropolitan contexts. On the other hand, there are few studies assessing city-level prevalence of these three main provider types jointly, as well as fully accounting for the diversity of institutional arrangements in drinking water service within individual cities.In this study, we construct an empirical profile of and analyze influences on diverse city-level water service provider arrangements using a dataset compiled for all 482 cities in California. Our analysis shows that 80% of cities are served by either a municipality, a private, investor-owned utility or a special district, with special districts being more common than private providers. Moreover, 20% of cities had more than one service provider, and 68% of these cities were served by more than one system type, including many where municipal and private providers co-existed. Using multivariate regression techniques, we analyze influences on different types of city-level drinking water service arrangements. We find that city incorporation date most profoundly influences the mix of water systems in cities, especially arrangements involving special districts or multiple system types. We also find that cities which run their own water system exclusively are more likely to institute conservation policies, and provide suggestive evidence that residents living in cities served by multiple water systems are exposed to wide variance in water rates. Water system fragmentation within city boundaries thus has implications for resource management policy and equity in intra-city resident essential service outcomes.

Water Engineering at Precolumbian AD 600–1100 Tiwanaku’s Urban Center (Bolivia)

The pre-Columbian World Heritage site of Tiwanaku (AD 600–1100) located in highland altiplano Bolivia is shown to have a unique urban water supply system with many advanced hydraulic and hydrological features. By use of Computational Fluid Dynamics (CFD) modeling of the city water system, new revelations as to the complexity of the water system are brought forward. The water system consists of a perimeter drainage channel surrounding the ceremonial center of the city. A network of surface canals and subterranean channels connected to the perimeter drainage channel are supplied by multiple canals from a rainfall collection reservoir. The perimeter drainage channel provides rapid draining of rainy season rainfall runoff together with aquifer drainage of intercepted rainfall; water collected in the perimeter drainage channel is then directed to the Tiwanaku River then on to Lake Titicaca. During the dry season aquifer drainage continues into the perimeter drainage channel; additional water is directed into the drainage channel from a recently discovered, reservoir connected M channel. Two subterranean channels beneath the ceremonial center were supplied by M channel water delivered into the perimeter drainage channel that served to remove waste from the ceremonial center structures conveyed to the nearby Tiwanaku River. From control of the water supply to/from the perimeter drainage channel during wet and dry seasonal changes, stabilization of the deep groundwater level was achieved—this resulted in the stabilization of monumental ceremonial structure’s foundations, a continuous water supply to inner city agricultural zones, water pools for urban use and health benefits for the city population through moisture level reduction in city ceremonial and secular urban housing structures.

A 2020. július végi rendkívüli vízkáresemények vízügyi igazgatási és közgazdasági tapasztalatai

In the scope of activities of the General Directorate of Water Management (further OVF) have been conspicuous parts water management of settlements and of rainwater since 2019. Organisations of the Ministry of Interior with nationwide competence have at least one feature in common, i.e. serving for safety of the citizens. The government has controlled - through the Ministry of Interior, by the deputy secretariat for water management - the managerial organisations for water management, which are primarily responsible for water management in Hungary. For water management, appearing on state level mainly as regional water management. It is important to note that water management is not organised by regions of public service but by water accumulators. Another important supporting column of consistent and effective water management is water management of the settlements. Our settlements are increased exposed to effects of climate change as on these areas are concentrated the majority of population and of economic activities and, on the other side, the cities are frequently placed on sensitive areas considering climate change (endangered among others by floods or internal waters or by droughts). City water systems – including drinking water system, dirty water and rainwater delivering and cleaning systems – are specially endangered, as climate change is manifested first of all in change of hydrological circle (Buzás, 2015). The elaboration of basic technical, economic and legal frames for water management of settlements is a highlighted duty of the Hungarian water management. To tasks and general goals belongs further strengthening of water management based on real and actual digital bases, suitable to achieve the goals fixed in the National Water Strategy. In the rainwater management of settlements are preventive measures especially important (no matter whether these are structural of not structural measures). When planning development, it is important to realise as far as possible holding waters locally. There is a great need to build reservoirs which are suitable both for protection against damages by floods, cloudbursts and for holding local waters, supporting also welfare and ecologic goals – supposed that they do not suppress the basic functions of reservoirs. In July 2020 there were floods of smaller water flows causing considerable damages on areas of several water management directorates. Restoration needs, in value of several billions, have been arisen (acts of nature in water and settlement matters). This comprehensive paper presents interventions and experiences acquired through activities of local water damage control.

An Enemy of the People

An Enemy of the People

Antimicrobial resistance patterns and genotypic diversity between clinical and water systems isolates of Pseudomonas aeruginosa in Cali, Colombia

Pseudomonas aeruginosa is considered an opportunistic pathogen, causing a wide variety of infections in compromised hosts, also frequently develops multi-resistance to antibiotics and can colonize various habitats, including water systems. The main aim of this study was to investigate antibiotics susceptibility pattern, genotypic diversity and detection of resistence genes in P. aeruginosa isolates from clinical and aquatic environment sources. Of the 220 P. aeruginosa isolates examined, 48 were clinical isolates and 172 isolates from wastewater and freshwater. Susceptibility to eight antimicrobial agents was carried out by disk diffusion method. Clinical and environmental isolates were screened for the presence of the genes encoding blaKPC-2, blaCTX-M-9, blaPER-1, blaOXA-10, blaIMP-1, blaVIM-2 and blaampC by polymerase chain reaction (PCR). Isolates were examined with PCR-SSCP analysis of partial DNAr 16S sequence. Isolates were mainly resistant to cefoxitin. Multidrug-resistant P. aeruginosa (MDRPA) strains were found in 70% and 90.3% of the clinical and environmental isolates, respectively. The prevalence rates of â-lactamase genes were recorded (blaKPC-2 41.3%, blaVIM-2 36.8%, blaIMP-1 13.6%, blaCTX-M-9 10.9% and blaampC 10.5%,). The PCR-SSCP analysis showed three conformational patterns. All clinical isolates and most environmental isolates were grouped into a single cluster. In this study, we found that P. aeruginosa strains recovered from city water systems must be considered potential reservoir for ESBL genes, especially blaKPC-2 and blaVIM-2.

The Protection and Inheritance of Changzhou Grand Canal Water Cultural Heritage

After China's Grand Canal was successfully listed in the World material and Cultural Heritage list in 2014, the report of the Nineteenth National Congress of the Communist Party of China stressed the need to “strengthen the protection and utilization of cultural relics and the preservation and inheritance of cultural heritage”. General Secretary Xi Jinping also attached great importance to the construction of the Grand Canal cultural belt, pointing out that the Grand Canal is a precious heritage left by our ancestors and a flowing culture, which should be protected, inherited and used well as a whole. As one of the Grand Canal cities, Changzhou was approved in 2015 as a national historical and cultural city, and its economic and cultural development is closely linked to the development of the Grand Canal culture. Changzhou section of the Grand Canal, known as the Mother River in Changzhou, through the city and around the city, and Changzhou City water system integration, but also has a very rich material and cultural heritage. In order to carry out the spirit of the Nineteenth National Congress of the Party, implement the important instructions of General Secretary Xi Jinping, promote the construction of the cultural belt of the Grand Canal, and promote the protection, inheritance and utilization of the cultural heritage of the Grand Canal, Changzhou is duty-bound. On the basis of the investigation and arrangement of the material cultural heritage of the Grand Canal in Changzhou City, this subject excavates and promotes the historical and cultural value of the material cultural heritage of the Grand Canal in Changzhou City, and further discusses the inheritance and protection of the material cultural heritage of the Grand Canal, which has important research value and practical significance.

Modified isolated power factor correction Cuk-converter fed BLDC motor drive with Fuzzy Logic Controller for pumping applications

ABSTRACT Water pumps are mostly used for supplying water to industries, commercial establishments, houses, hospitals, private residents, city water systems, agricultural irrigation, etc. Water pumping systems operated by three-phase induction motors reduce the Power Factor (PF) of the electrical network. To decrease the effect of poor PF, Power Factor Correction (PFC) circuits are added to the AC input side of the water pumping system to enhance the efficiency and PF of the system. This paper presents a Fuzzy Logic Controller (FLC) based modified Power Factor Correction Cuk Converter (PFCCC) operated Voltage Source Inverter (VSI) fed Brushless DC (BLDC) motor drive for agricultural water pumping applications. MATLAB/Simulink simulation results and experimental prototype model results are presented to validate the performance of the designed system.

Patchwork: Repair labor and the logic of infrastructure adaptation in Mexico City

This article introduces the concept of patchwork to understand how repair practices are carried out in Mexico City’s networked hydraulic infrastructure.Drawing on data gathered through a one-year participatory ethnography, patchwork follows the Mexico City Water System (SACMEX) workers’ descriptions of their own labor and how it relates to infrastructure in a context of structural austerity and rapid socio-material change. To do so, the article separates the analysis of repair practices from the logic of maintenance, challenging widely shared conceptions of how they relate to each other. Two distinct contributions are made possible by this move. On the one hand, it allows for a more detailed conceptualization of the work that repair labor does in relation to infrastructure and to other socio-material processes that are constantly shaping it. On the other, it enables an exploration of what I call the logic of adaptation, a form of infrastructure repair that is based not on returning objects and relations to a previously officially sanctioned order, but instead on fashioning normality as an ongoing process made possible through improvisational and incremental work. Exploring this logic, I argue that the endurance of urban infrastructure and of urban modernity requires the ad-hoc work of patchwork and of adaptive repair labor.

Protection and Renewal Strategy of Historical Remains Landscape in Urban Reconstruction -- A case study of Guilin ring water system

In recent years, with the rapid development of urban landscape, more and more attention has been paid to urban landscape protection. In this paper, based on the perspective of protection and renewal of historical monument landscape, a study was conducted in the Guilin ring city water system, and it was found that the water system has the problems of scattered historical relics, damaged historical spatial pattern, serious water pollution and lake waterlogging. To address these issues, this paper proposes strategies such as improving the historical space organization system, continuing the historical form and function of the city’s water system, integrating historical and cultural resources, restoring the historical space pattern of the city’s water system, formulating historical heritage conservation plans and continuing cultural practices. This article provides a beneficial discussion on creating an ideal environment with rich history and culture, suitable for human habitation, and shaping the region and character of the city.

Breaking bad: When does polycentricity lead to maladaptation rather than adaptation?

AbstractPolycentric governance structures are often touted as part of the solution to overuse and degradation of natural resources. In theory, when multiple, overlapping decision centers work independently and in coordination, they contribute more than either monocentric or atomized governance arrangements to ensuring robust, adaptive social‐ecological systems (SESs). However, the degraded state of many municipal drinking water systems demonstrate Vincent Ostrom's observation that multilevel governance structure alone does not guarantee increased functionality. Two U.S. case studies drawn from opposite ends of the SES performance continuum provide insights into the differences between structural and functional features of polycentricity and the cross‐cutting conditions under which these features lead to adaptation or maladaptation. New York City's water system has served as an international model of sustainable, collaborative governance for several decades, whereas Flint, Michigan's water system achieved notoriety for a tragic string of errors and a pattern of neglectful governance in the mid‐2010s. Through process tracing, this article analyzes the pathways that began from a shared governance structure of polycentric federalism to starkly different decisions and outcomes in the two cities. The results highlight the dynamic and interactive nature of polycentricity, including how it can be functionally disabled when key factors converge across levels and scales: these include norms of quiescent rule enforcement, incentives that favor blame avoidance over problem solving, persistent power imbalances, large wealth inequalities, and deficits of social capital and leadership.