Showing papers on "Water supply published in 2020"

Domestic water quantity, service level and health

Abstract: Sufficient quantities of water for household use, including for drinking, food preparation and hygiene, are needed to protect public health and for well-being and prosperity. This second edition reviews the evidence about the relationships between water quantity, water accessibility and health. The effects of water reliability, continuity and price on water use, are also covered. Updated guidance, including recommended targets, is provided on domestic water supply to ensure beneficial health outcomes.

Importance and vulnerability of the world's water towers

Abstract: Mountains are the water towers of the world, supplying a substantial part of both natural and anthropogenic water demands1,2. They are highly sensitive and prone to climate change3,4, yet their importance and vulnerability have not been quantified at the global scale. Here we present a global water tower index (WTI), which ranks all water towers in terms of their water-supplying role and the downstream dependence of ecosystems and society. For each water tower, we assess its vulnerability related to water stress, governance, hydropolitical tension and future climatic and socio-economic changes. We conclude that the most important (highest WTI) water towers are also among the most vulnerable, and that climatic and socio-economic changes will affect them profoundly. This could negatively impact 1.9 billion people living in (0.3 billion) or directly downstream of (1.6 billion) mountainous areas. Immediate action is required to safeguard the future of the world’s most important and vulnerable water towers.

The United Nations World Water Development Report 2020: Water and Climate Change

Abstract: The 2020 edition of the WWDR, titled ‘Water and Climate Change’ illustrates the critical linkages between water and climate change in the context of the broader sustainable development agenda. Supported by examples from across the world, it describes both the challenges and opportunities created by climate change, and provides potential responses – in terms of adaptation, mitigation and improved resilience – that can be undertaken by enhancing water resources management, attenuating water-related risks, and improving access to water supply and sanitation services for all in a sustainable manner. It addresses the interrelations between water, people, environment and economics in a changing climate, demonstrating how climate change can be a positive catalyst for improved water management, governance and financing to achieve a sustainable and prosperous world for all. The report provides a fact-based, water-focused contribution to the knowledge base on climate change. It is complementary to existing scientific assessments and designed to support international political frameworks, with the goals of helping the water community tackle the challenges of climate change, and informing the climate change community about the opportunities that improved water management offers in terms of adaptation and mitigation.

Finding High-Quality Groundwater Resources to Reduce the Hydatidosis Incidence in the Shiqu County of Sichuan Province, China: Analysis, Assessment, and Management

Abstract: The prevalence of hydatidosis due to animal husbandry development poses significant health risks to people in the Shiqu County of Sichuan Province, China, where people depend mainly on surface water for domestic uses, which, however, is contaminated due to the development of the animal husbandry. Therefore, groundwater which is protected by the vadose zone and has better quality is now proposed to replace the contaminated surface water as a new source of water supply in this area. To find a high-quality groundwater resource, a detailed investigation and assessment was carried out in this study. The occurrence and distribution of the hydatidosis caused by the consumption of the contaminated surface water were analyzed. The World Health Organization (WHO) and national standards were applied to assess the suitability of groundwater for drinking purpose, and SAR, RSC, %Na, PI were used to evaluate the groundwater quality for irrigation usage. In addition, the overall groundwater quality was assessed using an entropy water quality index (EWQI), and its relationships with the physicochemical indices were discussed using the multiple linear regression models to explore the most important physicochemical indices affecting the groundwater quality. Finally, some measures for the prevention and treatment of the hydatidosis disease were proposed. The results show that the groundwater found beneath the study area is generally in good to excellent quality with low salinity and major ions. Groundwater in all constructed wells except only one is suitable for domestic and irrigation purposes with majority of the samples falling into HCO3-Ca·Mg type. The overall groundwater quality is mainly affected by COD, SO42−, and TH. Measures to reduce the incidence of hydatidosis such as cutting off the hydatidosis exposure pathway and improving the sanitation system are proposed.

Circular economy model framework in the European water and wastewater sector

Abstract: One of the key elements in the transformation towards a circular economy (CE) is providing more sustainable practices for resources and waste management. Improvement actions focused on transformation towards a CE should be targeted at all groups of materials and waste. As water is essential for human survival and well-being and plays a significant role in sustainable development (SD), the actions related to the reuse of water and the recovery of raw materials from wastewater and other water-based waste should be taken. The paper presents a proposition for a new CE model framework in the water and wastewater sector, which includes the six following actions: reduction—prevent wastewater generation in the first place by the reduction of water usage and pollution reduction at source; reclamation (removal)—an application of effective technologies for the removal of pollutants from water and wastewater; reuse—reuse of wastewater as an alternative source of water supply (non-potable usage), recycling—recovery of water from wastewater for potable usage; recovery—recovery of resources such as nutrients and energy from water-based waste, and rethink—rethinking how to use resources to create a sustainable economy, which is `free` of waste and emissions. The novelty of the proposed CE model framework is that it presents possible ways of implementing CE principles in the water and wastewater sector, with a strong emphasis not only technological but also organisational and societal changes. Application of the proposed model may help to further transform the European economy to the CE model. Moreover, the indicated model can be significant tool supporting an assessment of local or regional progress towards CE in the water and wastewater sector and further environmental management and planning.

How afforestation affects the water cycle in drylands: A process-based comparative analysis.

Abstract: The world's largest afforestation programs implemented by China made a great contribution to the global “greening up.” These programs have received worldwide attention due to its contribution toward achieving the United Nations Sustainable Development Goals. However, emerging studies have suggested that these campaigns, when not properly implemented, resulted in unintended ecological and water security concerns at the regional scale. While mounting evidence shows that afforestation causes substantial reduction in water yield at the watershed scale, process‐based studies on how forest plantations alter the partitioning of rainwater and affect water balance components in natural vegetation are still lacking at the plot scale. This lack of science‐based data prevents a comprehensive understanding of forest‐related ecosystem services such as soil conservation and water supply under climate change. The present study represents the first “Paired Plot” study of the water balance of afforestation on the Loess Plateau. We investigate the effects of forest structure and environmental factors on the full water cycle in a typical multilayer plantation forest composed of black locust, one of the most popular tree species for plantations worldwide. We measure the ecohydrological components of a black locust versus natural grassland on adjacent sites. The startling finding of this study is that, contrary to the general belief, the understory—instead of the overstory—was the main water consumer in this plantation. Moreover, there is a strict physiological regulation of forest transpiration. In contrast to grassland, annual seepage under the forest was minor in years with an average rainfall. We conclude that global long‐term greening efforts in drylands require careful ecohydrologic evaluation so that green and blue water trade‐offs are properly addressed. This is especially important for reforestation‐based watershed land management, that aims at carbon sequestration in mitigating climate change while maintaining regional water security, to be effective on a large scale.

Water Supply and Water Scarcity

Abstract: This paper provides an overview of the Special Issue on water supply and water scarcity. The papers selected for publication include review papers on water history, on water management issues under water scarcity regimes, on rainwater harvesting, on water quality and degradation, and on climatic variability impacts on water resources. Overall, the issue underscores the need for a revised water management, especially in areas with demographic change and climate vulnerability towards sustainable and secure water supply. Moreover, general guidelines and possible solutions, such as the adoption of advanced technological solutions and practices that improve water use efficiency and the use of alternative (non-conventional) water resources are highlighted and discussed to address growing environmental and health issues and to reduce the emerging conflicts among water users.

Water reuse and recycling in Australia — history, current situation and future perspectives

Abstract: Most of Australia has low rainfall The population is small (25 ​M) but growing at 15%/yr Water limitations are being exacerbated by climate change By 1990, restraints placed on wastewater treatment plant (WWTP) discharges to receiving waters became an incentive for water recycling The millennium drought (2000–2009) was a further driver for water recycling and desalination Water reform policies, led to guidelines for recycled water, including stormwater and augmentation of drinking water Advanced purified recycled water plants for indirect potable reuse were built in Brisbane Dual pipes for drinking and recycled water were installed in new suburbs in Sydney, Melbourne and Adelaide Agricultural, industrial and amenity recycled water use was expanded Seawater desalination plants were installed in Gold Coast, Sydney, Melbourne, Adelaide and Perth After the drought, economics further influenced the future use of recycled water Since catchment water was cheaper than recycled or desalinated water, desalination plants were mothballed or maintained at low processing rates and Brisbane’s advanced water treatment plants were shut Water policy complacency followed However, Western Australia, which had declining rainfall, demonstrated to an accepting community that recycled water could be used for groundwater replenishment in Perth’s water supply By 2019, drought conditions had returned to eastern Australia Desalination plants were reactivated and Brisbane’s indirect potable recycling scheme prepared for reinstatement Regional towns faced water shortages and were looking for diversity of water supply Reviews have been undertaken of the future for direct potable recycling, a debate that needs to be initiated with the consuming public

Irrigation of World Agricultural Lands: Evolution through the Millennia

Abstract: Many agricultural production areas worldwide are characterized by high variability of water supply conditions, or simply lack of water, creating a dependence on irrigation since Neolithic times. The aim of this paper is to provide an overview of the evolution of irrigation of agricultural lands worldwide, based on bibliographical research focusing on ancient water management techniques and ingenious irrigation practices and their associated land management practices. In ancient Egypt, regular flooding by the Nile River meant that early agriculture probably consisted of planting seeds in soils that had been recently covered and fertilized with floodwater and silt deposits. On the other hand, in arid and semi-arid regions farmers made use of perennial springs and seasonal runoff under circumstances altogether different from the river civilizations of Mesopotamia, Egypt, India, and early dynasties in China. We review irrigation practices in all major irrigation regions through the centuries. Emphasis is given to the Bronze Age civilizations (Minoans, Egyptians, and Indus valley), pre-Columbian, civilizations from the historic times (e.g., Chinese, Hellenic, and Roman), late-Columbians (e.g., Aztecs and Incas) and Byzantines, as well as to Ottomans and Arabs. The implications and impacts of irrigation techniques on modern management of water resources, as well as on irrigated agriculture, are also considered and discussed. Finally, some current major agricultural water management challenges are outlined, concluding that ancient practices could be adapted to cope with present challenges in irrigated agriculture for increasing productivity and sustainability.

Outlook on the bottleneck of carbon nanotube in desalination and membrane-based water treatment—A review

Abstract: Perceiving the actuality, that clean water, along with potable water, is burgeoning worldwide owing to numerous reasons. Indeed, a possible choice should bring into being to crop up from this detracting predicament. About this issue, to tackle this state, a substitute is obligatory. Furthermore, the alternative approach should be offbeat from the existing techniques available to us, though it is quite caustic to convene the challenges of water supply. Numerous technologies archive for the aspiration the function of a membrane system in water purification along with desalination is utterly prominent and acknowledged, although the techniques above possess many complications during the process like membrane fouling, energy consumption, strength, etc. Hence, herein this present context, state of the art on carbon nanotube as a contemporary material for its usage in desalination membranes possessing their unique attributes competencies for the purification of water along with envisaging the outlook for the future on the environment additionally its energy standpoint.

Impacts of plant invasions on terrestrial water flows in South Africa

Abstract: Considerable advances have been made since the first estimates of the impacts of invasive alien plants on water resources in the early 1990s. A large body of evidence shows that invasive alien plants can increase transpiration and evaporation losses and thus reduce river flows and mean annual runoff. Riparian invasions, and those in areas where groundwater is accessible, have 1.2–2 times the impact of invasions in dryland areas. The magnitude of the impacts is directly related to differences between the invading species and the dominant native species in size, rooting depth and leaf phenology. Information on the impacts has been successfully used to compare the water use of invasive plants and different land cover classes, to quantify the water resource benefits of control measures, and to prioritise areas for control operations. Nationally, the impacts of invasive alien plants on surface water runoff are estimated at 1.44–2.44 billion m3 per year. The most affected primary catchments (>5% reduction in mean annual runoff) are located in the Western and Eastern Cape, and KwaZulu-Natal. If no remedial action is taken, reductions in surface water runoff could increase to 2.59–3.15 billion m3 per year, about 50% higher than current reductions. This review illustrates the importance of measuring water-use over as wide a range of species as possible, and combining this with information from remote sensing to extrapolate the results to landscapes and catchments. These methods will soon provide much more robust estimates of water use by alien plants at appropriate spatial and temporal scales. The results of these studies can be used in water supply system studies to estimate the impacts on the assured yields. This information can also be used by catchment water resource managers to guide decision-makers when prioritising areas for clearing and rehabilitation, and for targeting species for control measures.

Considerations on water quality and the use of chlorine in times of SARS-CoV-2 (COVID-19) pandemic in the community

Abstract: This review goal is to reflect on the challenges and prospects for water quality in the face of the pandemic caused by the new SARS-CoV-2 coronavirus (COVID-19). Based on the information available so far, the detection of SARS-CoV-2 RNA in wastewater has raised interest in using it as an early warning method, to detect the resurgence of infections and to report the risk associated with contracting SARS-CoV-2 in contact with untreated water or inadequately treated wastewater is discharged. The wastewater-based epidemiological approach can be used as an early indicator of infection within a specific population. On the other hand, it is necessary to collect information from the managers of drinking water supply companies and professionals who are related to water quality, to know SARS-CoV-2 data and information, and its influence on drinking water quality. The basic purpose of this review article is to try to provide a valuable and quick reference guide to COVID-19. Important topics were discussed, such as detection of SARS-CoV-2 in wastewater in various parts of the world; wastewater screening to monitor COVID-19; persistence of SARS-CoV-2 in aquatic systems; the presence of SARS-CoV-2 in drinking water; clean water as a mechanism to deal with the COVID-19 pandemic; chlorine as a disinfectant to eliminate SARS-CoV-2 and damage to ecosystems by the use of chlorine. Currently does not exist extensive literature on the effectiveness of water and wastewater treatment processes that ensure the correct elimination of SARS-CoV-2. Excessive use of disinfectants such as chlorine is causing effects on the environment. This document highlights the need for further research to establish the behavior of the SARS-CoV-2 virus in aquatic systems. This study presents an early overview of the observed and potential impacts of COVID-19 on the environment.

Quantifying water provision service supply, demand and spatial flow for land use optimization: A case study in the YanHe watershed

Abstract: The explicit quantification and spatial mapping of the ecosystem service (ES) supply and demand associated with land use changes can provide relevant insights for enhancing land management. However, few advancements and efforts have been applied to science policy processes and land management optimization because most studies to date neglected the supply-demand coupling mechanism. This paper considers the YanHe watershed to propose a comprehensive framework quantifying the supply, demand and spatial flow of the water provision service associated with land use changes. The results showed that land use changes had important effects on both the supply side and the demand side of the water provision service. The water provision service has significant spatial mismatches between water supply and water demand. A high water supply occurred in the upper and lower reaches, while a high water demand was distributed in the urban districts. We mapped and determined the spatial flow process of the water provision service now and in the future. The results highlight the need to fully understand the importance of service flow for improving the water security patterns of benefiting areas. This study provides a scientific basis for watershed policymakers to optimize land management and reduce water deficits and mismatches.