Showing papers on "Water supply published in 2019"

The United Nations World Water Development Report 2019: Leaving No One Behind

Abstract: The 2019 Report seeks to inform policy and decision-makers, inside and outside the water community, how improvements in water resources management and access to water supply and sanitation services are essential to overcoming poverty and addressing various other social and economic inequities. In an increasingly globalized world, the impacts of water-related decisions cross borders and affect everyone. Extreme events, environmental degradation, population growth, rapid urbanization, unsustainable and inequitable consumption patterns, conflicts and social unrest, and unprecedented migratory flows are among the interconnected pressures faced by humanity, often hitting those in vulnerable situations the hardest through their impacts on water. Addressing the inequalities faced by disadvantaged groups requires tailored solutions that take account of the day-to-day realities of people and communities in vulnerable situations. Properly designed and adequately implemented policies, efficient and appropriate use of financial resources, as well as evidence-based knowledge on water resources and water-related issues are also vital to eliminating inequalities in access to safe drinking water and sanitation. Titled ‘Leaving No One Behind ’, the report reinforces the commitments made by the UN member states in adopting the 2030 Agenda for Sustainable Development and in recognizing the human rights to safe drinking water and sanitation, both of which are essential for eradicating poverty and for building prosperous, peaceful societies.

Drought And Natural Resources Management In The United States: Impacts And Implications Of The 1987-89 Drought

Abstract: The 1987-89 drought was a signal event in the evolving interrelationshipsamong climate, natural resources management, technology,and society in the United States. Over half of the country experiencedsevere to extreme drought by midsummer of 1988 (Figure 1.1). Lossesupward to $39 billion illustrate the continuing, perhaps growing,vulnerability of many natural resources and economic sectors to droughtand other climate fluctuations.Despite decades of crop breeding, water system development, andother improvements in climate-sensitive technologies, the droughtdemonstrated that the simple lack of "normal" rainfall still provokesserious disruptions in agriculture, water supply, transportation,environmental quality, and other areas. It can affect the health and wellbeingof millions of people and evoke billions of dollars in governmentaid.

Plumbing Poverty: Mapping Hot Spots of Racial and Geographic Inequality in U.S. Household Water Insecurity

Abstract: Household water insecurity is a global threat to human health and development, yet existing metrics lack a systematic consideration of geographic inequality and spatial variation. In this article, ...

Flexibility and intensity of global water use

Abstract: Water stress is often evaluated by scarcity: the share of available water supply being consumed by humans. However, some consumptive uses of water are more or less flexible than others, depending on the costs or effects associated with their curtailment. Here, we estimate the share of global water consumption over the period 1980–2016 from the relatively inflexible demands of irrigating perennial crops, cooling thermal power plants, storing water in reservoirs and supplying basic water for humans and livestock. We then construct a water stress index that integrates the share of runoff being consumed (scarcity), the share of consumption in these inflexible categories (flexibility) and the historical variability of runoff weighted by storage capacity (variability), and use our index to evaluate the trends in water stress of global major river basins on six continents. We find that the 10% most stressed basins encompass ~19%, 19% and 35% of global population, thermal electricity generation and irrigated calorie production, respectively, and some of these basins also experience the largest increases in our identified stress indexes over the study period. Water consumption intensities (water used per unit of goods or service produced) vary by orders of magnitude across and within continents, with highly stressed basins in some cases characterized by high water consumption intensities. Our results thus point to targeted water mitigation opportunities (for example, relocating crops and switching cooling technologies) for highly stressed basins. Water consumption does not put a constant stress on available supplies, but is instead a function of flexibility in demands for food, water and energy. This analysis looks at 36 years of water consumption around the globe to identify basins under the most stress, and how they can lower their intensive uses.

Karst waters in potable water supply: a global scale overview

Abstract: Karst aquifers are one of the main potable water sources worldwide. Although the exact global karst water utilisation figures cannot be provided, this study represents an attempt to make an upgraded assessment of earlier and often circulated data. The main objective of the undertaken analysis is not only to provide an assessment of the utilisation of current karst aquifers, but also to estimate possible trends under various impact factors such as population growth or climate changes. In > 140 countries, different types of karstified rocks crop out over some 19.3 × 106 km2, covering > 14% of ice-free land. The main ‘karst countries’, those with > 1 × 106 km2 of karst surface are Russia, USA, China and Canada, while among those with > 80% of the territories covered by karst are Jamaica, Cuba, Montenegro and several others. In contrast, in a quarter of the total number of countries, karstic rocks are either totally absent or have a minor extension, meaning that no karst water sources can be developed. Although the precise number of total karst water consumers cannot be defined, it was assessed in 2016 at approximately 678 million or 9.2% of the world’s population, which is twice less than what was previously estimated in some of the reports. With a total estimated withdrawal of 127 km3/year, karst aquifers are contributing to the total global groundwater withdrawal by about 13%. However, only around 4% of the estimated average global annually renewable karstic groundwater is currently utilised, of which < 1% is for drinking purposes. Although often problematic because of unstable discharge regimes and high vulnerability to pollution, karst groundwater represents the main source of potable water supply in many countries and regions. Nevertheless, engineering solutions are often required to ensure a sustainable water supply and prevent negative consequences of groundwater over-extraction.

Learning about climate change uncertainty enables flexible water infrastructure planning

Abstract: Water resources planning requires decision-making about infrastructure development under uncertainty in future regional climate conditions. However, uncertainty in climate change projections will evolve over the 100-year lifetime of a dam as new climate observations become available. Flexible strategies in which infrastructure is proactively designed to be changed in the future have the potential to meet water supply needs without expensive over-building. Evaluating tradeoffs between flexible and traditional static planning approaches requires extension of current paradigms for planning under climate change uncertainty which do not assess opportunities to reduce uncertainty in the future. We develop a new planning framework that assesses the potential to learn about regional climate change over time and therefore evaluates the appropriateness of flexible approaches today. We demonstrate it on a reservoir planning problem in Mombasa, Kenya. This approach identifies opportunities to reliably use incremental approaches, enabling adaptation investments to reach more vulnerable communities with fewer resources. Water resources planning requires infrastructure development consider regional climatic uncertainties. Here the authors introduce a new dynamic planning framework that captures opportunities to learn about climate change over time. By applying it to reservoir planning in Kenya, they show the value of flexible approaches in responding to learning.

The crisis of water shortage and pollution in Pakistan: risk to public health, biodiversity, and ecosystem.

Abstract: Dear Editor, According to the International Monetary Fund (IMF), Pakistan ranked third among the countries facing severe water shortage. In May 2018, the Pakistan Council of Research in Water Resources (PCRWR) announced that by 2025, there will be very little or no clean water available in the country (Shukla 2018). It must be noted that while per capita availability in the 1950s was approximately 5000 m per annum, it has now declined to below 1000 m, which is an internationally recognized threshold of water scarcity (Aziz et al. 2018). Currently, only 20% of the country’s population has access to clean drinking water. The remaining 80% populations depends on polluted water primarily contaminated by sewerage (fecal, total coliforms, E. coli colonies), and secondarily by fertilizer, pesticides, and industrial effluents (Daud et al. 2017; Sahoutara 2017). Such water pollution is responsible for approximately 80% of all diseases and 30% of deaths (Daud et al. 2017). In the dried-out pipeline, a single E. coli bacterium can multiply into trillions in just a week (Ebrahim 2017), and such pipes are used for the water supply without any treatment. Consuming such polluted waters has not only resulted in the death of several people, but also cause bone and teeth diseases, diarrhea, dysentery, typhoid, hepatitis, cancer, and other waterborne diseases (Daud et al. 2017). According to World Health Organization (WHO), waterborne diarrheal diseases are responsible for over 2 million deaths annually across the world, with the majority occurring in children under 5 years (WHO 2018). In Pakistan, approximately 60 million people are at risk of being affected by high concentrations of arsenic in drinking water; the largest mass poisoning in history (Guglielmi 2017). Arsenic poisoning can cause cancer, restrictive pulmonary disease, skin lesions, cardiovascular problems, diabetes mellitus, gangrene, neurological impairments, and problems in endocrine glands, immunity, liver, kidney, and bladder as well as socio-economic hazards (Rahman et al. 2018). Unfortunately, still, no epidemiological data of arsenic poisoning, alternate drinking water, and health interventions are available to the people at risk. Taking into consideration the drought-hit deaths of approximately 1832 children in the last 4 years (The Newspaper’s Staff Reporter 2018), drying lakes (Ali 2015), rivers (Channa 2010), lowering water table, excessive use of water, lack of storage mechanism, population explosion, and climatic changes warrant ser ious attention (Kirby 2018). Furthermore, the lack of sound national water policy, lack of federal and provincial government’s interest, water conflict between nuclear-armed Pakistan and India (Kirby 2018), deforestation, the overwhelming potential threat to the country’s glacier reserves (Nabi et al. 2017, 2018), and the poor water supply will likely negatively affect agriculture, ecology, and local biodiversity. The wildlife has already entered the red zone (Shaikh 2018) and can possibly turn into human crisis with the danger of large-scale regional migration of people due to drought-like situation. We have recommended some suggestions that could possibly help the people of Pakistan to get rid of water shortage and pollution, maintain an ecology, improve agriculture, and conserve local biodiversity.

Water in the Hindu Kush Himalaya

Abstract: Commonly described as the “water tower for Asia,” the Hindu Kush Himalaya (HKH) plays an important role in ensuring water, food, energy, and environmental security for much of the continent. The HKH is the source of ten major rivers that provide water—while also supporting food and energy production and a range of other ecosystem services—for two billion people across Asia. This chapter takes stock of current scientific knowledge on the availability of water resources in the HKH; the varied components of its water supply; the impact of climate change on future water availability; the components of water demand; and the policy, institutions, and governance challenges for water security in the region.

Green and Sustainable Pathways for Wastewater Purification

Abstract: Clean water is one of the chief life-sustaining resources. But numerous anthropogenic activities have gradually and enormously deteriorated the quality of water. Besides freshwater crisis, it is also giving birth to numerous diseases which are fatal to all life forms. In this regard, wastewater treatment provides a solution which has twofold benefits: restoring shrinking water supply and protecting the planet from toxins. Although significant efforts have been directed toward wastewater purification, however, they are not sufficient for complete removal of pollutants. Thus, an integrated approach is highly desirable which could couple various processes together and provide efficient and economic strategy in an environmentally friendly manner. This chapter gives an overview of sustainable water remediation technologies and their application in treating various pollutants.

Quantifying urban water supply security under global change

Abstract: Urban water supply security is commonly measured in terms of per capita water availability at the city level. However, the actual services that citizens receive are influenced by several components, including (1) a city's access to water, (2) infrastructure for its treatment, storage and distribution, (3) financial capital for building and maintaining infrastructure, and (4) management efficacy for regulating and operating the water system. These four types of "capital" are required for the provision of public water supply services. A fifth capital “community adaptation” is needed when public services are insufficient. Here, we develop and test an integrated framework for the quantification of urban water supply security based on these five capitals. “Security” involves three dimensions: 1) the level of system function (i.e., supply services); 2) risks to these services; and 3) robustness of system functioning. We apply this Capital Portfolio Approach (CPA) to seven urban case studies selected from a wide range of hydro-climatic and socio-economic regions on four continents. Detailed data on urban water infrastructure and services were collected in two cities, and key stakeholder interviews and household surveys were conducted in one city. Additional cities were assessed based on publicly available utility and globally available datasets. We find that in cities with high levels of public services, adaptive capacity remains inactive, while cities with high levels of water insecurity rely on community adaptation for self-provision of services. Inequality in the capacity to adapt leads to variable levels of urban water security and the vulnerability of the urban poor. Results demonstrate the applicability of the presented framework for the assessment of individual urban water systems, as well as for cross-city comparison of any type of cities. We discuss implications for policy and decision-making.

The Groundwater‒Energy‒Food Nexus in Iran’s Agricultural Sector: Implications for Water Security

Abstract: This paper presents the first groundwater‒energy‒food (GEF) nexus study of Iran’s agronomic crops based on national and provincial datasets and firsthand estimates of agricultural groundwater withdrawal. We use agronomic crop production, water withdrawal, and energy consumption data to estimate groundwater withdrawal from electric-powered irrigation wells and examine agronomic productivity in Iran’s 31 provinces through the lens of GEF nexus. The ex-post GEF analysis sheds light on some of the root causes of the nation’s worsening water shortage problems. Access to highly subsidized water (surface water and groundwater) and energy has been the backbone of agricultural expansion policies in Iran, supporting employment in agrarian communities. Consequently, water use for agronomic crop production has greatly overshot the renewable water supply capacity of the country, making water bankruptcy a serious national security threat. Significant groundwater table decline across the country and increasing energy consumption underscore dysfunctional feedback relations between agricultural water and energy price and groundwater withdrawal in an inefficient agronomic sector. Thus, it is essential to implement holistic policy reforms aimed at reducing agricultural water consumption to alleviate the looming water bankruptcy threats, which can lead to the loss of numerous agricultural jobs in the years to come.

Machine learning approaches for anomaly detection of water quality on a real-world data set*

Abstract: Accurate detection of water quality changes is a crucial task of water companies. Water supply companies must provide safe drinking water. Nowadays in different areas, we find sensible sensors whic...

Rural water for thirsty cities: a systematic review of water reallocation from rural to urban regions

Abstract: Background: Competition for freshwater between cities and agriculture is projected to grow due to rapid urbanization, particularly in the Global South. Water reallocation from rural to urban regions has become a common strategy to meet freshwater needs in growing cities. Conceptual issues and associated measurement problems have impeded efforts to compare and learn from global experiences. This review examines the status and trends of water reallocation from rural to urban regions based on academic literature and policy documents. Methods: We conduct a systematic literature review to establish the global reallocation database (GRaD). This process yielded 97 published studies (academic and policy) on rural-to-urban reallocation. We introduce the concept of reallocation 'dyads' as the unit of analysis to describe the pair of a recipient (urban) and donor (rural) region. A coding framework was developed iteratively to classify the drivers, processes and outcomes of water reallocation from a political economy perspective. Results: The systematic review identified 69 urban agglomerations receiving water through 103 reallocation projects (dyads). Together these reallocation dyads involve approximately 16 billion m3 of water per year moving almost 13 000 kilometres to urban recipient regions with an estimated 2015 population of 383 million. Documented water reallocation dyads are concentrated in North America and Asia with the latter constituting the majority of dyads implemented since 2000. Synthesis: The analysis illustrates how supply and demand interact to drive water reallocation projects, which can take many forms, although collective negotiation and administrative decisions are most prevalent. Yet it also reveals potential biases and gaps in coverage for parts of the Global South (particularly in South America and Africa), where reallocation (a) can involve informal processes that are difficult to track and (b) receives limited coverage by the English-language literature covered by the review. Data regarding the impacts on the donor region and compensation are also limited, constraining evidence to assess whether a water reallocation project is truly effective, equitable and sustainable. We identify frameworks and metrics for assessing reallocation projects and navigating the associated trade-offs by drawing on the concept of benefit sharing.

Climate change, water resources and sustainable development in the arid and semi-arid lands of Central Asia in the past 30 years

Abstract: The countries of Central Asia are collectively known as the five ''-stans'': Uzbekistan, Kyrgyzstan, Turkmenistan, Tajikistan and Kazakhstan. In recent times, the Central Asian region has been affected by the shrinkage of the Aral Sea, widespread desertification, soil salinization, biodiversity loss, frequent sand storms, and many other ecological disasters. This paper is a review article based upon the collection, identification and collation of previous studies of environmental changes and regional developments in Central Asia in the past 30 years. Most recent studies have reached a consensus that the temperature rise in Central Asia is occurring faster than the global average. This warming trend will not only result in a higher evaporation in the basin oases, but also to a significant retreat of glaciers in the mountainous areas. Water is the key to sustainable development in the arid and semi-arid regions in Central Asia. The uneven distribution, over consumption, and pollution of water resources in Central Asia have caused severe water supply problems, which have been affecting regional harmony and development for the past 30 years. The widespread and significant land use changes in the 1990s could be used to improve our understanding of natural variability and human interaction in the region. There has been a positive trend of trans-border cooperation among the Central Asian countries in recent years. International attention has grown and research projects have been initiated to provide water and ecosystem protection in Central Asia. However, the agreements that have been reached might not be able to deliver practical action in time to prevent severe ecological disasters. Water management should be based on hydrographic borders and ministries should be able to make timely decisions without political intervention. Fully integrated management of water resources, land use and industrial development is essential in Central Asia. The ecological crisis should provide sufficient motivation to reach a consensus on unified water management throughout the region.

Effectiveness of Rainwater Harvesting Systems for Flood Reduction in Residential Urban Areas

Abstract: Rainwater harvesting (RWH) systems have many benefits being an effective alternative water supply solution, not only in arid and semi-arid regions. Also, these systems can be useful in the reduction of flood risk in urban areas. Nevertheless, most of the studies in literature focused on the potential of RWH in reducing water consumption, whereas few examples examined their efficiency in the retention of stormwater in flood-susceptible residential areas. The aim of this work was to investigate the reliability of RWH systems in terms of stormwater retention. Specifically, the performance of RWH tanks to supply water for toilet flushing, in more than 400 single-family houses in a residential area of Sicily (Southern Italy) was analyzed. The area of study was chosen due to its high susceptibility to flooding. A flushing water demand pattern was defined using water consumption data collected during a measurement campaign. The yield-after-spillage algorithm was used to simulate the daily water balance of the RWH tanks. The effect of the RWH implementation on flood volumes in the area of study was quantified using FLO-2D. Results point out that the potential of neighborhood RWH installation in the mitigation of flood risk is highly related to rainfall amount.