Showing papers on "Water scarcity published in 2012"

Chemical treatment technologies for waste-water recycling—an overview

Abstract: The global population is increasing and because of this, the world may experience great fresh water scarcity. Our water resources are limited and, hence, water treatment and recycling methods are the only alternatives for getting fresh water in the coming decades. Therefore, there is a great need for the development of a suitable, inexpensive and rapid wastewater treatment techniques and reuse or conservation methods in the present century. The different types of water treatment and recycling techniques have been discussed in terms of their basic principles, applications, costs, maintenance and suitability. Additionally, a systematic approach to water treatment and recycling involving their understanding, evaluation and selection parameters has been presented. A brief guideline for the selection of the appropriate technologies for specific applications has been evaluated. This review adds to the global discussions on water scarcity solutions.

Global monthly water scarcity: blue water footprints versus blue water availability.

Abstract: Freshwater scarcity is a growing concern, placing considerable importance on the accuracy of indicators used to characterize and map water scarcity worldwide. We improve upon past efforts by using estimates of blue water footprints (consumptive use of ground- and surface water flows) rather than water withdrawals, accounting for the flows needed to sustain critical ecological functions and by considering monthly rather than annual values. We analyzed 405 river basins for the period 1996–2005. In 201 basins with 2.67 billion inhabitants there was severe water scarcity during at least one month of the year. The ecological and economic consequences of increasing degrees of water scarcity – as evidenced by the Rio Grande (Rio Bravo), Indus, and Murray-Darling River Basins – can include complete desiccation during dry seasons, decimation of aquatic biodiversity, and substantial economic disruption.

Water Security: Research Challenges and Opportunities

Abstract: An estimated 80% of the world's population faces a high-level water security or water-related biodiversity risk ( 1 ). The issue of water security—defined as an acceptable level of water-related risks to humans and ecosystems, coupled with the availability of water of sufficient quantity and quality to support livelihoods, national security, human health, and ecosystem services ( 2 , 3 )—is thus receiving considerable attention. To date, however, the majority of academic research on water security is relatively poorly integrated with the needs of policy-makers and practitioners; hence, substantial changes to funding, education, research frameworks, and academic incentive structures are required if researchers are to be enabled to make more substantive contributions to addressing the global water crisis.

The energy-water nexus: managing the links between energy and water for a sustainable future.

Abstract: Water and energy are each recognized as indispensable inputs to modern economies. And, in recent years, driven by the three imperatives of security of supply, sustainability, and economic efficiency, the energy and water sectors have undergone rapid reform. However, it is when water and energy rely on each other that the most complex challenges are posed for policymakers. Despite the links and the urgency in both sectors for security of supply, in existing policy frameworks, energy and water policies are developed largely in isolation from one another—a degree of policy fragmentation that is seeing erroneous developments in both sectors. Examples of the trade-offs between energy and water security include: the proliferation of desalination plants and interbasin transfers to deal with water scarcity; extensive groundwater pumping for water supplies; first- generation biofuels; the proliferation of hydropower plants; decentralized water supply solutions such as rainwater tanks; and even some forms of modern irrigation techniques. Drawing on case studies from Australia, Europe, and the United States, this Special Issue attempts to develop a comprehensive understanding of the links between energy and water, to identify where better-integrated policy and management strategies and solutions are needed or available, and to understand where barriers exist to achieve that integration. In this paper we draw out some of the themes emerging from the Special Issue, and, particularly, where insights might be valuable for policymakers, practitioners, and scientists across the many relevant domains.

Water Sustainability for China and Beyond

Abstract: A water crisis has prompted the Chinese government to develop an ambitious water conservancy plan. However, the plan may not achieve water sustainability and may cause unintended environmental and socioeconomic consequences, unless it accounts for complex human-nature interactions ( 1 ). Water shortages, for example, force people to find alternatives, such as treatment facilities, whose land and energy requirements aggravate food and energy production, which need large amounts of water. Other nations face similar challenges and share real water from China along international rivers and/or virtual water through trade. Water problems are particularly challenging in China, which has the largest population, fastest-growing economy, rising water demand, relatively scarce water, dated infrastructure, and inadequate governance. We highlight China's water crisis and plan, and then offer recommendations.

The nature and causes of the global water crisis: Syndromes from a meta-analysis of coupled human-water studies

Abstract: Freshwater scarcity has been cited as the major crisis of the 21st century, but it is surprisingly hard to describe the nature of the global water crisis. We conducted a meta- analysis of 22 coupled human– water system case studies, using qualitative comparison analysis (QCA) to identify water resource system outcomes and the factors that drive them. The cases exhibited different outcomes for human wellbeing that could be grouped into a six “syndromes ”: groundwater depletion, ecological destruction, drought-driven conflicts, unmet subsistence needs, resource capture by elite, and water reallocation to nature. For syndromes that were not successful adaptations, three characteristics gave cause for concern: (1) unsustainability —a decline in the water stock or ecosystem function that could result in a long-term steep decline in future human wellbeing; (2) vulnerability —high variability in water resource availability combined with inadequate coping capacity, leading to temporary drops in human wellbeing; (3) chronic scarcity —persistent inadequate access and hence low conditions of human wellbeing. All syndromes could be explained by a limited set of causal factors that fell into four categories: demand changes, supply changes, governance systems, and infrastructure/technology. By considering basins as members of syndrome classes and tracing common causal pathways of water crises, water resource analysts and planners might develop improved water policies aimed at reducing vulnerability, inequity, and unsustainability of freshwater systems.

Biofuel scenarios in a water perspective: the global blue and green water footprint of road transport in 2030

Abstract: Concerns over energy security and climate change stimulate developments towards renewable energy. Transport is expected to switch from fossil fuel use to the use of fuel mixtures with a larger fraction of biofuels, e.g. bio-ethanol and biodiesel. Growing biomass for biofuels requires water, a scarce resource. Existing scenarios on freshwater use usually consider changes in food and livestock production, and industrial and domestic activities. This research assesses global water use changes related to increasing biofuel use for road transport in 2030 and evaluates the potential contribution to water scarcity. To investigate water demand changes related to a transition to biofuels in road transport, the study combines data from water footprint (WF) analyses with information from the IEA APS energy scenario for 2030. It includes first-generation biofuels, bio-ethanol from sugar cane, sugar beet, sweet sorghum, wheat and maize, and biodiesel from soybean, rapeseed, jatropha and oil palm. Under the IEA APS scenario, the global biofuel WF will increase more than tenfold in the period 2005–2030. The USA, China and Brazil together will contribute half of the global biofuel WF. In many countries, blue biofuel WFs significantly contribute to blue water scarcity. The research provides a first exploration of the potential contribution of transport biofuel use to blue water scarcity. In 2030, the global blue biofuel WF might have grown to 5.5% of the totally available blue water for humans, causing extra pressure on fresh water resources. When biofuel use continues to expand after 2030, countries should therefore consider the water factor when investigating the extent to which biofuels can satisfy future transport energy demand

The Indus basin in the framework of current and future water resources management

Abstract: . The Indus basin is one of the regions in the world that is faced with major challenges for its water sector, due to population growth, rapid urbanisation and industrialisation, environmental degradation, unregulated utilization of the resources, inefficient water use and poverty, all aggravated by climate change. The Indus Basin is shared by 4 countries – Pakistan, India, Afghanistan and China. With a current population of 237 million people which is projected to increase to 319 million in 2025 and 383 million in 2050, already today water resources are abstracted almost entirely (more than 95% for irrigation). Climate change will result in increased water availability in the short term. However in the long term water availability will decrease. Some current aspects in the basin need to be re-evaluated. During the past decades water abstractions – and especially groundwater extractions – have augmented continuously to support a rice-wheat system where rice is grown during the kharif (wet, summer) season (as well as sugar cane, cotton, maize and other crops) and wheat during the rabi (dry, winter) season. However, the sustainability of this system in its current form is questionable. Additional water for domestic and industrial purposes is required for the future and should be made available by a reduction in irrigation requirements. This paper gives a comprehensive listing and description of available options for current and future sustainable water resources management (WRM) within the basin. Sustainable WRM practices include both water supply management and water demand management options. Water supply management options include: (1) reservoir management as the basin is characterised by a strong seasonal behaviour in water availability (monsoon and meltwater) and water demands; (2) water quality conservation and investment in wastewater infrastructure; (3) the use of alternative water resources like the recycling of wastewater and desalination; (4) land use planning and soil conservation as well as flood management, with a focus on the reduction of erosion and resulting sedimentation as well as the restoration of ecosystem services like wetlands and natural floodplains. Water demand management options include: (1) the management of conjunctive use of surface and groundwater; as well as (2) the rehabilitation and modernization of existing infrastructure. Other demand management options are: (3) the increase of water productivity for agriculture; (4) crop planning and diversification including the critical assessment of agricultural export, especially (basmati) rice; (5) economic instruments and (6) changing food demand patterns and limiting post-harvest losses.

Assessing water footprint at river basin level: a case study for the Heihe River Basin in northwest China

Abstract: Increasing water scarcity places considerable importance on the quantification of water footprint (WF) at different levels. Despite progress made previously, there are still very few WF studies focusing on specific river basins, especially for those in arid and semi-arid regions. The aim of this study is to quantify WF within the Heihe River Basin (HRB), a basin located in the arid and semi-arid northwest of China. The findings show that the WF was 1768 million m3 yr−1 in the HRB over 2004–2006. Agricultural production was the largest water consumer, accounting for 96% of the WF (92% for crop production and 4% for livestock production). The remaining 4% was for the industrial and domestic sectors. The "blue" (surface- and groundwater) component of WF was 811 million m3 yr−1. This indicates a blue water proportion of 46%, which is much higher than the world average and China's average, which is mainly due to the aridness of the HRB and a high dependence on irrigation for crop production. However, even in such a river basin, blue WF was still smaller than "green" (soil water) WF, indicating the importance of green water. We find that blue WF exceeded blue water availability during eight months per year and also on an annual basis. This indicates that WF of human activities was achieved at a cost of violating environmental flows of natural freshwater ecosystems, and such a WF pattern is not sustainable. Considering the large WF of crop production, optimizing the crop planting pattern is often a key to achieving more sustainable water use in arid and semi-arid regions

China?s water?energy nexus: greenhouse-gas emissions from groundwater use for agriculture

Abstract: China is the world’s largest emitter of greenhouse gases (GHGs) and the agricultural sector in China is responsible for 17‐20% of annual emissions and 62% of total freshwater use Groundwater abstraction in China has increased rapidly from 10 km 3 yr 1 in the 1950s to more than 100 km 3 yr 1 in the 2000s, such that roughly 70% of the irrigated area in northern China is now groundwater-fed Pumping of water for irrigation is one of the most energy consuming on-farm processes; however, to date this source of GHG emissions in China and elsewhere has been relatively neglected We derive the first detailed estimate of GHG emissions from groundwater pumping for irrigation in China, using extensive village survey data from 11 provinces, broadly representative of the situation during the mid-2000s The 11 provinces cover roughly half of China’s irrigated cropland and we upscale to the national level using government statistics for the remaining 20 provinces Our results show emissions of 331 MtCO2e, just over half a per cent of the national total Groundwater abstraction represents an important source of GHG emissions that has been rapidly increasing and which at present is largely unregulated Water scarcity in China is already driving policies to improve water conservation These results suggest that significant potential exists to promote the co-benefits of water and energy saving in order to meet national planning targets

Water resources trends in Middle East and North Africa towards 2050

Abstract: Changes in water resources availability can be expected as consequences of climate change, population growth, economic development and environmental considerations. A two-stage modeling approach is used to explore the impact of these changes in the Middle East and North Africa (MENA) region. An advanced, physically based, distributed, hydrological model is applied to determine the internal and external renewable water resources for the current situation and under future changes. Subsequently, a water allocation model is used to combine the renewable water resources with sectoral water demands. Results show that total demand in the region will increase to 393 km3 yr−1 in 2050, while total water shortage will grow to 199 km3 yr−1 in 2050 for the average climate change projection, an increase of 157 km3 yr−1. This increase in shortage is the combined impact of an increase in water demand by 50 percent with a decrease in water supply by 12 percent. Uncertainty, based on the output of the nine GCMs applied, reveals that expected water shortage ranges from 85 km3 yr−1 to 283 km3 yr−1 in 2050. The analysis shows that 22 percent of the water shortage can be attributed to climate change and 78 percent to changes in socioeconomic factors.

Water and Energy: Threats and Opportunities

Abstract: Water and Energy – Threats and Opportunities creates an awareness of the important couplings between water and energy. It shows how energy is used in all the various water cycle operations and demonstrates how water is used – and misused – in all kinds of energy production and generation. Population increase, climate change and an increasing competition between food and fuel production create enormous pressures on both water and energy availability. Since there is no replacement for water, water security looks more crucial than energy security. This is true not only in developing countries but also in the most advanced countries. The western parts of the USA suffer from water scarcity that provides a real security threat. The book does not aim to show ‘how to design’ or to solve some of the very intricate conflicts between water and energy. Instead it systematically lists ideas, possibilities and a number of results. There are a few more technical chapters that act as entry points to more detailed technical literature. Part One of the book describes the water-energy nexus, the conflicts and competitions and the couplings between water security, energy security, and food security. Part Two captures how climate change, population increase and the growing food demand will have major impact on water availability in many countries in the world. Part Three describes water for energy and how energy production and conversion depend on water availability. As a consequence, all planning has to take both water and energy into consideration. The environmental (including water) consequences of oil and coal exploration and refining are huge, in North America as well as in the rest of the world. Furthermore, oil leak accidents have hit America, Africa, Europe as well as Asia. The consequences of hydropower are discussed and the competition between hydropower generation, flood control and water storage is illustrated. The importance of water for cooling thermal power plants is described, as this was so tragically demonstrated at the Fukushima nuclear plants in 2011. Climate change will further emphasize the strong coupling between water availability and the operation of power plants. Part Four analyses energy for water - how water production and treatment depend on energy. The book shows that a lot can be done to improve equipment, develop processes and apply advanced monitoring and control to save energy for water operations. Significant amounts of energy can be saved by better pumping, the reduction of leakages, controlled aeration in biological wastewater treatment, more efficient biogas production, and by improved desalination processes. The water-energy issue is not only about technology. It is our attitudes and our lifestyle that can significantly influence the consumption of both water and energy. We all have to be reminded that water is energy and energy is water. ISBN: 9781780400266 (Print) ISBN: 9781780400693 (eBook)

Evaluation of Spain's Water-Energy Nexus

Abstract: This paper explores the water-energy nexus of Spain and offers calculations for both the energy used in the water sector and the water required to run the energy sector. The article takes a prospective approach, offering evaluations of policy objectives for biofuels and expected renewable energy sources. Approximately 5.8% of total electricity demand in Spain is due to the water sector. Irrigated agriculture is one of the Spanish water sectors that show the largest growth in energy requirements. Searches for more efficient modes of farm water use, urban waste water treatment, and the use of desalinated water must henceforth include the energy component. Furthermore, biofuel production, to the levels targeted for 2020, would have an unbearable impact on the already stressed water resources in Spain. However, growing usage of renewable energy sources is not threatened by water scarcity, but legislative measures in water allocation and water markets will be required to meet the requirements of using these so...

Adaptation of grain legumes to climate change: a review

Abstract: Humanity is heading toward the major challenge of having to increase food production by about 50% by 2050 to cater for an additional three billion inhabitants, in a context of arable land shrinking and degradation, nutrient deficiencies, increased water scarcity, and uncertainty due to predicted climatic changes. Already today, water scarcity is probably the most important challenge, and the consensual prediction of a 2–4°C degree increase in temperature over the next 100 years will add new complexity to drought research and legume crop management. This will be especially true in the semi-arid tropic areas, where the evaporative demand is high and where the increased temperature may further strain plant–water relations. Hence, research on how plants manage water use, in particular, on leaf/root resistance to water flow will be increasingly important. Temperature increase will variably accelerate the onset of flowering by increasing thermal time accumulation in our varieties, depending on their relative responses to day length, ambient, and vernalizing temperature, while reducing the length of the growing period by increasing evapotranspiration. While the timeframe for these changes (>10–20 years) may be well in the realm of plant adaptation within breeding programs, there is a need for today’s breeding to understand the key mechanisms underlying crop phenology at a genotype level to better balance crop duration with available soil water and maximize light capture. This will then be used to re-fit phenology to new growing seasons under climate change conditions. The low water use efficiency, i.e., the amount of biomass or grain produced per unit of water used, under high vapor pressure deficit, although partly offset by an increased atmospheric CO2 concentration, would also require the search of germplasm capable of maintaining high water use efficiency under such conditions. Recent research has shown an interdependence of C and N nutrition in the N performance of legumes, a balance that may be altered under climate change. Ecophysiological models will be crucial in identifying genotypes adapted to these new growing conditions. An increased frequency of heat waves, which already happen today, will require the development of varieties capable of setting and filling seeds at high temperature. Finally, increases in temperature and CO2 will affect the geographical distribution of pests, diseases, and weeds, presenting new challenges to crop management and breeding programs.

Water Resources Management: What Should Be Integrated?

Abstract: Sustainable management of water resources (including provision of safe and reliable supplies for drinking water and irrigation, adequate sanitation, protection of aquatic ecosystems, and flood protection) poses enormous challenges in many parts of the world. Despite the global abundance of water and the mainly renewable character of this resource, it is estimated that one-fifth of the world's population lives under conditions of water scarcity ( 1 ). This is primarily the result of the heterogeneous distribution of freshwater in space and time, which is exacerbated by economic disparities, civil unrest, and failures of institutions ( 2 ).

Water Resources Flows Related to Urbanization in China: Challenges and Perspectives for Water Management and Urban Development

Abstract: China has been experiencing rapid urbanization since the reform and open policy launched in 1978, leading to the growth of urban water demands and aggravating water scarcity especially in the new millennium. Accordingly, water resources previously used for agriculture and environmental systems tend to be transferred to urban systems. Limited by the total quantity and frail environments, the patterns of water resources flows among different sectors and regions change obviously. Water related problems induced by rapid urbanization have become one of the key concerns for scientists and governments. The purpose of this paper is to analyze the new features of water resources flows related to urbanization in China, mainly with regard to bidirectional water resources flows between rural and urban areas, environmental and socio-economic systems, real and virtual water flows between the south and north. This paper also considers the socio-economic and environmental challenges which are resulted from water resources flows in such a case, and provides some countermeasures on how to promote water resources to flow healthily and swimmingly, so as to improve the urban development constrained by scarce water resources.

Efficient technologies for worldwide clean water supply

Abstract: An overview of the problems associated with worldwide water shortage problem and of the increasing public participation and awareness to this problem is presented in this work. The existing water treatment processes and their importance in terms of amount, quality and cost of water produced as well as their environmental impact are illustrated. That includes a survey of the current desalination techniques in use and an overview of possible future technologies, aiming at solving different water issues. The technological developments and challenges together with new possible production modes for the future urban water planning are also presented. Finally, routes towards a modern and advanced city planning in a cheaper and more sustainable way based on a more rational use of water, by supplying water of different quality to the final users according to their requirements, as well as the employment of process intensification principles are discussed.

Chemical Treatment Technologies for Waste‐Water Recycling — An Overview

Abstract: The global population is increasing and because of this, the world may experience great fresh water scarcity. Our water resources are limited and, hence, water treatment and recycling methods are the only alternatives for getting fresh water in the coming decades. Therefore, there is a great need for the development of a suitable, inexpensive and rapid wastewater treatment techniques and reuse or conservation methods in the present century. The different types of water treatment and recycling techniques have been discussed in terms of their basic principles, applications, costs, maintenance and suitability. Additionally, a systematic approach to water treatment and recycling involving their understanding, evaluation and selection parameters has been presented. A brief guideline for the selection of the appropriate technologies for specific applications has been evaluated. This review adds to the global discussions on water scarcity solutions.

Water footprint of livestock: comparison of six geographically defined beef production systems

Abstract: Purpose Water use in the livestock sector has featured in the debate about sustainable food systems. Most evidence has come from virtual water calculations which lack impact assessment and adequate consideration of the heterogeneity in livestock production. This study sought new evidence, using a recently developed life cycle impact assessment method for water use to assess six geographically defined beef cattle production systems in New South Wales, Australia, a major production region.

Drought Management Plans in the European Union. The Case of Spain

Abstract: Water is a strategic resource for the economic, social and environmental development. However, water scarcity and droughts are current challenges to this growth, as it is reflected in European Union (EU) water policies, and in national and regional growing initiatives. In addition, these water related issues could worsen by climate change effects, adding pressure to already water stressed areas. This paper presents a general overview of drought management in the European Union, reviews scientific and technical advances, the status of implementation of policy tools and focuses on drought management plans. It analyses the specific case of Spain, a country characterised by presenting a high irregularity in temporal and spatial distribution of water resources and numerous areas affected by water scarcity and droughts. Details are presented on the National Drought Indicator System and drought management plans approved in 2007 in Spain, which represent strategic tools with positive results in drought warning and impact mitigation respectively.

Water resources management strategy for adaptation to droughts in China

Abstract: Water Scarcity and drought are recurrent phenomena in China. In the context of environmental change, an increasing tendency in drought frequency and severity is observed in China in recent years. Therefore, it is imperative to take necessary initiatives to reduce the impacts of drought. In this paper, an attempt is made to identify the best water management strategies to cope with droughts. For this objective the records of historical droughts and their impacts in China over the period of 1950–2009 are analyzed. It is observed that the drought affected area has increased nearly by 12 folds and the drought damaged area has increased by about 22 times in China in last 60 years. Over 87,000 reservoirs were built with a total water storage capacity of about 7,064 billion m3 to cope with droughts. However, this structural supply-based management strategy was not enough to meet the increasing water demand caused by rapid economic development and population growth. A typical relationship between socio-economic development and water resources management strategy to attain sustainability in water management is developed in this study. The relationship shows that the demand-side water management strategies can be the best option to meet the challenges posed by increased severity of drought, population growth, economic development and possible climate change. The concept is later verified through the analysis of changing pattern of water consumptions by different sectors in last 60 years.

System dynamics modeling for complex urban water systems: Application to the city of Tabriz, Iran

Abstract: In this study, Tabriz's urban water system is modeled using a system dynamics approach The model is used to simulate conditions in the near future until 2020 The Tabriz SD model considers potential water supply resources (groundwater, imported fresh water, and treated wastewater), potential sources of demand for water resources (domestic, irrigation and industry uses) and management tools (wastewater reuse and recycling, inter-basin water transfer, water price and conservation tools) Domestic price is varied so its effect on the water shortage could be determined The model also analyses the effect of expanding the wastewater network on groundwater resources According to the study results, both inter-basin water transfer and demand management tools reduce the water shortage up to 45% in 2020 but water transfer is more effective The model has proven to be useful for Tabriz's water authorities, and its methodology is applicable to other cities, especially those in arid or semi-arid regions