Water footprints of nations: Water use by people as a function of their consumption pattern

The water footprint shows the extent of water use in relation to consumption of people. The water footprint of a country is defined as the volume of water needed for the production of the goods and services consumed by the inhabitants of the country. The internal water footprint is the volume of water used from domestic water resources; the external water footprint is the volume of water used in other countries to produce goods and services imported and consumed by the inhabitants of the country. The study calculates the water footprint for each nation of the world for the period 1997–2001. The USA appears to have an average water footprint of 2480,m³/cap/yr, while China has an average footprint of 700,m³/cap/yr. The global average water footprint is 1240,m³/cap/yr. The four major direct factors determining the water footprint of a country are: volume of consumption (related to the gross national income); consumption pattern (e.g. high versus low meat consumption); climate (growth conditions); and agricultural practice (water use efficiency).     

海河平原地下水储量变化的重力卫星反演和流域水量平衡

南水北调工程向华北输水与地下水压采的实施,一定程度改变了海河平原供用水格局,影响了海河平原的地下水储量。准确监测地下水储量变化是水安全保障和地下水战略储备的基础。本研究以水资源公报数据为基准,比较了重力卫星(GRACE)不同的信号处理方法和相关产品,反演了2003—2020年海河流域总水储量及其平原区地下水储量变化,分析了海河流域2000—2019年供用水结构变化和水量平衡关系,量化了总水储量变化对流域蒸散发估算的影响。结果表明：GRACE JPL Mascons数据反演的海河平原地下水储量变化与水资源公报数据的决定系数最高;2003—2020年海河平原地下水储量总体分3阶段呈下降趋势,2003—2011年、2012—2015年和2016—2020年的下降速率分别约为-23.9±1.3亿m³/a、-75.5±5.3亿m³/a、-37.3±2.6亿m³/a;在不考虑海河流域年总水储量变化条件下估算的2003—2019年多年平均蒸散量(521 mm/a),与考虑年总水储量变化的多年平均蒸散量(530 mm/a)相差约10 m...     

An alternative solution of the water shortage problem in Libya

In Libya there is a growing awareness of increasing demand for fresh water while fossil groundwater supply is limited. This situation of water supply has become more problematic with rapidly increasing population and low rainfall. Hence soon after the discovery of fresh groundwater in the deserts of southern Libya, the local authority has made huge efforts to address its water deficit problems, mainly through the implementation of “The Great Manmade River Project” to sustain its economy. Especially the agriculture sector exceeds its traditional supplies. The Libyan authority began to design and install the hydraulic infrastructure needed to withdraw and transport this fossil water to various demand sites along its Mediterranean coast where most of the population lives and where the water is used. There is an over-exploitation of fossil groundwater resources to meet the irrigation demands as a result of adapting a self-sufficing policy in food. Rapid development of agricultural activity, expansion of irrigated areas and over irrigation practices will lead to more depletion of water resources since most of the country's groundwater resources are non-renewable. The supply-driven approach for water management has demonstrated its inability to deliver a substantial degree of water sustainability on the national Libyan level. Despite the strenuous efforts made by the country, it still faces serious water deficits due to continuously increasing water demands beyond the limits of its available water resources. As pressure on water converges on the country's fossil water resources, an immediate reconsideration of agricultural water extractions is needed and appropriate actions have to be implemented in response to its huge consumption. This policy aims at rescuing the present water situation and at avoiding serious environmental and economical crises. Reorganisation of the water consumption pattern, to maintain the country's standard of living and to ensure the economical security for the future generation is drastically needed. This paper considers the country's water management that requires water policy reforms, with emphasis on supply and demand management measures and improvement of the legal and institutional provisions. This could be achieved by reviewing agricultural water policies in order to minimise some local deficits in water resources and to avoid water quality deterioration in the coastal areas. Developing additional non-conventional sources of water supply needs to be considered. This should be supported by creating authorised water institutions lead by a high-professional staff and enabling them in making the appropriate legislation and decisive measurements to allocate water among consumptive sectors as well as to ensure the protection of the environment.     

Will the energy industry drain the water used for agricultural irrigation in the Yellow River basin?

This article employs the case of the Yellow River basin to advance understanding of the water–energy–food nexus by demonstrating how the country’s energy and agriculture sectors are competing for limited water supplies and by quantifying the future water demands in the two sectors. The results show that in 2030 the water demands for food and energy are likely to increase by less than 4 km³ and 1 km³, respectively, in the Yellow River basin. The analysis suggests that agricultural water savings and inter-basin water transfers are the main ways to ensure sufficient water flows through the basin to fulfil demand for both sectors while preserving the natural ecosystems.     

Economic efficiency of the Volga-Kama dam system

Conclusions The national economy will be greatly benefited by construction of the Volga and Kama hydraulic installations, and the benefits will be progressively greater: higher electric power output, higher capacity of river transport, and further improvement in water supply for agriculture, industry, and household use. Storage basins of the Volga-Kama dam system will supply water for various branches of the national economy. Tentative calculations show a future deficiency of 15–20 km³ of water in connection with the rising industrial and household demands and the planned irrigation of 2.5 million hectares in the Trans-Volga region-this even in the presence of reservoirs which control drainage but also must maintain the navigation channel depth in the dry summer months. This is one of the factors that lends urgency to the task of drainage diversion from the northern rivers to the Volga-Kama basin. Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 15–18, February, 1969.     

Water Resource Development Study for a Mining Region

A water resource development study has been carried out for a proposed lignite mining area at Bhavnagar district of Gujarat state in India. This work is essentially a case study that uses standard methodology already applied in earlier research studies. The study covers assessment of water resources for the present and future, water balance status and formulation of a management and conservation strategy for the area. Ramdasiya watershed is considered as influencing zone having 31.92 km² area and covering full or part of ten villages with 13 647 population. There is no perennial river or major surface water bodies in the study area and annual average rainfall is only 567 mm. The groundwater is generally potable. Annual utilisable groundwater resource available in the area is 3.30 hm³ and present annual ground water demand for area is 2.967 hm³, whereas annual demand for various uses in theyear 2010 and 2020 would be around 3.298 and 3.659 hm³, respectively. The above problem of water scarcity in theregion has to be mitigated by immediate initiation of suitable short- and long-term water supply augmentation strategy for enhancing the groundwater recharge. To reduce the heavy surface runoff loss (around 40% of rainfall, although some part of it is also utilized as consumptive used) and enhance the groundwater recharge capacity of the area, suitable water retaining structures should be constructed. Interbasin transfer of water is also required to artificially recharge the aquifers for the augmentation of the groundwater potential of the area so as to meet the future demands.     

The Yellow River: Managing the Unmanageable

Abstract

Hydrosolidarity in the Yellow River is a complex and difficult task, especially as this river has sediment problems that are unique in the world. The balancing of discharge needed for sediment management, relative to that needed for augmentation of water supply within and outside the basin, and for conservation of threatened ecosystems downstream presents a series of compromises that must rank as amongst the most challenging in basin-wide management of major world rivers. Until such time as south-to-north diversions are in place, the Yellow River is the only major water supply to the North China Plain, where water scarcity is now estimated to be some 40 km³ annually, representing 70 percent of the flow of the Yellow River. The hydrological management of Yellow River erosion involves three major factors: erosion and sediment transport, flooding, and river desiccation in the downstream reaches. This paper outlines several major development projects in the Yellow River basin that are attempting to achieve hydrosolidarity while, at the same time, providing needed water supplies to water-scarce parts of the basin.     

The effect of diet changes and food loss reduction in reducing the water footprint of an average American

ABSTRACT

We analyzed the consumptive water reduction of diet shifting along with food waste reductions in the case of the United States. We find that a dietary shift to healthy diet will not always lead to reduced water footprint. Dietary shifts to vegan and vegetarian diets provide larger reduction in the consumptive water footprint. Reducing food loss and waste produced the largest potential water footprint reduction in our analysis of the US food system. Our findings suggest that a combination of measures that include dietary shift, reducing caloric intake, and reducing food waste result in a significant decline in water footprint.     

谈城市应急水源地工程的设计原则——结合马池口水源地工程的方案优化

结合马池口水源地工程设计中对水源地的论证、规模确定以及供水方案的比选等,对应急水源地设计中应优先解决的问题进行了论述。笔者认为应急供水工程设计应符合以下原则:(1)方案应与当地规划相结合,使工程在应急任务完成以后还能够持续发挥工程效益,实现近期与远期、城区水源地与当地供水结合的多目标多效益模式;(2)由于应急备用水源地工程是城市的备用水源工程,设计中供水规模和供水方案应当考虑到其应急备用性质,因此在用水需求与水资源承载能力关系的协调中应考虑这一因素,同时供水方案确定中应当尽量利用已建工程,减少工期和投资。     

Integrated water and food analysis at the global and basin level. An application of WATERSIM

Several recent studies warn that under ‘Business-as-Usual’ a water crisis is impending, suggesting that appropriate actions need to be taken on the water supply and demand side. While many measures to alleviate water scarcity are within the water sector, it is increasingly recognized that many drivers, policies and institutions outside the water sector have large and real implications on how water is being allocated and used. Important drivers for water use include population and income growth, urbanization, trade and other macroeconomic policies, environmental regulations and climate policy. While some of these processes and trends, especially those at global level, may prove difficult to influence directly, it is important to understand their linkages with water issues to analyze the relative impact of various policies in the agricultural and water sectors on water and food security. The strong linkages between economic trends, agricultural policies and water use call for an integrated and multidisciplinary modelling approach. The WATERSIM model, developed by the International Water Management Institute (IWMI) is a suitable tool to explore the impacts of water and food related policies on global and regional water demand and supply, food production and the environment. This paper introduces the WATERSIM model and, using some preliminary results, illustrates the importance of global economic trends on food and water outcomes.     

Enhancement of a global lake and reservoir database to aid climate studies and resource monitoring utilizing satellite radar altimetry

Here, we describe the expansion and enhancement of a large (surface area ≥100 km²) lake and reservoir database (1.GREALD). These efforts have also resulted in the spin-off of two additional databases, one containing lakes and reservoirs (2.GREALD, area 10–99 km²), and the other containing ephemeral lakes (3.GELD, area ≥100 km²). These databases are unique sources for projects that utilize satellite radar altimeter data to monitor surface water levels. While 1.GREALD aims to be a complete catalog, 2.GREALD focuses on reservoirs in response to applied sciences programs that monitor water and energy resources. The creation of 3.GELD has climate change objectives as well as water resources and ecosystem conservation applications. The recording of information pertaining to the potential overpasses (waterbody crossings) of the current and archive satellite altimeters is a primary objective as is the need to highlight any form of controlled water level variation. The permanent water databases now contain 6282 entries, half experience some form of anthropogenic influence and ～430 have been identified as potential climatically sensitive terminal lakes. The revised integral surface area distribution is a power law with exponent ?1.016. Statistics reveal that with altimetric repeat visit times of 10-day to monthly, at least 80% of the permanent water bodies (≥10 km²) have been overflown at some period since the 1990s. Current information on water use and reservoir formation date show that the primary use of the reservoir class is hydroelectric power, and that China, Brazil, India, Turkey, and Vietnam dominate the dam building in recent decades.     

Water and the CGIAR: A Strategic Framework

Abstract

Among the many institutions addressing development issues at the international level, the 16 research centers of the Consultative Group of International Agricultural Research (CGIAR) focus on the goal of reducing poverty, hunger, and malnutrition by sustainably increasing productivity of resources in agriculture, forestry, and fisheries. The CGIAR has certain comparative advantages in carrying work in water at the various scales, from the farm up to global, that should be offered to the international community. This discussion paper addresses the question: what are the major water issues relevant to the CGIAR goal? The paper also presents a justification of the research needs and opportunities as well as some initial ideas for the development of a specific research agenda on each area. While other international organizations are very active in many international initiatives, the CGIAR is one of the few that could contribute much needed research information in many world areas. The CGIAR must focus more on water in relation to the plight of the poor in particular. There is a need to increase the adaptive capacity of the poor, and to manage the water supply and quality constraints. This could be achieved by focusing at the community level and by developing inexpensive, easy to use monitoring tools that would alert the communities of forthcoming problems and provide them with means to take remedial action. This action is often needed long before there is any hope of changes in policy and other macro-level interventions. The fundamental issue of water as a food requires that attention be given to the quantity and quality of water available for domestic use in poor households and communities. Health issues associated with domestic supply and with irrigation management have been important research themes in the CGIAR and demand increasing attention. Given the current composition, activitiesm and comparative advantages of the CGIAR, it is proposed that research on water management should focus on the following four broad general areas: (1) improving the efficiency of water use in agriculture through increased water productivity; (2) management of watersheds for multiple functions; (3) management of aquatic ecosystems, in particular those sharing boundaries with terrestrial ecosystems; and (4) policy and institutional aspects of water management. As the aim of water management research is to address water constraints and issues in an integrated manner, the four areas cannot be treated in isolation from each other. There is thus a need for the fifth area for achieving integration at and across different scales.     

Virtual Water in Global Food and Water Policy Making: Is There a Need for Rethinking?

The argument that economies that face acute water scarcity problems can and should meet their water demand for food through cereal imports from water-rich countries; and that virtual water trade can be used to achieve water securities has become dominant in global water discussions. Analysis of country level data on renewable freshwater availability and net virtual water trade of 146 nations across the world shows that a country's virtual water trade is not determined by its water situation. Some countries have the advantage of high “economic efficiency” in food production and have surplus water, but resort to food import, whereas some water scarce countries achieve high virtual water trade balances. Further analysis with a set of 131 countries showed that virtual water trade increased with increase in gross cropped area. This is because of two reasons: First, when access to arable land increases, the ability to utilize available blue water for irrigation increases. Second, increasing access to arable land improves the access to water held in the soil profile as “free good”, a factor not taken into account in assessing water availability. Hence, many of the humid, water-rich countries will not be in a position to produce surplus food and feed the water scarce nations; and virtual water often flows out of water-poor, land rich countries to land-poor water-rich countries. This means that “distribution of scarcity” and “global water use efficiency”, are goals that are difficult to achieve through virtual water trade in a practical sense. For a water-poor, but land rich country, virtual water import offer little scope as a sound water management strategy as what is often achieved through virtual water trade is improved “global land use efficiency”. The important policy inferences emerging from the analyses are two: First, assessing the food security challenges posed to nations in future purely from a water resource perspective provides a distorted view of the food security scenario. National policies on food security should take into account “access to arable land” apart from water availability. Second, analysis of water challenges posed by nations purely from the point of view of renewable water availability and aggregate demands will be dangerous. Access to water in the soil profile, which is determined by access to arable land, would be an important determinant of effective water availability.     

EVALUATING TRADEOFFS BETWEEN ENVIRONMENTAL FLOW PROTECTIONS AND AGRICULTURAL WATER SECURITY

River basin managers responsible for water allocation decisions are increasingly required to evaluate tradeoffs between environmental flow protections and human water security. However, the basin‐scale effects of environmental flow regulations on water users are not well understood, in part because analyses are complicated by the spatial and temporal variation in water availability, human demands, and ecosystem needs. Here, we examine alternative regional environmental flow policies and their effects on a distributed network of water users in a small (182 km²) river basin in coastal California. We use a hydrologic model to simulate water diversion operations under three policy scenarios and quantify potential impacts to bypass flows for adult migrating salmon and agricultural water storage. The results indicate that there are inherent tradeoffs between environmental flows and agricultural water security, with the most restrictive environmental policy associated with the greatest impacts to water users. Surprisingly, the moderate environmental flow policy had larger impacts to bypass flows than the unregulated management scenario, suggesting that ecological benefits of the moderate policy are small relative to the adverse effects on agricultural water users. Conflicts between environmental and human water needs were greatest in upper catchments (<2.5 km²), where flow protections caused the greatest reduction in water storage. Although natural supplies were adequate for meeting water needs in most years regardless of policy restrictions, potential for conflict between environmental flow protections and water security was evident in dry years. Therefore, strategies are particularly needed for drought‐year water management to ensure adequate environmental flows while reducing human water allocations in an equitable manner. Copyright © 2013 John Wiley & Sons, Ltd.     

高校教学楼用水特征及节水潜力分析

近年来高等院校办学规模不断扩大,高校用水情况已经发生了很大的变化,建筑用水定额的修订对建立节水型社会有着至关重要的意义.以北京工业大学教学楼为对象,进行用水量调查研究,分析了大量实测资料,与现行用水定额进行比较,探讨了高校用水特征及学校内部用水的行为特点,以期达到在保证教学、科研等活动正常运行的前提下,更加科学合理地用水,进而缓解区域供水压力,并为建立节约型高校以及高校教学楼用水量定额标准的修订提供一定的参考.     

Critical Environmental Flows to Support Integrated Ecological Objectives for the Yellow River Estuary,China

The volume of inflowing water needed to meet multiple demands in the Yellow River Estuary of China was examined and quantified. Pressure on available environmental flows comes from varied ecological objectives, including maintenance of freshwater habitat for hundreds of plant and animal species, salinity balance, sediment transport and general equilibrium of the hydrologic cycle. Temporal fluctuations of flow input and output were considered and the amount of water needed for both consumptive and non-consumptive uses was evaluated. The rule of summation was used to calculate consumptive water requirements and the rule of compatibility (i.e., maximum principle) was adapted to estimate the non-consumptive ones. It was determined that the minimum, medium and high levels of annual environmental flows are 134.22 × 10⁸, 162.73 × 10⁸ and 274.9 × 10⁸ m³, respectively, in the Yellow River Estuary, which represent 23.7, 28.7 and 48.5% of the natural river discharge. Water requirements differ across months. The months of May through June, August and October were identified as the most critical periods for maintaining the environmental flows. The basic purpose of water entering the system is to compensate for water losses due to evaporation and to maintain an acceptable level of salinity in the estuary. Sediment transport into and through the estuary area are likely to be directly impacted by variations in river discharge. Improved efficiency in the sediment transport regime of the Yellow River could potentially reduce environmental flow requirements of the estuary, thus freeing water resources for other beneficial uses.     

Multi‐scale modelling of land‐use change and river training effects on floods in the Rhine basin

Land‐use changes effects on floods are investigated by a multi‐scale modelling study, where runoff generation in catchments of different sizes, different land uses and morphological characteristics are simulated in a nested manner. The macro‐scale covers the Rhine basin (excluding the alpine part), the upper meso‐scale covers various tributaries of the Rhine and three lower meso‐scale study areas (100–500 km²) represent different characteristic land‐use patterns. The main innovation is the combination of models at different scales and at different levels of process representation in order to account for the complexity of land‐use change impacts for a large river basin. The results showed that the influence of land‐use on storm runoff generation is stronger for convective storm events with high precipitation intensities than for long advective storms with low intensities. The simulated flood increase at the lower meso‐scale for a scenario of rather strong urbanization is in the order of 0 and 4% for advective rainfall events, and 10–30% for convective rain storms with a return period of 2–10 years. Convective storm events, however, are of hardly any relevance for the formation of floods in the large river basins of Central Europe, because the extent of convective rainstorms is restricted to local occurrence. Due to the dominance of advective precipitation for macro‐scale flooding, limited water retention capacity of antecedent wet soils and superposition of flood waves from different tributaries, the land‐use change effects at the macro‐scale are even smaller, for example at Cologne (catchment area 100 000 km²), land‐use change effects may result in not more than 1–5 cm water level of the Rhine. Water retention measures in polders along the Upper and Lower Rhine yield flood peak attenuation along the Rhine all the way down to the Dutch border between 1 and 15 cm. Copyright © 2007 John Wiley & Sons, Ltd.     

基于地表径流量预测的玛纳斯河流域绿洲适宜规模计算

基于神经网络算法和水热平衡原理,结合水文、气象数据,构建了玛纳斯河绿洲适宜规模模型,分析计算了1990-2020年绿洲适宜规模与现状规模,预测了2021-2030年流域地表径流量和绿洲适宜规模.结果表明:1990-2000年、2001-2010年、2011-2020年绿洲适宜规模分别为11003.3 km2、9902....     

Reuse of oil and gas produced water in south-eastern New Mexico: resource assessment,treatment processes,and policy

The Permian Basin of south-eastern New Mexico in the United States exemplifies the combination of rapidly expanding oil and gas production with freshwater shortages and aquifer stress. Reuse of saline produced water can provide a stable supply of water for drilling, fracturing and completion and minimize consumptive use of freshwater. We discuss water withdrawals and use by the oil and gas industry in this region, processes for reuse and recycling of produced water in place of freshwater, and operational and policy changes to help improve maximal use of all available water resources in this arid region.     

面向供水对象转型的引大入秦工程水资源优化配置研究

引大入秦工程（以下简称引大工程）建成初期主要以秦王川农业供水为主,但随着兰州新区的建设发展,其供水对象开始向城市生活用水和工业用水转型,如何实现有限水资源的合理配置是目前研究的重点问题。基于此,依据引大工程供水区（以下简称引大供水区）可持续发展要求,构建以实现经济、社会、生态效益最大化为目标函数,可供水量、输水能力、用户需水量、排水系统排水量与变量非负为约束条件的多目标水资源优化配置模型,使用遗传算法进行求解。结果表明：2025年引大供水区不同用水部门配水量（保证率P=50%、P=75%）分别为生活用水8 323.85×10⁴、8 322.49×10⁴ m³,农业用水15 001.95×10⁴、15 631.53×10⁴ m³,工业用水11 111.00×10⁴、11 100.00×10⁴ m³,生态用水946.88×10⁴、947.02×10⁴ m³,各部门总配水量与优化前供水量4.23×10⁸ m³相比,达到供需平衡;2030年引大供水区不同用水部门配水量（保证率P=50%、P=75%）分别为生活用水12 650.51×10⁴、12 666.53×10⁴ m³,农业用水16 397.77×10⁴、17 019.70×10⁴ m³,工业用水20 498.00×10⁴、20 508.00×10⁴ m³,生态用水948.00×10⁴、948.88×10⁴ m³,不同保证率下各部门总体缺水率分别为12.27%、13.38%。2025—2030年引大供水区的非农业用水结构将大幅提升,农业灌溉用水量降低。研究结果可为引大供水区优化水资源配置决策提供参考依据。