Spatial Heterogeneity of Embedded Water Consumption from the Perspective of Virtual Water Surplus and Deficit in the Yellow River Basin,China

Virtual water trade(VWT)provides a new perspective for alleviating water crisis and has thus attracted widespread attention.However,the heterogeneity of virtual water trade inside and outside the river basin and its influencing factors remains further study.In this study,for better investigating the pattern and heterogeneity of virtual water trade inside and outside provincial regions along the Yellow River Basin in 2015 using the input-output model(MRIO),we proposed two new concepts,i.e.,virtual water surplus and virtual water deficit,and then used the Logarithmic Mean Divisia Index(LMDI)model to identify the inherent mechanism of the imbalance of virtual water trade between provincial regions along the Yellow River Basin and the other four regions in China.The results show that:1)in provincial regions along the Yellow River Basin,the less developed the economy was,the larger the contribution of the agricultural sector in virtual water trade,while the smaller the contribution of the industrial sector.2)Due to the large output of agricultural products,the upstream and midstream provincial regions of the Yellow River Basin had a virtual water surplus,with a net outflow of virtual water of 2.7×10^(8) m^(3) and 0.9×10^(8) m^(3),respectively.3)provincial regions along the Yellow River Basin were in a virtual water deficit with the rest of China,and the decisive factor was the active degree of trade with the outside.This study would be beneficial to illuminate the trade-related water use issues in provincial regions along the Yellow River Basin,which has farreaching practical signific-ance for alleviating water scarcity.

Virtual Water Trade and Food Security for Iraq

Iraq depends on its water resources from the water of the Tigris and Euphrates Rivers and their tributaries. Now, the flow of these rivers is decreasing, and Iraq is experiencing a water shortage problem. The situation is expected to be graver in the future if no action is considered. It is expected that the population will be about 70 million in 2050 and about 90 million in 2070. In such a case, thus, the quantities of water available in the future will not be sufficient to produce most of the requirements of food security, whether that be from agricultural or animal products. To overcome this problem, water management planning should be based on scientific background to overcome the present and expected problems. One of the main factors to be considered should be based on scientific studies of the virtual water footprint of different food crops to provide the largest possible amount of virtual water and avoid the acute shortage of its national water from surface and ground irrigation water (blue water) and rainwater (green water), in addition to working hard to provide the largest possible amount of desalinated water and refined sewage (gray water). In addition, any strategic plan for sustainable development in the country must be comprehensive so that it is not satisfied with improving the situation in the field of food security related to water security, but rather among its other elements is community development that directly affects food security, including setting policies to reduce consumption by reducing the steady increase in population where the population rate is 2.97% now. Collective awareness and guidance programs in all the fields of water and food security are very important to be adopted, so that everyone knows that the issue of food security and what derives from it are an existential issue related to the survival of Iraq as a state and people. In this research, facts are stated so that action is to be considered to minimize the water shortage problem. The new strategic water resources management plan is to be adopted that considers existing and future expected problems.

Regional Virtual Water Trade Strategy in Drought Area in China

[Objective]The aim was to analyze the virtual water trade in drought area in China.[Method]Taking agricultural production which was related to water resources as study object and by dint of opportunity cost and comparative advantage theory,water resources have been included into a series of state macro-objective models,such as economic growth,crops safety,and increase of people’s well-fare.Virtual water resource strategy was verified effectively and relevant suggestions on virtual water trade in the drought areas in China were proposed.[Result]Virtual water strategy can be implemented in places where water resource was limited so as to get low-water-demand products and change products with humid areas.But the premise was that the production technology of watery product in humid area was higher than the limited-water area,so that there can be adequate impetus to involve into virtual water strategy program and enhance each other’s benefits through commerce and ease water resources shortage and ecological destruction problem and stimulated economic development.[Conclusion] The study provided scientific basis to solve the water shortage problem in China.

Efficiency,Equity and Effect:a case study on virtual water consumption characteristics

Scarcity of water is the key factor restricting the growth of social economy.The virtual water theory provides a new way to solve the problem of water scarcity.For this paper,we have calculated the virtual water consumption of each household,grouped by income,of Gansu province for 1992-2005.Then we advanced the indicator of virtual water with per-unit-of-consumption expenditure to analyze the efficiency of virtual water consumption.Additionally,we recurred to the diversity theory advanced by Ulanowicz,which is broadly employed by ecologists and biologists,to analyze the characteristics of virtual water consumption.As a result,the virtual water consumption of each group decreased yearly from 1992 to 2005,on the whole;decreasing proceeded slower during the period of 1992-1997 than during 1998-2005.Per-unit-consumption expenditure of virtual water for each group represents the same characteristics,on the whole,as virtual water consumption.The largest variation of this indicator exists in the group of the lowest income,which ranges from 1.58 to 0.18 m3/Yuan.yr;whereas the least exists in the highest income group,which is 0.58 to 0.07 m3/Yuan.yr.The virtual diversity indicator increased year by year,and the change of this indicator in 1992-1997 was more obvious than in 1998-2005.Finally,from this study we find that,in view of virtual water,we can save water by means of changing consumption patterns and increasing consumption diversity,but without degrading the quality of living and reducing the demands of living.When the problem of water scarcity becomes more and more serious in Gansu of China,this suggestion becomes more and more important.The consumption,the role of guiding production produce,is very important.An unsustainable consumption pattern is the main factor causing the deterioration of the world environment,especially in a developing country.The sustainable consumption is the only way to develop human beings and achieve the economical sustainable economics.

Sustainability and virtual water:The lessons of history

This article aims to show that virtual water has historically been an adaptation strategy that enabled some arid regions to develop a prosperous economy without putting pressure on their scarce water resources.Virtual water is referred to as the total amount of water that is consumed to produce goods and services.As an example,in arid central Iran,the deficiency in agricultural revenues was offset by more investment in local industries that enjoyed a perennial capacity to employ more workers.The revenues of local industries weaned the population from irrigated agriculture,since most of their raw materials and also food stuff were imported from other regions,bringing a remarkable amount of virtual water.This virtual water not only sustained the region’s inhabitants,but also set the stage for a powerful polity in the face of a rapid population growth between the 13th and 15th centuries AD.The resultant surplus products entailed a vast and safe network of roads,provided by both entrepreneurs and government.Therefore,it became possible to import more feedstock such as cocoons from water-abundant regions and then export silk textiles with considerable value-added.This article concludes that a similar model of virtual water can remedy the ongoing water crisis in central Iran,where groundwater reserves are overexploited,and many rural and urban centers are teetering on the edge of socio-ecological collapse.History holds an urgent lesson on sustainability for our today’s policy that stubbornly peruses agriculture and other high-water-demand sectors in an arid region whose development has always been dependent on virtual water.

Evaluation on Water Resources and Determining the Values of Exported and Imported Virtual Water in Hashtgerd Region

The concept of virtual water in recent years has been proposed with the world’s water resource consumption management approach. Hashtgerd study area is one of 609 study areas of the country that is located entirely in Alborz Province. Average annual rainfall in this region was about 200 to 340 mm and the average agricultural production per year was more than one million tons and had more than 16 million cubic meters surplus recovery from underground water resources. The aim of this study is to evaluate resources and amounts of virtual water in the agricultural sector of the study area and its impact on the area water resources balance and ultimately provide solutions to reduce water consumption by the agricultural sector. The most important exported water products in Hashtgerd area in order of importance are peaches and nectarines (33% of water exports), plums (15% of water exports), vegetables (5.14 percent of water exports), cherry (4.7% of water exports) and wheat (6.5 percent of water exports). Virtual water trade balance of agricultural and horticultural products in the digital range is equal to 260+ million cubic meters. Density of agricultural lands can be mentioned as the main reasons for positive balance of virtual water trade in this area.

Analysis of China’s Water Security and Virtual Water Trade

Producing goods and services all needs water consumption.The water used in the process of an agricultural or industrial product is called the"Virtual Water"contained in this product. Through international trade,water-scarce countries and regions could purchase water-intensive products--especially foods,from water-rich countries to balance their water deficits and achieve water safety.China is one of the 13 most water-deficit countries whose water safety have been severely challenged.This paper generalized the recent global research development and made a brief introduction about the methods calculating virtual water content in specific products.As a case study,we qualified China's annual virtual water flows from year 2000 to 2002 with trade in crops,and ended with some policy advice for application and practice of virtual water strategy.

Virtual Water Trade as a Strategy to Water Resource Management in Iran

Agriculture has historically played a central role in the economy, life and culture of the Iranian population. Nowadays, this sector is facing the reality that its natural fresh water resources become fully utilized. Considering the climate conditions and limitation of using new water resources and the necessity of increasing agricultural product as a result of population growth, there is a general doubt about Iran’s ability to maintain this level of production amid the mounting water challenges, among other obstacles. Therefore, the evaluation of virtual water and water footprint can provide new indicators for informing water policy decisions. So, in order to study the situation at the national level, we estimated virtual water consumption in term of virtual water theory as well water footprint in agriculture sector of Iran. Data from 2001-2008 were used to account for yearly. The results of this study show that Iran has water import dependency and also net water import is 12.7 billion m3 averages. So Iran country saved 12.7 billion m3 from their domestic water resource for utilization in other sectors. Finally, it should be concluded that virtual water trade as a policy measure to water resources management will be provided to a great extent in order to reach both significant water saving and environmental sustainability.

Areal differentiation of virtual water for agricultural products and its effect on regional agricultural structure adjustment in China: 1995-2007

With a vast territory, the space time distribution of water resources is uneven in China. There is a great dif ference in natural conditions and farmland management of agricultural production in different regions. The areal dif ferentiation of agricultural products virtual water is obvious. Comparison with the agricultural products virtual water from 1995 to 2007 in China shows an increase in the first ten years and a little decrease in recent years. There has been a tendency of increase all the time in Northeast and Northwest, but a decrease after an increase firstly in other regions. The virtual water of food crops is the maximum which accounts for more than 70% in China, and that of veg etables is in a fast growth. The proportion of agricultural products virtual water to the total water resources in each region has a large difference, showing the imbalance of agricultural water in different regions, which accounts for 50% 90% in Northeast, and 125% 185% in North China. Under the guidance of virtual water strategy, based on the differences of resource endowment, each region should adjust agricultural structure, decide production by water, and select water suitable crops. In water rich region, agricultural products of high water consumption should be planted appropriately, which will make full use of the abundant local water resources. In water shortage region the crop pro duction of high water consumption and low efficiency should be depressed, and that of low water consumption and high efficiency should be supported and increased. It will achieve reasonable disposition of water resources, promote ecological restoration and environmental protection, as well as ensure food security.

Analysis of water resource benefits due to power grid interconnections using the virtual water method

The global water demand and supply situation is becoming increasingly severe due to water shortage and uneven distribution of water resources.The highest water demand in the energy sector is attributable to power generation.With cross-country and cross-continental power grid interconnections becoming a reality,electricity trading across countries and the creation of new opportunities for re-allocation of water resources are possible.This study expands the concept of virtual water and proposes a generalized virtual water flow in an interconnected power grid system to accurately estimate water resource benefits of clean power transmission from both the production and the consumption sides.By defining the water scarcity index as a price mechanism indicator,the benefits of water resources allocation through power grid interconnections are evaluated.Taking the Africa-Asia-Europe interconnection scenario as an example,the total water saving would amount to 88.95 million m^3 by 2030 and 337.8 million m^3 by 2050.This result shows that grid interconnections could promote the development of renewable energy and expand the benefits of available water resources.

Virtual Water on the Southern High Plains of Texas: The Case of a Nonrenewable Blue Water Resource

This paper utilizes the virtual water concept to evaluate water usage of agricultural production in West Texas. This work evaluates the measure of virtual water, as it relates to informing water policy in a semi-arid, agriculture-intensive region, which relies upon a minimally renewable groundwater resource. The results suggest that production in the region reflects a collective effort to capture the highest value from the water resource, consistent with the virtual water philosophy, even in the absence of specific water policy toward that goal. Additionally, this work takes advantage of high resolution data to reinforce the need to calibrate virtual water calculations to account for regional differences.

Agricultural Water Foot Print and Virtual Water Budget in Iran Related to the Consumption of Crop Products by Conserving Irrigation Efficiency

In this study we estimate agricultural water footprint and its components from consumption perspective in arid and semi-arid region like Iran. This study is based on blue water consumption in irrigated land. Iran has imported net virtual water about 11.64 billion cubic meters (bcm) as international crop trade in 2005-2006. Therefore, Iran has depended on virtual water imports. By conserving about 60% irrigation efficiency, the total water requirement to produce imported crops in Iran is nearly 20.78 billion cubic meters. It is nearly 9 percent of renewable water resources and 12.65% agricultural appropriated water which has added to internal water resources. Agricultural virtual water budget is about 112.78 Gm3/yr. Agricultural water footprint is 110.2 Gm3/yr. About 12.83% of agricultural water footprint of Iran is related to external water resources on the country boundaries. It means external water footprint. Water dependency, water self-sufficiency and water scarcity indexes in agricultural sector of Iran, are estimated 10.1%, 89.9% and 70.8%, respectively.

Virtual water: an effective mechanism for integrated water resources management

In regions, which suffer from water shortage or potential water shortage like the Middle East, water policies and different mitigation measures are formulated. With the increasing population and increasing demand for food and drinking water with the fixed supply of water, the demand management policies have been introduced. Virtual Water has been adopted as an alternative or potential alternative water resource. In the application of the Integrated Water Resources Management (IWRM), virtual water has to be considered as a resource of water. In this paper, the practical value of the virtual water concept as well as the possibility of the application of the concept in the regional and national level are discussed. The paper emphasizes on the application of virtual water in agriculture products and virtual water trade of these products. This research concluded that, there is a possibility for the application of the virtual water concept on the national level taking into account water endowments, and other natural and social economic conditions. The virtual water strategy seeks ways to consciously and efficiently utilize the internal and external water resources to alleviate water scarcity. This, however, by no means implies that importing food is the only response the water scarce countries and regions should and can take. Other measures concerning the supply and demand sides of water management are imperative. The argument here is that the virtual water strategy should be an integral component in the whole package of integrated water resources management.

比较优势视角下我国虚拟水流动归因分析

虚拟水是近年来水资源领域的研究热点,而相关研究成果主要集中于虚拟水转移的规模核算及其特征分析,对虚拟水转移的动力成因较少讨论,所以借助比较优势理论中的区位商、增长商指数,量化解析农林牧渔、工业、建筑业、批发零售、交通运输、住宿餐饮、金融、房地产、其他服务业9大行业的发展优势及增长潜力,并分析这9大行业虚拟水流动格局与行业比较优势的相关关系。研究结果表明:各行业虚拟水流动格局与行业比较优势具有明显关联,2002—2017年间我国72%的虚拟水会从具有比较优势的地区向不具备优势的地区转移,71%的虚拟水转移量会受到行业发展速度影响。研究成果预期可为我国水资源宏观管理及节水政策制定提供理论依据及决策参考。决策参考。

中国燃煤发电水足迹时空特征研究

中国燃煤发电行业需要消耗大量水资源。基于生命周期方法,建立了中国燃煤发电水足迹评估模型。该模型包括煤炭开采、煤炭加工、煤炭运输、燃煤发电和电力输送五个阶段,水足迹不仅考虑了直接水足迹,还有间接水足迹。基于该模型,定量分析了2000—2020年中国燃煤发电整个生命周期的用水量和废水排放对环境的影响,中国各省份燃煤发电的水足迹以及跨省煤电运输所产生的虚拟水的时空变化特征。结果显示:从时间上看,2000—2020年,中国燃煤发电总水足迹逐年上升,从160亿立方米增加到661亿立方米。单位水足迹处于先上升后下降的趋势,2015年达到最大值15.6 m3/MW·h。期间,灰水足迹占比较大,为76%~83%。整个生命周期中,间接水足迹占总水足迹的36%~45%。从空间上看,2020年,内蒙古、安徽、宁夏、陕西和新疆是主要虚拟水输出省份,而内蒙古、山西、山东和新疆是2000—2020年水足迹增长最多的省份。研究结果以期为我国煤炭和水资源高效利用以及水环境管理提供重要借鉴。

虚拟仿真技术在给水排水实验教学中的应用探索

虚拟仿真技术在教学中应用意义重大,得到了我国和其他国家教育界的重视,国内的虚拟仿真实验课程、虚拟仿真教学平台、虚拟仿真教学理念已经在连续多年的建设下蓬勃发展,取得长足积累。由于虚拟仿真实验教学在知识点学习、实验内容、课程规模、考评机制和安全性等方面较传统实验教学优势显著,实验教学与实际运用可以较好统一。在虚拟仿真技术和学科教学的结合下,一些给排水学科原本不易获得的实验和工程场景也可以生成,并可由学生自主进行实验探索,进行相应的工程解决。虚拟仿真技术教学可以基于平台取得技术支持和相应的考评机制,具体到设计与应用中也存在完善的课程设计的路径。

断层虚位错模式揭示的2022年1月8日青海门源M_(S)6.9地震前的地电阻率变化

选取2022年1月8日青海门源M_(S)6.9地震震中400 km范围内四个地电阻率观测台站的观测精度高、具有稳态年变、震前无显著干扰的地电阻率ρ_(s)观测数据,结合ERA5同化数据集中的多层土壤温度和土壤水分含量,在利用多项式拟合获取各台站(或测道)地电阻率正常年动态的基础上,分析了门源地震前地电阻率的异常变化。结果显示:金银滩台EW测道、武威台NS测道和山丹台EW测道、N45°W测道震前存在超阈值的异常变化,并呈现各向异性特征。基于断层虚位错模式分析了地电阻率异常变化与孕震过程之间的联系,结果表明:金银滩台震前处于压缩区并受到NNE方向的挤压,与主压应变近似正交的EW测道于震前10个月出现负异常;同样位于压缩区的武威台,受到了ENE向的挤压,NS测道的地电阻率在孕震早期(震前13个月)以负异常为主,孕震中晚期(震前3个月)出现了正异常;山丹台,位于膨胀区,受到近似NS向的拉张,与主张应变平行的NS测道未发现异常,但EW测道震前一年地电阻率出现正异常,N45°W测道的地电阻率也在震前半年左右出现超阈值并呈正异常。此外,金银滩台、山丹台和武威台距离门源地震震中的距离分别为92 km,113 km和139 km,相应的地电阻率异常最大变化幅值分别为−3.0σ,2.2σ和−2.1σ。此外,门源地震前地电阻率异常变化的时空特征与岩石实验结果及理论模型一致,也符合震源区应力应变积累程度较高、向外围方向逐渐衰减的分布特征。由此推断,2022年门源M_(S)6.9地震前地电阻率的时空变化可能与区域介质变形及应力变化有关。

An Integrated Framework for Regional Assessment of Water, Energy, and Nutrients from Food Loss of Selected Crops in the Lower Fraser Valley, Canada

Although there is no global shortage of food or water, food security has not been achieved, as human activity has turned these vital resources into “waste”. Wasted food not only loses valuable water resources but embedded calories of human energy and nutrients for healthy human populations. The Food and Agricultural Organization of the United Nations, in addressing these concerns, focuses on a global scale largely on an economic estimate of individual components of energy or water or nutrient loss. It is suggested that more information is required through local or regional assessments to provide better estimates, incorporating regional factors of the losses along the food supply chain. To address this suggestion, this study focused on an intensive agricultural and rapidly urbanizing region of Canada, the Lower Fraser Valley of British Columbia. Seven selected crops, including annual crops such as green peas, sweet corn and potato, and perennial crops that included three berry crops were assessed for their water, both constituent and virtual, as well as embedded energy, protein, and Vitamin C. Annual virtual water losses were higher for sprinkler than drip irrigation, ranging from 82 × 106 kg of water for strawberry to 7570 × 106 kg for blueberry. These high virtual water losses estimated along the food chain confirm the significance of food loss impacts on local water resources. Estimates of losses of food in kg were highest at the consumer level along the food chain and it was estimated that wasted food from the seven crops selected would have supplied the protein and caloric energy of over 33,000 men per year and Vitamin C of about 240,000 men per year. This assessment increases the awareness of food loss impacts from a regional perspective and provides a framework for future research on both environmental and nutritional implications of wasted food.

基于水足迹理论的西北5省(区)水资源评价

基于水足迹理论,对西北甘肃、青海、陕西、宁夏和新疆5省(区)2000-2019年水足迹进行分析和比较,利用水足迹人口密度、水足迹经济效益以及水资源压力指数对水资源现状进行评价,为区域水资源可持续利用提供理论依据。结果显示,研究时段内陕西、甘肃、宁夏和新疆人均水足迹和人均虚拟水足迹均呈现波动增长趋势,青海呈现下降趋势;2019年甘肃、青海、陕西、宁夏、新疆虚拟水足迹作为水足迹的主要贡献者,占比分别为89.48%、86.00%、81.75%、80.88%、75.68%,其中农产品虚拟水占虚拟水足迹最高的是甘肃(71.47%),其次是陕西(65.40%)、新疆(54.30%)、青海(49.93%)、宁夏(49.92%);西北5省(区)水足迹人口密度除青海略有增加以外,陕西、甘肃、宁夏、新疆均表现为波动下降;水足迹经济效益逐年升高,至2019年最高的是陕西(125.88元/m^(3)),其次是宁夏(70.26元/m^(3))、青海(56.11元/m^(3))、甘肃(39.03元/m^(3))、新疆(43.40元/m^(3))。除2019年的宁夏外,其余时段及省(区)的水资源压力指数均小于1;研究时段内新疆、甘肃、宁夏水资源压力指数波动升高,增幅分别为93.58%、71.33%、27.12%;陕西、青海波动下降,降幅分别为5.46%、3.14%。研究表明,西北5省(区)水资源压力总体不高,水足迹经济效益逐年增加,但人均水资源拥有量的不均衡以及居高不下的人均水足迹,说明西北5省(区)水资源的可持续利用能力较弱。