Bilateral virtual water trade in agricultural products: a case study of Germany and China

Most studies in the field of virtual water trade concentrate either on the global, national or sub-national level, or on the water footprint of individual products. This article assesses the virtual water trade in agricultural products between Germany and China during the period 2008–2010. Germany exported 192 million m³ of virtual water to China and imported 801 million m³ from China. Through the bilateral trade, Germany saved 69.8 million m³ water, while China had a net water loss of 469.4 million m³. Thus, the global water loss amounts to 399.6 million m³.     

济南市部分农作物产品虚拟水含量的研究

基于虚拟水的理论,利用标准彭曼公式和Cropwat软件,对济南市2008年的部分农作物产品虚拟水含量进行了计算分析。结果表明:小麦的虚拟水净进口量为-77477.9×103m3,属于虚拟水出口型作物,稻谷、棉花、豆类和花生果的虚拟水净进口量都是正值,属于虚拟水进口型作物。但总的来说,虚拟水的出口大于进口,这直接危及到济南市的水资源安全。针对这一现状,提出了通过虚拟水贸易和调整农作物种植结构的途径来实现济南市水资源的安全和可持续利用发展。     

Domestic water access and pricing in urban areas of Mozambique: between equity and cost recovery for the provision of a vital resource

This article first presents the urban domestic water access situation in Mozambique. Then it analyzes the country's tariff system as a tool to recover water supply costs and to secure equity and affordability for the urban households served. The analysis focused on those households with in-dwelling water access (less than 50% of the urban population in Mozambique). Urban families using 5 m³, 10 m³, and 15 m³ of in-dwelling piped water per month pay an average of USD 0.86, 0.74, and 0.76 per m³, respectively. At the national level, cost recovery is an issue because in most urban areas operation and maintenance costs are not fully covered. The average coverage ratio for the country is 0.85. The presented figures indicate that a revision of the water tariffs currently applied in Mozambique could help improve equity, affordability and cost recovery.     

Economic Value of Tree Fruit Production in Jordan Valley from a Virtual Water Perspective

The continuous high demand of water resources for agricultural uses in Jordan is leading to a water crisis. A possible partial solution may be to import food which requires large amounts of water to grow instead of cultivating high water consuming crops. Crops such as banana and citrus cause a huge virtual water loss, which can be reduced by cultivating other less water-demanding crops. This paper focuses on analyzing the economic value of cultivating tree fruit from a virtual water perspective. The virtual water calculations in this study depend on the average rainfall, water quota, and the crops’ water requirements (CWR). The gross profit to the water use ratio showed that banana has the lowest value 0.085 JD/m³, while lemon has the highest value 1.65 JD/m³. The calculations show that the average embedded water in fruits varies from about 470 m³/ton for grapes to about 2,500 m³/ton for dates. Banana and citrus plantations consume about 21 and 71 million cubic meters (MCM) annually, respectively, which represent about 85% of the total water consumption in fruit tree plantation. The virtual water flow estimation embedded in fruits shows that Jordan imports about 77 MCM per year. However it exports about 29 MCM per year. The results were analyzed from an integrated water resources management (IWRM) perspective. The analysis shows that a way to recover some of the water costs involved in, e.g., banana production would be to increase the fertilizer cost by about 10%. This would double the water cost and increase the banana production cost by about 6.8%. Using this alternative could be a way to better manage the huge losses in virtual water involved in banana production in the Jordan Valley.     

Exporting water from the desert? An analysis of the virtual water content of Saudi Arabian agricultural exports

This study applies input-output analysis to evaluate and trace Saudi Arabia’s virtual water exports arising from exports of agricultural products. Saudi Arabia’s total virtual exports in 2011 were around 2.42 km³, mainly to neighbouring Arab countries. This amount is enough to meet the water demand of the country’s entire population. Agricultural exports seem economically beneficial only because they rely on groundwater; however, since the indirect cost of desalinating equivalent amounts of water for domestic purposes is much higher, a better strategy would have been to direct those water resources towards domestic needs.     

黄河流域粮食生产水足迹及虚拟水流动影响评价EI北大核心CSCD

为分析黄河流域粮食生产用水的可持续性,引入水足迹和虚拟水相关理论方法,对研究区主要粮食生产水足迹及粮食贸易伴生的虚拟水流动格局进行了量化解析,并对未来粮食生产水足迹进行了预估。结果表明:2011—2016年,全流域粮食生产总水足迹和单位水足迹分别由460亿m^(3)和1.20 m^(3)/kg降为402 m^(3)和0.93 m^(3)/kg,均呈下降趋势;从粮食贸易伴生的虚拟水流动特点来看,流域全口径粮食虚拟水从2011年的110.7亿m^(3)减小到2016年的50.3亿m^(3),呈输入态势;除稻谷之外的粮食虚拟水由82.6亿m^(3)增加到193.4亿m^(3),呈输出态势;在流域不同气候情景下,2035年粮食生产总水足迹为481.9亿~518.7亿m^(3),其中绿水足迹增幅达20%,而蓝水足迹增长不显著;未来流域内粮食输出量的增加会进一步加剧本地农业生产的用水矛盾,但粮食灌溉总用水量的增速可能放缓。     

Impact of planned water resource development on current and future water demand in the Koshi River basin,Nepal

The water resources of the Koshi Basin (87,311 km²) are largely untapped, and while proposals for their development exist, their impacts on current and future water demand are not quantified. The current study is the first to evaluate the impacts of 11 proposed development projects for hydropower generation and water storage. We find that 29,733 GWh of hydropower could be generated annually and 8382 million m³ of water could be stored. This could satisfy unmet demand in the current (660 million m³) basin situation and in future scenarios – i.e. population, agricultural and industrial growth – that are projected to have 920, 970 and 1003 million m³ of unmet demand, respectively, by 2050.     

Measuring the Economic Benefits of the Tap Water Supply Service in Urban Areas: The Case of Korea

This paper attempts to measure the economic benefits of tap water supply services in some urban areas of Korea. According to micro-economic theory, the economic benefit of water consumed is the sum of the actual water price and the additional willingness to pay (WTP) for the consumption. We apply the dichotomous choice contingent valuation method to assess the additional WTP using specific cases of four cities located in the metropolitan area of Korea. Both parametric and non-parametric approaches to obtaining the mean WTP estimates are used. The results show that the mean additional WTP for the tap water supply service is estimated to be KRW 163.38 (USD 0.13) and KRW 223.89 (USD 0.18) per m³ using parametric and non-parametric approaches, respectively. Given that the price of tap water is 641.66 per m³, the residents’ economic benefits that ensue from the tap water supply service are computed as KRW 805.04 (USD 0.63) and KRW 865.55 (USD 0.68) per m³, respectively. This information can be beneficially utilized in conducting an economic feasibility study for a new project related to tap water supply service.     

Role of Virtual Water in Optimizing Water Resources Management in Jordan

Role of virtual water (VW) in optimizing water resources management in Jordan, a far water-short country, was explored by calculating VW content of imported commodities and their costs. Feasibility of farming and water required to produce all crops growing in Jordan were evaluated using net return per unit volume of water and VW embedded in unit mass of production. The results of these analyses showed that there were regional differences in crop profitability and thus net return from unit volume of irrigation water. This was attributed to variations in agro-climatic zones punctuated by production and irrigation technologies and access to water resources. In this regard, opportunity cost of water should be considered when allocating water to different consumption sectors. Agricultural systems generating net profits less than an arbitrary limit of $1.0?m^?3 of irrigation water and producing yield at water use efficiency of 50?C60?m³?ton^?1 or more were viewed not feasible. The key challenge facing decision makers would be to ensure that the opportunity cost of water was incorporated into the analysis process when determining future cropping pattern. Such a cost of water should be combined with crop-embedded VW analysis and expected net return from unit volume of irrigation water. Therefore, water allocation mechanism (e.g. water market) need to be developed for more efficient water use than the commonly practiced farm quota. Optimization of the usage of the limited water resources can be envisaged by continuous imports of VW, especially that embedded in cereal, oil, meat, live animals and sugar. Appropriate amendment of water legislations and concerned institutions are encouraged to provide better guidelines to policy makers, water managers, extension and advisory services, water use associations and farmers. Optimization of water resources management could be based on contract farming to ensure that water allocation and cropping pattern respond to water scarcity. Furthermore, Jordan should concentrate on production and export of crops having low VW contents and high return per m³.     

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).     

基于通径分析的海河流域冬小麦水足迹及影响因素

为量化冬小麦对水资源的消耗、合理利用区域水资源,基于彭曼公式、日尺度土壤水量平衡与通径分析法核算了1958—2016年海河流域冬小麦水足迹,分析了气象、农业生产投入因素对冬小麦水足迹的直接和间接影响。结果表明:流域冬小麦多年平均总水足迹为239. 6亿m3,平均水足迹为1 840 m3/t;海河流域冬小麦水足迹呈整体下降趋势,空间上京津地区最高,山西次之,山东、河南地区最低;农业机械总动力、化肥施用折纯量对冬小麦水足迹直接影响最大;气象因素主要通过农业生产投入因素对冬小麦水足迹产生影响。可通过提高农业生产力的方式降低冬小麦水足迹,京津等灰水足迹较高的地区应减少施肥。     

Facing Water Scarcity in Jordan

Abstract

Jordan is extremely water-scarce with just 167 m³ per capita per year to meet domestic, industrial, agricultural, tourism, and environmental demands. The heavy exploitation of water resources has contributed to declines in the levels of aquifers and the Dead Sea. Rapid growth in demand, particularly for higher quality water for domestic, industrial, and tourism uses, is significantly increasing pressure on agricultural and environmental uses of water, both of which must continue to adapt to reduced volumes and lower quality water. The agricultural sector has begun to respond by improving irrigation efficiency and increasing the use of recycled water. Total demand for water still exceeds renewable supplies while inadequate treatment of sewage used for irrigation creates potential environmental and health risks and presents agricultural marketing challenges that undermine the competitiveness of exports. The adaptive capability of the natural environment may already be past sustainable limits with oasis wetlands having been most seriously affected. Development of new water resources is extremely expensive in Jordan with an average investment cost of US$4 to $5 per cubic meter. This paper examines four integrated water resources management (IWRM) approaches of relevance to Jordan: water reuse, demand management, energy-water linkages, and transboundary water management. While progress in Jordan has been made, the Ministry of Water and Irrigation continues to be concerned about the acute water scarcity the country faces as well as the need to continue working with concerned stakeholders to assure future water supplies.     

Managed aquifer recharge using quaternary-treated wastewater: an economic perspective

An excess of 31 million m³/y of tertiary-treated wastewater is expected in Muscat, Oman, by 2015. This paper addresses the technical and cost estimation of managed aquifer recharge after reverse-osmosis treatment. The results indicate that the project is appealing from an economic perspective. The total cost varies between USD 0.353 and USD 0.550 per cubic metre, depending on the cost of electricity, the interest rate and the life span of the project. The project may face rejection from domestic users, who may be unwilling to accept mixing treated wastewater with the current water supply due to health risks. An alternative to indirect potable reuse is the installation of a separate network to service industrial users.     

辽宁省春玉米生产水足迹的时空变化研究

为降低农业生产活动中农作物对水资源的高消耗,提高用水效率,借助辽宁省1987—2018年19个气象站点逐日气象数据及春玉米产量数据,全面计算绿水足迹、蓝水足迹及灰水足迹的真实消耗。结果表明：（1）辽宁省春玉米生产水足迹自2002年起变化幅度不明显,多年平均值是1424.21 m³/t,其中绿水足迹占54%,灰水足迹占27%,蓝水足迹占19%。（2）从绿水足迹看,辽宁省春玉米绿水足迹每年以6.28 m³/t速率减少,空间分布上2002年绿水足迹高值区主要集中在东部地区;2010年辽宁省整体绿水足迹较高。（3）从蓝水足迹看,每年以1.06 m³/t的速率增长;2002年辽宁春玉米蓝水足迹高值区主要分布在环渤海、宽甸及其周围地区;2010年,辽宁省大部分地区蓝水足迹较低。（4）灰水足迹整体以每年14.03 m³/t的速率降低,主要与农作物产量及氮肥施用量相关。     

Changes in the Coastline and Water Level of the Akşehir and Eber Lakes Between 1975 and 2009

The Ak?ehir and Eber Lakes, relatively shallow, small freshwater lakes with an area of 361 km² and 150 km² and average depth of 7 m and 2 m (1998), respectively in southwestern Turkey, have experienced a severe decline in water levels in recent decades. This study aimed to investigate coastline and water level changes of lakes and identify the causes for the decline in lake levels. Nine Landsat images from different times, monthly temperature, precipitation, discharge, lake level records and population data were used to analyze these changes. From 1975 to 2009, the water surface areas of the Ak?ehir and Eber Lakes decreased from 356,929 to 126,482 km² and from 119,882 to 85,663 km², a loss of 64.5% and 28.4% over the 34-year period, respectively. From 1975 to 2004, the Ak?ehir Lake level declined by 2.67 m from 956.02 m to 953.35 and the Eber Lake level declined by 2.03 m from 966.75 m to 964.72 m from 1975 to 2004 based on ground lake level data (in situ). The results of the temperature and precipitation analysis showed that although the annual mean climatic factors vary substantially, they show small increasing trend over the record periods. Annual discharge records on the Akarçay River and its tributaries decreased over the basin during the same period. Irrigation systems, three dams and seven pounds built in recent decades for agricultural irrigation and domestic use, made the major impact on lowering the lake levels because they derive water from the river for human use upstream of the lakes’ catchments. Population growth, rising water consumption for agricultural and domestic purposes and building dams has led to lake levels declining. The change of lake levels might depend more on anthropogenic factors than on climatic factors.     

唐山市2007年农产品虚拟水测评与分析

虚拟水是指生产商品和服务所需要的水资源数量。本文简要介绍了虚拟水含量的计算方法,同时根据唐山市的实际情况和统计资料,计算了唐山市2007年主要农产品单位质量的虚拟水含量、生产产品的虚拟水含量和城乡居民消费的虚拟水含量,结果表明:唐山市2007年生产产品的虚拟水含量为134.22亿m3,城镇居民和农村居民全年消费的虚拟水数量分别为24.76亿m3和19.96亿m3,全社会全年消费的虚拟水数量为44.72亿m3,实际生产产品的虚拟水含量远远大于各项消费的总虚拟水含量。     

2002-2015年西北地区陆地水储量时空变化特征

在干旱—半干旱地区,陆地水是经济社会发展的重要水源。本文利用高斯平滑滤波处理的2002—2015年逐月GRACE卫星时变重力场数据,反演了西北地区陆地水储量变化。结果表明：在时间上,西北地区陆地水储量总体呈现下降趋势,每月减少0.014 cm,相当于每年减少53.5亿m³。在空间上,2002—2015年间陆地水储量减少区域约为224万km²,增加区域约为106万km²。各地区陆地水储量呈现明显的季节变化,7月达到年内最大值,陆地水储量处于盈余状态;冬、春季节为年内的低值区,陆地水储量处于亏损状态;陆地水储量的变化与降雨季节变化一致,表明西北地区降水是最重要的陆地水来源。     

Economic Value of Water in the Korean Manufacturing Industry

Water is important to manufacturing firms because industrial water is used for a variety of purposes as one of the most important inputs in the production process. This paper estimates the economic value of water in the Korean manufacturing industry by employing the concept of the value of marginal product (VMP). We use data on 53,912 factories surveyed in 2003 and consider two types of production functions: the Cobb-Douglas and trans-log functions. The specification test revealed that the trans-log function was more appropriate for estimating the data. The industry-wide output elasticity and VMP of industrial water were estimated to be 0.0104 and KRW 1,156 (USD 1.05) per m³, respectively. The estimated VMP ranged from KRW 428 (USD 0.39) per m³ for the precision instrument sector to KRW 13,760 (USD 12.51) per m³ for the transportation equipment sector, indicating that the VMP varies across sectors. The results have important implications for various areas of industrial water management. Any cost-benefit analysis of new projects providing industrial water requires information on the economic value of industrial water. Moreover, such information is required for determining the ways in which scarce water resources could be distributed to various sectors.     

Effectiveness of Rainwater Harvesting in Runoff Volume Reduction in a Planned Industrial Park,China

It is urgent to effectively mitigate flood disasters in humid mountainous areas in southeastern China for the increasing flood risk under urbanization and industrialization. In this study, a rural district with an area of 13.39 km² that planning to build an industrial park covering an area of 7.98 km² in Changting was selected to estimate the potential of collectable rainwater and the extent to which runoff volume can potentially be mitigated by rainwater harvesting. In addition, the optimum cistern capacity of a rainwater harvesting system in the planned industrial park was evaluated using daily water balance simulation and cost-efficiency analysis. The results showed that rainwater harvesting in the planned industrial park has great potential. The annually collectable rainwater is approximately 9.8?×?10⁶ m³ and the optimum cistern capacity is determined to be 0.9?×?10⁶ m³. With the optimum cistern capacity, the annual rainwater usage rate is 0.99, showing neither financial savings nor deficits. Rainwater harvesting can reduce 100 % of runoff volume in the cases of critical rainfall storm (50 mm) and annual average maximum daily rainfall (111.2 mm), and 58 % of runoff volume in the case of maximum daily rainfall (233.6 mm), respectively. All surface runoff can be collected and stored in the cisterns when rainfall amount is less than 135.5 mm in a rainstorm event.     

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.