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.     

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.     

Water quality and quantity in Jordan's Dead Sea wadis

An evaluation of a potential water supply for the city of Amman, Jordan was conducted for five tributaries (wadis) to the Dead Sea. The total average discharge of approximately 0.85 m³/s (26.8 million cubic metres (MCM)/year) represents a significant quantity of water given the limited fresh-water supplies in the region. Although the raw water concentrations sometimes exceeded allowable concentrations for metals and pathogens, standard drinking water treatment associated with desalination facilities should alleviate most water quality concerns. The total construction cost is estimated to be between $85 and $95 million. Assuming a 15-year design life, this corresponds to a cost of $0.22/m³. This is feasible compared to alternative water supply options.     

Water Resources Assessment and Regional Virtual Water Potential in the Turpan Basin,China

Located in the centre of the Eurasian Continent, the Turpan Basin, as the second deepest lowland in the world, is extremely short of water resources. Aimed at this key scientific issue, this paper based on years of meteorological and hydrological observation data, carried out a scientific calculation and evaluation of surface and groundwater resources in the Turpan Basin, and then, with the help of modified Penman formula, calculated the virtual water potential in the basin in 2004. The results show that the average total usable surface water resources per year in the last decade were about 6.673×10⁸ m³, while adduction volume of surface water in 2003 was about 4.94×10⁸ m³, which means that most of the region has reached or approached the limit of water resources and, as a result serious crises and constraints on the development of the basin were thus caused. The exploitation content of groundwater in the Turpan Basin in 2003 was about 6.12×10⁸ m³, which has basically reached its upper limit, and the ground water level has fallen about 10~40 m in the Turpan Basin in recent years. The daily reference crop water requirement in the Turpan Basin in 2004 was about 1,053.39 mm, and the total virtual water potential contained in six main crops was about 5.25 ×10⁸ m³ in 2004. All these showed that research works on scientific assessment of water resources and regional virtual water strategy have great significance for the best social, ecological, economic benefits and regional sustainable development of the Turpan Basin.     

Water conservation through trade: the case of Kenya

This study quantifies and maps the water footprint of Kenya from both production and consumption perspectives and estimates the country’s virtual water export and import. Kenya’s virtual water export related to trade in agricultural products was 4.1 km³/y; its virtual water import was 4.0 km³/y. The average export earning per unit of water consumed or polluted in producing agricultural export products was USD 0.25/m³, while the average expenditure on imported commodities per unit of virtual water imported was USD 0.10/m³. In addition to increasing water productivity in crop production, Kenya can mitigate its water scarcity by increasing imports of water-intensive products such as cereals and exports of high-value products such as cut flowers, vegetables, spices and tea.     

Agricultural Multi-Water Source Allocation Model Based on Interval Two-Stage Stochastic Robust Programming under Uncertainty

Numerous uncertainties and complexities exist in the agricultural irrigation water allocation system, that must be considered in the optimization of water resources allocation. In this paper, an agricultural multi-water source allocation model, consisting of stochastic robust programming and two-stage random programming and introducing interval numbers and random variables to represent the uncertainties, was proposed for the optimization of irrigation water allocation in Jiamusi City of Heilongjiang Province, China. The model could optimize the water allocaton to different crops of groundwater and surface water. Then, the optimal target value and the optimal water allocation of different water sources distributed to different crops could be obtained. The model optimized the economic benefits and stability of the agricultural irrigation water allocation system via the introduction of a the penalty cost variable measurement to the objective function. The results revealed that the total water shortage changed from [18.6, 32.3]?×?10⁸ m³ to [15.7, 26.2]?×?10⁸ m³ at a risk level ω from zero to five, indicating that the water shortage decreased and the reliability improved in the agricultural irrigation water allocation system. Additionally, the net economic benefits of irrigation changed from [287.21, 357.86]?×?10⁸ yuan to [253.23, 301.32]?×?10⁸ yuan, indicating that the economic benefit difference was reduced. Therefore, the model can be used by decision makers to develop appropriate water distribution schemes based on the rational consideration of the economic benefit, stability and risk of the agricultural irrigation water allocation system.     

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.     

Water Resources Management under Competitive Sectoral Demand A Case Study from Jordan

Abstract

Jordan is a country plagued with water scarcity. The annual per capita share of water is currently estimated at 170 m³ and the figure is expected to drop to 90 m³ in the year 2020 as a result of the disproportional increase in population relative to water resources development. Moreover, about 70 percent of the country's water resources are consumed in irrigated agriculture. For most crops growing in all areas and seasons and managed with different production technologies, analysis of net return from unit volume of irrigation water showed, with few exceptions, low values pertaining to production under protected agriculture. Such a result indicated unjustified waste of water in the agricultural sector at the expense of the domestic sector. This paper reviews current challenges facing water management in the country and proposes short- and long-term alternative solutions.     

Simulation-Optimization Modeling for Conjunctive Use Management under Hydrological Uncertainty

The canal water supply, which is the only source of irrigation, in the rice-dominated cropping system of the Hirakud canal command (eastern India) is able to meet only 54 % of the irrigation demand at 90 % probability of exceedance. Hence, considering groundwater as the supplemental source of irrigation, conjunctive use management study by combined simulation-optimization modelling was undertaken in order to predict the maximum permissible groundwater pumpage from the command area. Further, optimal land and water resources allocation model was developed to determine the optimal cropping pattern for maximizing net annual return. The modelling results suggested that 2.0 and 2.3 million m³ of groundwater can be pumped from the bottom aquifer during monsoon and non-monsoon seasons, respectively, at 90 % probability of exceedance of rainfall and canal water availability (PERC). Optimal cropping patterns and pumping strategies can lead to about 51.3–12.5 % increase in net annual return from the area at 10–90 % PERC. The sensitivity analysis of the model indicates that the variation in the market price of crops has very high influence on the optimal solution followed by the cost of cultivation and cultivable area. Finally, different future scenarios of land and water use were formulated for the command area. The adoption of optimal cropping patterns and optimal pumping strategies is strongly recommended for sustainable management of available land and water resources of the canal command under hydrological uncertainties.     

Water-saving strategies for irrigation agriculture in Saudi Arabia

Agriculture policy changes in Saudi Arabia are investigated by water footprint (WF) assessment. WF is calculated with the model SPARE:WATER for 3758 irrigated sites. The WF of agriculture areas (WF_area, km³ yr^?1) has decreased (–17%) since the year 2000 to 13.84 km³ yr^?1 (2011), which is mainly caused by the reduction of cropland by –33%. Nevertheless, water consumption per field has increased about 16%, which can be attributed to the cultivation of fodder crops (+12%). A scenario analysis revealed that a shifting cropping pattern towards less fodder crops reduces WF_area by –15%, and implementing improved irrigation technology leads to a combined reduction of up to 32%     

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.     

A High Resolution Assessment of Water Footprint of Wheat to Understand Yield and Water Use Heterogeneity

Efficient water use remains a major challenge globally. Semi-arid regions of the eastern plains of the state of Uttar Pradesh are no different. With stagnating yields and increased input achieving homogeneity in crop yield remains the only way to increase production. Water being the main drive, its judicious use is to be encouraged. Heterogeneity in water usage resulting in yield heterogeneity has to be quantified. It explains the extent of problem. This research conducted at Samrakalwana village at Allahabad reveals that a 36.12 % heterogeneity in water usage results in wheat yield heterogeneity of 44.04 %. Based upon this, management practices can be recommended to the farmers to minimize yield gap. Water footprints for wheat were obtained. The obtained water footprints for wheat were found to vary between 9844 to 2951 l/Kg. The water productivity ranged from 3.88 to 1.01 Tonnes/m³. This huge variation also explains the large heterogeneity is present in utilizing existing water as a resource at the Samrakalwana village.     

Application of Integrated Hydrologic and River Basin Management Modeling for the Optimal Development of a Multi-Purpose Reservoir Project

Multi-purpose reservoir development have been always a big challenge for the management of water resources. This paper describes an integrated approach for investigating catchment hydrology in the development of a hydropower and a canal irrigation system based on model analyses. The investigation aims to adequately determine an optimal domestic and irrigation water resources allocation scheme based on an assessment of the reservoir water balance and capacity for hydropower. The soil and water assessment tool (SWAT) which characterizes basin hydrology and the water management and planning model MODSIM which provides a decision support system for water allocation optimization, were used in this study. The integrated approach was applied to Prek Te River basin in Cambodia. The water demand aspect was examined based on domestic water use, irrigation water, environmental flow, and water losses. An operational rule curve was developed for hydropower operation with respect to a power potential of 13 MW. Hydrologic modeling revealed 90 % dependable water of about 2.7 m³/s during the dry season and 214.3 m³/s during the wet season, indicative of a wet-season dependent reservoir for storage. Results from the 26-years simulation period also showed that diversions for domestic water and irrigation water supply were 92.3 % dependable for a 13 MW capacity hydropower development. The integrated approach was shown to be a valuable decision support tool for water resources management with the determination of an optimum policy for multi-purpose reservoir operation based on available basin water supply.     

Incorporating Virtual Water into Water Management: A British Columbia Example

Virtual water is the water required to produce food or a commodity, and includes rainwater in addition to irrigation and the water required to grow feed in livestock systems. Measuring virtual water is a useful concept in assessing water management as it permits the comparison of crops and livestock from the perspective of embedded water. To evaluate trade-offs in water allocation in countries like Canada with large regional variability in climate, virtual water should be calculated on a watershed scale. Two watersheds in Canada were selected representing wet and dry regions, and virtual water requirements for crop and livestock products were evaluated. For both the Lower Fraser Valley and the Okanagan basins, the results indicate that the most water demanding agricultural activities are livestock and fodder production. In the Lower Fraser basin, berry crops require 32 Mm³ of virtual water per year and have a potential value of $95 million. In contrast, the major fruit crops in the Okanagan require 63 Mm³ of virtual water per year and have a potential value of $95 million. In contrast, the major fruit crops in the Okanagan require 63 Mm³ of virtual water per year and have a potential value of 68 million. Blueberries and grapes which have moderately high virtual water contents have been expanding in the Lower Fraser and Okanagan basins respectively. Water to grow feed dominates overall animal virtual water requirements. Livestock requires nearly 4.5 times more virtual water per year than crops in the Lower Fraser, poultry and dairy having the largest virtual water requirements. In the dry Okanagan basin the total virtual water requirements for crops and livestock are similar. To accommodate future growth, decisions on water management will need to be made, particularly in dry basins such as the Okanagan. Virtual water calculations provide information that can assist decision makers in the strategic choices of reallocation and conservation water use.     

Evaluating the Relative Importance of Groundwater Recharge Sources in a Subtropical Alluvial Plain Using Tracer-Based Ternary End Member Mixing Analysis (EMMA)

In Taiwan’s humid climate, proximal fan groundwater (PFG) is mainly sourced from local precipitation (LP), mountain front recharge (MFR), and mountain block recharge (MBR). This study evaluates the relative importance of the above sources’ respective contributions to the PFG of the Langyang alluvial plain (LAP), northeastern Taiwan. To this end, we first identify stable isotopic characteristics of these target waters and evaluate the hydrological relations among them. Further, we employ ternary end member mixing analysis (EMMA) based on δ ¹⁸O and electrical conductivity to semi-quantitatively calculate contributing fractions and amounts of water for respective LP, MFR, and MBR end members. EMMA results indicate that the respective contribution fractions of LP, MFR, and MBR to PFG at the LAP are approximately 28, 60, and 12 %, respectively. Further, we employ the obtained contribution fractions to understand the corresponding water amounts of each end-member contributed to PFG. In total, 325 × 10⁶ m³ of water recharges PFG annually; of which, 226 × 10⁶ m³/yr. is from MFR, 76 × 10⁶ m³/yr. from LP, and 23 × 10⁶ m³/yr. from MBR. MFR is clearly the greatest source of water at the LAP and local water resource management and protection authorities should concentrate their energies on this important contributor to groundwater. To keep these results in context, limitations to the EMMA approach are evaluated in the text.     

Sediment geochemistry and contributions to carbon and nutrient cycling in a deep meromictic tropical lake: Lake Malawi (East Africa)

The biogeochemical functioning of large tropical lakes differs substantially from temperate lakes, yet remains poorly understood. We characterized the carbon, nitrogen, and phosphorus cycling in the water column and sediments of a deep meromictic tropical Lake Malawi (East Africa) by measuring geochemical distributions and compiling whole-lake geochemical budgets. Four locations (100 to 650 m water depth) were characterized. The results reveal that sediments contribute significantly to lake-wide biogeochemical budgets. Sedimentation rates have significantly increased in recent decades. While the export efficiency of organic matter from photic zone to deep sediments is low (14%), organic carbon is buried in the anoxic sediments with high efficiency (27–46%). Area-specific rates of carbon mineralization (4.1 mmol m^? 2 d^? 1) are similar to those in temperate well-oxygenated large lakes and marine sediments in similar water depths. Ammonium effluxes from sediments (0.44 mmol m^? 2 d^? 1) contribute 29% to the total nitrogen inputs into the water column, while sediment denitrification (0.035 mmol m^? 2 d^? 1) and burial of organic nitrogen (0.27 mmol m^? 2 d^? 1) remove 28% of total inputs in the lake. The recycling efficiency of phosphorus in anoxic sediments is high (73%). P effluxes average 0.037 mmol m^? 2 d^? 1, suggesting a large and previously unquantified contribution (42%) to water column P inputs. The results underscore the importance of sediments in the geochemical budgets of even large lakes and suggest trends in lacustrine carbon cycling that hold across a wide range of environments.     

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。     

Storm Water Harvesting in Saudi Arabia: a Multipurpose Water Management Alternative

This work evaluates the potential for rainwater harvesting at the household level in the dry climate of Saudi Arabia. The amounts of rainwater that can be harvested in several cities in Saudi Arabia were estimated and it was found that a significant volume, exceeding 7.5 m³/100 m² per year, can be harvested. The per cubic meter cost of harvesting rainwater was compared to that of producing desalinated water. It was found that harvested rainwater is cheaper to capture than desalinated water produced from renewable energy-driven desalination plants, but that is not the case for fossil fuel-powered desalination. The study also considered the effects of rainwater harvesting on mitigating floods and reducing greenhouse gas emissions. A cost-benefit analysis of installing rooftop rainwater harvesting systems in Saudi Arabia was performed. It revealed that it is economically feasible to harvest rain in cities including Hail, Jeddah, Taif, and Riyadh, while it is not recommended in the holy cities of Makkah, Medina, and Buraidah.     

The Compensation Mechanism and Water Quality Impacts of Agriculture-Urban Water Transfers: A Case Study in China’s Chaobai Watershed

Water transfer from agriculture to urban uses will likely become increasingly common worldwide. The objectives of this study were to evaluate the effects of converting paddy rice to dry land crops (PPRDC) on local farmers’ income in China’s Chaobai watershed and to analyze the responses of surface water quality to the change in cropping system. An on-site investigation of 485 households and water quality data from 1999 to 2008 are presented in this study. The cost of cultivation as a percentage of the total revenue was 22.3 % for rice and 30.1 % for corn, and the calculated compensation level (CCOM) should be 6172.3 Yuan?ha^?1. PPRDC provided farms with stable income without regard to drought and flood: thus, farmers responded positively to PPRDC, and 76.7 % of farmers expected to continue PPRDC. Inflow water quality was improved in terms of total nitrogen (TN) and nitrate (NO₃–N) because of the reduction in fertilizer and pesticides after PPRDC, but there was no significant change in total phosphorus (TP). PPRDC not only reallocates water resource to different users but also improves water quality through crop adjustment. A dynamic compensation mechanism based on changing crop price is required for the future water transfer project.     

Water Footprint of Grain Product in Irrigated Farmland of China

China faces the dual challenge of grain production pressure and water scarcity. It is significant to reduce water footprint of grain product (WFGP, m³/t) in irrigated farmland. The focus of grain production and agricultural water use, and the precondition is to determine the WFGP and its composition. This paper estimates the WFGP in irrigated farmland of 31 provinces (including municipalities, autonomous regions) a by collecting actual data of 443 typical irrigation districts in 1998, 2005 and 2010, and analyses its temporal and spatial variation in irrigated farmland of China. The result shows that the WFGP in each province decreases with time except in Jiangxi and Hunan, and the average value of all provinces reduced from 1494 m³/t in 1998 to 1243 m³/t in 2010. The WFGP decreases faster in more developed municipal cities and major grain production provinces. The annual average WFGP in irrigated farmland is 1339 m³/t and the blue and green water account for 63.5 % and 36.5 % of the total, respectively. The WFGP and its composition are significantly different between provinces. Generally, provinces distributed inside and beyond Huang-Huai-Hai Plain, have a higher water productivity, lower WFGP and blue water footprint of grain product, while most provinces located in northwest, northeast, southeast and south China have a higher WFGP and lower proportion of green water in the WFGP as a whole. Portion of the blue water footprint (BWFGP) is not consumed for crop evapotranspiration (BWFGP _ET ) but conveyance loss (BWFGP _cl ). The national averaged BWFGP _cl decreases with time and but still remains up to 466 m³/t in 2010, making up 34.8 % of the WFGP. In order to safeguard grain security and ease the water resource pressure, the Chinese government should increase investment and apply advanced technology for developing water-saving agriculture, improve the efficiency of water use and further reduce the WFGP. Considering also the contribution of grain output and the relatively high WFGP, the government should give priority to developing water-saving agriculture in the Northeast of China.