In such an environment a query language will serve for more than "a souped-up version of X-Pointer". Our position focuses on the use of an XML query language as a view definition language that drives XML mediator systems. A mediator selects, restructures and merges information from multiple autonomous sources/sites. It exports an integrated XML view document. Possible applications of such media...

the main objective of this study was to develop an assessment model for the virtual water of irrigation networks using analytical hierarchy process. for this purpose, 14 modern irrigation networks of iran were selected. also, 14 effective factors on the virtual water of these systems were considered as decision criteria. expert choice software was used for ranking the virtual water values of th...

Due to the increase in population, growing urbanization, and higher demands for processed unprocessed foods, resources related food production have become scarce. Water land can be considered as primary determine crop potential of a country. Ideally, countries that lack water import these virtual form. Sri Lanka is country rich faced bankruptcy recently. This study analyzes explores use land–wa...

on one hand, iran due to the low annual rainfall and lack of appropriate spatial and temporal distribution in precipitation is considered as an arid and semi-arid country experiencing stress and water scarcity; on the other hand, 90% of annual water consumption has been allocated to agriculture sector in iran and efficiency and productivity of water consumption do not enjoy favorable status in ...

As a water-scarce country and the world’s largest trader of industrial products, China’s virtual water (VW) flow may exacerbate its scarcity problem. Thus, VW flows’ spatial temporal evolution in international trade should be analyzed, influencing factors must identified. This study developed multiregional input–output (MRIO) model, combined with Leontief inverse matrix, to measure decompose fl...

The inefficient application of water resources has become an urgent problem restricting the world’s sustainable development. Virtual Water Trade opens a new perspective on improving resource utilization efficiency. Based multi-regional input–output model and logarithmic mean Divisia index, virtual flows between 2000–2014 in 43 countries regions have been evaluated, driving forces changes for Eu...

the concept of virtual water trade refers to transact of the water consumed for production of goods and agricultural products through international trade. the anthony allan introduced this concept to improve global water used efficiency. in this paper, the original theory of allen has been investigated through incorporating virtual water as a factor of production in heckscher-ohlin internationa...

fresh water scarcity has become a global problem which needs a serious attempt to find proper solutions for decreasing the pressure on the limited water resources. the exact estimation of crop virtual water would help with choosing crops with high crop and water productivity which lead to both food and water security. thus, in this research, maize virtual water was estimated using hydrus2d base...