The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Zhifu Mi - One of the best experts on this subject based on the ideXlab platform.
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virtual water flow pattern of Grain Trade and its benefits in china
Journal of Cleaner Production, 2019Co-Authors: Zongzhi Wang, Lingling Zhang, Xueli Ding, Zhifu MiAbstract:Abstract Urbanization, industrialization and their associated water shortage pressures have brought great challenges to agricultural development and water security. Understanding the virtual water flow involved in the Grain Trade is critical to ensuring water security and agricultural production. However, there are few studies on the comprehensive benefits provided by virtual water flow in the Grain Trade. This paper proposes a linear optimization model to fill this gap. The model is used to estimate the virtual water flow via interregional Grain Trade within China in 2015 and corresponding benefits to resources, the economy, and the environment from both outflow and inflow comparative perspectives. Three results characterize the virtual water flow pattern of interprovincial Grain Trade in China in 2015: (1) In terms of resource benefit, 31. billion cubic meters of water resources were saved, accounting for approximately 39.7% of the total virtual water flow. (2) A positive economic benefit was realized, with an increase of 6.4 trillion yuan in industrial value added. (3) Certain regions with a high crop green water occupation index account for a considerable proportion of the green water of the local agricultural ecosystem. Simultaneously, massive output of virtual water would aggravate the destruction of terrestrial ecosystems. Finally, the results suggest that promoting the marketization of water resources, improving water productivity, exploring regional compensation mechanisms and improving green water conservation capacity should be considered for water security policies.
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optimization of virtual water flow via Grain Trade within china
Ecological Indicators, 2019Co-Authors: Zongzhi Wang, Lingling Zhang, Xueli Ding, Qing Zhang, Jinwei Wang, Zhifu MiAbstract:Abstract The irrational virtual water flow caused by Grain Trade makes water use efficiency low and further threatens Grain security in China. However, optimizing the Grain virtual water Trade flow from the perspective of the economic value of water resources has rarely been carried out in current research. This paper proposes a linear optimization model considering opportunity cost to fill this gap. The current situation of Grain virtual water Trade is analyzed and we find an irrational Trade mode which quantity and direction of Grain virtual water Trade in some provinces are not consistent with actual demand. Then, opportunity cost is added to the linear optimization model to adjust Grain virtual water Trade which shows several advantages compared to general linear optimization model. Results show that huge virtual flow is generated, up to 1179.24 billion cubic meters of water. And the economic value generated by Grain virtual water Trade can not only cover the transportation cost but can also eventually generate economic benefits of 7410 billion yuan. Finally, the relevant conclusions and implications of adjusting China’s Grain virtual water Trade are obtained.
Bruce L Dahl - One of the best experts on this subject based on the ideXlab platform.
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longer term forecasting and risks in spatial optimization models the world Grain Trade
Transportation Research Part E-logistics and Transportation Review, 2009Co-Authors: Eric A Devuyst, William W Wilson, Bruce L DahlAbstract:This study develops a methodology to quantify risks associated with projected commodity flows in a spatial optimization model. In this paper it is applied to the world Grain Trade which is characteristic of numerous commodities and with complicated and competing logistical channels in world Trade. The model provides a longer-run solution by simultaneously allowing for changes in production patterns, Trade flows, and intermodal, interport and inter-reach allocation of shipments. Results show that important factors affecting shipments include: changes in demand across countries, delay costs, and the increased domestic use of Grains. Findings of interest show delay costs on barges shift movements to rail, other origins and ports. Second, there is much greater uncertainty for projections for more distant periods forward. Finally, the model can be applied similarly to other commodities and/or be used to analyze spatial flows concentrated in other geographic regions.
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fundamental factors affecting world Grain Trade in the next two decades
Agribusiness & Applied Economics Report, 2005Co-Authors: William W Wilson, Richard D Taylor, Bruce L DahlAbstract:Changes are occurring in the world Grain Trade that are impacting the spatial distribution of Grain flows. Important amongst these are developments in ethanol production in the United States, soybean production in Brazil, and increased imports of soybeans for China. This article develops a spatial optimization model based on a longer-term competitive equilibrium to make projections in the world Grain Trade and shipments from individual ports to the year 2025. Results indicate that world Trade should increase by about 47%, with the fastest growth occurring in imports to China and Pakistan. Japan and the EU, traditionally large markets, have the slowest growth. Most of the increases are expected in soybeans (49%), followed by corn (26%), and most of the U.S. export growth is expected through the U.S. Gulf.
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long term forecasting of world Grain Trade and u s gulf exports
Transportation Research Record, 2005Co-Authors: William W Wilson, Richard D Taylor, Bruce L DahlAbstract:Important changes occurring in the world Grain Trade will affect the spatial distribution of Grain flows and affect large-scale transportation projects. Most important among these are developments in ethanol and in Brazil and China. This paper develops a spatial optimization model based on a long-term competitive equilibrium to make projections in the world Grain Trade and shipments from individual ports to 2025. Results indicate that world Trade should increase by about 47%, with the fastest growth occurring in imports to China and Pakistan and the slowest growth in Japan and the European Union, traditionally large markets. Most increases in terms of volume are expected in soybeans (49%), followed by corn (26%). Most of the U.S. export growth is expected through the barge system to U.S. ports on the Gulf of Mexico, with negligible growth through the Pacific Northwest and lakes. Although a multitude of reasons explain this expected trend, one is the growth in ethanol concentrated in the western states, wh...
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Reciprocal Access in U.S./Canadian Grain Trade Background Issues for the U.S. Grain Trade *
1998Co-Authors: William W Wilson, Bruce L DahlAbstract:The purpose of this paper is to review past Trade relations in the Grains sector between the United States and Canada and to document Trade barriers and the potential for the evolution of reciprocal Trade. Historical Trade flows between the United States and Canada in the Grains sector are reviewed. Terms of recent Trade agreements and other Trade restrictions are described. Then, some of the important differences in the marketing system are described and compared as well as changes in the Canadian Grain marketing system. Finally, the concept of reciprocal access is developed in the context of the evolving trading relations between these two countries.
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reciprocal access in u s canadian Grain Trade background issues for the u s Grain Trade
AE Series, 1998Co-Authors: William W Wilson, Bruce L DahlAbstract:The purpose of this paper is to review past Trade relations in the Grains sector between the United States and Canada and to document Trade barriers and the potential for the evolution of reciprocal Trade. Historical Trade flows between the United States and Canada in the Grains sector are reviewed. Terms of recent Trade agreements and other Trade restrictions are described. Then, some of the important differences in the marketing system are described and compared as well as changes in the Canadian Grain marketing system. Finally, the concept of reciprocal access is developed in the context of the evolving trading relations between these two countries.
Consuelo Varelaortega - One of the best experts on this subject based on the ideXlab platform.
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are virtual water flows in spanish Grain Trade consistent with relative water scarcity
Ecological Economics, 2009Co-Authors: Paula Novo, Alberto Garrido, Consuelo VarelaortegaAbstract:Virtual water adds a new dimension to international Trade, and brings along a new perspective about water scarcity and water resource management. Most virtual water literature has focused on quantifying virtual water "flows" and on its application to ensure water and food security. Nevertheless, the analysis of the potential gains from international Trade, at least from a water resources perspective, needs to take into account both spatial and temporal variations of blue (groundwater and stream flow) and green (soil moisture) water, as well as the socioeconomic and policy conditions. This paper evaluates whether Spanish international Trade with Grains is consistent with relative water scarcity. For this purpose, the study estimates the volume and economic value of virtual water "flow" through international Grain Trade for the period 1997-2005, which includes 3years with different rainfall levels. The calculations show that Spain is a net virtual water "importer" through international Grain Trade. The volume of net virtual water "imports" amounts to 3420, 4383 and 8415million m3 in wet (1997), medium (1999) and dry (2005) years, respectively. Valuing blue water at its shadow price or scarcity value, blue water "exports" oscillate between 0.7 and 34.2million Euros for a wet and dry year, respectively. Overall, Grain Trade is apparently consistent with relative water scarcity as net imports increase in dry years. However, the evolution of Grain exports, expressed as a variation in quantity and volume, does not match the variations in resource scarcity. A disaggregated crop analysis reveals that there are other factors, such as quality, product specialization or the demand for a standardized product, which also influence Trade decisions and are not included in the notion of virtual water. These facts, among others, can therefore create potential distortions in the application of virtual water to the analysis of specific Trade patterns. Nevertheless, from a water resources perspective, virtual water can bring important insights across countries for improving water and land management globally, fostering adaptation strategies to climate change and to transboundary resource management.
Zongzhi Wang - One of the best experts on this subject based on the ideXlab platform.
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virtual water flow pattern of Grain Trade and its benefits in china
Journal of Cleaner Production, 2019Co-Authors: Zongzhi Wang, Lingling Zhang, Xueli Ding, Zhifu MiAbstract:Abstract Urbanization, industrialization and their associated water shortage pressures have brought great challenges to agricultural development and water security. Understanding the virtual water flow involved in the Grain Trade is critical to ensuring water security and agricultural production. However, there are few studies on the comprehensive benefits provided by virtual water flow in the Grain Trade. This paper proposes a linear optimization model to fill this gap. The model is used to estimate the virtual water flow via interregional Grain Trade within China in 2015 and corresponding benefits to resources, the economy, and the environment from both outflow and inflow comparative perspectives. Three results characterize the virtual water flow pattern of interprovincial Grain Trade in China in 2015: (1) In terms of resource benefit, 31. billion cubic meters of water resources were saved, accounting for approximately 39.7% of the total virtual water flow. (2) A positive economic benefit was realized, with an increase of 6.4 trillion yuan in industrial value added. (3) Certain regions with a high crop green water occupation index account for a considerable proportion of the green water of the local agricultural ecosystem. Simultaneously, massive output of virtual water would aggravate the destruction of terrestrial ecosystems. Finally, the results suggest that promoting the marketization of water resources, improving water productivity, exploring regional compensation mechanisms and improving green water conservation capacity should be considered for water security policies.
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optimization of virtual water flow via Grain Trade within china
Ecological Indicators, 2019Co-Authors: Zongzhi Wang, Lingling Zhang, Xueli Ding, Qing Zhang, Jinwei Wang, Zhifu MiAbstract:Abstract The irrational virtual water flow caused by Grain Trade makes water use efficiency low and further threatens Grain security in China. However, optimizing the Grain virtual water Trade flow from the perspective of the economic value of water resources has rarely been carried out in current research. This paper proposes a linear optimization model considering opportunity cost to fill this gap. The current situation of Grain virtual water Trade is analyzed and we find an irrational Trade mode which quantity and direction of Grain virtual water Trade in some provinces are not consistent with actual demand. Then, opportunity cost is added to the linear optimization model to adjust Grain virtual water Trade which shows several advantages compared to general linear optimization model. Results show that huge virtual flow is generated, up to 1179.24 billion cubic meters of water. And the economic value generated by Grain virtual water Trade can not only cover the transportation cost but can also eventually generate economic benefits of 7410 billion yuan. Finally, the relevant conclusions and implications of adjusting China’s Grain virtual water Trade are obtained.
Yubao Wang - One of the best experts on this subject based on the ideXlab platform.
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evaluating drivers and flow patterns of inter provincial Grain virtual water Trade in china
Science of The Total Environment, 2020Co-Authors: Haiyang Qian, Bernard A Engel, Xiaoyu Tian, Pute Wu, Yubao WangAbstract:Abstract China’s food security is facing serious threats because the virtual water triggered by Grain Trade flows from the water-scarce north region to the water-rich south region in recent years. Thus, quantitatively evaluating Grain virtual water flow is increasingly important. We established a multi-objective linear optimization model based on analyzing drivers of Grain Trade by the entropy method, and the two drivers of transport cost and Grain consumption structure between provinces were analyzed. The results show that the virtual water flow of inter-provincial Grain Trade of China was 98.38 Gm3 in 2015, accounting for 15% of the total water consumption of Grain production. The impact weights of Grain transportation cost and difference of Grain consumption structure between provinces on virtual water flow were 0.665 and 0.335, respectively. Although the production and consumption of Grain in northern region were almost the same, the virtual water imbedded in Grain Trade still flowed from the north to the south under the influence of Grain imports from abroad and Grain consumption structure. Compared to previous methods, the model added the principle of the entropy method into linear programming analysis. This innovative model not only quantitatively evaluated the driving forces of Grain Trade through the weight coefficient, but also established a universal model of quantifying Grain virtual water flow. Moreover, we reduced data assumptions, such as not considering actual Grain imports and transport modes of Grain, which improves the credibility of quantitative results. The model quantified virtual water from the perspective of driving impacts and precluded the limitations of Trade data. The model can be used in other countries and regions, where Trade data is difficult to obtain, to calculate Trade patterns. The results are useful for decision makers to implement virtual water strategies, mitigate national water scarcity, and facilitate sustainable development of Grain production.
