虚拟水贸易及其作用

水安全和粮食安全是我国社会发展的关键,而虚拟水同时连接着粮食和水资源.本文应用机会成本和比较优势理论阐述虚拟水贸易,同时详细阐述了粮食安全与国家安全、经济增长、生活质量的提高之间的关系.在此基础上.提出了我国在进行虚拟水贸易时应考虑虚拟土地、虚拟技术、虚拟劳动力以及虚拟资金等因素.本文对国家多目标的评价、国际交易利润的计算和有限资源的使用提供了有效的理论依据.     

虚拟水研究综述

虚拟水是指社会生产和服务所需要的水资源数量。这一概念是随着水资源商品化和资源配置全球化的变化而提出来的,一些缺水国家或地区必须通过贸易的方式从富水国家或地区购买水密集型产品,尤其是粮食来获得本地水资源和粮食的安全。文章主要论述虚拟水战略的概念和内涵,阐述产品虚拟水的量化方法,在分析国内外研究进展的基础上,预测以后的研究方向。     

虚拟水贸易在解决中国和全球水危机中的作用

水资源短缺已经威胁到中国一些地区的社会经济发展和生态安全,经济的发展将会进一步加剧水危机。近年来,农产品贸易中的虚拟水引起了全世界的关注,被看做是一种缓解水资源压力的手段。本文利用虚拟水的概念和方法分析了中国1996～2001年间的粮食贸易,发现:这些年间中国通过粮食贸易净进口了3.28×1 010m3虚拟水;通过粮食进口,中国相当于节省了1.86×1011 m3的水资源;中国的粮食贸易由于基本符合水利用效率的比较优势,因而给全球节省了1.01×1011m3的水资源。中国通过虚拟水贸易不能完全解决国内水危机问题,但是可以节省国内水资源,缓解农业区的水危机状况,提高全球水资源利用效率。尽管当前中国采取虚拟水进口策略会遇到很多问题,但是虚拟水的概念给我们理解粮食贸易和调水工程提供了全新的角度。     

虚拟水贸易及其影响因素研究

由于水资源的分布不均和大量消耗,水资源短缺成为很多国家和地区经济社会发展的约束。虚拟水贸易作为一种解决水资源短缺的方式被提出,成为水资源研究领域的热点。以农产品的国际贸易为主体的虚拟水国际贸易也不仅仅涉及水资源的平衡问题,还涉及到很多政治、经济等因素。本文从政治、经济、社会、生态四方面对虚拟水贸易的影响因素进行分析,从而对虚拟水贸易展开研究。     

虚拟水贸易及其影响因素研究

由于水资源的分布不均和大量消耗,水资源短缺成为很多国家和地区经济社会发展的约束。虚拟水贸易作为一种解决水资源短缺的方式被提出,成为水资源研究领域的热点。以农产品的国际贸易为主体的虚拟水国际贸易也不仅仅涉及水资源的平衡问题,还涉及到很多政治、经济等因素。本文从政治、经济、社会、生态四方面对虚拟水贸易的影响因素进行分析,从而对虚拟水贸易展开研究。     

虚拟水及其在缓解区域水资源短缺中的应用研究

虚拟水是指生产商品和服务所需要的水资源数量。虚拟水战略是指贫水国家或地区通过贸易的方式从富水国家或地区购买水密集型农产品(粮食)来获得本地区水和粮食的安全。本文在综述前人对虚拟水研究的基础上,计算了2002年甘肃省及不同地区主要农产品虚拟水含量,并对甘肃省加强虚拟水贸易的战略进行了探讨。     

我国粮食的虚拟水贸易探究

水足迹和虚拟水是当前国际水资源领域研究的热点问题,被称为当前测度人类活动水资源系统环境的最好指标。文章通过对1992年至2008年,我国粮食五种代表作物的虚拟水贸易作简要的叙述和分析,从虚拟水贸易的角度用比较优势的理论探讨我国的粮食贸易。     

基于投入产出法的浙江省虚拟水贸易实证分析

基于"虚拟水"理论,利用2005年和2007年浙江省的投入产出表(延长表)和各产业部门的用水数据,采用投入产出分析法构建价值型-实物型水资源投入产出模型,计算并分析了2005年和2007年浙江省各产业部门的虚拟水贸易量。结果表明:浙江省通过商品贸易向他省和国外输出的虚拟水主要集中在纺织、缝纫及皮革产品制造业和机械设备制造业;通过商品贸易向省内输入的虚拟水集中在农业、化学工业、金属冶炼及加工制造业、采掘业和食品制造和烟草加工业;从虚拟水贸易结构来看,农业和重工业为净输入虚拟水贸易行业,轻工业为净输出虚拟水贸易行业。     

基于虚拟水理论的泰州市农业可持续发展研究

水资源有着明显的稀缺性,一个区域经济的发展与水资源有着密切的联系,目前虚拟水理论作为水资源管理领域提出的新概念,对如何利用好水资源为区域经济发展提供了新思路。基于虚拟水理论对泰州市2012年水足迹进行了计算分析,其结果表明泰州社会经济发展中水资源利用并不乐观,只有尽快实施虚拟水战略、改变消费模式、提高水资源利用率,才能尽快实现泰州经济转型和农业可持续发展。     

基于虚拟水理论的西安水资源利用评价

水资源问题已成为世界普遍关注的问题,其根本原因就在于它不仅影响、制约现代社会的可持续发展,而且成为本世纪全球资源环境的首要问题,直接威胁人类的生存和发展。文章引用虚拟水理论,计算了2011年西安的水足迹状况,并对西安市的水资源相关指标进行分析。结果表明西安市2011年的水足迹为57.66×108m3,人均水足迹为677.28m3·a,水资源自给率为0.504,水资源压力指数为174.3%,说明西安市水资源严重短缺,高虚拟水进口依赖度会给西安的经济发展带来巨大的压力。     

The water footprints of Morocco and the Netherlands: Global water use as a result of domestic consumption of agricultural commodities

The volume of international trade in agricultural commodities is increasing faster than the global volume of production, which is an indicator of growing international dependencies in the area of food supply. Although less obvious, it also implies growing international dependencies in the field of water supply. By importing food, countries also import water in virtual form. The aim of the paper is to assess the water footprints of Morocco, a semi-arid/arid country, and the Netherlands, a humid country. The water footprint of a country is defined as the volume of water used 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 shows that both Morocco and the Netherlands import more water in virtual form (in the form of water-intensive agricultural commodities) than they export, which makes them dependent on water resources elsewhere in the world. The water footprint calculations show that Morocco depends for 14% on water resources outside its own borders, while the Netherlands depend on foreign water resources for 95%. It is shown that international trade can result in global water saving when a water-intensive commodity is traded from an area where it is produced with high water productivity to an area with lower water productivity. If Morocco had to domestically produce the products that are now imported from the Netherlands, it would require 780 million m³/year. However, the imported products from the Netherlands were actually produced with only 140 million m³/year, which implies a global water saving of 640 million m³/year.     

基于主要国家截面数据的虚拟水进口影响因素实证分析

基于39个主要国家的截面数据,选取反映资源、经济、制度、人口四个因素的11个变量,采用逐步回归分析方法对影响虚拟水进口量的因素进行实证分析。回归结果表明,国际储备、人均国内生产总值、耕地面积、粮食单产4个变量对虚拟水进口量具有显著影响且均具有正向效应。     

Water trade in Andalusia. Virtual water: An alternative way to manage water use

The main idea of this paper is to analyse the relationships between the productive process and the commercial trade with water resources used by them. For that, the first goal is to find out, by means of the estimation of virtual water, the exported crops which have the highest water consumption. Similarly, we analyse the crops that are imported and therefore, might contribute to save water. The second objective is to put forward new ways to save water by means of the virtual water trade.This first conclusion contradicts not only the comparative advantages theory but also the environmental sustainability logic. The previous conclusion is derived from the great exports of water via potatoes and vegetables, and also via citrus fruit and orchards; and, on the other hand, from the imports, such as cereals and arable crops, with lower water requirements. The second conclusion affirms as Andalusia utilises large amounts of water in its exports, and in turn, it does not produce goods with low water requirements, the potential saving would be very significant if the terms of our trade were the other way round. We are convinced that the agricultural sector must modify the use of water to a great extent in order to reach significant water savings and an environmental sustainability path.     

基于虚拟水视角的东北粮食作物发展战略分析

本文主要研究我国东北地区主要粮食作物的虚拟水含量以及东北三省的虚拟水流量,一方面旨在为东北地区粮食作物的布局和贸易战略调整提供依据,另一方面也为我国粮食安全和水安全的宏观调控提供政策依据。本文基于联合国粮农组织提供的CropWat软件以及ClimWat数据库来计算粮食作物虚拟水含量,采用联合国教科文组织水资源教育研究院提供的虚拟水相关公式来计算虚拟水流量,得出了东北三省五种主要粮食作物2000—2007年的虚拟水含量及该地区虚拟水的时序流量。最后得出结论:东北地区的粮食作物具有普遍的节水种植优势;东北地区的虚拟水输出量可观,进入量稀少。     

Free trade: what are the terms-of-trade effects?

Changes in trade policy affect a nation’s economic welfare through terms-of-trade and volume-of-trade effects. A move to global free trade would imply higher world economic welfare equal to the sum of all nations’ volume-of-trade, or efficiency, effects. Since the sum of the terms-of-trade effects across all nations is zero, terms-of-trade effects are contentious. Konishi, Kowalczyk and Sjöström (2003) have shown that if customs unions do not affect trade with non-member countries, immediate global free could be achieved if free trade were proposed together with international sidepayments equal to the terms of trade effects. How large would these terms of trade effects, and hence transfers, be? This paper presents estimates from a simple computable general equilibrium model of a world economy of perfect competition. We show that, in some cases, terms-of-trade effects are small compared to efficiency gains, and transfers are not necessary for free trade. In other cases, terms-of-trade gains may account for more than 50% of a country’s gains from free trade and transfers could be large.     

Are virtual water “flows” in Spanish grain trade consistent with relative water scarcity?

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 3 years 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 8415 million 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 34.2 million 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.     

Regionalism as Industrial Policy: Evidence from MERCOSUR

This paper empirically explores whether trade preferences can be used as a substitute for industrial policy and help countries achieve their industrialization objectives at the expense of other regional members. Results show that Mercado Común del Sur (MERCOSUR) preferences obtained by Brazilian exporters have led to an increase in exports of relatively sophisticated products in which Brazil does not enjoy a global comparative advantage. On the contrary, smaller members of MERCOSUR export to the region products in which they have strong comparative advantages and with relatively low levels of sophistication. This suggests that MERCOSUR has helped Brazil achieve its industrialization objectives, but has not contributed to the industrialization of its smaller members.