灌溉虚拟水流动特征及其对气候变化的响应

Virtual Water Flow Characteristics of Irrigation and Their Responses to Climate Change

由于我国水资源的时空分布和社会需求间存在巨大矛盾,地区间农业灌溉虚拟水流动能够有效缓解不同地区的水资源短缺的矛盾,促进水资源向更高效益的产业或地区流动。采用2007年30省(区、市)区域间6部门投入产出表和北京气候中心气候系统模式输出结果,开展了地区间农业灌溉虚拟水流动特征及其对气候变化响应的研究,通过对不同气候变化情景下各省市农产品流动蕴含的虚拟水流量的计算和虚拟水流动对各省市的重要性的评价,量化全国农业灌溉虚拟水输出格局相对水资源分布、虚拟水输入格局相对经济总量分布的不均衡程度。研究发现,采用农业灌溉虚拟水流动强度、输入份额和不均衡程度等评价指标能够对地区间虚拟水流动特征进行良好评价,高虚拟水流动强度省市在气候变化条件下的虚拟水流动强度变幅较其他地区大很多;未来大部分时期虚拟水输入对具有高输入份额省市的重要性还将进一步增加;中国虚拟水输出格局与水资源分布不匹配,气候变化有加重这一状况的趋势。

This study estimates the virtual water flows embodied in agricultural commodity trade among Chinese provinces on the basis of input-output analysis combining the Chinese interregional input-output table and agricultural water consumption information. After the estimation,the intensity of virtual water flow（ the proportions about virtual water outflow and inflow against local water resources） and scale of virtual water inflow（ the proportion about virtual water inflow against total water flow within local area） are set up to reflect the trade frequency of products having high virtual water content and the importance of virtual water flow,respectively. The future fluctuations of every province are calculated by using the precipitation and temperature output data from Beijing Climate Center Climate System Model in different climate change scenarios. The fluctuations are then used to estimate the variations about virtual water flows and relevant evaluation indexes.Results show that the virtual water flow intensity＇s variations of the provinces with high intensity are much bigger than other administrative regions under climate changes. It is also found that the virtual water flow have both positive and negative effects on the distribution of water resources,and the climate change has a very small influence on the situation that most of the virtual water flowing in the developed areas come from water scare regions.