基于投入产出表的中国水足迹走势分析

水足迹是近年来国内外研究水资源压力的常用方法.基于投入产出表的水足迹分析方法,分析了我国1997-2007年的水足迹状况,改进了耗水系数的计算方法,研究了基于稀释理论的灰水足迹计算方法,计算了外部水足迹及额外水足迹负重以及相应系数,分析了我国水足迹消费的商品(服务)结构.结果表明,1997-2007年我国年均水足迹总量为2.83万亿m3,总体呈现下降趋势,其中蓝水足迹为2183亿m3,灰水足迹为2.62万亿m3(以Ⅲ类水标准核算).在水足迹总量中,间接水足迹占据比例达到90％,可见水资源压力的产生主要基于商品或服务的消费.我国水足迹基本上依靠自给,同时我国承担其他国家的水资源压力的比例很大,但是整体上呈现下降趋势.从水足迹消费商品(服务)结构上看,与饮食相关的商品或服务占较大比例.

China water footprint trend analysis based on input-output tables

Water footprint (WF) method is a common way to study the water resources pressure in recent years. The total water footprint of China from 1997 to 2002 were calculated by using water footprint method based on the input-output tables in this paper, the method for calculating the water consumption coefficients was improved, and the method for calculating the gray water footprint based on dilution theory was studied in the paper. The external water footprints, the extra water footprints and the corresponding coefficients were also calculated, and the goods (services) structures of the water footprint consumption were analyzed in this study. The results showed that the annual WF of China had a downward trend from 1997 to 2007, with an average annual of 2.83 trillion cubic meters, in which the blue WF was 218.3 billion cubic meters and the gray WF was 2.62 trillion cubic meters (accounting to the third level surface water quality standards). The indirect water footprint accounted for 90% of the total WF, which meant the pressure of water resources mainly comes from the consumption of goods or services. The WF of China depends on self-sufficiency largely, and at the same time China bears a large proportion of the water pressure of other countries, but which has a it shows a downward trend on the whole. In the sight of the structure of goods or services, the diet-related goods or services occupied a higher proportion of WF.