应用ImPACT等式, 分析了甘肃省1990-2003年虚拟水消费中人类活动对环境的影响. 结果表明: 相比1990-1995年, 1996-2000年和2001-2003年甘肃省收入显著提高, 而使用强度(单位GDP的农产品消费量)和效率(单位农产品消耗的虚拟水量)大幅度改善, 对环境影响(虚拟水消费量)起到了调节作用. 收入弹性分析表明, 收入增加1%将引起人均农产品消费量增加0.13%, 使用强度下降0.87%, 而环境影响增加0.14%. 2000年甘肃省城镇和农村虚拟水消费对比分析表明, 农村的虚拟水强度(0.706 m^3·元^-1)显著高于城镇(0.051 m^3·元^-1), 合理改善消费结构能降低虚拟水强度从而减轻对环境的影响. 应用ImPACT等式设置环境目标并检验其可行性, 结果表明: 在1990-2003年的基础上, 使用强度降低1.5倍, 效率提高1倍, 能够保障经济的增长, 并在合理的时间范围内(28 a)实现虚拟水消费量减少到2003年的50%, 是一种可行的选择方案.
Analysis of environment impact of human activities has become a hot topic in the current time. On the basis of introducing the IMPACT identity, combined with a case study of virtual water consumption in Gansu province during 1990-2003, the utility of the IMPACT identity in environment impact assessment is explored. It is found that, compared with the period of 1990-1995, in 1996-2000 and 2001-2003 income of Gansuprovince increases dramatically, and use intensity and efficiency improve greatly, which adjust the virtual water consumption. Income elasticity analysis shows that when income increases 1%, the amount of agricultural production consumption per capital will increase 0.13%, while use intensity will decrease 0.87% and environment impact will increase 0.14%. Comparison analysis shows that, in 2000, the virtual water intensity of rural area (0. 706 m^3·Yuan^-1) is dramatically higher than that of urban (0.051 m^3·Yuan^-1). Adjusting the consumption structure in a proper way will do good to reduce environment impact. Setting up an environment objective and examining the responsibility of driving forces shows that higher objective requires higher improvement for both producer and consumer. As the environment objective of achieving 50% of the amount of virtual water consumption in 2003, with the use intensity deqrease by 1.5 times and efficiency improve one time based on the "actual situation" of the period 1990-2003, it is possible to achieve the objective in a reasonable period (28 years) meanwhile with a more rapid economic development. In conclusion, IMPACT identity can be used to analyze the effect of driving forces on environment impact quantificationally and it is significant for seeking sustainable policies.