中文摘要：

生态足迹和水足迹作为定量测度人类对自然资本利用程度和可持续性发展的综合性指标，已经被广泛应用到我国的生态评价和可持续发展能力评价。食物是人类首要的消费品，其消耗的生态足迹和水足迹将反映维持一个区域的人口基本食物需求所占用的土地资源和水资源。本研究在生态足迹和水足迹理论和模型的基础上，根据北京市的现状，重新计算了均衡因子和单位质量虚拟水含量等模型关键参数，改进计算方法，计算和分析了北京市居民食物消耗的生态足迹和水足迹。研究结果表明，北京市居民食物消耗人均土地面积达到1．967hm^2／人，人均生态足迹为2．025hm^2／人；北京市居民食品消耗人均虚拟水为1023．05m^3／人，约为居民消耗实体水的5倍，反映了北京居民食物消耗需要大量的土地面积和水资源来满足，将对区域土地和水资源造成很大胁迫。本研究采用基于北京市实际食物来源的估算参数更能反应北京市的实际情况，其结果表明北京市食物供应选择从国内其他地方输入有利于减少北京市食物消耗所引起的生态足迹和水足迹，研究成果可为北京市农林渔牧产业结构调整布局，以及食物供应方案的制定提供决策依据。

英文摘要：

In order to quantify the extent of human influence on ecosystems, accounting frameworks of quantitative assessments are required. The ecological footprint （EF） and water footprint （WF） are new methods for calculation of human utilization of natural capital and measurement of sustainability of development. Since food is the foremost consumable of human beings, its EF and WF can essentially reflect the utilization of land and water resources for meeting the food demand for the population in a certain region. In order to investigate land and water utilization related to food consumption in Beijing, the authors calculated EF and WF. EF and WF methods were improved with new parameters so as to make the calculation more suited for Beijing City. In this paper, EF was calculated based on food supply sources while the WF calculation depended largely on virtual water consumption in the food production process. Results show that land used on food is about 1.967 hm^2/cap and the per capita ecological footprint is 2.025 hm^2. The main contribution of EF is meat, accounting for more than 50% of the total food consumption EF. The average virtual water consumption is 1023.05 m^3/cap, almost 5 times the real water consumption by residents in daily life. The meat takes up 42.27% of the total. Results also indicate that the food consumption has a great impact on urban ecosystems in Beijing. Beijing needs more biological production fields and water to support residents and the environment. In addition, Beijing has a relatively good food supply plan, which reduces, to some extent, the EF and WF of food consumption. Importing food from other provinces seems to be effective in reducing EF and WF in Beijing. On the other hand, Beijing tends to be suitable for developing animal husbandry and fishery. The results of this study were also compared with those from the original theory, indicating that some reasonable differences could be attributed to the improved parameters in this study, which appeared to make the results more relia