城市食物生态足迹的测算模型及实证分析

Modeling for Measuring City Food Footprint with Applied Empirical Analysis

随着全球人口不断向城市集中及饮食需求多样化,城市食品安全正在成为一个全球关注的重要议题。为探寻城市与食物之间的关系,论文应用食物生态足迹的概念提出其测算方法,并以北京为研究区域进行实证分析,从供需平衡的角度,测算了供养北京城市所需要的食物生态足迹变化。研究发现,尽管人均食物生态足迹仍然相对稳定在0.127 hm2左右,但北京食物生态足迹总体增长迅速,已从1993年的1.18×104km2增加到2010年的2.94×104km2,达到北京市国土面积的1.79倍,并且有继续增加的趋势。随着北京内部耕地面积的不断减少,食物承载力不断降低,北京也会不断将其食物赤字转移到外埠区域,来维持食物生态足迹的供需平衡。因此,北京若要增强自身的食物供给能力,减少食物生态足迹,就需要采取不同于目前的发展策略,加大都市农业的开发力度。

Urban food security is becoming a global important issue as more and more world population are gathering in cities with more diversified needs for food. In order to explore the relationship between city growth and food supply, this paper applies the concept of food footprint and formulates a measuring modeling for it. Then taking Beijing as an example, it calculates its food footprint over times from the perspective of supply and demand. The results show that the food footprint in Beijing has continuously experienced a fast increase, from 11800 km2 in 1993 to 29400 km2 in 2010, nearly 1.8 times that of Beijing＇ s territory area, although the per capita food footprint has relatively remained stable at 0. 127 hm2. As the increase of population and the decrease of arable land continue, Beijing will be inevitable to enlarge its food footprints to the far outer regions. Therefore, if Beijing wants to enhance its food supply and reduce its food footprint, it needs to take different development strategies from the current one and strengthen its local food supply capacity by promoting urban and peri-urban agricultural development.