成都市人均生态足迹和人均生态承载力空间分布差异

生态足迹方法是通过比较人类活动消耗的自然资源与自然生态系统所提供的生态承载力,定量的判断区域的可持续发展状态。采用生态足迹模型对2009—2014年成都市生态足迹、生态承载力状况进行了测算,并结合空间分析揭示了其空间演化规律。结果表明:(1)2009—2014年,各区市县人均生态足迹平均值有着逐年下降的趋势,由2009年的2.759hm~2/人下降至2014年的1.937hm~2/人,基本格局呈现出中间低,西南高,两翼居中的分布特征,高水平人均生态足迹集中分布在西南方向的蒲江县、大邑县,邛崃市;(2)2009—2014年成都市人均承载力呈现出较为稳定且有下降的趋势,由2009年的0.2314hm~2/人下降至2014年的0.2215hm~2/人,其空间分布特征与生态足迹呈现出较好的空间一致性;(3)人均生态亏盈,在时间上表现为逐渐向好,但其本质是趋势为生态赤字愈发严重,空间上呈现出与人均生态承载力情况"高-低,低-高"相反分布的特征,分布呈扩散型,即由中部的五城区向四周扩散,除五城区外,其余地区在研究期间内都为赤字,最严重区域集中在西南方向的蒲江县,最高达到-9.3189hm~2/人,亟需建立有效的生态足迹调控和补充机制。

Spatial differences in per capita ecological footprint and per capita ecological carrying capacity in Chengdu

By comparing the natural resources consumed by human activities and the ecological carrying capacity of natural ecosystems, the ecological footprint method was employed to quantitatively estimate the status of regional sustainable development. Through the calculation of the ecological footprint and ecological carrying capacity, regional resource and energy consumption could be transformed into a certain amount of land for production of resources. If demand, based on the ecological footprint, was greater than the ecosystem carrying capacity the region could provide, it was deemed an ecological deficit area. In these areas, the pressure on land resource production was great and the ecosystems were less stable. Conversely, if demand, based on the ecological footprint, was less than the ecological carrying capacity of the region, it was an ecological surplus area. These areas exhibited reasonable regional land use, with sustainable use of land resources. In this study, the ecological footprint model was used to investigate ecological footprints, ecological carrying capacity, and ecological surplus and deficit, and ArcGIS was used to conduct spatial analyses to determine the relationship among these areas in Chengdu from 2009 to 2014. Using spatial evolution law analysis, the results showed the following: (1) overall, the spatial pattern of the per capita ecological footprints was relatively stable, and the change was not severe. There was strong variation among regions with high- and low-level areas. The per capita ecological footprint decreased annually, from 2.759 hm²/cap to 1.937 hm²/cap. Because agricultural products are numerous in Chengdu, the per capita ecological footprint was the most affected by the ecological footprint caused by cultivated land. The basic distribution pattern characteristics were low in the middle region, high in the southwest, and medium in the two side areas. For example, low-level per capita ecological footprints were found in the five urban districts. High-levels per capita ecological footprints were found in Pujiang, Dayi, and Qionglai. Medium per capita ecological footprints were distributed in the two side areas, including Dujiangyan, Jintang, and Pengzhou, among others. These areas reflected the average level of ecological footprints in Chengdu, which was approximately 3.53 hm²/cap. (2) The per capita ecological carrying capacity of Chengdu was relatively stable and presented a downward trend, from 0.2314 hm²/cap to 0.2215 hm²/cap, from 2009 to 2014. Having the most stringent farmland protection system, the per capita ecological carrying capacity was relatively stable. Low-level per capita ecological carrying capacity areas were the five urban districts, among others. The high-level per capita ecological carrying capacity areas were Pujiang, Dayi, and Qionglai. The spatial distribution characteristics of the per capita ecological footprint and per capita ecological carrying capacity were positively correlated. (3) The per capita ecological surplus and deficit of this area exhibited improving trends with time. But in fact, the developing trend in ecological deficits was becoming increasingly serious, which was opposite to that of the ecological carrying capacity distribution. The per capita ecological surplus and deficit distribution was dispersed in the five urban districts. During the study period, the rest areas were deficit and the most serious areas were concentrated in Pujiang which located in the southwest and the maximum was -9.3189 hm²/cap. It was suggested that effective regulation of ecological footprints and complementary mechanisms were needed in the future.