中国西北地区基于GIS的生态承载力定量评价与空间格局

基于生态足迹方法,利用地理信息系统的空间分析技术,从图斑、县、省三级不同空间尺度对2000年西北地区生态承载力的供给与需求进行定量计算和空间格局分析.结果表明:2000年整个西北地区生态承载力总供给小于总需求,处于生态赤字状态,但各省区情况不同,其中:陕西、新疆生态承载力供给小于需求,处于生态赤字状态,而甘肃、青海和宁夏生态承载力供给大于需求,处于生态冗余状态;西北地区内部不同区域生态承载力供给空间分异明显,呈东南、西北部较高,东北、西南、中部较低的空间分布格局;不同地理单元的生态承载力供给差异也较大,表现为黄土高原中西部、青藏高原东北缘、祁连山山地、天山山地和阿尔泰山地等地区的生态承载力整体供给较高,而其他地区的则较低,其中:关中盆地、银川盆地和干旱区绿洲地区的生态承载力供给最高,塔里木盆地、柴达木盆地、准葛尔盆地和吐鲁番盆地腹地的广大戈壁、沙漠地区的最低,呈连片分布状态;黄土高原丘陵沟壑区内部由于景观破碎严重,生态承载力供给呈现明显的空间异质性特征,表明西北地区生态承载力供给与该地区的地形地貌、气候、土地利用/覆盖及人类活动强度具有密切的空间关联与空间异质性;西北地区单位面积生态承载力供给和人口密度基于县级尺度的相关系数为0.66,呈明显的正相关关系,且空间分布格局相似,表明西北地区人口分布具有显著的生态承载力偏向性.2000年西部地区生态承载力供给的空间分布极不均匀,表现为明显的地带性分布与局地性分布相符合的空间分布格局,整个地区生态承载力供需矛盾突出,处于生态不安全与不可持续性发展状态,而各省区、县及其内部生态承载力供需矛盾差异较大,生态安全与可持续发展状态各异.研究实践证明GIS技术的应用为空间生态承载力研究提供了新途径和新方法.

Quantitative estimation and spatial pattern analysis of ecological carrying capacity in northwestern China based on GIS

Based on the ecological footprint (EF) methodology and with the help of the spatial analysis approaches of geographic information system (GIS), we calculated, in a case study of northwestern China in 2000, the ecological carrying capacity (ECC) demand and supply in the area, and analyzed the spatial distribution of ECC supply and its related indicators at multiple spatial scales. The main conclusions are shown as follows: the per capita ECC demand was greater than ECC supply in this area in 2000, implying that the natural capital consumption of human beings had overshot the EC limitation and northwestern China was faced with a severe ecological deficit and unsustainable development. The crisis degree of ECC demand and supply varied among 5 provinces within this area: the per capita ECC demand was greater than ECC supply in Shanxi and Xinjiang, and the per capita ECC demand was less than ECC supply in Gansu,Qinghai and Ningxia. The spatial distribution of ECC supply was very uneven in the area, showing that the ECC supply in the southeastern and northwestern parts of the area was greater than other parts; here, the ECC supply was found to be the best in lowland areas such as Guanzhong Basin, Yinchuan Basin and some oases in the arid area. The ECC supply status of highlands and desert regions were the worst, including the Gobi areas of Tarim Basin, Jungger Basin, Qaidam Basin and Turpan Basin. All of results showed that the uneven distribution of ECC supply was caused by different geographical characteristics, environment conditions and land use & land cover. For spatial ECC research, GIS is a powerful new tool to break down barriers of conventional EF methods to reflect the spatial information of ECC.