兰州市城区生态地质环境承载力空间格局

摘要

根据兰州市城区生态地质环境特征,从地质环境、生态环境和社会环境3个方面选取了12个评价指标,构建了兰州市城区生态地质环境承载力综合评价指标体系,运用层次分析法、加权综合评价法,借助ArcGIS 10.2空间分析技术,对兰州市生态地质环境承载力进行了基于栅格尺度的综合评价,得到城区生态地质环境承载力高分辨率的空间评价结果,并将综合评价值从高到低划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ4个等级进行空间展示.结果显示:Ⅰ级为优,区域面积最小,仅占研究区总面积的9.13％,主要分布于西固区、安宁区和城关区等黄河沿岸的部分高漫滩和一、二级河流阶地;Ⅱ级为良,占比33.58％,大部分位于兰州市七里河区北部、城关区南部的一、二级阶地等区域,以及主城区南北两侧的小部分山区;Ⅲ级为中,区域面积最大,占比46.72％,连片分布于主城区南北两侧的二、三级阶地区域和南北两山后缘的高海拔山区;Ⅳ级为差,占比11.07％,主要位于主城区南北两侧三级及三级以上高阶地、南北两山,并呈条带状在南北两侧环绕兰州市城区.研究结果为兰州城区的建设发展提供了重要的科学参考,对城市发展具有重要的指导意义.%According to the characteristics of eco-geological environment in Lanzhou,12 basic evaluation indexes were selected from its eco-geological and social environment,to construct an evaluation index set of its eco-geological carrying capacity.Analytic hierarchy process,synthetic evaluation method and GIS technology were used to calculate the comprehensive values for assessment,and high resolution spatial evaluation results of the carrying capacity of eco-geological environment were obtained.The city was divided into four grades from the high to low according to the comprehensive evaluation values and the results showed that Grade Ⅰ was in the excellent category,but making up only 9.13％ of the total study area and mostly located in some of the high floodplain along the banks of the Yellow River and the first and secondary river terraces of Xigu,Anning and Chengguan District.Grade Ⅱ was in the good category,accounting for 33.58％ of the total study area,and mostly located in the urban areas of Lanzhou;for exampie,in the north of Qilihe District and the first and secondary river terraces in the south of Chengguan District and parts of the mountain areas on both sides of the city.Grade Ⅳ was of the medium category,with the largest area making up 46.72％ of the total study area,and mostly located in the secondary and third river terraces on the south-north sides of the city,and also on the trailing edge of high altitude moun-tain area in south-north hills.Grade Ⅳ was the worst accounting for 11.07％ of the study area and mainly located in the third terrace and upper places on both south-north sides and southern-northern mountains of the main urban area,being mainly strip-shaped around both south-north sides of the main urban area.The evaluation results can offer a reference for the development of urban construction in Lanzhou City,which is of great significance to the development of urban area.