兰州市生态系统健康评价及协调性分析

进行区域生态系统健康评价,可以为当地制定生态系统保护政策和措施、生态系统协调和可持续发展提供科学依据。受数据源获取困难等因素制约,从乡（镇、街道）尺度开展的生态系统健康研究尚不多见。本文通过压力-状态-响应模型,选取15个指标因子构建了适宜于乡（镇、街道）尺度的评价指标体系,然后以第一次地理国情普查成果、统计年鉴数据和Landsat8、HJ-CCD、OMI遥感影像为主要数据源,对部分指标使用统计降尺度处理的基础上,以乡（镇、街道）为评价单元,运用熵值法综合评价兰州市生态系统健康状况,并对压力-状态-响应协调度进行分析。研究结果表明：① 生态系统健康整体表现出由城市中心区较差向城市外围区较好的过渡和替换趋势,从乡镇（街道）尺度来看,属于“不健康”、“亚健康”、“健康”、“很健康”的分别有13.5%、28.8%、51.3%、6.2%;② 就协调度而言,有59%的乡（镇、街道）为中度协调区,主要连片分布在城市郊区,其余分布在安宁区的街道,剩余的41%街道为高度协调区和低度协调区,占国土面积的25%,主要分布在城区的街道,零星分布在城市郊区的一些乡镇。

The Health Assessment of the Urban Ecosystem and Analysis of Coordination for the City of Lanzhou

It is important to comprehensively assess regional ecosystem health, which can offer scientific basis for the development of the policy and measures of protecting ecological system and the coordination and sustainable development of the ecosystem. Restricted by factors such as difficulty of obtaining data sources, carrying out the ecosystem health research from the township （town, street） scale is still few. In this paper, the pressure-status-response model is used in the ecosystem evaluation. There were 15 indicators selected to build an ecosystem health assessment system suitable at the township （town, street） scale. It includes GDP energy intensity, point density ofmonitoring and prevention of geological disasters, biological abundance index, the first national census geography results of Lanzhou region, the 2015 statistical yearbook of Lanzhou city and three counties and five districts, Landsat8, HJ-CCD, OMI remote sensing images as the main data source. Also, based on the statistical scale reduction to some indices such as the per capita water use and environmental protection investment accounting for GDP consumption, taking the township （town, street） as the evaluation unit, entropy method was used to evaluate health status of the ecological system of Lanzhou City. to The coordination degree of pressure-status-response was also analyzed. The results indicated that: （1） the ecosystem health showed a transition from poor status of downtown to better status of suburbs. From the township （street） scale, the "unhealthy" is 13.5%, the "sub-health" is 28.8%, the "healthy" is 51.3% and the "very healthy" is 6.2%. （2） From the aspect of coordination, 59% of township （town, street） is moderate coordination area, majorly distributed in the outskirts of the city and the streets of An Ning District. The remaining 41% streets are high coordination area and low coordination area, accounting for 25% of the land area, mainly distributed in the streets of the city and scattered on some towns of the outskirts. The results of this study will provide a scientific basis for the fine management, rational use and protection of land resources in the city of Lanzhou.