平顶山新区生态用地的识别与安全格局构建

生态用地对城市生态安全具有重要意义,关键性生态用地的识别与安全格局的构建是实现城市精明增长和生态保护的重要途径。以河南省平顶山新区为例,结合GIS(Geographic Information System)空间技术,分析得到基于水资源安全、地质灾害规避、生物多样性保护三种单一过程的生态用地,进而综合叠加并重分类为理想型、缓冲型和底线型三类生态用地,并以底线型生态用地为源,现状土地覆被为阻力因子,应用最小累积阻力模型构建了平顶山新区生态用地的安全格局。结果表明:新区内最小生态用地,即底线型生态用地的面积为88.44 km2,占研究区总面积的29.35%;缓冲型和理想型生态用地的面积分别为22.28 km2和43.87 km2。确定了三种安全水平的生态用地范围、"源"与外部联系的辐射道、"源"间连接的生态廊道、关键的生态节点等。关键性生态用地综合安全格局的构建,旨在为研究区城市生态规划和城镇空间布局规划等提供科学参考。

Identification and security pattern of ecological land in Pingdingshan newly developed area

Ecological services provided by natural ecosystems are essential to human survival, while the maintenance of ecosystem services is the basis for regional sustainable development. However, ecological services have not been given enough attention, particularly in recent years in China, where has an accelerated urbanization, with high intensity of human activities. These anthropologic activities have greatly altered its natural ecosystem structure, decreased its ecosystem service functions, and seriously threatened its regional ecological security and sustainable development. In this context, a term of "ecological land", which is of great significance in safeguarding important ecological processes and providing essential ecosystem services, was proposed and gained more and more attention. We thus recognize that an identification and security pattern building of critical ecological land is a crucial way to achieve a win-win of urban ecological protection and smart growth. The research area of this paper is a newly developed area, locating in the western region of the old of Pingdingshan City, Henan Province, with a total area approximately 301.28 km². This region is rich in natural landscape resource and wildlife, with good geological conditions and relatively flat lands. As a major future urban development area in Pingdingshan City, it is necessary to build a comprehensive security pattern for ecological land, which would play a critical role in guiding future urban sustainable development. We firstly utilized a GIS spatial technology and local data base, to analyze three different types of ecological lands based on the single process of water resource security, geological disasters avoidance, biodiversity conservation. Then we overlaid the three different ecological lands and obtained the comprehensive ecological lands, which had been further classified to three types (ideal, buffered and minimum) on the basis of natural break clustering method. Furthermore, we selected the minimum ecological land as source and the land cover as resistance factor, and then applied the minimum cumulative resistance model to build a comprehensive security pattern of critical ecological land. Results showed that the size of minimum ecological land in the newly developed area is 88.44 km², accounting for 29.35% of the total region. The minimum ecological land is not only the core area to maintain natural ecosystem service functions, but also the base line of future urban construction and development. The size of buffered ecological land is 22.28 km², accounting for 7.39% of the total region, mainly including the tidal flat wetland, forest and grassland on the edge of the minimum ecological land. Both the minimum and buffered ecological lands, which are the key ecological lands, with important significance in maintaining key ecological processes, should be protected seriously and developed restrictedly, with an accumulative area being greater than 1/3 of the total region. The size of ideal ecological land is 43.87 km², which is the ideal pattern that maximally protects ecological infrastructures and services, under the premise of meeting the demand of future urban expanding. Furthermore, a number of strategic landscape pattern portions and positions were identified from the security pattern of critical ecological lands, including three-level ecological function zones, ecological corridors among sources, radiating routes between the source and external area, and ecologically strategic points, then the corresponding ecological protection and construction countermeasures were proposed. We believe that the comprehensive security pattern of critical ecological lands, with the advantages of high efficiency and spatial linkage, is an efficiently spatial approach to species conservation and landscape optimization. Therefore, our results could provide scientific reference for urban ecological planning and spatial layout planning for national urban development and future sustainability.