基于GIS的区域关键性生态用地空间结构识别方法探讨

A Method for Identifying Spatial Structure of Regional Critical Ecological Land Based on GIS

随着我国城镇化进程的加速,如何协调好城镇建设与地域生态系统的关系成为当前规划界的热点问题之一。本文基于GIS技术,从水资源安全、生物多样性保护、灾害规避与防护和自然游憩等4个方面,构建了空间尺度上的生态用地重要性综合指数和区域关键性生态用地空间结构识别方法,并进行了京津冀地区的实例研究。结果表明,京津冀地区核心型生态用地的面积为54943.87km2,占全区总面积的1/4,分布在西北部山区,主要是区域的河流水系、湿地、自然保护区、森林公园和风景名胜区的核心区,是维护区域生态安全的底线生态用地。识别结果能较好地反映关键性生态用地维护区域水、生物、灾害防护和游憩安全的空间特征。该识别方法将有利于指导我国土地的生态管理,开展生态保育和生态建设,维护区域生态系统健康与安全。

Land use is defined as regulation measures to meet human demands. Its contribution to ecology and environment has drawn increasing attention from the scientific community. Addressing problems associated with food and clothing supply is the first priority in China’s national policy-making. Economic development is placed on the second, followed by environment protection. Under the combined effects of these policies, China’s long-term emphasis is placed on the major functions of land use in food production and construction. During the processes of accelerating urbanization in China, coordinating the relationship between urbanization and regional ecosystem protection serves as a basis for current land planning. Urban expansion would probably transform ecological land use, such as forest, farmland, grassland, swamps, and water bodies, which have a multitude of critical ecological service functions, into land for urban construction. To make explicit the disturbing state and structure of ecological land systems, it is necessary to systematically diagnosis the space structure of ecological land. The diagnostic object was to provide spatial implications for formulating development strategies, and to reserve key regions for ecological conservation. In this paper, the eco-land importance index at space scales was constructed by accounting for water security, eco-protection, disaster control, and recreation. A method for identifying the spatial structure of regional critical eco-land was put forward based on GIS. Results show that in the Beijing-Tianjin-Hebei area, the core eco-land area was estimated to be around 54 943.87 km2, accounting for 25% of the region. It is mainly distributed in northwestern mountainous areas, including rivers, wetlands, the core areas of nature reserves, forest parks, and scenic spots. These areas serve as the baseline eco-land for maintaining regional ecological integrity. Non-critical eco-land areas were around 97 727.53 km2, taking up 45% of the study region. Land use types of these areas are dominated by construction land and arable land. Functions of these areas are supporting human living and agricultural production. Results of the study can provide a basis for reasonably examining spatial characteristics of critical eco-land that plays a key role in providing water resources, sustaining ecosystems, preventing natural disasters, and ensuring recreation security.