Regional Ecological Security Pattern Evaluation And Construction

Taking Chaoyang District, Beijing, which is under the rapid urbanization as the study area, this paper referred to domestic and international researches on ecological security patterns assessment and construction, and was based on theories and technologies such as landscape ecology,3S and so forth. Selecting Google Earth satellite images as the main data source, studies on regional ecological security evaluation and construction was carried out, through the collection of the social, economic and natural data, as well as the application of landscape pattern and ecological process relationships, landscape connectivity, landscape pattern optimization theory, On this basis, Chaoyang District was taken as an example of landscape pattern optimization based on ecological security. This study provided a reference and practice for ecological assessment and planning in related urbanized areas.There are three parts in this study:(1) Remote sensing image data processing and landscape classification. On the basis of field survey and the establishment of reading standards, geometric correction and visual interpretation of remote sensing images were carried out. The landscape of the study area were divided into eight types including construction land, cultivated land, grassland, garden, water area, woodland, road and abandoned wasteland.(2) Analysis and evaluation of the ecological security pattern in the study area. The variation of landscape connectivity of ecological areas (including woodland, grassland, lakes, water) at different distance threshold was researched and three connectivity indicators including NC, IIC, PC were selected. The result was that 500m is the most appropriate threshold on the analysis and evaluation of ecological landscape's connectivity. On the basis, the effects of the small ecological patches that area is under 10hm2 and river corridor on landscape connectivity were analyzed. Small ecological plaque and river corridors were thought to have the positive significance in maintaining the regional ecological security pattern.(3) The ecological security pattern construction. According to the landscape classification, different landscape type was assigned different ecological function value, and the spatial differences of these values were analyzed. Taking the ArcGIS spatial analysis function, the cost surface of landscape ecological flow was generated. Combination of cost distance model, based on the cost surface which was generated through the ArcGIS spatial analysis function, the cumulative cost surface of the study area was built, and the best potential location of key components in the space were determined such as the ecological source, ecological corridors, ecological landscape nodes. On the basis, landscape pattern optimization program based on the goal of ecological security was proposed, which provided a reference and practice method for the regional ecological security construction in similar areas.