| Based on the theory and principles of Landscape Ecology, taking Shunyi District as an example, the landscape types and and landscape pattern were analyzed with the support of 3S technology and field survey data. The landscape ecological risk index was built based on landscape disturbance index and landscape fragility. Spatial auto-correlation and geostatistical analysis by GS+ and ArcGIS was used to study temporal and spatial changes of ecological risk. And natural disaster risk index was used to analyze distribution of disaster risk. Landscape ecological risk index and natural disaster risk index were overlaid to study integrated ecological risk. In the meanwhile, the potential ecological corridors were simulated using the least cost path method. Given that city is at the center of social-economic development, the article build a social-economic network to form a ecological network which combines green space, water area and economic patches. Finally, suggestions on optimizing the landscape pattern were put forward, which can provide a reference for city planning. The main results show that:(1)Landscape structure of Shunyi District covered five types, such as plow land, grassland, water area, construction land, and woodland. Plowland and construction land were dominant landscapes. In the process of urbanization, construction land had an increased area as plowland largely translating into construction land. At the same time, natural landscapes like water area, woodland, grassland also were partly occupied by construction land. On the whole, urbanization had a harmful impact on natural and semi-natural landscape, which caused fragmentation increasing and patch shape more complex.(2) The landscape ecological risk of Shunyi was primarily at moderate level during the study period. The area of the district with higher and lower ecological risk has increased. The district with lower risk mainly located in the central region and southeastern of Shunyi District, and the area was increasing with the urbanization. The district with high ecological risk mainly included large area of water, such as Chaobai River, where is very fragile.(3) The main natural disaster sources in Shunyi District were drought, flood, soil erosion, geologic hazard. Ecosystems, such as plow land, grassland, water area, construction land, and woodland, was influenced by these risk sources. The result shows that area of the district with high risk was small, which means a large area was at low risk level.(4)Comprehensive ecological risk in large area of Shunyi was at a high level, so it is necessary to optimize landscape structure. Protecting ecological source contributes a lot to landscape pattern optimization. Green space resource has a uneven distribution, with more size in east more west less. In the whole Shunyi District, the most important ecological patches include Hanshiqiao wetland, Tangzhishan mountain and Chaobaihe river., which need to be substantial protected.(5)Ecological network can powerfully reduce ecological risk. Ecological corridors which let biogenic component migrating and patch connecting were built by the least cost path model. The built corridors are divided into two types, important corridor and general corridor. Based on ecological network and economic network, some knick points which hinder the ecological flow are discerned. To restore these knick points can protect biodiversity and reduce the building cost. In the meanwhile, stepping stone can be built to strengthen the connection of regional ecological structure and function and increase the security and stability of the ecosystems.(6) Urban ecological network and integrated ecological risk were overlaid to produce zoning of land use suitability. The land use suitability of Shunyi District was divided into four types, namely ecological conservation zone, construction suitable land, construction mid-suitable land and construction non-suitable land. The result can provide reference for urban planning and construction. |
PDF Full Text Request