Study On Layout Evaluation And Optimization Of Urban Ecological Infrastructure Based On GIS

As urbanization and land expansion have had an extensive influence on thenatural ecological environment, the support and survive function provided by urbanecological system for human society faces a great threat. Therefore, there has beenincreasing attention to the ecological urban planning and construction. It is of greatsignificance to reasonably plan the urban ecological hinterland and make theecological hinterland in preference to the urban construction land. The urbanecological hinterland is also important for coordinating the relationship betweenresource and environment.Based on the Negative Planning theory, the urban ecological infrastructuresystem was built up. Before the urban construction land planning, planning of theecological infrastructure system was conducted to realize the balance and stability ofurban ecosystem. In addition, the specific planning method was discussed. The urbanecological infrastructure system built up in this paper contains environment functionfacilities, safety function facilities, recreation function facilities and culture functionfacilities. The planning methods of the four types of ecological infrastructures werediscussed and the Cangzhou was studied as a case. Based on GIS, the ecologicalinfrastructure database of Cangzhou was established, and geostatistic and spatialanalysis were used to assist planning. By buffer analysis and DEM, the areasvulnerable to flooding were analyzed and the safety function facilities were planned;based on cost-distance analysis and GIS, the road networks and the populationdistribution were combined to analyze the accessibility and the service efficiency ofrecreation function facilities; the layouts of ecological function facilities and culturefunction facilities were vectorized and combed.The layout evaluation results and spatial planning recommendations are asfollows.(1)The ecological function facility layout is balanced and reasonable，and aneast-west ecological corridor is suggested to be constructed.(2)Waterfront areas ofNanyun river and Erzhi canal, as well as west of Yundong district are the areasvulnerable to flooding and the core of flood control safety facilities.(3)There are noprominent contradictions between radiation service area of the recreation functionfacilities and the population distribution,76.86%area is accessible within30min and the population ratio reaches77.21%.Howerer, there are still5.57%of service blindspots. Therefore, recreation function facilities are suggested to be increased inYundongnan district, Chengxibei district and Yunxinan district.(4)For culturefunction facilities, a one axis, three belts, multipoint layout scheme is proposed.In this paper, the urban ecological infrastructure layout method system is studied,which reflects the reflection on the traditional urban planning method. This methodsystem is also of great significance for achieving environmentally friendly andsustainable path of urban development. In addition, the case of the Cangzhou verifiesthe reasonableness and replicability of the methodology.