Study On The Optimization Of Ecological Spatial Structure Of Basin-type Cities Based On Ecological Security Pattern

Based on the theory of landscape ecology,with the support of GIS technology,the paper uses the ETM remote sensing image data and socio-economic data of the study area in 2000,2009 and 2015 to integrate the minimum cumulative resistance model for the basin-type city—the ecological space of Fuzhou central urban area.The structure has carried out research on land use evolution,ecological land use identification,ecological security pattern construction and urban space expansion prospects.The research results can provide a scientific reference for the land use planning and ecological city construction in the central city of Fuzhou.The specific conclusions are as follows:(1)The forest land is the landscape matrix of the central city of Fuzhou.During the past 15 years,the land use change mainly occurred in Cangshan District,Jin’an District,Mawei District,Shangjie Town and Nanyu Town.The land use and industrial and mining transportation land increased and the forest land,garden land and grassland increased.The reduction of waters,cultivated land,and other land uses;construction land is expanding in the southern part of the city,which is closely related to the mountainous,northern,and flat“T”-shaped urban expansion system in northern Fuzhou.(2)The four ecological process indicators of geological disasters,local cultural heritage,biodiversity conservation and hydrological safety in the central area of Fuzhou are superimposed and equalized,and the comprehensive ecological land in the central area of Fuzhou is obtained.The area of the extremely important ecological land is 8322.49hm~2.The ecological service has the highest value and is the core area of Fuzhou’s green infrastructure;the area of important ecological land is 76,557.87 hm~2,which is the key ecological land in Fuzhou.It should focus on ecological protection and restrict development and construction;generally important and unimportant ecological land Distributed in villages,towns and urban land areas,on the basis of ensuring ecological security,project construction activities can be arranged reasonably.(3)The low security pattern in downtown Fuzhou is mainly located in the mountainous hilly area around the basin,with an area of 75895.84hm~2.The medium security pattern is mainly distributed along the banks of the Lancang River and Wulong River,with an area of 48548.51hm~2.The high security pattern mainly includes Cangshan District and Gulou District.Jinan District,etc.,the area is 11595.55hm~2.By constructing an ecological network system of“two rings,two corridors,five wedges and eight groups”,the overall ecological security pattern of Shanshui City is perfectly combined.(4)In the urban spatial expansion simulation based on different ecological security patterns,the urban space expansion under the“no ecological security pattern”scenario,the ecological land occupation is more occupied,the ecosystem service function is seriously damaged;the city under the“low ecological security pattern”scenario Space expansion,important ecological land can be minimally maintained;urban space expansion under the“middle ecological security pattern”scenario,the built-up area is organized in groups,and the ecological infrastructure is well maintained;under the“high ecological security pattern”scenario The urban space is expanded.The built-up area is distributed in the vicinity of the city center.The other areas are surrounded by ecological land,and the ecological service function can be sustained for a long time.