Research On Characteristics And Optimization Of The Ecological Space In Beijing Plain Area

The research range in this paperis the plain area of Beijing city.The Beijing forest resources survey in 2009(1:10000),the plain afforestation project in 2014(1:10000),the Landsat-8 image in September 2014 and other foundational geographic information(1:10000)were used as the main basic data under the ArcGIS platformto explore the characteristic of plain ecological space pattern and the heat island effect.The purpose of this paper is to study the relationship between ecological space and urban heat island effect,the connection between different size of ecological space and cold island effect and finally provide scientific strategy for ecological spaceoptimization in plains.The main results showed:(1)The current land use intensity in Beijing plain is really high,the landscape matrix is non-ecological space(area proportion 65.84%),while theforestry(24.94%)is plain's main ecological space,garden space(5.48%)takes the second place,the area of water body(2.93%)is the least,in addition to there is small scale of other ecological space(0.26%);the number of small patches of each ecological space reaches more than 90% in the plain area,and the plain landscape belongs fine grained texture;from view of differentareas,the garden space dominants in the first green isolation zone and inside the forth ring road,while the forestry dominants in the second green isolation zone and other region in plain.(2)From 2009-2014,the ecological land fragmentation,diversity and evenness in plain area have increased.From the perspective of urban development this change was to enable more people to enjoy the city's ecological products and service performancewhich provided byurban forest;from view of four different areas,the diversity and evenness in the second green isolation was higher than other areas,and the shape of interior patchesbecame more irregularly,whilethe patches inside ecological space connectivity was poor;from the view of different types ecological space,the fragmentation of garden space increased,and difference between different size patches became larger,the shape of patches tended to more irregularly;the scale of different forestrybecame small,and its shape tends to rule development,which illustratedthe influence of human disturbance in foresty was being greater;the fragmentation of water bodyhad decreased;the fragmentation of other ecologicalspace increased.(4)As for the distribution ofheat island in the plain area,the middle,strong and powerful island mainly concentrated in City development area,City expanded function area and two green isolationzones.(5)With respect to the study of ecological space for mitigation of urban heat island found thatthe maximum effective range of cold island effect produced by ecological spaceis 300 meters.When the area of ecological space reached 10 hectares or more can help ease the heat island effect,but to eliminate heat island its scale must required to achieve at least 100 hectares.(6)The overall management ofplain ecological optimization is "one core,two ring,threecorridors and fiveregions".There four main measures to optimize the plains ecological space pattern: firstly,ensure the priority zones of ecological space,secondly,ensureresidents' daily leisure space,thirdly,ease the urban heat island effect,and the last one is cutting off the pathes of environmental pollution diffusion.