Study On The Evolvement Of Green Space Landscape Pattern In Hefei City

Urban green space has good ecological benefits,is an important part of urban systems.The distribution and spatial structure characteristics of urban green space,not only affect the ecological benefits,but also have an impact on urban green space landscape pattern.In August 2011,Anhui province had adjusted the administrative division and changed Chaohu from prefecture-level city to county-level city,meanwhile,Chaohu and Lujiang were incorporated into Hefei.With the adjustment of administrative divisions,the increase of urban area,the overall planning of urban green space is becoming more and more important,and the research of green space landscape pattern is more and more urgent.At present,there is no research about consolidated situation of green space landscape pattern in Hefei after the adjustment of administrative divisions,therefore,to study Hefei green space landscape pattern of temporal and spatial evolution satisfy the development of Hefei city.Studying on green space landscape characteristics is beneficial to optimize the urban green space system,exert the ecological benefit of urban green space,alleviate the ecological environment problems which are carried by urbanization,beautify the environment,create healthy and comfortable living environment,and promote the sustainable development of economic and social.This study used the theory of landscape ecology,with the administrative divisions adjustment of Hefei as the research object,and combined with ENVI4.7,Arc GIS,Fragstats3.3 and other software in order to extract urban green space information from TM remote sensing image of four periods during 1995 to 2013.Then the study analyzed the temporal and spatial distribution and the transfer of green space referring to the map of Hefei city and other data.By choosing 11 kinds of landscape pattern index,urban green space landscape pattern index was analyzed from two aspects of the plaque level and landscape level,at the same time,the greenspace distribution of the administrative district in Hefei,the landscape pattern index,the green space gradient analysis on 12 gradient zones were also studied.Finally,the study analyzed the driving force of green space landscape pattern evolution based on Hefei statistical yearbook.The results were as that:(1)Land use types in the study area were divided into water,construction land,green space,farmland,bare land.Through the four stages of TM remote sensing images supervised classification,the study achieved land use distribution map and analysis of urban green space which was mainly distributed in the main city park,around rivers,lakes and reservoirs,residential area and office units,nursery,urban forest which contained Shushan mountain,Zipeng mountain,Daqian mountain,Fucha mountain,Dai mountain,Yefu mountain,Woniu mountain,Fuding mountain and so on.The whole area of green land was increasing and was mainly transferred by farmland,construction land and water.(2)At the plaque level,the study had selected 6 kinds of landscape pattern index,including Number of Plaques(NP),Plaque Density(PD),Edge Density(ED),the Largest Plaque Index(LPI),Landscape Shape Index(LSI),Average Plaque Fractal Dimension(FRAC-MN).At the landscape level,the study had selected 7 kinds of landscape pattern index that consisted of Number of Plaques(NP),Average Plaque Size(AREA-MN),largest Plaque Index(LPI),landscape Shape Index(LSI),Shannon Diversity Index(SHDI),Shannon Evenness Index(SHEI),Landscape Division Index(DIVISION).The research showed that the green space landscape was influenced by human activities,so the urban green land plaque was more fragmented,even the degree of uniformity was reduced,and the landscape was more irregular.(3)The green space area of Yaohai district,Shushan district,Baohe district,Luyang district,Feixi country,Feidong country,Changfeng country had a declining trend from 1995 to 2000,especially the main city.From 2000 to 2013,the districts green space area was grew fast,especially the main city and the landscape pattern tended to be stable.In Lujiang and Chaohu,green space area also showed a growth trend from 1995 to 2013.The green space landscape in the districts was more obviously disturbed by human factors,so the landscape of green space was broken,the function of dominant landscape was weakened,the landscape complexity was strengthened,and the physical connection degree of patch type was better.(4)For the green space gradient analysis of Hefei,urban green space mainly distributed on east,west and south gradient zones,including the main city park,the surrounding of rivers,lakes,and reservoirs,residential area,office units,nursery,peripheral urban forest,but the north of Hefei,mainly in Changfeng country,the distribution of green space was relatively small.Green space overall was dispersed,and the landscape was fragmented,which was affected by human factors.(5)With the accelerated process of urbanization,green space landscape was fragmented,which was closely related to human activities.The main driving forces of the evolution of green space landscape pattern included urbanization and population growth,urban construction and transportation construction,social economy and the third industry development,land use policy.