Multi-Scale Evaluation Of Landscape Ecological Sustainability Based On Land Use Of Wuhan

How to ensure the ecological value of urban ecological environment and ensure the sustainable development of urban economy,society and environment in the process of rapid urbanization is an urgent problem that many developing countries need to solve,and it is also a problem that academia pay close attention to.Land is the important resource for the society to survive and develop,thus rational and effective use of land resources is the top priority in implementing the strategy of sustainable urban development.The change of landscape pattern is the most intuitive form of land use change,exploring the characteristics and changes of the spatio-temporal distribution of landscape pattern,accurately evaluating the sustainable development conditon and potential of landscape ecology in the process of urban land use is of great significance to supervise and control urban planning and construction efficiently.Therefore,it is necessary to propose a scientific and rational evaluation system of landscape ecological sustainability.In order to establish and verify the landscape ecological sustainability evaluation system,Wuhan,a city with extreme speed is taken as the research area and sustainable evaluation index system of landscape ecology of Wuhan based on land use is constructed.From three scales of city,district and street,based on the comprehensive analysis of land use structure and change,landscape pattern distribution and spatio-temporal variation characteristics of Wuhan from 1990 to 2015,the improved Entropy Method was applied to carry out the multi-scale evaluation of landscape ecological sustainability of Wuhan City.Finally,spatial autocorrelation analysis was used to explore the spatial dependence of landscape ecological sustainability of Wuhan.The main conclusions are as follows:(1)In the preparation stage of landscape ecological sustainability evaluation,the spatio-temporal variation characteristics of land use at three scales is analyzed in order to understand the land use structure and changes in Wuhan.From 1990 to 2015,significant changes were taken in the area of Wuhan,but the land use structure did not change much.The farmland,construction land,water and forest were the main landscape bases.There are similarities and differences in land use change on three scales.The similarities are mainly due to the continuous increase of construction land area and the continuous decline of farmland.There are scale differences and spatial heterogeneity in areas,proportions and changes of other type of land.Overall,Wuhan has high land use development intensity and insufficient reserve resources.The landuse structure and changes reflect the undeveloped development level of the main urban area and the far urban area in the urbanization development of Wuhan,The development level of the main urban area far exceeds the far urban area.Therefore,in order to promote the healthy and coordinated development of Wuhan City,it is necessary to make a scientific evaluation of the sustainability of landscape ecology of Wuhan.(2)In order to construct the evaluation system of landscape ecological sustainability of Wuhan,12 landscape pattern indicators that represent five aspect:(1)landscape fragmentation,(2)landscape heterogeneity,(3)ecological landscape connectivity,(4)farmland guarantee ability and(5)intensive utilization of construction land are selected,and the distribution and variation of the landscape pattern indicators of are described from multi-scale.The results show that there are obvious scale effects on landscape fragmentation,landscape heterogeneity and ecological landscape connectivity,while farmland guarantee ability and intensive utilization of construction have not shown significant scale differences.Most landscape pattern indicators show significant spatial differences at district and street scale.On the whole,landscape fragmentation of Wuhan is at a good condition,but it is intensifying;landscape tends to be fragmented and homogenized,and the heterogeneity is enhanced;and ecological landscape connectivity degree,farmland guarantee ability and intensive utilization of construction land are good,but the trend of change is not optimistic.These conclusions indicate that there is a scale effect on the distribution and change of landscape pattern in Wuhan.Therefore,the scale effect should also be considered when evaluating the landscape ecological sustainability of landscape.(3)On the basis of the above,the proposed landscape ecological sustainability evaluation system are applied in this paper,finally draws the conclusions as follow:(1)The sustainable development level of landscape ecology of Wuhan shows a downtrend at each scale and shows a obvious scale effect and spatial differences;(2)The landscape ecological sustainability evaluation system proposed in this paper can effectively evaluate the landscape ecological sustainability of Wuhan,and the best application effect appears at the district level.Specifically: from 1990 to 2015,the sustainability of ecological landscape of each scale of Wuhan shows a downtrend,but the levels of sustainable development and degree of degradation were different,showing a significant scale effect,and the deterioration of the sustainability at street scale is the most serious.By 2015,at the district scale,the sustainability of landscapeecological of most districts are at a level of “general sustainability”,while at the street scale,the sustainability of landscape ecological of most streets are at a level of “weak sustainability”.From the perspective of the size and characteristics of the administrative unit and evaluation system,the district scale is more suitable for the evaluation of landscape ecological sustainability of Wuhan.In addition,the spatial dependence and agglomeration of landscape ecological sustainability of Wuhan are also explored.It is found that the landscape ecological sustainability at the district scale shows a random distribution pattern,but it shows obvious agglomeration mode at the street scale,the spatial autocorrelation is significant.The analysis of spatial autocorrelation of landscape ecological sustainability at the street scale shows that the distribution of main urban area is mainly “low-low”,and distribution of far urban area is “high-high”.It illustrates that there is a scale effect on the spatial dependence of landscape ecological sustainability of Wuhan,and the spatial dependence is much stronger at street scale.Finally,according to the research conclusions above,the problems of land use landscape pattern in the process of urbanization in Wuhan are analyzed,and some strategic suggestions are proposed:(1)orderly optimize the landscape structure and strengthen the ecological landscape construction;(2)rationally design the landscape patches and reduce the landscape fragmentation;(3)adhere to the ecological priority and protect the farmland;(4)strictly control the expansion of construction land and improve the intensive conservation.These suggestions may guide Wuhan City to effectively improve the sustainable development level of landscape ecology in the national land planning and comprehensive land improvement.