Urban Greenbelt Landscape Based On Highe-Resolution Images

As an important part of urban ecosystem,urban greenbelt’s eco-efficiency and integrated features play an irreplaceable role in urban ecosystems.With increasing urbanization, urban land is more intense.How to optimize spatial layout and structure of urban green space with limited land resources so as to promote sustainable urban development and coordinate the relationship between environmental protection and urban construction has become a key issue.In this passage,we take Nanjing space image which was obtained from Google map as information source,using software ARCGIS,we extracted greenbelt information and made greenbelt map of Nanjing main city.On this basis,I calculate the indices of Nanjing main city from three levels,including patch level,class level and landscape level,by comparing the indices of different towns,we can analysis whether the patch’s distribution is reasonable.Finally,we make a summary of greenbelt’s feature of Nanjing main city,and make optimization recommendations.The main results of the study are as follows:(1) Among the six types of greenbelt of Nanjing main city,the distribution of each type is uneven,and the area occupied by each of them is quite different. Appertain greenbelt and other greenbelt occupy utterly predominance by the proportion of each type patch accounts for the total area of patch, respectively occupied 47.3984%>33.8567%.Other types of greenbelt occupies little,especially protective greenbelt,it only occupies 2.3368%of the total area.(2) The patch’s size structure in Nanjing main city distributes unevenly.Patches that area is less than 0.5hm2 occupy 92.97% of the total number of patch,however,patches that area is more than 0.5hm2 occupy 7.03%, so the landscape shows a feature that small has an absolute advantage,but short of large patches.(3) By calculating fragmentation index,patch density index,aggregation index,it shows that the patch continuity of Nanjing main city has been weakening with higher fragmentation characteristics, all these are due to the influence of human’s activities.Appertain greenbelt has the highest fragmentation index of 30690.17.Other greenbelt are in to a film distribution,so its fragmentation index is only0.0068.(4) Though the analysis patch shape index of Nanjing greenbelt,we find that the patch shape index is of low level,the patch tends regularization and has simple shape.This shows that the natural ecological succession subject to greater human disturbance.Protecting greenbelt has the highest fractal dimension index,followed by park greenbelt,other greenbelt,and production greenbelt has the lowest index.(5) Though the analysis of diversity index,the largest diversity index,evenness index,density index,rich density index of Nanjing main city,we found that the greenbelt of Nanjing has dominance patch,and each type of patch distributes unevenly,it has a low diversity.(6) Through comparative analysis of different towns’s landscape pattern of Nanjing we find that the greenbelt in different towns develops unevenly and has a large difference.Due to the large population,developed traffic and strong human activities,the central city has the highest fragmentation index,lowest fractal dimension index and lowest diversity index.Ecological benefits of urban green landscape is relatively poorer than other parts.(7) Through the landscape pattern analysis of Nanjing main city,this passage pointed out the problems.On this basis,this passage proposed optimization tips for Nanjing greenbelt which are as follows:①Improve urban green coverage and promote the balanced development of urban green space.② Promote large and medium green patch construction, improve the landscape ecological benefits.③Create the natural landscape,reduce human disturbance. ④ Optimize green corridor construction and improve the ecological connectivity of the landscape. ⑤ Create various types of landscape and improve the diversity index.⑥Strengthen the central city green construction.