Information Extraction And Landscape Pattern Analysis Of Xiapu County Based On RS And Fragstats

The formation of the green landscape pattern is the result of a combination of different factors,such as intricate external disturbances,diverse biological factors and complex social environments,which can be expressed using landscape pattern analysis methods.By quantitatively describing the landscape pattern of urban green space,on one hand,it can provide data support for the improvement of urban green space system construction,on the other hand,it can provide scientific basis for the construction of urban green space system.Based on the Landsat 8 remote sensing image data photographed in2017,the paper took Xiapu County as the research object.After a series of image preprocessing,the SVM classification method was used to extract the land use topic information,and the land use types in the county were divided into forest land,cultivated land,and unused land,building land and water body.combining with high-resolution remote sensing image classification and artificial visual interpretation,green spaces of the main urban area were extract into five types including park green space,auxiliary green space,protective green space,road green space and production green space.According to the principle of landscape pattern index selection,the plaque type level and landscape level index were analyzed respectively from county scale and the main urban scale.The main conclusions of the thesis were as follows:(1)The accuracy evaluation of county land use classification shows that overall accuracy is 85%and the Kappa coefficient is 0.807,which improves that the accuracy of the experiment meets the requirements required for research.The land use structure of Xiapu County is mainly forest land.The research data shows that the total area of the county is148,402.35 hm~2,of which the forest land area adds up to 101,133.72 hm~2,accounting for 68.15%of the total area;the cultivated land area adds up to 24,279.39 hm~2,accounting for 16.36%of the total area.The unused land area adds up to 4555.08 hm~2,accounting for 3.07%of the total area;the construction land area is 16565.22 hm~2,accounting for 11.16%of the total area;the water area adds up to 1868.94 hm~2,accounting for 1.26%of the total area.(2)Analyzing from the macro level of the entire county,Xiapu county is mainly composed of forest land,and the plaque shapes of land type are complicated.The landscape shape index is only 18,and the value of FRAC_MN approaches 1.The shape of the county landscape is relatively simple and vulnerable to human interference.In general,the plaque landscape distribution in the county is uneven,and as the dominant plaque the forest land occupies most of the area occupies the most area of the county.The overall ecological benefits of the county are good.However,the other plaque types are less distributed overall which results in a lower overall diversity of landscapes and a richer landscape.The natural ecological network structure of urban-rural integration has not yet been formed.(3)Analyzing from the middle level like the main urban area,the average area of park green patches is larger,but the patch shape index is smaller,the park green space as a whole has a large and simple trend,and the diversity and richness are not enough,scattered in the urban area.The ecological effects of the surrounding area cannot be radiated into the urban area.The value AREA_MN is only about 0.2,which accounts for more than 80%of the total of all green land types,and the overall distribution shows a fine distribution.The number of green spaces produced is small,and the distribution is relatively fragmented,failing to exert its due ecological benefits.In general,the green patches in the main urban area are highly dispersed with each other.The connection between different plaque types is weak and the corridor construction is less.The accessibility between the plaques is less,and the internal and external landscape ecological processes and patterns in the central urban area are not enough.Continuous,no systematic greening network was formed.The natural landscape ecological process and pattern structure outside the urban area is single.The spatial patterns in the urban area is unbalanced where the landscape uniformity is not enough and the overall lack of coordination and stability.