DCCA-based Analysis Of The Characteristics And Driving Factors Of Urban And Rural Construction Land Changes

With the acceleration of the development process of small and medium-sized cities,the demand for urban and rural construction land will continue to expand,and the land use mode will change greatly.In this process,urban and rural construction land will expand blindly,The phenomenon of large-scale occupation of cultivated land occurs frequently,the land appears idle,waste and other phenomena,the rural residential land does not reduce but increases.Unreasonable use of construction land makes the fragmentation and complexity of urban and rural construction land increase rapidly,which limits the rapid development of urbanization.Therefore,this article is based on the theoretical basis of landscape ecology,taking Xiangxiang City as the research object,using RS and GIS technology to interpret remote sensing images,Therefore,this article is based on the theoretical basis of landscape ecology and Xiangxiang City as the research object,using RS and GIS technology to interpret remote sensing images.Then use Arc GIS10.3 and Fragstats 4.2 software to analyze the dynamic evolution of the spatial pattern of urban and rural construction land at the landscape level and type level in Xiangxiang City from 2000 to 2020.Finally,the Detrended Canonical Correspondence Analysis Model(DCCA)is used to quantitatively analyze the driving factors of the changes in the spatial pattern of urban and rural construction land.The main conclusions are as follows:(1)During the study period,on the landscape level from 2000 to2020,the degree of fragmentation of urban and rural construction land in the city area gradually increased,the shape of the landscape gradually became more complex,the dominance of urban and rural construction land gradually declined,and the degree of aggregation also showed a downward trend.In the type level from 2000 to 2020,the degree of fragmentation and complexity of rural construction land is greater than that of urban construction land,and the landscape superiority and landscape aggregation degree are smaller than urban construction land.(2)The spatial pattern changes of urban and rural construction land in villages and towns show different evolution characteristics.The villages and towns with higher fragmentation,more complex shape,lower aggregation degree and no significant change in dominance are distributed in the hilly areas in the south,North and west of the city,and are far away from the central city of Xiangxiang.The villages and towns with low degree of fragmentation,gradually regular shape,increasing degree of aggregation and significant change of dominance are mainly located in the eastern plain area of the city,and are closer to the downtown area of Xiangxiang.(3)The two-dimensional plan of the DCCA ranking in different time periods shows that there is a close relationship between the changes in the urban and rural construction land landscape index and the socio-economic factors.In the same quadrant,the correlation between the landscape pattern index and the economic and social development factors is consistent.From the DCCA ranking of the relationship between landscape index and 18 townships in each time period,it shows that,to a certain extent,the changes of landscape index of townships in the same quadrant are similar.The DCCA ranking of the correlation between the driving factors of each period and the township samples shows that the driving factors of each township sample in different periods are different,and the correlation between the township samples and the driving factors in the same quadrant that are closer to each other is consistent.