Monitoring And Analyzing Urban And Rural Built-up Land Expansion In Yangzhou City In The Last 30 Years Based On Multi-Temporal Remote Sensing Data

Yangzhou is an important member of the Yangtze River economic belt.It is also the source of the East Route Project of the south to North Water Diversion Project.It is also the first batch of historic cities in the country.Since the reform and opening up,the pace of urbanization in Yangzhou has been gradually accelerated,and the urban and rural construction land has been expanding and evolving,and the structure of urban and rural areas has changed significantly.In this paper,the six Landsat TM/OLI remote sensing images of 1990,2000,2005,2009,2013 and 2017 are the main data sources,and the land cover information of Yangzhou is classified.With the support of the GIS spatial analysis technology,the net change,exchange change and total of land cover transfer are calculated by using the land use transfer matrix.The change of land cover change and transformation relationship in Yangzhou is analyzed.On the basis of the construction land extracted,urban construction land and rural construction land are distinguished with the help of night light data.By using buffer zone analysis and spatial azimuth analysis and landscape index,the number characteristics,expansion intensity,and expansion intensity of urban land construction land use in the last 30 years are analyzed.The direction characteristic,the spatial form evolution and so on.The main conclusions of the study are as follows:(1)Agricultural land has always been the largest type of land cover in Yangzhou.Before 2013,the water body accounted for second of the land cover type,but the construction land area in 2013 was more than the water body area for the first time;the proportion of forest grassland and other land cover types was relatively small.The net area of agricultural land and construction land is the largest in each period.The increase of construction land area is mainly occupied by agricultural land.(2)For urban construction land,the area of 1990?2017 year is increasing year by year.The expansion intensity of urban construction land in four regions of Yangzhou is increasing first and then decreasing,and the speed of expansion is the fastest in the period of 2000?2009.The urban construction land in urban areas mainly expands in the eastern direction,which is due to the acceleration of urbanization in the eastern part of Jiangdu.The urban construction land in Gaoyou,Yizheng and Baoying has a particular emphasis on the expansion of different stages.(3)For rural construction land,the total area of 1990?2017 increased year by year.The intensity of rural construction land expansion was greater in the four districts and counties during the period 1990?2005.According to the landscape index,the area of rural construction land increased year by year,so the patch density(PD)of the four areas decreased year by year,and the average patch size(MPS)increased year by year.In the process of evolution,the rural construction land increased and the number of patches decreased,and the complex fragmentation degree of patch area increased first and then decreased.Therefore,the landscape shape index(LSI)first increases and then decreases,while the Euclidean nearest distance(ENN)first decreases and then increases.