Study On Landscape Pattern Change Of Land Use In Chengdu

As the foundation of human survival,land can not be ignored.The change of landscape pattern is one of the main causes of changes in the global ecological environment.Chengdu is one of the rising “new first-line” cities,as southwestern China.The central city is experiencing a period of rapid urbanization,and the landscape pattern has undergone tremendous changes under the influence of urbanization.How to deal with the role and influence of urbanization on urban landscape pattern,making urban construction and sustainable development of ecological civilization go hand in hand is one of the key points in the construction of Chengdu today.Carrying out the urban land use landscape pattern evolution and prediction research,understanding the changes of landscape pattern in Chengdu in recent years,can provide a scientific basis for optimizing the landscape pattern of Chengdu,and provide support and reference for urban planning.In this paper,11 administrative districts in Chengdu are used as research areas.Based on Landsat TM/OLI remote sensing data in 2005,2010,2015 and 2018,the data classification of land use types in the study area is carried out by supervised classification.The-Markov landscape pattern prediction model predicts and analyzes the landscape pattern,spatial dynamics of the study area,and the changes and driving trends of the surface table.The research results are as follows:(1)The area of cultivated land,forest land and grassland in the study area showed a decreasing trend during 2005-2018.The area of cultivated land and forest land decreased the fastest,the area of construction land increased significantly and the landscape types changed strongly.(2)The landscape pattern of the study area changed significantly during 2005-2018.The advantage of cultivated land is gradually weakened,the advantage of construction land is gradually enhanced,the landscape fragmentation degree of cultivated land,forest land and grassland is increased,the fragmentation degree of construction land is reduced,the distribution is more concentrated,and the fragmentation degree of water area is kept at a low level.In the development of the city,the shape of cultivated land,woodland,grassland and construction land is more regular,and the shape of the water is more complicated.At the same time,the degree of polymerization of construction land and cultivated land has been maintained at a high level,and the degree of polymerization of grassland has been significantly reduced.(3)During the period of 2005-2018,the degree of landscape fragmentation in the study area decreased with the development of urbanization level,the connection degree of land use type patches increased,and the spatial structure of plaques became more complex and more regular.The boundary shape of the block tends to be simple and regular,the dominance of each land use type plaque is more even,no landscape elements are missing,and each type of plaque is evenly distributed in the landscape,with the greatest diversity.(4)The suitable water area and grassland distribution in the flat terrain with low slope grade,the suitable cultivated land distribution in the middle slope area,and the suitable forest land distribution in the high slope area;the proportion of cultivated land and forest land in the buffer zone of each road shows a downward trend,and the construction land is in The area in each road buffer is increasing and the growth rate is the largest in the 0~1000m buffer zone;the area ratio of cultivated land and forest land in the central buffer zone of each urban area is decreasing,and the construction land is in the buffer zone of each urban center.The area is growing and the growth rate is the largest in the 0~10000m buffer zone;population growth and population urbanization are one of the main drivers for the growth of construction land;socio-economic development and industrial restructuring are the key factor of promoting the evolution of the landscape pattern of the study area.(5)By constructing the CA-Markov model using the conclusions obtained in the previous section,and simulating the landscape pattern distribution in the study area in 2021,the study found that the land use landscape pattern in the 2021 study area will continue the trend from 2010 to 2015,also in cultivated land.,the trend of forest land and grassland reduction and transfer to construction land.