| Land resources provide basic conditions for the reproduction of human society,and the evolution of land use landscape pattern reflects the process of human society ’s transformation and reuse of land resources.This thesis takes Alxa Left Banner as the research object,based on the land use data,meteorological data,soil data,DEM data,accessibility data and socio-economic data of the study area in 1980,1990,2000,2010 and2020,using Arcgis10.5,Fragstats4.2 and PLUS models and other software tools.By using the methods of land use transfer matrix,land use dynamic degree and landscape index,the quantitative change of land use types,the spatial evolution of landscape pattern,the driving mechanism of land use landscape pattern and the future land use landscape pattern in Alashan Left Banner were studied.The conclusions are as follows :1.During the study period from 1980 to 2020,the unused land area of Alxa Left Banner decreased by 15865.59km~2,the grassland area increased by 13355.25km~2,the cultivated land area increased by 245.85km~2,the water area decreased by 9.11km~2,and the forest area increased by 1996.08km~2.The proportion of construction land in the total area increased by 277.52km~2.2.In terms of the number of landscape types,the number of patches of grassland and cultivated land landscape showed a trend of decreasing first,then increasing and then decreasing,the number of patches of forest land and water landscape showed a trend of increasing first and then decreasing,the number of patches of construction land increased year by year at a lower level of change,the landscape patches of unused land were divided into smaller patches,and the fragmentation of landscape increased.In the change of landscape level,the connectivity and accessibility between patches of landscape types become higher,and they are more vulnerable to human activities.However,the uniformity of land use landscape pattern is rising,and the anti-interference ability of landscape ecosystem is becoming stronger.3.The main driving factors of cultivated land change are Euclidean distance and population density;the driving factors of forest land change are mainly annual average precipitation,annual average temperature and elevation.The main driving factors of grassland are annual average precipitation,annual average temperature and soil erosion.The main driving factors of water area change are the distance to the water system and the average annual precipitation.The main driving factors of construction land change are accessibility driving factors and socio-economic factors;the driving factor of unused land change is soil texture.4.The simulation accuracy of Markov-PLUS model is 78.2%,which meets the research needs.The prediction results show that in the change of land use landscape pattern in Alashan Zuoqi,the natural development scenario is similar to the other two scenarios in the overall change trend and historical period,which is more in line with the future change reality. |
