Temporal And Spatial Evolution Characteristics Of LUCC And Its Response To Climate Change In Zhangjiang River Basin Of Upper Ganjiang River

With the continuous increase of the global population,human activities are increasingly intensified,and the global warming has become an indisputable fact.The research on global climate and environmental change and the impacts of land use / cover change(LUCC)to climate change have become hot topics in the world.LUCC changes the climate mainly from the land and air ecosystems,and the basin can best reflect the integrity of the ecosystem.Because of the land cover,landscape pattern,climate change and so on.LUCC has become a hot topic in the academic field.Therefore,this paper chooses the typical area of the upper reaches of Ganjiang River,Zhangjiang River Basin as the research area,using "3S" technology and the theoretical method of landscape ecology.Based on the Landsat TM /OLI remote sensing image data,meteorological data and hydrological data of the basin,the single dynamic degree and development degree of land use type,transfer matrix,center of gravity shift,landscape pattern index,linear trend method,correlation analysis method and other methods are used.The spatial-temporal characteristics of land use / cover change and the distribution of landscape pattern from patches to the whole in the last 30 years were analyzed.The spatial-temporal characteristics of climate change in Zhangjiang basin in the past 50 years were discussed.Finally,with the help of the yearbook data,the main driving factors of land use type and landscape level index change in the basin are analyzed quantitatively.The main conclusions are follows:(1)In the past 30 years,land use / cover in the basin has been in a slow development state.The main landscape types are forest land,grassland and cultivated land.Among them,the forest land area increased first and then decreased.The maximum coverage rate(46.01%)appeared in 2017,with the center of gravity in Chongyi county.The construction land has the largest development degree(9.8%),in 2008,the center of gravity was transferred from Shangyou County to Nankang district.(2)In the past 30 years,the dominant landscape types in the basin are forest land and cultivated land,but both of them are declining.The fragmentation state of landscape is a trend of increase,decrease and increase,and 1987-1996 is a period of great fragmentation.Landscape diversity as a whole shows a decreasing increasing decreasing trend.In 1996,landscape diversity was the worst,and may still have a downward trend after 2017.(3)In the past 60 years,the temperature and precipitation increased at the rate of 0.155 ?(10a)-1 and 6.62 mm ·(10a)-1,and the average temperature and precipitation over the years were 19.24 ? and 1594.15 mm respectively.The high temperature area is located in the southeast of the basin.The area with abundant precipitation is concentrated in the southwest of the basin,and the area with relatively small precipitation is located in the east of the basin.The relative humidity and sunshine percentage decreased at the rate of 0.24% ·(10a)-1 and 1.08% ·(10a)-1.The average relative humidity and sunshine percentage over the years are 77.65% and 39.67%.The area with high relative humidity is concentrated in the high altitude area in the middle of the basin.The distribution of the highest sunshine percentage is basically the same as that in the high temperature area.(4)The main landscape types in Zhangjiang River Basin are more affected by natural factors than social and economic factors.The change of forest land area is mainly affected by natural factors such as elevation,slope and rainfall.The change of grassland area is mainly affected by elevation,slope,sunshine percentage and GNP,of which the influence of topography and geomorphology is greater than that of climate.The change of cultivated land area is mainly controlled by social and economic factors such as GNP Value,first GDP,second GDP and third GDP.The area change of construction land is influenced by elevation,slope,GNP,per capita GNP,second GDP and many other factors,and the most influential factors are social and economic factors.Only the CONTAG and SHEI indexes' driving factors are significant in landscape level index,but the two factors are mainly social and economic factors,followed by natural factors.