Research On The Spatial And Temporal Evolution Of Ecological Land In Xiangjiang River Basin Based On Quality Correction

China has entered the stage of high-quality development.Quality has replaced speed as an important indicator of regional development.Ecological civilization construction has received more and more attention.The Xiangjiang River diagonally across Hunan and is an important ecological axis of Hunan Province.The Xiangjiang River Basin is the golden zone for social and economic development in Hunan Province.Under the requirement of the "three highs and four new" strategy,and the construction of demonstration zone for undertaking industrial transfer in southern and western Hunan and the Hunan Free Trade Zone,the Xiangjiang River Basin has ushered in greater development opportunities,faced with higher development requirements,and also suffered heavier ecological protection pressure.Therefore,this paper takes the Xiangjiang River Basin as the research area,comprehensively analyzes the evolution of ecological land in the in terms of quantity and quality,and hopes to provide a reference for the precise implementation of ecological protection policies in the Xiangjiang River Basin.This article is based on the sustainable development theory,landscape ecological protection theory,Ecological space theory,Kezeng cycle theory and other related theories.forest land,grassland,water area and wetland are regarded as the research object of this paper according to the discussion on the connotation of ecological land and the actual situation of the Xiangjiang River Basin.Taking the land use transfer matrix,the dynamic degree of ecological land,and the ecological land grid as the starting point to analyze the changes in the net area of ecological land in the Xiangjiang River Basin.At the same time,based on the net area of ecological land,the internal stability,external disturbance,and ecological importance are introduced for quality correction,and the spatial and temporal evolution of ecological land in the Xiangjiang River Basin under the premise of quality correction is discussed.Aims to solve two key issues:(1)Explore the more realistic evolution of ecological land in the Xiangjiang River Basin under the quality correction mode;(2)Locate the low-value area of ecological land in the Xiangjiang River Basin,the two-way degraded area of net area and quality correction area,and the quality degraded area under the appearance of net area increase..Research indicates:(1)In terms of spatial distribution,ecological land in the Xiangjiang River Basin is mainly concentrated in the Dongting Lake in the north,Nanling in the south,Xuefeng Mountain in the west,and Luoxiao-Mufu Mountain in the east.The urban areas of Loudi City,Shuangfeng County,Shaoyang City,Shaodong County,Yongzhou City,and Hengyang City constitute "C"-shaped low-value areas.During the study period,the overall ecological land degradation was obvious,the dynamic change intensity increased,and the scope expanded.(2)Returning farmland to forests,grasses and wetlands is the main source of ecological land growth,and construction land expansion is the main direction of ecological land transfer.The net area of ecological land in the Xiangjiang River Basin showed a decreasing trend,among which the decrease of woodland and grassland was obvious,and the water area and wetland increased steadily.The ecological land in the Xiangjiang River Basin is developing towards fragmentation and disorder,the ecological importance has increased with the increase in the area of waters and wetlands and the improvement of the NDVI,thus overall the quality has been improved.(3)The main influencing factors of the temporal and spatial changes of ecological land in the Xiangjiang River Basin include natural geographical conditions,human activities,and policy factors.Natural geographical conditions have laid the basic distribution pattern of ecological land in the basin,and the impact of human activities is manifested in the high-intensity agglomeration of decrease in quantity and quality degradation in the urban areas and changes direction change of the gravity center.Policy factors are concentrated in the transfer of forest land,cultivated land,construction land,water and wetland caused by the conversion of farmland to forest and wetland,the balance of occupation and compensation of farmland,and the linkage of increase and decrease of construction land.The quantity and quality both increased after the enhancement of ecological civilization construction is proposed with the improvement of the intensity of the quality change.(4)There are four types of key areas for ecological land protection in the Xiangjiang River Basin.The first is the "low-low" clustering and the"reduction-reduction" superimposed area of the Changzhutan urban agglomeration.The second is the triangular "low-low" clustering areas in Shaoyang,Hengyang and Yongzhou.The third is the "reduction-reduction"area of Chenzhou.The fourth is the "increase-decrease" agglomeration areas represented by Chaling County and Yanling County where the quality is degraded under the appearance of an increase in quantity.Areas with a large ecological area and rugged terrain are more susceptible to quality than the net area.lt is recommended to promote the protection of ecological land in the river basin through measures such as constructing a quantity-quality monitoring system,refining time-space planning indicators,ensuring accurate matching of problems and measures,and forming a mechanism of element flow Between administrative districts.