Analysis On The Change Of Land Use Structure And Efficiency And Their Correlation Degree In Changsha

As a kind of basic natural resource,land resource has the characteristics of limited quantity,fixed location and non-renewability,which is closely related to human life.With the continuous development of the economy and the progress of the society,the land use structure has also changed.In the process of land use,not only will it bring considerable economic,social and ecological benefits,but also bring problems such as waste and pollution of land resource that can not be ignored,which will further affect the efficiency of land use.Therefore,the study of the correlation between the two can provide the basis for the area in land use planning and optimal allocation of resources,so as to achieve goals of equal cost-saving and output enhancement,higher land-use efficiency and coordinated development in economy,society and ecology.This paper takes Changsha City as the study area and 1997-2016 as the study period.First,establish the information entropy model based on information entropy theory to reveal the dynamic change of land use structure of Changsha city in stages;Second,construct the index system of land use efficiency evaluation and use data envelopment analysis(DEA for short)method to analyse the law of land use efficiency in time and space series of Changsha City;Finally,use gray relational analysis(GRA)method to analyse the quantitative relationship between the changes of the information entropy of land use structure along with the various land types and the three major types of land use efficiency.The main conclusions are as follows:(1)During 1997-2016,the information entropy and equilibrium of land use structure in Changsha show an upward trend of fluctuation,while the decline in some years did not affect the overall upward trend.The information entropy increases from 1.3598 in 1997 to 1.3750 in 2016 and the equilibrium degree increases from 0.6539 in 1997 to 0.6612 in 2016.The dominance degree decreases from 0.3461 in 1997 to 0.3388 in 2016.This indicates that the homogeneity of land use types in Changsha is strengthening,the degree of disorder is increasing,presenting a balanced trend of development.(2)From 1997 to 2016,the effective years of land use efficiency in Changsha are 12,the comprehensive efficiency values are all above 0.92,and the average is 0.989,which is at the upper level.This result indicates that Changsha has made a reasonable allocation in resource investment in the process of land use and so then realize the ideal input-output level,but there is still room for rise and it can be promoted by projection analysis.(3)The change of the information entropy of land use structure in Changsha was highly correlated with the change of the comprehensive efficiency of land use,the correlation degree reached 0.9301,and the correlation degree with the pure technical efficiency and the scale efficiency are as high as 0.9871 and 0.9316 respectively.In addition,land types that are highly correlated with land use efficiency are arable land and forest land;moderately-correlated:water and water conservancy facilities,urban and rural industrial and mining land,transportation land,pasture land and other land;low-correlated:garden.In conclusion,a reasonable land use structure is the basis of the effective utilization of land use efficiency.The change of land use efficiency is the common result of the immediate effect and cumulative effect of the temporal and spatial changes of land use structure.