Healthy Dynamic Assessment Of Land Use System Based On Gray Relational TOPSIS Model

Land resources are the basic carrier of social and economic production,and it can not be separated from the support of land to China's economic construction and development.With the acceleration of urbanization and industrialization in China,the law of natural development has been neglected in the excessive pursuit of economic growth,resulting in unreasonable development of land resources and other issues,which has gradually attracted people's attention to land use security.At present,it is particularly important to evaluate and diagnose the health of land use system and put forward reasonable suggestions based on the results.The relative closeness of land use system in Jinan City from 1992 to 2016 was obtained by grey relational TOPSIS model.From the point of view of environmental subsystem,the relative proximity increased from 0.4044 in 1992 to 0.5817 in 2016,and the relative proximity health grade was critical health state,and there are mainly two stages of development: from 1992 to 1999,the degree of closeness increased;from 1999 to 2016,the degree of closeness decreased first and then increased,showing a good development trend.From the point of view of economic subsystem,Jinan's land economic system closeness tends to decrease first and then increase.From 1994 to 1998,the land use economic system closeness is unhealthy state,and other research periods are critical health state,and during the period of study,the economic system development mainly presented two stages:from1992 to1996,the stage of closeness decreasing;from1996 to 2016,the degree of closeness increased as a whole.From the point of view of social subsystem,the health grade of land use social subsystem in Jinan is critical health state,and the closeness degree is increasing in general,and there are mainly two stages of development: from 1992 to 2009,the frequency of proximity fluctuation was obvious,which is between 0.4 and 0.5;from 2010 to 2016,the proximity increased and it is ranging from 0.5 to 0.6.On the whole,the relative closeness degree of land use system in Jinan was on the rise,rising from 0.3688 in 1992 to 0.6024 in 2016.The health level of land use system has changed from unsafe level to critical health level,and finally to sub-health level.Jinan hadcontinuously increased investment in environmental construction,economic construction and social construction,and had made some progress.However,there was still a gap between the optimal closeness.Through the analysis of obstacle degree model,it can be seen that: from 1992 to 2008,the top two indicators ranking with greater resistance were the average public budget expenditure and pipeline input density.From 2013 to 2016,the top three indicators ranking with greater resistance were the amount of chemical fertilizer used per unit crop area,the average population load and the per capita arable land occupancy.From the criterion level,the barrier degree of state index and response index of environmental subsystem decreased,while the barrier degree of pressure index gradually increased.And the barrier degree of pressure index and state index of economic subsystem gradually decreases,while the barrier degree of response index gradually increases.The barrier degree of social subsystem response mainly concentrates on the social response index,and the latter part of the study mainly concentrates on the social pressure index.From the overall resistance level of land use system in Jinan,the obstacle degree of state index and response index gradually decreased,while the obstacle degree of pressure index gradually increased.The results of the prediction model show that the health degree of land use system in Jinan had been constantly improving,and the relative closeness of land use system is still at the critical health level from 2017 to 2021.In order to promote the healthy development of land use system in Jinan,it is necessary to strictly protect the land ecological environment,increase land investment scientifically,and plan land rationally and scientifically,which is of great significance to the social and economic construction of Jinan.