Study On Land Carrying Capacity Based On Load-carrier Perspective

In line with the urbanization process,the human demands for land resources have broken through the supply capacity of land resources,which restricts sustainable land use and affects ecological civilization and high-quality development.Therefore,it is imperative to study land carrying capacity(LCC).It has been proven that LCC is influenced not only by the foundation of land resources(e.g.land size and land quality)but also by human socio-economic activities,so it should be researched based on both the pressure imposed by human activities and the supply capacity of land resources.This can help governments to achieve sustainable land use,ecological civilization,and high-quality development from both land management and human activities regulations.Firstly,this study discusses five types of LCC: 1)LCC based on limiting food,2)LCC based on ecological footprint,3)LCC based on multi-factors,4)LCC based on a reference region,and 5)LCC based on planetary boundaries framework.And each type is reviewed concerning the application of reasonable context and suitable spatial scale.Secondly,this paper clarifies the concept of land and land resources and analyzes the traditional connotation of LCC which includes five elements(tempo-spatial conditions,carriers,loads,expressing result,and land carrying capacity system).According to the five elements,this research extends the LCC connotation.To understand the carrying relationships between land carriers and land loads,this study draws on multifunctional land use theory and divides the carrying relationships into 11 types including the food supply,available freshwater supply,industrial products supply,commercial services supply,housing supply,transportation services supply,supply of public administration and public services,gas regulation function,waste purification function,educational and literary carrying,and leisure and aesthetic supply for human demands.Furthermore,these 11 types of carrying supply are expressed as food production,available freshwater resources,industrial and mining land area,commercial and service land area,residential land area,transportation land area,land area for public administration and public service,carbon sequestration,waste purification,scientific and educational land area,as well as park and green space.On the other hand,this paper draws on ecological footprint theory and divides the pressure caused by human activities into 11 indicators including per capita food demand,per capita available freshwater demand,per capita industrial and mining land area,per capita commercial and service land area,per capita residential land area,per capita transportation land area,per capita public administration and public service land area,per capita carbon emission demand,per capita waste emission demand,per capita scientific and educational land area,per capita park and green space area.Finally,based on the ecological footprint theory and the principle of the barrel,a load-carrier perspective method for LCC is established.Thirdly,this research takes Chongqing in 2019 as an empirical study area,and collects multi-source and type-heterogeneous data,as well as processes and calculates data based on GIS software and In VEST software.Therefore,the results for supply capacity of land resources,the pressure caused by human activities,and LCC are demonstrated from raster,plot,and county spatial scales.Fourthly,this paper analyzes the validity of the LCC model and discusses the LCC conditions and problems for Chongqing in 2019.Fifthly,this research proposes some policies to enhance LCC.Results indicate that: 1)The five LCC research paradigms mentioned above occur in different contexts,thus they are applied in different conditions.Researchers should further deepen one type of research paradigms combining with their understanding.2)This study extends the LCC connotation from a load-carrier perspective and points out that LCC should include land carriers and land loads,and gives the carrying relationships between land carriers and land loads,and the LCC result is expressed by the number of populations that can be carried.3)There are 11 indicators to assess the supply capacity of land resources: food production,available freshwater resources,industrial and mining land area,commercial and service land area,residential land area,transportation land area,land area for public administration and public service,carbon sequestration,waste purification,scientific and educational land area,as well as park and green space.And there are 11 indicators to evaluate the pressure caused by human activities: per capita food demand,per capita available freshwater demand,per capita industrial and mining land area,per capita commercial and service land area,per capita residential land area,per capita transportation land area,per capita public administration and public service land area,per capita carbon emission demand,per capita waste emission demand,per capita scientific and educational land area,per capita park and green space area.Furthermore,the LCC evaluation model is the ratio between the supply capacity of land resources and the pressure caused by human activities.4)The LCC assessment model based on a load-carrier perspective is effective.5)The supply capacity of land resources shows obvious spatial heterogeneity for Chongqing in 2019,and the results are highly related to the geographical conditions and regional planning.And the LCC problems include lower food production,less land area for park and green space,lower waste purification,less land area for industrial and mining,and unbalanced LCC between counties.6)Some policy recommendations for improving LCC proposed by Chongqing can be extended to other counties including a.the protection of cultivated land quantity and the improvement of cultivated land efficiency;b.the construction of park and green space;c.the development of a pollutants management system containing“source reduction,process interception,and end of the consumption treatment”;d.the increasing supply of industrial and mining land area and the optimization of its layout;e.the promotion of overseas territory;f.the optimization of population layout and the guidance of rational human living and human production.