Spatial-temporal Evolution Pattern And Future Scenario Analysis Of Land Resources Carrying Capacity In Shaanxi Province Based On The Relationship Between Human And Food

Land provides the most basic material guarantee for the survival of population and the development of social economy,is the most important means of production and carrier,and plays a key role in many natural resources.With the development of social economy and the continuous growth of population scale,the intensity of land resource utilization is increasing,the limitation of land resource supply is becoming more and more prominent,and the imbalance between population demand and land supply is gradually increasing.The saturated growth trend of land load leads to the increasingly prominent contradiction of population land food,which directly endangers the national and regional food security.It is the foundation and key to coordinate the development of population land food system,optimize the structure of land resource utilization,ensure food security and coordinate development to start the study of the bearing capacity of land resources in the region,and reasonably predict and simulate the future trend of population scale,land load and food production.This paper systematically summarizes and draws lessons from a variety of research results at home and abroad,and in view of the actual shortcomings,determines a research framework with clear geographical definition,standardized method model and appropriate space-time accuracy.The research methods include qualitative analysis and quantitative evaluation,mathematical model and spatial analysis,law evolution and future prediction.Taking the relationship between human and grain as the main line and the relationship between land,grain and population as the research object,this paper studies the three modules based on land use change and grain yield,comprehensive consideration of animal husbandry products and based on dietary nutrition demand(including heat demand and protein demand),and systematically analyzes the temporal evolution of the real land productivity in Shaanxi Province since 1949 The quantity reveals the general trend of bearing capacity change and the regional characteristics and spatial pattern of bearing status of each city.According to the scenario settings of cultivated land area,per capita consumption demand,multiple cropping index,grain production ratio,and sowing per unit yield,the future prospects of land resources carrying capacity in 2035 and 2050 in Shaanxi Province under different scenarios are predicted and analyzed.Based on the analysis of bearing capacity in recent 70 years from different perspectives,this paper discusses the development space and growth mode of bearing capacity under the development of different natural influencing factors and policy regulation,analyzes the interactive relationship between population,land and grain in Shaanxi Province,reveals the land bearing capacity and population development space in different regions of Shaanxi Province in 2035 and 2050,in order to coordinate the dynamic coupling of population,food and land We should optimize the matching between supply and demand of resource allocation,realize the regional differential utilization and management of land resources,improve the production capacity,realize the healthy development of resources,production,regional economy and the coordinated development of human food relations,and ensure the stable production of grain for reference.The conclusions are as follows:(1)Based on the current situation of grain production,the evaluation of land resources carrying capacity shows that:The bearing capacity of land resources based on grain production has reached 33 million people level.In recent years,the bearing capacity fluctuates,mainly due to the adjustment of planting structure.The productivity and carrying capacity of land resources have not been weakened.In 2018,the carrying capacity of land resources in Shaanxi Province is more than 30 million people,and the current per capita grain accounts for more than 310 kg,which can basically meet the demand for rations.Since 1949,the total population of Shaanxi Province has increased,the cultivated land area has continued to decrease,and the grain to crop ratio has gradually decreased.However,thanks to the continuous improvement of the quality of cultivated land and the productivity of cultivated land,the high-level growth of grain output and per capita grain share in Shaanxi Province has been ensured,and the production capacity and bearing capacity of land resources have been gradually improved.(2)The comprehensive land resources carrying capacity evaluation considering food and animal husbandry products shows that:The comprehensive bearing capacity of grain and animal husbandry products is strong,which can completely realize the balance of human and food.With the continuous increase of grain output and the large-scale and high-speed improvement of production level of meat,egg and milk,the growth rate of comprehensive land resource carrying capacity is larger than the population growth rate,and the overall land resource carrying capacity is gradually improved.By 2018,the comprehensive land resource carrying capacity is equivalent to 116%of the real population.The index of land resource carrying capacity is 0.86,which is in the surplus state of healthy development,1/2 of the urban comprehensive land resources carrying capacity has gradually turned into good,and 9/10 of the urban areas are in the state of balance or surplus of human and food.The structure of the relationship between human and food has been significantly optimized.The relationship between human and food is characterized by balance surplus or surplus.(3)The assessment of land resources carrying capacity based on dietary and nutritional needs shows that:The output of all kinds of agricultural products in Shaanxi Province is increasing steadily and orderly,and the dietary structure of residents is changing from plant food to animal and plant.Based on the calculation of the land resource carrying capacity of food,meat,eggs,milk,vegetable oil,fruits,vegetables,sugar and other agricultural products based on the demand of heat and protein,it can be concluded that the land resource carrying capacity has reached the level of nearly 78 million people and 80 million people respectively,the self-sufficiency rate of land resources has reached 201%and 206%respectively,and the carrying space has reached twice the real population in 2018.The land resource carrying capacity index of each city is less than 1.Under the condition of the balance of human and food,the relationship between human and food is constantly optimized,and each city has a great potential of land resource carrying.(4)The prediction of land resources carrying capacity of grain production in the future shows that:In 2035,under the conditions of medium multiple cropping index,medium grain ratio and medium grain per unit yield,grain self-sufficiency can be basically realized.Under the scenario of setting the highest conditions for various elements,grain output in 2035 can reach 31.5 million tons,and the population carrying potential can accommodate more than 70 million people,exceeding the carrying space of the predicted population of 27 million people.In 2050,under the situation of low multiple cropping index,low grain proportion and low sowing per unit area yield,the grain output can reach 17.09 million tons,with a population of 47.92 million.There is still a potential space for 870000 people to carry out grain self-sufficiency.Under the condition of high multiple cropping index,high yield per unit area and high grain ratio,the population carrying potential can reach about 77 million people,exceeding the carrying space of the predicted population of 30 million people.