Spatio-temporal Evolutionof Construction Land And Cultivated Land And Its Game Mechanism

China has abundant arable lands in total,but a small number of averages.Therefore,while rationally planning the construction land,maintaining the red line of cultivated land and improving the quality of cultivated land are urgent problems to be solved in China.Since the reform and opening up,Yantai city has been in the rapid development stage of urban expansion.However,with the advent of urbanization and industrialization,the expansion of construction land has occupied a large amount of agricultural land,resulting in a sharp decline in agricultural land.Therefore,this paper takes Yantai city as the research object,based on remote sensing technology and mathematical statistical methods,in 1986-2018 for the study period,from 1986,1996,2006,2013 and 2018,five periods of remote sensing images get basic data.And combined with a variety of mathematical methods,this paper analyzes the characteristics of construction land expansion and cultivated land change in the time and space pattern in Yantai city during the past 32 years,and explores the game mechanism between construction land and cultivated land.The conclusions are as follows:1.The construction land area of Yantai city has grown significantly between 1986 and 2018.It has experienced three stages of rapid expansion,medium-low speed expansion and low speed expansion.During the expansion process,the scope of expansion is increasing,and the main land occupation is cultivated land.There are differences in the direction of spatial expansion in different periods;the trends of the average annual growth rate of both construction land and non-agricultural population are basically the same,but the relationship between them is not coordinated.By using the correlation analysis method: with the development of the economy,the transfer of agricultural population to cities has led to a rapid increase in demand for residential land.At the same time,the accumulation of labor has further affected the economic development,the people's living standards have improved,and the extension of related construction land such as industrial land and living land has been promoted,which will result in a large amount of agricultural land flowing to non-agricultural land.Therefore the expansion of construction land in Yantai city is an inevitable trend.2.The area of cultivated land in Yantai city decreased year by year during the study period,and the distribution of cultivated land area became more and more uneven with time.The shift of the center of gravity of the cultivated land indicates that the loss of cultivated land in the eastern and northern regions is serious,and the cultivated land in the west and the south has been protected;most of the transferred amount has changed into forestry grassland,followed by construction land;cultivated land experienced volatility reduction process in 32 years,and the per capita cultivated land area in each time period is lower than the national average.With the increase of regional GDP,more and more fixed asset investment tends to invest in real estate development investment,which has intensified the expansion speed of urban construction land,thus eroding a limited amount of cultivated land;with the increase of rural population income and the transfer to the city,the problems of rural population reduction,arable land reclamation,arable land reforming results garden,new home improvement and expansion of housing sites are increasing.The reduction and occupation of cultivated land is an inevitable trend.3.The game relationship between construction land and cultivated land change is essentially a problem between urban development and food security.By constructing a game model and conducting relevant analysis,it shows that higher-level governments can increase penalties and increase the penalties for local non-participation in farmland protection.Supervise the input cost and realize the protection of cultivated land;put forward corresponding suggestions for the problems existing in the expansion of construction land and the protection of cultivated land in Yantai City.