Driving Forces For Cultivated Land Use Change In Chongqing Based On Multi-Spatial Scale

Studying the driving factors that cause the change of cultivated land is conducive to solving the contradiction between current population,economic and social development and cultivated land resources.Nowadays,the simulation analysis of the changing trend,driving mechanism and changing process are mainly focused on the research of cultivated land use change.Many researches are carried out at different spatial scales.However,the stratified nature of cultivated land data is not well reflected when it it analyzed.Lots people ignored the comprehensive analysis of cultivated land change in the regional perspective.They have not further explored the regularity of cultivated land change at different scales.Based on the linear analysis of the related factors of cultivated land change,I improved the model that used for the research of the driving force of cultivated land change based on time series.Then I used the combination of spatial statistics and econometrics to analyze the change of cultivated land at different spatial scales in Chongqing.On this basis,the model is used to simulate the change trend of cultivated land area in different spatial scales,and the driving factors of cultivated land change are measured.The spatial and temporal dimensions of cultivated land change are analyzed to reveal the driving factors to cultivated land under different spatial and temporal scales.The theoretical framework of cultivated land use at different spatial scales is constructed with the scale effect and the mechanism of driving factors in this paper.Furthermore,I proposed the countermeasures for the management and protection of cultivated land in the study area.The results show that:(1)The rate of cultivated land change in Chongqing increased from southeast to northwest over time during the study period.The regional differences in cultivated land area between county scales and functional block scales have increased year by year.The smaller the research scale,the easier the spatial correlation of the distribution of cultivated land was.(2)The system dynamics model was used for the simulation of the cultivated land change.And the results have shown that the impact of urbanization rate on cultivated land area in the longevity area> the impact of GDP on cultivated land area> the impact of population growth on cultivated land area.(3)In the one-hour economic circle of Chongqing,the overall change trend of the radiation circle in the core area during the 10-year research period was expanding.83.33% of the urban gravitational change value in the scope of gravitation is significantly correlated with the change of cultivated land area,while only 33.33% of the urban gravitational change value outside the administrative scope is correlated with the cultivated land area.And the greater the gravity of the area,the more easily the correlation was expressed.(4)For Chongqing,the spatial difference at the county scales is relatively large,and it is more suitable to study the change of cultivated land.The driving force of cultivated land change in Chongqing is 33.80% at block level and 66.20% at district and county level.Large-scale driving factors will change the positive(negative)correlation of small-scale driving factors on cultivated land changes.In view of the above research results,the following conclusions can be drawn.In the future,Chongqing should consider the scale effect problem in the management of cultivated land,and scientifically decompose the farmland protection task according to the spatial scale to improve the efficiency of farmland protection work.The primary task is to intensive use of urban construction land within the scale of each functional block and control over the occupation of cultivated land.Then they should improve the farming conditions at county scales,especially in the counties away from the city center,followed by continuous and stable intensive use of cultivated land.