Research On Spatial-temporal Disparities And Influencing Factors Of Cultivated Land Intensive Utilization In Various Cities And Prefectures Of Sichuan Province

Cultivated land is an indispensable resource for human survival.Its scarcity and non-renewability make it strategically important in the national economy and human sustainable development.In recent years,with the rapid expansion of cities and towns and the rapid growth of population,the contradiction between man and land has become increasingly intensified.In order to ensure national food security and long-term social stability,while ensuring the number of arable land,exploring ways to improve the efficiency of arable land use is alternative.Sichuan Province,located in the upper reaches of the Yangtze River,is one of the major grain-producing provinces in China.Its soil and water conservation status directly affects the ecological balance of the whole Yangtze River basin,and ensuring its food security is an important link to ensure the food security of the whole country.In recent years,with the implementation of the "land consolidation" project and the "targeted poverty alleviation" policy in many cities and prefectures of Sichuan Province,the input of cultivated land has increased,and the cultivation conditions have greatly improved.Therefore,it is necessary to find out the current situation of intensive use of cultivated land in Sichuan Province and its dynamic changes under different policies,to explore the influential factors that restrict intensive use of cultivated land in Sichuan Province,and to find out the best utilization conditions of every influential factors.At the same time,it is also helpful to verify the effectiveness of the recent national policy in promoting the cultivated land use intensity in the province,and to provide a reference for the continued implementation or adjustment of the policy.Based on this,the agricultural economic statistical data of Sichuan provinces from 2000 to 2016 was selected to calculate the intensive degree by using the entropy method in this paper,and on the basis of guaranteeing the objective and scientific weights of indicators.the entropy method was improved by a secondary standardization of every indicators so that data in different years could be compared to reflect the vertical change of arable land use intensity.Further,the standard deviation ellipse was drawn using the spatial statistical module inArcGIS10.2,and the ellipses of different years were superimposed to represent the spatial differences and dynamic changes of cultivated land intensive use degree of each city and prefecture in Sichuan Province.In order to explore the reasons for the spatial difference of the intensive degree among cities and prefectures,five natural and human factors affecting the intensive degree of cultivated land in Sichuan Province were determined after consulting experts.The fresh GeoDetector model was introduced to explore the attribute values of the intensive degree,the contribution rates of each factor,the optimum utilization conditions of each factor and the interaction between the factors are discussed based on ArcGIS platform,meanwhile the method of extracting the spatial data was explored.Finally,the following conclusions are drawn:(1)For the spatial and temporal differences of cultivated land intensive use in Sichuan Province,the intensity of cultivated land use in Sichuan Province has been greatly improved in the past 20 years,with a slow growth rate before 2006 and fast after 2006,the average annual growth rate of is 12.87%.Spatially,the arable land use intensity of the cities on Chengdu Plain is generally higher,followed by the northeast ones,and the lowest in the west.Generally,the intensive degree of the cities in the northeast-southwest direction is higher than those in other directions.The intensities' spatial differences among the cities is gradually increasing,which shows an enhanced polarization effect.And the arable land intensive utilization center in the province has moved to the northeast direction by 55 km.(2)As far as the influencing factors of cultivated land intensive use in Sichuan Province are concerned,the regional GDP,annual precipitation of cities,policy support,the number of agricultural labor force and elevation have higher contribution rates than others.Among all the affecting factors,regional economic level,policy support,irrigation index and soil maturity are positively relative with cultivated land intensive use degree;slope and elevation are negatively correlated;precipitation and intensive use degree are approximately normal distribution;while the impact of earthquakes is not significant when the amounts is less than 38,but when over 38,the intensive use of cultivated land will be obviously restrained.(3)In order to improve the intensive use of arable land,the following measures couldbe adapted by governments at all levels: deepening land management to ensure the quality and quantity of arable land;attaching importance to agriculture,countryside and farmers,formulating reasonable policies to attract labor back home;further developing the economy,vigorously improving the conditions of arable land utilization;improving the ecological environment of arable land utilization and strengthening early warning of natural disasters.