Study On Spatial-temporal Characteristics And Influencing Factors Of Cultivated Land Intensive Use Degree In Hilly And Gully Areas Of The Loess Plateau In Gansu Province

The natural conditions of cultivated land resources determine the potential productivity of cultivated land,and the degradation of cultivated land quality and the low degree of intensiveness are far more threatening to China’s food security than the reduction of cultivated land area.So,it is of great significance to alleviate the contradiction between agricultural production and consumption demand by improve the intensive degree of cultivated land.Therefore,the purpose of this paper is to provide reference for land use planning and sustainable development by study the temporal and spatial variations of cultivated land intensive use,and uses Kernel estimation and GWR model to explore the characteristics and influencing factors of intensive use level in Hilly and gully areas of the Loess Plateau in Gansu Province.The purpose of this paper is to provide a reference for the efficient and rational use of cultivated land resources in the region and to ensure regional food security.The results show that:(1)From 2001 to 2016,the intensive level of cultivated land use showed a gradual upward trend,but the growth rates were different in different research periods in the hilly and gully region of the Loess Plateau in Gansu Province.The intensive grade of cultivated land use has changed from extensive use to intensive use or highly intensive use.However,due to the differences of resource endowment and input factors,the intensive degree of cultivated land use among regions has increased while the regional differentiation has increased gradually.The intensive level of each criterion layer varies greatly and shows a trend of“Utilization > Output Efficiency > Input Degree”as a whole.(2)In the past 16 years,the spatial distribution of cultivated land intensive use level,input level,utilization intensity level and output efficiency level showed the rule of "point-zone-piece" in the hilly and gully region of the Loess Plateau in Gansu Province.The overall level of intensive degree of cultivated land utilization and output efficiency has been greatly improved,regional differences have been significantly expanded,and polarization characteristics have been highlighted.Intensive degree of investment and intensive degree of utilization change slightly but the spatial difference is obvious,and the distribution pattern of each time node using intensive degree of utilization is basically similar.(3)Besides the intensity-density curve of cultivated land utilization,the central position,peak shape,peak value of main peak and wave number of other all nuclear density indicated that the intensive level of cultivated land utilization was increasing continuously during the study period.The change range of cultivated land intensive use degree and output efficiency intensive degree is obviously increased,and the right extensibility is further enlarged and this phenomenon shows that the regional disparity in the intensive degree of cultivated land use and output efficiency continues to widen,and there are polarization characteristics in different degrees in the process of development.The conclusion is that the low and middle value intensive counties are gradually flowing to the high value areas,but at the same time,due to the difference of resource endowment and the degree of social and economic development,there is a big gap in the input of labor,capital and agricultural science and technology,which leads to a widening gap in the combination effect of cultivated land intensive use.(4)In a short period of time,the main factors affecting the intensive degree of cultivated land use are social and economic factors,and the driving factors have obvious spatial characteristics in different counties(districts).During the research period,the influence of the driving factors on the intensive degree of cultivated land use has gradually increased.The GWR model was used to analyze the regression coefficients of three dominant factors of fertilizer application rate per unit area of cultivated land,multiple cropping index and agricultural output value per unit area of cultivated land.The regression coefficients directly reflected the influence degree of each factor on different counties(cities and districts).