Spatial-Temporal Pattern And Zoning Of Cultivated Land Functions In Shandong Province

Shandong Province is the major agricultural production area in China,but the contradiction between people and land is serious now and people have neglected the function of cultivated land for a long time.So researching the function of cultivated land is of great significance to optimize the pattern of cultivated land use and promote the sustainable development of agriculture in Shandong Province.Applying data-intensive knowledge mining,integrating geographic information methods and models,and using multi-source big data such as land use,topography,climate,socio-economic,remote sensing and other data,this paper divided five functions of cultivated land including grain production,social security,habitat maintenance,water conservation and landscape aesthetics,and the evaluation methods of each function were determined.Then the 1 km × 1 km grid was used as the evaluation unit to carry out precise evaluation of cultivated land functions in 2000,2005,2010 and 2015.After that,the spatial pattern,temporal evolution and spatiotemporal correlation of cultivated land functions were revealed by GIS spatial analysis,hotspot analysis and bivariate spatial autocorrelation,the numerical features and spatial pattern of trade-offs and synergies were analyzed by Spearman rank correlation and spatial autocorrelation.Finally,using spatial clustering and geodetector,the cultivated land functions in 2015 were rationally zoned,and the cultivated land management modes of different areas were proposed.The findings are as follows:(1)Spatial pattern and temporal evolution of cultivated land functions.In Shandong Province,the grain production function of cultivated land was stronger in the west,the social security function was prominent in the Jinan metropolitan area,the high value area of habitat maintenance function was concentrated in the middle mountain area,the water conservation function gradually weakened from south to north,and the high value area of landscape aesthetic function was concentrated in the eastern region.Overall,habitat maintenance and water conservation functions showed weakening trend in 15 years,and other functions showed increasing trend.The multi-functionality of cultivated land was weakest in 2000 and strongest in 2005,strong in south and weak in north.(2)Temporal and spatial correlation characteristics of cultivated land functions.The temporal and spatial related Global Moran?s I of all cultivated land functions were positive and exceed 0.5,and the correlation of outward diffusion was significant.From a local point of view,the positive correlation was obvious,for each function of cultivated land was mostly high or low agglomeration at different time periods,and low-high or high-low concentration units were rare.The spatial and temporal correlation pattern of habitat maintenance and landscape aesthetic functions was relatively stable,and others were relatively changeable.(3)Trade-offs and synergies of cultivated land functions.The habitat maintenance function,social security and food production functions showed a growing trade-off relationship.The relationship between food production function,social security and water conservation functions changed from synergies to growing trade-offs.The water conservation function and social security function showed a weakening synergy relationship.There were strong synergies between habitat maintenance,water conservation,and landscape aesthetics functions.From the perspective of spatial pattern,the trade-off and synergy coupling pattern of landscape aesthetics and habitat maintenance functions was relatively stable,while the coupling pattern between other functions showed a certain degree of change.(4)Zoning of cultivated land functions and its management modes.The food production area ought to promote grain production efficiency and ensure stable and high grain yield.The efficient agricultural area should take the road of intensive agricultural development and guarantee the ecological security of cultivated land.Urban agriculture area should develop modern urban agriculture with emphasis on leisure agriculture and characteristic landscape.The balanced development area should highlight agricultural advantages and promote the compound utilization of cultivated land space.The ecological agriculture area should focus on developing sightseeing agriculture and building green agriculture production base.The weak functional areas should around the improvement of saline-alkali land,with a focus on improving the productivity of cultivated land and maintaining the sustainable use of cultivated land resources.This paper only carried out a preliminary research on functions of cultivated land in Shandong province,which needs to be further improved in the future.For example,the evaluation of cultivated land functions is not comprehensive,for only five typical cultivated land functions were researched,so there is an urgent need to construct a theoretical and widely accepted standard and system for the classification of cultivated land functions.Besides,with the improvement of evaluation models and data accuracy,the uncertainty in the evaluation can be further reduced by narrowing evaluation units and using more scientific evaluation methods.Moreover,through selecting smaller statistical units such as township,subdistrict and village,or directly using grids to analyze the characteristics of cultivated land functions,the accuracy of spatial-temporal pattern analysis and zoning can be improved.