Spatial And Temporal Change Analysis Of Crop Planting Structure In Binxian Based On RS Technology

In recent years,the government has attached great importance to the problem of agriculture,rural areas and farmers,and the planting and production of grain is the foundation of agricultural development.The adjustment of crop planting structure is an important measure of rural economic development in recent years,which can promote the sustainability of grain development,enhance the market competitiveness of crops and increase farmers' enthusiasm for planting.Binxian as an important grain planting area in Harbin,can understand the distribution characteristics of crops and promote the sustainable development of agriculture by analyzing the change of crop planting structure.It is of great significance to increase farmers' economic income and ensure food security.Based on RS technology,this paper uses ERDAS software and Arc GIS software to deal with the situation of crop cultivation in Binxian,which is divided into five periods: 1997,2002,2007,2011 and 2017.The remote sensing data used in this paper are Landsat4-5-TM image,Landsat7-ETM image,Landsat8-OLI image and Wfv2-GF image.Non-remote sensing data mainly include Binxian Land use status Map,Harbin Meteorological data,socio-economic data and so on.When processing remote sensing data,use the The remote sensing image was pre-processed by ERDAS software,then the unsupervised classification was used to classify the crops.Finally,the accuracy was verified.Based on GIS spatial analysis,this paper studies the spatial and temporal variation characteristics of crop structure in Binxian by analyzing the changes of crop quantity,gravity center,crop spatial auto correlation and crop planting structure.Fragstats3.4 software was used to calculate the landscape pattern index of five study periods in Binxian.Finally,the reasons for the change of planting structure in Binxian were analyzed through the natural and cultural conditions of Binxian in recent years.Studies have shown that:(1)Analysis of the spatio-temporal variation of crop quantity.From 1997 to 2017,the planting quantity of soybean,corn and rice in Binxian showed a trend of "two minus one increase",and the planting area of soybean decreased from 43454 hm2to 4915 hm2.The range of change was-88.69%,and the dynamic attitude was-4.44%.The growing area of maize increased from64452 hm2to 147455 hm2,changing by 128.78% and dynamic by 25.68%,while the area of rice decreased from 10089 hm2to 6535 hm2by-35.23%.And the dynamic attitude is-7.05%.(2)Analysis of the characteristics of crop planting structure.Through the calculation of the center of gravity migration model,it was found that the center of gravity of the main crops in the study area had obvious changes.The center of gravity of soybean and maize moved to thesoutheast,the center of gravity of rice moved to the north,and the moving track was "C".The global auto correlation and spatial auto correlation of crops in the study area were calculated by using Arc GIS software combined with data collection.The results showed that there was significant spatial positive correlation and aggregation phenomenon in the variation of each unit.The high and high concentration areas of soybean changed obviously and showed a decreasing trend;the low and low planting areas of maize were more stable and high.The accumulation area increased,and the accumulation area of rice was more stable,and the change was not very obvious.The change trend of crop proportion in Binxian was analyzed by univariate regression analysis according to the year.The results showed that the main increasing areas of soybean were in Baidu town,Shengli town and so on.The soybean planting level in most townships has decreased,and the corn planting structure has shown an increasing trend,generally ending in the south of Juren Town and the southern part of Shengli Town,with an overall growth trend in the north and a decreasing trend in the south.There was no significant change in rice planting structure,but the structure was relatively stable.(3)Analysis of crop landscape pattern.The degree of polymerization and patch cohesion index of maize and rice in the study area generally showed an upward trend,while the soybean showed a downward trend and a larger extent.The landscape shape index of rice was lower,but the value of soybean and corn was higher,which was influenced by man-made factors,and the stability was relatively weak.The change trend of maximum patch index and patch area ratio index in maize decreased first and then increased,while soybean showed the opposite trend.Through the analysis of the changes of planting structure in Binxian County in the past 20 years,combined with socio-economic data,population data,meteorological data and related agricultural policies,This paper analyzes the changes of agricultural planting structure from two aspects: natural factors and humanistic factors,and provides the basis for the development of agriculture in Binxian.