Exploratory Research Of Space Sampling Method In Grain Yield Survey

When traditional sampling technology processes data with spatial information,it is difficult to fully capture its spatial characteristics and ignore the influence of the spatial attributes of the overall unit.In fact,there is a general spatial correlation between any overall unit.As a revolution and expansion of classical sampling,spatial sampling technology is a hot topic of current interdisciplinary research.Especially with the development of GIS and other technologies,it provides methodological support for the expansion of classical sampling design.Based on the background of grain production in Inner Mongolia,this article mainly designs sampling for spatially relevant resources and survey objects.The article first sorts out the basic theories and methods of sampling survey,compares and analyzes the theoretical differences between traditional probability sampling and spatial statistics,and summarizes the advantages of spatial sampling methods on this basis.Then,from the perspectives of time and space,the regional differences and evolution trends of the spatial distribution of per capita grain occupancy patterns in the counties of Inner Mongolia are discussed.Through spatial correlation tests,it is found that the target population has a strong spatial correlation,which is suitable for spatial sampling.method.In the empirical part,first use the traditional sampling method PPS sampling and ratio estimation to carry out sampling design and statistical inference on the per capita grain occupancy.In the sampling design,select the cultivated land area and crop sown area with high correlation with the target variable as auxiliary Information to improve the representativeness of the sample.Then,on the basis of traditional sampling design,combined with the spatial distribution characteristics of per capita grain occupancy,the spatial information of the overall unit is introduced into the sampling design,and the spatial clustering distribution map generated by local spatial autocorrelation analysis is used to obtain the sampling frame "dynamically",To achieve spatial stratified sampling,and use spatial correlation Poisson sampling to obtain balanced samples using latitude and longitude coordinates.Finally,compare the inferred results obtained by the spatial sampling method and several traditional sampling methods with the true values,and select multiple indicators such as sampling error,Moran's I,and survey cost as the evaluation criteria to measure the sampling efficiency,according to different sampling methods Perform performance evaluation and comparative analysis,and finally realize the optimal selection of sampling methods.The research results show that the level of food security in Inner Mongolia's counties continues to be optimized,but there are large differences in the level of per capita food occupancy between regions.The main food production areas are mostly concentrated in the eastern and central western regions with obvious spatial characteristics.The empirical results show that when the survey subjects have a strong spatial correlation,the sampling units obtained by the two spatial sampling methods designed in the article are obviously more representative when the same sample size is drawn,and the spatial stratification The result of sampling method estimation has the smallest variance,and the spatial pattern of the sample has the strongest similarity with the overall spatial pattern;while the estimation result of spatial balanced sampling method has the smallest relative error,and the spatial correlation of the sample points is the weakest,To achieve the uniform distribution of sample points in space.This proves that under the assumption of spatial correlation based on the non-independent sample,spatial sampling in practical applications can not only improve the representativeness of the sample,but also reduce the cost of the survey to a certain extent,which is conducive to improving the estimation of overall parameters.quality.Therefore,in view of the excellent nature of spatial sampling methods,spatial sampling techniques may provide new ideas for the application in the field of agricultural sampling surveys,which may provide a certain reference for the design of relevant departments to carry out sampling surveys of agricultural output.