A Spatial Convenience Sampling Method For Forest Biomassfield Investigation

Forest Biomass is an important indicator of forest production capacity,which is a direct manifestation of forest environmental quality and structure and function.In the process of estimating regional forest biomass,ground-based data are required to be supported to statistical inference or model validation,and the ground space sampling method currently used is usually to cover the entire study area in probability,and the investigators need to Long distance travel,sampling efficiency is low,the current ground survey is still very few in taking the sampling accuracy at the same time,a significant reduction in the cost of sampling methods.In this paper,a spacial convenience sampling method for field investigation of forest biomass is proposed by combining the advantages of convenience sampling and stratified sampling.The specific sampling steps were carried out for the dynamic monitoring and inventory of forest biomass,and implemented in the Xiaoxing'anling area.Select appropriate sampling accuracy(sampling standard error,mean value of sample)and sampling cost(sampling time)evaluation index to measure the performance of the sampling method.Factors which may affect the efficiency of the method such as sampling area width,stratification numbers,sample size and other factors were analyzed in both qualitative and quantitative ways and provided reference for optimizing sampling design.The main conclusions are as follows:1)This paper constructs a spatial convenience sampling method for field investigation of forest biomass.The basic idea is to ensure that the sampling accuracy is achieved by making the sampling area similar to the frequency distribution of the forest biomass in the study area,and the sampling area of the forest biomass is limited to the sampling area on both sides of the road to greatly reduce the sampling cost of the ground.And the advantages of both sampling costs.2)The specific design steps of the convenient space sampling method for the field investigation of forest biomass mainly include the determination of the three main parts of the sampling area,the stratified sampling design and the sampling of the inner sample;and the sampling unit for the forest biomass inventory and dynamic monitoring and extraction And the extraction steps will be different,the former is the forest biomass of the ground sample extraction,the latter is the vegetation index pixel extraction.3)In the case of the same sample size,the sampling sampling area has the same sampling accuracy as the forest biomass sampling in the study area.The sampling samples for convenience sampling are located in the sampling area on both sides of the road.The sampling cost is reduced effectively,and the sample of the traditional spatial sampling is located in the whole research area,which causes the survey personnel to walk away from the ground,and the sampling cost is greatly increased.Through the simulation test in the test area,Convenience space sampling can improve the sampling efficiency by 64.65%,the advantage is more obvious.