空间抽样方法估算冬小麦播种面积

为改进现行农作物播种面积空间抽样技术体系,该文以山东省为研究区,以冬小麦播种面积为研究对象,通过"3S"技术(遥感、地理信息及全球定位技术)与传统抽样方法的联合应用,选取4种抽样技术(简单随机抽样、按冬小麦种植区划分层抽样、按耕地类型分层抽样和按分县冬小麦面积大小分层抽样),设计8种样本容量水平(变化范围74～333)进行了冬小麦播种面积空间抽样方法试验研究,结果表明:4种抽样方法中,在外推总体相对误差相近条件下,以分县冬小麦播种面积大小为分层标志的分层抽样方法效率最高;基于8种样本容量下的样本观测值进行研究区冬小麦播种面积总体外推与误差估计时,随着样本容量增加,外推总体总值估计值与真值的相对误差随之减小,但总体总值估计量的变异系数(CV)值仍较大。

Spatial sampling method for estimating winter wheat sown area

In order to improve the current crop acreage sampling survey systems,the experiment on spatial sampling methods for estimating winter wheat sown acreage was conducted combining the "3S"techniques(Remote Sensing,Geographic Information Systems and Global Positioning techniques) with the traditional sampling methods.Taken Shandong province as study area and winter wheat sown area as the study object,8 kinds of sample size from 74 to 333 and 4 sets of spatial sampling methods(simple random sampling method,stratified sampling with the winter wheat planting regionalization as stratification symbol,stratified sampling with cultivated land types as stratification symbol,stratified sampling with winter wheat sown area as stratification symbol in each county in study area) were designed in this experiment.The results demonstrated that:the efficiency of stratified sampling method which the winter wheat sown area in each county was selected as the stratum symbol is the highest among 4 sampling methods under the condition that the relative errors of 4 sampling methods were nearly equivalent.Inferring population values and estimating sampling error under 8 kinds of sample size level based on sample observations,and the relative errors between population total truth-values and estimates decreased with the sample size increased,however,variation coefficient(CV) of population total estimator was still higher.