基于控制区空间变异性的耕地质量监测样点布控方法%Sampling Method of Cultivated Land Quality Monitoring Based on the Monitoring Control Region Spatial Variability
河南省科学院地理研究所,郑州,450052 中国航空工业集团公司凯迈电子有限公司,河南洛阳,471003
2014-12-19
耕地质量 监测 空间变异 空间抽样 Kriging
监测样点布设是实现对区域耕地质量监测的基础。为了提高耕地质量监测精度,建立了一套基于监测控制区空间变异性的耕地质量监测样点布控方法。利用Neyman法确定在给定置信度和抽样误差下的研究区最优样点总数;根据耕地质量及其影响因素划定监测控制区,为研究区进行空间分层;利用变异系数为各控制区分配监测样点;在各控制区内采用空间随机法布设监测样点。为了对比该抽样法的估算精度,又采用空间随机抽样法和基于自然质量等别、基于控制区权重的分层抽样法等进行了其余4种抽样布设方案,并计算了5种样点布设方案的Krig-ing估计误差,通过对比发现,在相同的取样总数下,不同的样点布设方案估算精度差别显著,基于控制区空间变异性的耕地质量监测样区分层布控方法的RMSE最小。得出科学的监测样点布设方案,可以在最小的投入下获取最大的信息量,提高耕地质量监测效率和精度。%The basis for monitoring the cultivated land quality is the sampling method .In order to improve monitoring accuracy of the cultivated land quality , the study built a spatial sampling method of cultivated land qual-ity based on the monitoring control region spatial variability .This method calculated the optimal sampling number of the whole study area by Neyman method under a certain confidence and sampling error firstly .Then the whole study area was divided into several monitoring control regions based on the cultivated land quality and factors which af -fected the cultivated land quality .These monitoring control regions were used to stratified sampling .Samples dis-tributing for every monitoring control regions based on their spatial variance coefficient were the next step .The spa-tial random sampling method was used to array these distributed samples in every monitoring control regions .4 other kinds of sampling methods were used in this paper to contrast the estimation accuracy of this method include the spatial random sampling method , the stratified sampling method based on the physical quality grades of cultivated land and the stratified sampling method based on weights of monitoring control regions , etc.By contrasting the Kriging estimation error of these 5 kinds of methods , the estimation accuracy of different methods were different sig-nally with the same number of samples , and the estimation error ( measured by RMSE ) of the spatial sampling meth-od of cultivated land quality based on the monitoring control region spatial variability was smallest .In conclusion , a scientific sampling method can obtain the largest information and increase the efficiency and accuracy of the culti -vated land quality monitoring .
