采样点数量对黄河三角洲垦利县土壤盐分空间变异的影响

发布时间：2018-08-01 12:58

【摘要】：对土壤盐渍化的监测是合理利用盐渍化土壤的前提,采样点数量不同会影响土壤盐分空间变异的表达。本文以黄河三角洲典型地区垦利县为研究区,采用地统计学方法,抽取了12个样本子集,探讨不同的采样点数量对土壤盐分空间变异表达的影响。研究结果表明,黄河三角洲地区土壤盐分变异程度较大,随着样点数量的减少,对于细节的刻画能力也在减弱,样点数量过小时(150个),不能很好地表达空间变异结构。不同采样点数量下的预测值均方根误差(RMSE)随样本量的增大而减少,说明克里格插值的准确度随样本量的减少呈现降低趋势,平均误差(ME)则随样本量的减小而没有明显的趋势。综合ME、RMSE和ASE 3个指标可以得出,满足黄河三角洲地区县域尺度土壤盐分空间变异表达的土壤样点数量不能小于150个,相当于每1000km2需采集107个样点。
[Abstract]:Monitoring of soil salinization is the premise of rational use of salinized soil. Different sampling sites will affect the expression of spatial variation of soil salinity. Taking Kenli County, a typical area of the Yellow River Delta, as the study area, 12 subsets of samples were collected by geostatistics to study the effect of different sampling sites on the spatial variation of soil salinity. The results show that the variation degree of soil salinity in the Yellow River Delta region is great. With the decrease of the number of samples, the ability to depict the details is also weakened, and the number of samples is too small (150 points), which can not well express the spatial variation structure. The root mean square error (RMSE) of the predicted values at different sampling points decreases with the increase of sample size, which indicates that the accuracy of Kriging interpolation decreases with the decrease of sample size, while the mean error (ME) decreases with the decrease of sample size. It is concluded that the number of soil samples satisfying the spatial variation of soil salinity in the county scale of the Yellow River Delta can not be less than 150, which is equivalent to 107 samples per 1000km2.
【作者单位】：青岛农业大学资源与环境学院;中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室;长江水利委员会长江科学院;东营市农业局;
【基金】：青岛农业大学高层次人才启动基金项目(1114344) 土壤与农业国家重点实验室开放基金项目(Y20160007) 国家自然科学基金项目(41601211)
【分类号】：S156.41

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