基于现场快速检测技术的土壤采样优化策略

合理的土壤采样策略是精确刻画场地污染情况的关键。以湖南某铬污染场地为研究对象,基于现场快速检测数据对反距离加权法(IDW)、普通克里金法(OK)、局部多项式法(LPI)和径向基函数法(RBF) 4种空间插值方法的精确度和适用性进行了比较;通过冗余分析确定了实验室分析样品的布点数量;分析对比了实验室检测与快速检测空间插值结果。结果表明:1)不同空间插值方法对场地污染分布识别存在明显差异,适用性排序为IDW法>RBF法>OK法>LPI法; 2)经基于快速检测阶段235个点位数据进行的采样策略优化,需送往实验室分析的采样点位减少至113个;3)快速检测技术可有效反映场地铬污染区域分布趋势。

FIELD RAPID SCREENING TECHNOLOGY DRIVEN SOIL SAMPLING OPTIMIZATION

A rational soil sampling approach is critical to accurately characterizing potentially contaminated sites. Rapid element screening was applied to a case study for a chromium-contaminated site in Hunan Province. The results were processed by four spatial interpolation methods, including inverse distance weighted (IDW), ordinary kriging (OK), local polynomial interpolation (LPI), and radial basis function (RBF) methods, aiming to compare their accuracy and feasibility on predicting contaminated area. Then, the redundancy analysis was leveraged to determine the number of samples collected for laboratory evaluation. Finally, the results of spatial interpolation between field rapid screening and laboratory analysis were compared. The findings were as follows: 1) the results of predicted contaminated area evaluated by four spatial interpolation methods were significantly different, the accuracy decreased in the qequence of IDW > RBF > OK > LPI; 2) the number of sampling locations needed for laboratory analysis decreased from 245 to 113; and 3) the rapid screening technology was effective in evaluating contamination distribution for chromium-contaminated sites.