反距离加权插值法在污染场地评价中的应用

Application of inverse distance weighted interpolation method in contaminated site assessment

确定污染场地的土壤修复范围在实际操作中存在很大的难度.本文以北方某废弃农药厂为例,结合专家判定采样法与网格采样法,采用地统计学方法中的反距离加权空间插值法,分两种情形将大于土壤环境基准值的区域划定为治理范围.结果表明,由于国家土壤环境二级标准主要适用于农业生产的土地,依据反距离加权空间插值后,以此标准确定的治理范围较大,而基于健康风险水平阈值所确定的修复范围和修复成本较小,较合理且经济可行.采用风险评价的反距离加权插值法确定污染场地的污染范围,为今后的场地评价和土壤修复提供了思路.

There are many difficulties in ascertaining the area that needs to be remedied in contaminated site. This paper integrated the experts＇ judgments with grids as the sampling strategy in an abandoned pesticide plant in northern China, and applied a geostatistical method, inverse distance weighted interpolation （IDW）, to simulate the pollutants- and risk spatial distribution. Based on soil environmental benchmark, two scenarios were designed for ascertaining the polluted area. The results showed that the area needed to be remedied and determined by IDW was somewhat larger, according to the national environmental 2nd standard for agricultural soils, but the area and cost needed for remedy were smaller and more economic and reasonable, based on the health risk threshold level and IDW method. A combination of IDW and health risk assessment in ascertaining polluted area would be a new way for site assessment and soil remediation in the future.