高放废物地质处置新场候选场址地下水位异常值识别方法  

A method for identifying anomalous values of groundwater levels at candidate sites for the geological disposal of high-level radioactive waste

作　　者：吉子健 周志超[1,2] 赵敬波 季瑞利[1,2] 张明 JI Zi-Jian;Zhou Zhi-Chao;Zhao Jing-Bo;JI Rui-Li;ZHANG Ming(Division of Environmental Engineering,Beijing Research Institute of Uranium Geology,Beijing 100029,China;CAEA Innovation Center for Geological Disposal of High-Level Radioactive Waste,Beijing 100029,China)

机构地区：[1]核工业北京地质研究院环境工程研究所,北京100029 [2]国家原子能机构高放废物地质处置创新中心,北京100029

出　　处：《物探与化探》2024年第6期1530-1538,共9页Geophysical and Geochemical Exploration

基　　金：铀资源探采与核遥感全国重点实验室基金项目(NKLUR-2024-QN-004);国防科工局核设施退役治理专项科研项目(科工二司〔2022〕736号);中核集团2022年基础研究项目(CNNC-JCYJ-202206)。

摘　　要：地下水动态监测为高放废物地质处置候选场址的安全评价提供了关键基础数据,但研究发现实际的监测数据中存在较多异常值,严重干扰了对动态过程的准确判断。因此,亟须建立一种高效的方法对异常值进行准确识别。本文基于局部加权回归的时间序列分解和最小协方差行列式方法构建了地下水位异常值检测组合模型,使最小协方差行列式方法可以在更独立的残差项中进行异常值检测。结果表明,构建的组合模型相较于最小协方差行列式方法的单一模型,其对异常数据具有更好的敏感性和检测精度;并进一步确定了组合模型的阈值应接近实际的异常值比例,以获取最佳的检测效果;此外,根据新场地段BSQ01、BSQ25、BS35、BS26钻孔的水位数据对组合模型的适用性进行验证,表明其能够准确识别出混淆于大量正常水位数据中的异常值,同时也适用于不同类型异常事件的检测。Dynamic groundwater monitoring provides critical foundational data for the safety assessment of candidate sites for the geological disposal of high-level radioactive waste.However,research has revealed that actual monitoring data frequently contain numerous anomalous values,severely interfering with the accurate assessment of the dynamic monitoring process.Therefore,there is an urgent need to develop an efficient method to accurately identify these anomalous values.This study built a combined model for anomalous value detection of the groundwater level using local weighted regression-based time series decomposition and the minimum covariance determinant(MCD)method.This combined model allowed the MCD method to achieve anomaly detection in more independent residuals.Results indicate that the combined model exhibited higher sensitivity and detection accuracy for anomalous data than the single MCD model.Furthermore,this study established that the threshold of the combined model should be close to the actual proportion of anomalous values to achieve optimal detection results.Besides,this study validated the applicability of the combined model using groundwater level data from boreholes BSQ01,BSQ25,BS35,and BS26 at the new site.The validation results demonstrate that the combined model can accurately identify anomalous values amidst a large volume of data on the normal groundwater level and is applicable to the detection of different types of anomalous events.

关 键 词：时间序列异常检测 STL分解 最小协方差行列式方法 高放废物 地质处置 

分 类 号：P641[天文地球—地质矿产勘探]