A geostatistical approach is applied for extracting the geochemical background from gamma dose rate data acquired downstream of a former French uranium mining area. The exploratory data analysis shows that the spatial structure of the gamma dose rate consists of two components: a short isotropic component (10 m-range) that corresponds to the geochemical background; and a long anisotropic component (30–60 m-range) that corresponds to the drainage network features previously fed by the mine discharge water. The gamma dose rate on the whole area of interest was estimated and simulated (to deal with uncertainties) through a kriging of the measured values. The spatial component related to the geochemical background was then extracted through factorial kriging. The proportion of the gamma dose rate explained by the geochemical background according to factorial kriging is consistent within uncertainties with geochemical analyses performed on soil and sediment samples. This study thus highlights the potential of such geostatistical approaches for better exploiting radiometric data.

应用地质统计学方法从前法国铀矿区下游采集的伽马剂量率数据中提取地球化学背景。探索性数据分析表明，伽马剂量率的空间结构由两部分组成：与地球化学背景相对应的短各向同性分量（10 m 范围）；和一个长的各向异性分量（30-60 m 范围），对应于以前由矿井排放水供给的排水网络特征。通过测量值的克里金法估计和模拟整个感兴趣区域的伽马剂量率（以处理不确定性）。然后通过阶乘克里金法提取与地球化学背景相关的空间分量。根据析因克里金法由地球化学背景解释的伽马剂量率的比例与对土壤和沉积物样品进行的地球化学分析的不确定性一致。因此，这项研究强调了这种地质统计学方法在更好地利用辐射数据方面的潜力。