一种基于地层相关结构约束的地质模型修正方法  

Error Correction in Geological Model Based on Stratigraphic Interdependency

作　　者：梁栋 花卫华[1] 赵亚博 刘志鹏 刘修国[1] Liang Dong;Hua Weihua;Zhao Yabo;Liu Zhipeng;Liu Xiuguo(School of Geography and Information Engineering,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中国地质大学地理与信息工程学院,湖北武汉430074

出　　处：《地球科学》2023年第8期3179-3192,共14页Earth Science

基　　金：国家重点研发计划课题“城市地下全要素信息集成与智能建模技术”(No.2019YFC0605102)。

摘　　要：在地质勘探中,多数钻孔存在深部地层底板未采样的情况,不完整的采样信息限制了地质模型的准确性.为了提高模型准确性,提出了一种基于地层相关结构约束的地层面模型修正方法.由于地层的形成机制及后期构造运动,相邻地层的形态具有相似性.基于此,利用Copula函数对相邻地层面的相关结构进行建模,构建相邻地层面的联合分布模型和待更新地层面的似然函数.在贝叶斯框架中,利用似然函数对待修正的模型进行贝叶斯更新,得到地层面的后验分布,计算地层面的条件期望作为模型修正值.利用该方法,对北海海岸带地区的钻孔数据和地层面模型进行了实验.实验结果表明,模型修正后,地层面模型的误差降低,所提方法可以提高地质模型准确性.In geological exploration,the bottom interface of deep stratum is not sampled in most boreholes,and incorrect sample information limits the accuracy of geological models.In order to improve the accuracy of geological model,we proposes a method to correct geological model based on stratigraphic interdependency.Due to the formation mechanism of the strata,the morphology of the adjacent strata is similar.Based on this character,the Copula function is used to model the dependence structure of adjacent strata,and the joint distribution model of adjacent strata and the likelihood function of the stratum to be corrected are constructed.In the Bayesian framework,the established interface model is taken as the prior model,and the likelihood function is used to update the prior model to obtain the posterior distribution.In the end,the condition expectation of the interface is calculated as the posterior model.The proposed approach is illustrated through a case study of the geological interface model of the coastal zone near Beihai.The results show that the error of the geological interface model is reduced after model correction.

关 键 词：地质模型 误差修正 地层相关结构 贝叶斯 COPULA 

分 类 号：P628[天文地球—地质矿产勘探]