基于Fisher判别准则的河湖相判别模型的构建:以江汉盆地汉江上游段为例  

Discriminant Model of River-Lake Facies in the Upper Reach of Hanjiang Section of Jianghan Basin Based on Fisher Principle

作　　者：张鑫[1] 梁杏[1] 孙立群[1] 宋晨 李琳[2] Zhang Xin;Liang Xing;Sun Liqun;Song Chen;Li Lin(School of Environmental Studies,China University of Geosciences,Wuhan 430074,China;State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中国地质大学环境学院,湖北武汉430074 [2]中国地质大学生物地质与环境地质国家重点实验室,湖北武汉430074

出　　处：《地球科学》2020年第11期4254-4266,共13页Earth Science

基　　金：国家自然科学基金项目(No.41772268);中国地质调查局项目(No.12120114069301)。

摘　　要：为了探究Fisher模型在盆地第四纪河湖相演变上的实用性,以江汉盆地汉江上游段某单一钻孔的粒度资料和沉积相划分作为模型的训练样本,利用Fisher基本原理计算得到河湖相判别模型,最终利用模型实现对研究区沉积环境演化分析.依据单因素方差以及显著性分析结果可知,Fisher模型对河流相、河湖过渡相、湖相具有很好的区分效果.留一交叉验证结果达到80.6%,超过了判别模型应用要求的75%标准.同时,将多孔沉积相判别结果与定性划分结果进行了对比,其综合吻合率达到85.06%,进一步验证了Fisher模型在河湖相判别上的实用性.依据判别分析结果可知,自早更新世开始,研究区存在4期较大的沉积旋回,可划分为8个沉积阶段,不同沉积阶段水动力来源复杂且变化迅速,区域沉积环境演化与新构造运动相吻合.本研究说明依据粒度资料建立Fisher模型用于沉积相以及沉积环境的分析是可行的,同时丰富了江汉盆地汉江段沉积环境资料,为盆地水资源调查及保护提供重要参考.In order to explore the practicality of the Fisher model in the Quaternary river-lake evolution of the basin,in this paper it takes the particle size data and sedimentary facies of a single borehole in the upper reach of the Hanjiang River in the Jianghan basin as the training samples of the model,which is calculated by Fisher’s basic principle.Then the river-lake phase discrimination model is used to analyze the sedimentary environment evolution of the study area by using the model discrimination results.According to the one-way variance and the significance analysis results,the Fisher model has a good distinguishing effect on the river phase,the river-lake transition phase,and the lake phase.The leave-one-out-cross-validation result reaches 80.6%,exceeding the 75%standard required for the discriminant model application.At the same time,the results of the quantitative evaluation of porous sedimentary facies are compared with the qualitative classification results,and the comprehensive coincidence rate reaches 85.06%,which further verifies the practicality of the Fisher model in the identification of rivers and lakes.According to the results of discriminant analysis,since the Early Pleistocene,there are four large sedimentary cycles in the study area,which can be divided into eight sedimentary stages.The hydrodynamic sources are complex and changing rapidly in different sedimentary stages,and the regional sedimentary environment evolution and Neotectonic movement are consistent.This study demonstrates that it is feasible to establish Fisher model based on particle size data for analyzing sedimentary facies and sedimentary environment,and enrich the sedimentary environment data of Hanjiang Section of Jianghan basin.It provides an important reference for basin water resources investigation and protection.

关 键 词：Fisher模型 沉积相识别 江汉盆地 第四纪 沉积环境 环境地质 

分 类 号：P53[天文地球—古生物学与地层学]