基于PCA-GWR的包气带不同土层饱和导水率的传递函数及其回归克里金估计  

Pedo-Transfer Function and Regression Kriging Estimation of Saturated Hydraulic Conductivity of Different Soil Layers in Vadose Zone Based on PCA-GWR

作　　者：湛江 李志萍 赵贵章 王琳 袁巧灵 Zhan Jiang;Li Zhiping;Zhao Guizhang;Wang Lin;Yuan Qiaoling(College of Geosciences and Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450003,China;Collaborative Innovation Center of Water Resources Efficient Utilization and Protection Engineering of Henan Province,Zhengzhou 450003,China;Geological Environment Monitoring Institute of Henan Province,Zhengzhou 450003,China)

机构地区：[1]华北水利水电大学地球科学与工程学院,河南郑州450003 [2]水资源高效利用与保障工程河南省协同创新中心,河南郑州450003 [3]河南省地质环境监测院,河南郑州450003

出　　处：《地球科学》2024年第3期978-991,共14页Earth Science

基　　金：国家自然科学基金项目(No.41972261);河南省自然资源厅2019-2020年度科技项目(No.201937913)。

摘　　要：饱和导水率是重要的土壤水力学参数,对渗流和溶质运移研究起着至关重要的作用.土壤传递函数可以代替大规模采样和室内外试验间接预测该参数,但由于土壤的空间变异性以及方法的局限性等原因,以往的传递函数往往精度有限.本文以黄河下游沿岸兰考县闫楼乡包气带不同土层为研究对象,基于64个钻孔数据,将土壤粒径分布(黏粒、粉粒和砂粒含量)、土壤结构分形维数、干容重、总孔隙度、pH值、有机质和电导率等9个基本理化特性参数作为影响因素,基于逐步回归、主成分回归和主成分-地理加权回归(PCA-GWR)三种方法,分别对研究区包气带不同土层的饱和导水率进行回归分析,比较精度后基于PCA-GWR对饱和导水率进行地理加权回归克里金插值.结果显示,除表层粉土以外,PCA-GWR法的预测精度有显著优势.不同土层传递函数和饱和导水率分布的差异性表明,由于黄河下游地区快速多变的沉积过程、黄河的决口改道以及人类活动等因素,包气带土层相变剧烈,土壤饱和导水率在平面上亦具有明显的非平稳特征.而局部地质作用和人类活动是第二层粉土层回归克里金估计结果欠佳的深层原因.Saturated hydraulic conductivity is a significant soil hydraulic parameter,which plays an important role in the research of seepage and solute transport.Pdeo-Transfer Functions(PTFs)can indirectly predict this parameter instead of large-scale sampling and indoor and outdoor tests.However,due to the spatial variability of soils and the limitations of methods,previous predictions of PTFs are not accurate enough.This study takes different soil layers in the vadose zone of Yanlou Township,Lankao County,the lower reaches of the Yellow River as the research object.Based on 64 borehole data,nine basic physicochemical properties such as soil particle size distribution(clay,silt and sand content),soil structure fractal dimension,dry bulk density,total porosity,pH value,organic matter and electrical conductivity are considered as the influencing factors of the PTFs.Based on Stepwise Regression,Principal Component Regression and Principal Component AnalysisGeographically Weighted Regression(PCA-GWR),the saturated hydraulic conductivity of different soil layers is regressed separately.After comparison of precision,Geographically Weighted Regression Kriging is carried out for saturated hydraulic conductivity based on PCA-GWR.The results reveal that the prediction accuracy of PCA-GWR method has significant advantages except for the surface silt.The difference of the distribution of saturated hydraulic conductivity and PTFs in different soil layers shows that,due to the rapid and changeable sedimentation process in the lower reaches of the Yellow River,the breach and diversion of the Yellow River and human activities,the phase change of soil layer in the vadose zone is intense,and the saturated hydraulic conductivity also has obvious non-stationary characteristics in the plane.The local geological process and human activities are the deep reasons for the poor regression Kriging estimation results of the second layer of silt.

关 键 词：包气带 土壤饱和导水率 土壤传递函数 地理加权回归 地质统计学 回归克里金插值 水文地质 环境地质 

分 类 号：P641[天文地球—地质矿产勘探]