基于Hydrus-1D对西坝镇农田土壤重金属迁移模拟及空间解析  

Simulation and Spatial Analysis of Heavy Metal Migration in Xiba Town Soil Based on Hydrus-1D

作　　者：万朔阳 吴勇[1,2] 唐学芳 邓东平 兰真 韩莉璧 WAN Shuo-yang;WU Yong;TANG Xue-fang;DENG Dong-ping;LAN Zhen;HAN Li-bi(College of Environment and Civil Engineering,Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu 610059,China)

机构地区：[1]成都理工大学环境与土木工程学院,成都610059 [2]地质灾害防治与地质环境保护国家重点实验室,成都610059

出　　处：《科学技术与工程》2020年第2期854-859,共6页Science Technology and Engineering

基　　金：四川省科技重点研发项目(2018SZ0327)。

摘　　要：为了研究区域内土壤重金属迁移规律及分布特征,在基于整体土壤重金属背景值的基础上,选用四川西坝镇高产农田作为研究对象,通过对研究区所取土样进行淋滤实验,得到不同时间渗漏液中Cd、Cu、Zn、Cr离子浓度变化量,并运用Hydrus-1D对研究区土壤建立非饱和带一维水流溶质运移模型,模拟在稳定水流作用下,垂向上各迭代时间土壤重金属的迁移量;同时借助地下水建模系统(groundwater modeling system,GMS)对研究区建立空间模型,分析区域内土壤重金属空间分布特征。模拟结果表明:随淋滤时间增加土壤重金属含量逐渐降低,淋滤第4 d四种离子迁出量都已接近最小值,Cd、Cu、Zn、Cr离子变化量实验值均能与模拟值较好拟合,线性回归R2分别为0.932、0.951、0.936、0.965;空间分布特征显示:研究区重金属分布与地下水流向和土壤重金属的初始含量相关,外界污染源及浅层地下水水流路径迁移过程中的溶滤作用是造成研究区域内不同土壤重金属分布差异的主要因素。此次研究结果为进一步研究区域重金属迁移特征提供了理论依据及分析方法。To study the migration and distribution characteristics of heavy metals in soils of the Xiba Town,Sichuan,SW China,leaching experiments on soil samples were carried out to reveal the changes in Cd,Cu,Zn,and Cr ion concentrations in the leachate of different times,in which the Hydrus-1D software was applied.An one-dimensional flow solute transport model in unsaturated zone of soil in the study area was established,and the migration of heavy metals in the soil during the vertical iteration was simulated under the action of stable water flow.At the same time,the spatial model of the study area was established by using groundwater modeling system(GMS),and the spatial distribution of soil heavy metals in the area was analyzed.The simulation results show that the heavy metal content in the soil decrease with the leaching time,and the four ion migrations are close to the minimum on the fourth day of leaching.The experimental values of Cd,Cu,Zn,and Cr ion variations agree well with the simulated values,and the R 2 values of linear-regression analysis are 0.932,0.951,0.936,and 0.965,respectively.Spatial distribution characteristics show that the distribution of heavy metals in the study area is related to the groundwater flow direction,the initial content of heavy metals in the soil,the dissolution of external pollution sources,and shallow groundwater flow paths.The results provide a theoretical basis and analytical method for further study of regional heavy metal migration characteristics.

关 键 词：土壤重金属 溶质迁移 HYDRUS-1D 淋滤实验 空间分布 地下水建模系统 

分 类 号：X131.3[环境科学与工程—环境科学]