旱区不同层状结构土壤的水分运移过程与模拟  

Water transport process and simulation of layered soils with different configurations in an arid region

作　　者：王强民 赵明[3] 彭鸿杰 胡贵明 马开峰 郭珂珂 刘璞 WANG Qiangmin;ZHAO Ming;PENG Hongjie;HU Guiming;MA Kaifeng;GUO Keke;LIU Pu(Xi’an Research Institute of China Coal Technology&Engineering Group Corp,Xi’an,Shaanxi 710077,China;Shaanxi Union Research Center of University and Enterprise for Mine Ecological Environment Protection and Restoration in the Middle of Yellow River Basin,Xi’an,Shaanxi 710077,China;School of Land Engineering,Chang’an University,Xi’an,Shaanxi 710061,China)

机构地区：[1]中煤科工集团西安研究院(集团)有限公司,陕西西安710077 [2]陕西省“四主体一联合”黄河流域中段矿区(煤矿)生态环境保护与修复校企联合研究中心,陕西西安710077 [3]长安大学土地工程学院,陕西西安710061

出　　处：《水文地质工程地质》2023年第4期84-94,共11页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金项目(42007179);大学生创新创业训练计划项目(G202210710131)。

摘　　要：针对位于干旱-半干旱气候带的我国西北部矿区生态修复过程中重构层状土壤水分运移规律不清等问题,通过设置不同层状结构土壤进行水分运移入渗试验,监测土壤剖面水分变化,采用Hydrus-1D模拟降雨入渗过程,从土壤水分、水势和水通量3个方面揭示层状土壤水分运移特征,并基于优化后的模型进行情景模拟,探究夹层特征对浅层土壤水分运移的影响。研究结果表明,夹层明显改变了土壤水分的分配与运移过程,土壤水势在夹层界面连续分布,而土壤水分在夹层界面发生突变;虽然黄土夹层和风化砂岩夹层都阻滞了土壤水分的下渗,但其阻滞原理不同,前者表现为黏质夹层渗透性能差导致夹层以上土壤水分滞留,后者归因于粗质夹层土壤基质势小造成水分持留在上部黏质土壤中;根据不同夹层属性的情景模拟结果,提出在风积沙40 cm深度处设置20 cm厚的黄土夹层有利于提高夹层以上土壤水分以供植被利用。研究探明了风积沙区充填黄土对土壤水分运动的影响,并为土壤类型以风积沙和黄土为主的我国西北部矿区在生态修复中的土壤重构方式提供了参考依据。The mining area in northwest China is located in the arid and semi-arid zone,in which the surface water resource is sparse and the ecological environment is fragile.Coupled with the exploitation of mineral resources,the land has been degraded seriously.How to realize the efficient reclamation of soil and the effective utilization of soil water is an urgent scientific and technical problem.In this study,the layered soil with different configurations is set up for water transport and infiltration test to monitor the moisture changes in the soil profile.Hydrus-1D is used to simulate the rainfall infiltration process and reveal the water transport characteristics of layered soil from three aspects:soil moisture,water potential and water flux.The scenario simulation is conducted based on the optimized model to explore the effect of interlayer characteristics on shallow soil water.The results show that the interlayer significantly changes the distribution and transport of soil water,and the soil water potential is continuously distributed at the interlayer interface,while the soil water abruptly changes at the interlayer interface.Although loess interlayer and weathered sandstone interlayer both block the infiltration of soil water,the principle and the source of water increase are different.The former is the retention of soil water above the interlayer due to the poor permeability of loess,while the latter is the retention of water above the interlayer due to the small matrix potential of the coarser interlayer.According to the results of the model,it is suggested that setting loess interlayer of 20 cm thick at the depth of 40 cm of aeolian sand is conducive to increase soil moisture above the interlayer for vegetation utilization.Summarily,the results can provide a theoretical basis for understanding and mastering the layered soil hydrological process in arid regions and optimizing the soil reconstruction mode in the process of land reclamation and ecological restoration.

关 键 词：层状结构 降雨入渗 水分运移 Hydrus-1D模拟 干旱-半干旱区 

分 类 号：P641[天文地球—地质矿产勘探] S156.1[天文地球—地质学]