摘要
黄土地区地质灾害问题的发生大多与水在黄土中的入渗有关,而马兰黄土-古土壤互层结构对土壤水分入渗规律的影响显著。为揭示古土壤阻滞作用下黄土水分运移规律及其对黄土体微结构的影响,为黄土地区工程实践提供理论基础,该研究以陕西省泾阳县南塬的黄土为研究对象,采用土柱模型进行水分入渗试验,研究黄土-古土壤互层条件下土壤水分运移规律。在此基础上,通过微结构测试、分形维数和概率熵等指标的计算,分析黄土-古土壤互层条件下土壤水分运移对黄土微结构的影响。结果表明:古土壤层的透水性弱,湿润锋抵达黄土与古土壤界面处产生瞬态滞水,且随着入渗强度增加滞水时间增加;古土壤层影响下黄土与古土壤界面处的滞水会导致孔隙结构相互连通,孔隙空间平均增加4.13%,孔隙方向概率熵平均减少0.029,分形维数平均减小0.076,即古土壤层的阻水作用使得界面处黄土的孔隙空间增大,孔隙排列有序,孔隙形态规则。研究结果为黄土地区的工程建设和生态环境保护提供科学支撑。
Geological disaster occurrences in loess regions are intrinsically linked to water infiltration in loess,with the Malan loess-paleosol interlayer structure significantly influencing the infiltration patterns of soil moisture.This research was carried out to reveal the moisture migration characteristics in loess-paleosol interlayers,and to investigate the influence of the moisture migration on the microstructure of loess,providing a theoretical basis for engineering practice and scientific research in loess areas.In this study,we focused on the loess of the South Plateau in Jingyang County,Shaanxi Province,and conducted water infiltration tests using a soil column model to investigate the soil moisture transport dynamics under loess-paleosol interlayer conditions.Subsequently,we analyzed the impact of soil moisture transport on the loess microstructure under these conditions through microstructural testing,and calculation of fractal dimension and probability entropy.The findings revealed that the permeability of the paleosol layer was low,causing transient water stagnation when the wetting front reached the loess-paleosol interface.The stagnant water at the interface of loess and paleosol under the influence of the paleosol layer will lead to the interconnection of pore structure,and the pore space will increase by 4.13%on average,and the analysis of the indexes of fractal dimension and probability entropy shows that the probability entropy of the pore direction decreases by 0.029 on average,and the fractal dimension decreases by 0.076 on average,i.e.,the water-blocking effect of the paleosol layer makes the pore space of the loess at the interface increase,the pores are arranged in an orderly manner,and the pore morphology is regular.The results of the study provide scientific support for the engineering construction and eco-environmental protection in loess areas.
作者
李培月
李佳慧
吴健华
王远航
陈银富
LI Peiyue;LI Jiahui;WU Jianhua;WANG Yuanhang;CHEN Yinfu(School of Water and Environment,Chang’an University,Xi’an,Shaanxi 710054,China;Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Regions of the Ministry of Education(Chang’an University),Xi’an,Shaanxi 710054,China;Key Laboratory of Eco-Hydrology and Water Security in Arid and Semi-arid Regions of the Ministry of Water Resources(Chang’an University),Xi’an,Shaanxi 710054,China)
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2024年第3期1-11,共11页
Hydrogeology & Engineering Geology
基金
国家自然科学基金项目(42272302,42072286,42090053)
国家重点研发计划项目(2023YFC3706901)。
关键词
黄土
古土壤
土柱试验
水分入渗
微观结构
loess
paleosol
soil column test
water infiltration
microstructure
