摘要
为探究淹水时长对土壤物理特性的影响,采用室内土柱模拟的方法,基于热脉冲技术与热导率模型,明确土壤淹水及脱湿过程中土壤热特性和容重动态变化特征。在此基础上,利用压力板法、沙箱法和微型圆盘入渗仪测定不同淹水时长土壤的水分特征曲线和入渗速率变化,分析土壤结构和孔隙分布对土壤容重和热特性的影响。结果表明:随着淹水时长的增加,土壤物理性质的变化可分为两个阶段:淹水1~7 d,土壤容重、热导率和热容量均表现为阶段性增加的趋势;淹水7 d后,土壤容重和热特性基本达到稳定状态。在淹水过程中,土壤孔隙分布也发生明显变化,土壤入渗速率随着淹水时长的增加呈先升高后降低的过程。淹水过程会导致土壤结构变化、土壤孔隙分布和连通性改变,最终土壤持水性减弱、导水率降低。研究结果有助于深入认识长期淹水过程中土壤结构以及土壤热特性的变化特征,可为科学指导洪涝灾害后的农业生产提供科学依据。
In order to study the influence of flooding duration on soil physical properties,we analyzed the dynamic characteristics of soil thermal properties and bulk density during soil flooding and drying process using indoor soil column simulation method,heat pulse technology and thermal conductivity model.The soil water retention curve and the infiltration rate were measured by pressure plate method,sandbox method and mini-disk infiltrometer under different flooding duration.Analysis of influence of soil structure and pore distribution on soil bulk density and thermal characteristics was further performed.The results showed that the dynamics of soil physical properties could be divided into two stages with the increase of flooding duration.Soil bulk density,thermal conductivity and heat capacity increased gradually from 1 day to 7 days after flooding.After 7 days of flooding,soil bulk density and thermal properties reached a stable state.In the process of flooding,soil pore size distribution also changed obviously,and the soil infiltration rate increased first and then decreased with increase the of flooding time.Flooding caused the changes of soil pore distribution and connectivity,while finally soil water holding capacity increased and water conductivity decreased.The research is helpful for understanding the changes of soil structure and thermal characteristics during long-term flooding,and can provide scientific basis for guiding agricultural production after flood disaster.
作者
王希凤
赵春雷
张猛
WANG Xifeng;ZHAO Chunlei;ZHANG Meng(College of Resources and Environment Science,Hebei Agricultural University,Baoding 071000,China;Key Laboratory of Ecological Network Observation and Simulation/Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China)
出处
《河北农业大学学报》
CAS
CSCD
北大核心
2022年第6期32-38,共7页
Journal of Hebei Agricultural University
基金
国家重点研发计划项目(2018YFD0300504-4)
河北省省属高等学校基本科研业务费研究项目(KY2021069)。
关键词
土壤容重
土壤热特性
土壤结构
土壤水分特征曲线
土壤入渗速率
soil bulk density
thermal properties
soil structure
soil water retention curve
soil infiltration rate
