摘要
水资源短缺是黄土高原地区农业生产和生态环境建设主要的限制因子。土壤水分入渗过程不仅决定着土壤对雨水和灌溉水等有限水源的利用程度,而且也深刻影响着地表径流和土壤侵蚀强度。土壤表面电场对团聚体稳定性具有重要影响,团聚体破碎后土壤孔隙将发生重要变化,并影响水分入渗过程。然而,目前关于土壤电场作用对黄土母质发育土壤水分入渗过程的影响尚不清楚,同时考虑表面电场作用后经典土壤水分入渗模型的适用性还有待进一步验证。因此,本研究采用室内一维定水头土柱模拟试验,通过定量调控土壤表面电场,研究了不同土壤电场强度对水分入渗速率、湿润锋运移、累积入渗量的影响,并采用Kostiakov模型和Philip模型对土壤水分入渗过程进行拟合。结果表明:(1)湿润锋运移速度、入渗速率和累积入渗量均随入渗电解质浓度的减小、表面电位(绝对值)和电场的增大而降低,这表明土壤表面电场对土壤水分入渗具有重要的、不可忽略的影响。(2)当电解质浓度<0.01 mol·L^-1,塿土和褐土的电位绝对值大于233 mV和223 mV时,土壤水分入渗特性参数随时间的变化曲线较为接近,表明233 mV和223 mV分别是影响两种土壤水分入渗过程的临界电位值。(3)Kostiakov模型和Philip模型对于塿土和褐土入渗过程的模拟均有较好的适用性,但通过进一步分析其拟合统计特征值(决定系数R^2、残差平方和、均方根误差RMSE值),发现Kostiakov模型的拟合结果更优。该研究结果可为黄土高原土壤水分入渗的内部调控新技术提供理论参考。
【Objective】The Loess Plateau of China is one of the world’s most severely eroded regions.In this region water shortage is the main limiting factor in agricultural production and ecological environment construction.Therefore,it is of great significance to improve utilization efficiency of the limited water resources in the region to the maintenance of regional ecological environment security and efficient development of green agriculture.The process of soil water infiltration not only determines utilization rate of the limited water sources,such as precipitation and irrigation,but also profoundly affects intensity of surface runoff and soil erosion.Soil water infiltration is mainly affected by soil organic matter content,bulk density,texture,structure stability and soil porosity,water quality and so on.Recent researches have demonstrated that soil surface electric field influences soil water infiltration by affecting stability of soil aggregates and distribution of soil pores.Although quite a number of studies have been reported on water infiltration,water availability and their affecting factors in soils developed from Loess,it is still not clear that how soil interfacial properties(surface electric field and surface potential of soil particles)vary in the process of water infiltration and affect water infiltration characteristics and how applicable the classical soil water infiltration model is when effect of the surface electric field is taken into account.So further studies need to be done.【Method】In this study,two representative Loess soils,Lou soil and Cinnamon soil,were used.According to the double layer theory of charged particles,the surface electric field of soil particles could be quantitatively adjusted by applying a series of electrolyte solutions different in concentration.Soil water infiltration rate,moisture front migration and cumulative infiltration in the two soils was determined.The Kostiakov model and the Philip model was used to fit the process of soil water infiltration.【Result�
作者
杨志花
胡斐南
刘婧芳
许晨阳
马任甜
王子龙
赵世伟
YANG Zhihua;HU Feinan;LIU Jingfang;XU Chenyang;MA Rentian;WANG Zilong;ZHAO Shiwei(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,Shaanxi 712100,China;College of Natural Resources and Environment,Northwest Agriculture and Forestry University,Yangling,Shaanxi 712100,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《土壤学报》
CAS
CSCD
北大核心
2019年第6期1359-1369,共11页
Acta Pedologica Sinica
基金
国家自然科学基金项目(41601236,41701261)
中国科学院西部之光项目(XAB2016B07)资助~~
关键词
土壤表面电场
湿润锋
入渗速率
累积入渗量
入渗模型
Soil surface electric field
Wetting front
Infiltration rate
Cumulative infiltration
Infiltration model
