土壤分形结构对其水力性质的指示作用

The indicative effect of soil fractal structure on its hydraulic properties

研究土壤的水力性质是进行生态水文模拟、农业水分管理和环境监测的关键,然而强烈的空间变异造成土壤的物性特征异常复杂,特别是水力性质测定困难,试验结果随机性强,耗费大量人力物力,却难以准确描述。本文在综合分析了国内外30余种量化土壤水力性质的研究方法的优劣后,系统总结了分形理论在土壤物性特征研究中的应用,剖析了分形理论与土壤水力性质之间的关系,旨在探讨土壤分形结构在水力性质领域的发展前景,以及在测定水力特性参数时所具备的优势。结果表明:(1)采用分形方法定量研究土壤结构具备可行性;(2)分形结构方法能够指示水力性质,并能为快速准确刻画不同尺度下的土壤水分分布特征提供科学依据;(3)利用已知土壤水力性质建立分形模型可以有效反演土壤结构。

Understanding the hydraulic properties of soil is key to ecological hydrological simulation,agricultural water management and environmental monitoring.However,soils are extremely complex due to its spatial variability,which makes the determination of its physical properties,specially hydraulic properties very difficult.Often,test results are random and demand substantial manpower and material resources to acquire,yet soil property is difficult to describe accurately.In this report,based on a comprehensive analysis of more than 30 research methods for quantifying soil hydraulic properties,we summarized the advantages and disadvantages of using fractal theory to study soil physical properties,and analyzed the relationship between fractal theory and soil hydraulic properties.We aimed to explore the prospects and advantages of using soil fractal structures in hydraulic property determination.The results show that(1)it is feasible to use fractal analysis to study soil structure quantitatively;(2)fractal structural analysis can reveal hydraulic properties and provide a scientific basis for quick and accurate characterization of water distribution in soils at different scales;and(3)use of known soil hydraulic properties can inversely reveal soil structure effectively.