科尔沁沙地土壤水分特征曲线传递函数的构建与评估  

Development and evaluation of pedo-transfer functions of soil water characteristic curves in Horqin sandy land

作　　者：姚姣转 刘廷玺[1] 王天帅[1] 童新[1] 

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,呼和浩特010018

出　　处：《农业工程学报》2014年第20期98-108,共11页Transactions of the Chinese Society of Agricultural Engineering

基　　金：教育部博士点基金项目(20111515110003);国家自然科学基金重点与地区项目(51139002;51479086);教育部创新团队发展计划(IRTI3069);内蒙古自治区草原英才产业创新创业人才团队;内蒙古农业大学寒旱区水资源利用创新团队(NDTD2010-6)

摘　　要：为了快速准确的获取某一区域的水力性质,该文以科尔沁沙地典型沙丘-草甸相间地区为研究区,在对该区49个不同地貌类型采样点土壤水分特征曲线与土壤基本物理化学特性参数测试分析的基础上,采用函数参数非线性规划法构建了土壤干容重、粒径分布、有机质、pH值、电导率值等基本参数与水分特征曲线之间的传递函数,并进行了精度评估与分析。结果表明:1)研究区土壤水分特征曲线的坡度陡峭,不同地貌类型与土地利用方式下,土壤水分特征曲线有较大差异,相同负压下,土壤持水量按照流动沙丘-半固定沙丘-固定沙丘-农田-草甸的顺序递增;土壤的供水能力按照流动沙丘-半固定沙丘-固定沙丘-草甸-农田的顺序递减;2)利用土壤基本物化特性参数通过函数参数非线性规划法建立了研究区土壤水分特征曲线的传递函数,干容重和砂粒含量是预测土壤水分特征曲线模型参数的主要变量,增加土壤的理化指标可以提高预测精度,然而有机质含量、pH值、电导率值对本区土壤水分常数的影响并不大,对水分特征曲线模型3个参数的影响略微增加;3)通过对传递函数的检验与精度评估分析,各参数的平均误差均在0附近;饱和含水率、残余含水率的均方根误差分别为0.017、0.023;土壤水分常数的相关系数在0.95附近,饱和含水率、残余含水率的误差比的几何标准偏分别为1.04、1.27。表明所建土壤水分特征曲线传递函数的精度较高,可用于该区土壤水分特性研究。该研究可为该区水分、溶质运移、水-热-盐耦合运移模拟提供技术支持和理论保证。In the regional basin water system or ground-water soil-plant-atmosphere continuum system, soil moisture migration simulation and water-heat-solute coupled modeling often require values of soil hydraulic properties such as soil water retention and permeability. In order to quickly and easily obtain accurate soil water characteristic curves （SWCC）, the typical dune-meadow areas in Horqin sandy land was selected as the study area. The pedo-transfer functions （PTFs） between the soil water characteristic curves and the basic soil properties was established by the nonlinear programming method in term of bulk density, soil particle size distribution, soil organic matter （SOM）, electricity conductivity and pH. Nonlinear optimal programming method, which is based on the minimum absolute deviation as the objective function, was used for minimizing residuals, especially diminishing the effect of extremes. PTFs at the soil depth of 20 cm were evaluated based on parameters such as residual mean square error, and correlation coefficient between the fitted and predicted values. Results showed that： 1） Soil texture in the Horqin was mainly sand, partially sandy loam or loamy sand, most of the volume content of the sand particle was higher than 83%, even up to100%; Soil water constant was correlated with sand content and bulk density, but weakly associated with clay and silt content. SWCC in different landscapes and land use was different under the same suction, and the soil water holding capacity increased following the order of sand dune, semi-fixed dune, fixed dune, farmland and meadow; The soil water capacity decreased in an order of sand dunes, semi-fixed dune, fixed dune, meadow, and farmland. With the increase of suction, soil moisture changed in a stage from rapid decline and slow decline to stable stage; Specific water capacity of sand dune, semi-fixed dune, fixed dune was reduced after the first growth with the increase of soil suction; However, specific water capacity of farmland and meadow was gradual

关 键 词：土壤 水分特征曲线 物理性质 化学特性 传递函数 科尔沁沙地 

分 类 号：S152.7[农业科学—土壤学]