农业工程学报
農業工程學報
농업공정학보
2014年
9期
76-83
,共8页
聂卫波%武世亮%马孝义%费良军
聶衛波%武世亮%馬孝義%費良軍
섭위파%무세량%마효의%비량군
土壤%入渗%分形%修正Kostiakov公式%空间变异%归一化
土壤%入滲%分形%脩正Kostiakov公式%空間變異%歸一化
토양%입삼%분형%수정Kostiakov공식%공간변이%귀일화
soils%infiltration%fractals%modified Kostiakov equation%spatial variation%normalization
土壤入渗特性是田块尺度参数估值的重要基础。该文以陕西省杨凌区一级阶地砂壤土和三级阶地粘壤土所选典型田块的双环入渗试验为基础,分析了归一化因子在单一尺度和多尺度上的分形特征,并在此基础上建立了估算归一化因子的土壤转换函数。结果表明:对于修正 Kostiakov 公式所采用的归一化处理方法是可行的,可较好地预测典型田块各测点的土壤入渗过程;在单一尺度上,一级阶地和三级阶地所选典型田块的归一化因子最优半方差函数均为球状模型,其分形维数分别为1.796和1.840;在多尺度上,一级阶地典型田块归一化因子的空间变异受粉粒含量、砂粒含量和土壤容重的影响显著,三级阶地典型田块归一化因子的空间变异与黏粒含量、粉粒含量、砂粒含量和土壤初始含水率相关程度最高(显著性水平0.01);估算归一化因子的土壤转换函数具有较高的精度和可靠性,其一级阶地和三级阶地典型田块验证样本归一化因子的实测值与估算值相对误差绝对值均值分别为13.15%和9.95%。研究结果可较好地解决田块尺度内土壤入渗点面转换及入渗参数难以取得的问题。
土壤入滲特性是田塊呎度參數估值的重要基礎。該文以陝西省楊凌區一級階地砂壤土和三級階地粘壤土所選典型田塊的雙環入滲試驗為基礎,分析瞭歸一化因子在單一呎度和多呎度上的分形特徵,併在此基礎上建立瞭估算歸一化因子的土壤轉換函數。結果錶明:對于脩正 Kostiakov 公式所採用的歸一化處理方法是可行的,可較好地預測典型田塊各測點的土壤入滲過程;在單一呎度上,一級階地和三級階地所選典型田塊的歸一化因子最優半方差函數均為毬狀模型,其分形維數分彆為1.796和1.840;在多呎度上,一級階地典型田塊歸一化因子的空間變異受粉粒含量、砂粒含量和土壤容重的影響顯著,三級階地典型田塊歸一化因子的空間變異與黏粒含量、粉粒含量、砂粒含量和土壤初始含水率相關程度最高(顯著性水平0.01);估算歸一化因子的土壤轉換函數具有較高的精度和可靠性,其一級階地和三級階地典型田塊驗證樣本歸一化因子的實測值與估算值相對誤差絕對值均值分彆為13.15%和9.95%。研究結果可較好地解決田塊呎度內土壤入滲點麵轉換及入滲參數難以取得的問題。
토양입삼특성시전괴척도삼수고치적중요기출。해문이합서성양릉구일급계지사양토화삼급계지점양토소선전형전괴적쌍배입삼시험위기출,분석료귀일화인자재단일척도화다척도상적분형특정,병재차기출상건립료고산귀일화인자적토양전환함수。결과표명:대우수정 Kostiakov 공식소채용적귀일화처리방법시가행적,가교호지예측전형전괴각측점적토양입삼과정;재단일척도상,일급계지화삼급계지소선전형전괴적귀일화인자최우반방차함수균위구상모형,기분형유수분별위1.796화1.840;재다척도상,일급계지전형전괴귀일화인자적공간변이수분립함량、사립함량화토양용중적영향현저,삼급계지전형전괴귀일화인자적공간변이여점립함량、분립함량、사립함량화토양초시함수솔상관정도최고(현저성수평0.01);고산귀일화인자적토양전환함수구유교고적정도화가고성,기일급계지화삼급계지전형전괴험증양본귀일화인자적실측치여고산치상대오차절대치균치분별위13.15%화9.95%。연구결과가교호지해결전괴척도내토양입삼점면전환급입삼삼수난이취득적문제。
Soil water infiltration characteristics is one of the important factors for estimating the infiltration parameters at field scales. Based on the double-ring infiltration experiments conducted in typical fields of the first terrace (Sandy loam) and the third terrace (Clay loam) in Yangling District, Shaanxi Province, China, the spatial variability of soil infiltration characteristics under different soil textures were studied at field scales. The objectives of this paper are to apply the normalization method for modified Kostiakov function, to analyze the fractal characteristics of normalization factors under single scale and multi scales, and finally, to develop the Pedo-transfer function for estimating the normalization factors. The results show that the normalization method is feasible for modified Kostiakov function, which has high accuracy in predicting the infiltration process of every soil infiltration experiment spot. The correlation coefficients between the predicted values of the cumulative infiltration and the measured values of all the experimental spots in the first terrace and third terrace are 0.9759 and 0.9576, the errors of the root mean square are 2.795cm and 1.266cm, and the mean absolute values of relative error are 10.58%and 9.26%, respectively. Under the single scale, the semi-variance functions of the normalization factors in first terrace and third terrace are shown to be the spherical model, the spatial variance is mainly caused by the structural elements, and the fractal dimensions are 1.796 and 1.840 respectively. The results show that the uniformity of spatial variance of the soil infiltration characteristic in the third terrace is higher than that of the first terrace. During the multi-scale analysis, the spatial variation of the normalization factors in the first terrace are greatly influenced by silt particle, sand particle, and soil bulk density, and the normalization factors in the third terrace are greatly influenced with clay particle, silt particle, sand particle, and soil initial moisture content(0.01 level of significance). The Pedo-transfer function for estimating the normalization factors is accurate and reliable, and the measured and the estimated values of the normalization factors of the verification samples in the first terrace and the third terrace are in good agreement with each other, the mean absolute value of relative error are 13.15% and 9.95%, respectively. The research results of this paper could be used to convert point-based soil infiltration measurements to regional scale.