Uncertainty in predicting soil hydraulic properties at the hillslope scale with indirect methods
Uncertainty in predicting soil hydraulic properties at the hillslope scale with indirect methods
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DOI：
10.1016/j.jhydrol.2006.10.024
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发表时间：
2007-02-28
影响因子：
6.4
通讯作者：
Romano, N.
中科院分区：
文献类型：
--
作者：
Chirico, G. B.;Medina, H.;Romano, N.
一些水文应用需要在大的空间尺度上的土壤水力特性的表征。土壤传递函数（PTFs）正在开发作为一种简化的方法来估计土壤水力特性作为替代直接测量，这是不可行的，在大多数实际情况下。本研究的目的是量化的不确定性PTF的空间预测在hiltstope规模相关的采样密度，由于：（i）估计的土壤物理化学性质的误差和（ii）PTF模型误差。在意大利南部的一个2公里长的实验山坡上进行了分析。所采用的方法是基于随机生成的土壤变量的模式，使用连续高斯模拟，条件是所观察到的样本数据。应用以下PTF：Vereecken的PTF（Vereecken，H.，Diets，J.，货车Orshoven J.，费恩，J.，Bouma，J.，1992.土壤水力特性估算用的土壤传递函数的功能评价。土壤科学美国社会J.56，13711378]和HYPRES PTF [Wosten，J.H.M.，Lilly，A.，尼弥斯，A.，勒巴斯角1999.欧洲土壤水力特性数据库的开发和使用。Geoderma 90，169-185]。这两个PTFs可靠地估计土壤水分保持特性，即使是相对粗糙的采样分辨率，预测的不确定性与直接实验室或现场测量的不确定性。由于模型误差引起的土壤持水预测的不确定性与估计输入相关的不确定性一样多或更显著，即使对于相对粗糙的采样分辨率。当应用PTF估算饱和导水率时，预测的不确定性更为重要。在这种情况下，模型误差占主导地位的整体预测的不确定性，使输入误差的影响可以忽略不计。(c)2006 Elsevier B. V.保留所有权利。
Several hydrological applications require the characterisation of the soil hydraulic properties at large spatial scales. Pedotransfer functions (PTFs) are being developed as simplified methods to estimate soil hydraulic properties as an alternative to direct measurements, which are unfeasible for most practical circumstances. The objective of this study is to quantify the uncertainty in PTFs spatial predictions at the hiltstope scale as related to the sampling density, due to: (i) the error in estimated soil physico-chemical properties and (ii) PTF model error. The analysis is carried out on a 2-km-long experimental hillstope in South Italy. The method adopted is based on a stochastic generation of patterns of soil variables using sequential Gaussian simulation, conditioned to the observed sample data. The following PTFs are applied: Vereecken's PTF (Vereecken, H., Diets, J., van Orshoven J., Feyen, J., Bouma, J., 1992. Functional evaluation of pedotransfer functions for the estimation of soil hydraulic properties. Soil Sci. Soc. Am. J. 56, 13711378] and HYPRES PTF [Wosten, J.H.M., Lilly, A., Nemes, A., Le Bas, C., 1999. Development and use of a database of hydraulic properties of European soils. Geoderma 90, 169-185]. The two PTFs estimate reliably the soil water retention characteristic even for a relatively coarse sampling resolution, with prediction uncertainties comparable to the uncertainties in direct laboratory or field measurements. The uncertainty of soil water retention prediction due to the model error is as much as or more significant than the uncertainty associated with the estimated input, even for a relatively coarse sampling resolution. Prediction uncertainties are much more important when PTF are applied to estimate the saturated hydraulic conductivity. In this case model error dominates the overall prediction uncertainties, making negligible the effect of the input error. (c) 2006 Elsevier B.V. All rights reserved.