Characterizing scale- and location-dependent correlation of water retention parameters with soil physical properties using wavelet techniques.
Characterizing scale- and location-dependent correlation of water retention parameters with soil physical properties using wavelet techniques.
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DOI：
10.2134/jeq2007.0179
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发表时间：
2008-10
影响因子：
2.4
通讯作者：
Qiaosheng Shu;Zuo-xin Liu;B. Si
中科院分区：
文献类型：
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作者：
Qiaosheng Shu;Zuo-xin Liu;B. Si
了解土壤水力参数与土壤物理性质之间的相关性是从土壤物理性质预测土壤水力性质的前提。本研究的目的是使用小波技术来检验货车Vancchten（1980）函数中的两个持水参数（α和n）与土壤物理性质（含砂量、容重[Bd]和有机碳含量）之间的尺度和位置相关性。土壤样品采集自中国阜新的样带。测定了土壤水分特征曲线，通过曲线拟合得到了货车水分特征参数。小波相干分析被用来阐明这些参数和土壤物理性质之间的位置和尺度依赖的关系。结果表明，在小尺度（8-20 m）和30 ~ 470 m范围内，α与含沙量的小波相关性与红噪声有显著差异。它们的子波相位谱主要是反相的，表明这两个变量之间的负相关性。α与Bd的强负相关主要存在于中等尺度（30-80 m）。然而，参数n只有在20和80米之间的尺度与Bd有很强的正相关。这两个保留参数与有机碳含量均无显著的小波相关性。这些结果表明，位置相关的尺度分析是必要的，以提高土壤水分特征预测的性能。
Understanding the correlation between soil hydraulic parameters and soil physical properties is a prerequisite for the prediction of soil hydraulic properties from soil physical properties. The objective of this study was to examine the scale- and location-dependent correlation between two water retention parameters (alpha and n) in the van Genuchten (1980) function and soil physical properties (sand content, bulk density [Bd], and organic carbon content) using wavelet techniques. Soil samples were collected from a transect from Fuxin, China. Soil water retention curves were measured, and the van Genuchten parameters were obtained through curve fitting. Wavelet coherency analysis was used to elucidate the location- and scale-dependent relationships between these parameters and soil physical properties. Results showed that the wavelet coherence between alpha and sand content was significantly different from red noise at small scales (8-20 m) and from a distance of 30 to 470 m. Their wavelet phase spectrum was predominantly out of phase, indicating negative correlation between these two variables. The strong negative correlation between alpha and Bd existed mainly at medium scales (30-80 m). However, parameter n had a strong positive correlation only with Bd at scales between 20 and 80 m. Neither of the two retention parameters had significant wavelet coherency with organic carbon content. These results suggested that location-dependent scale analyses are necessary to improve the performance for soil water retention characteristic predictions.