Effects of spatial variability of soil hydraulic properties in water budget modeling
Effects of spatial variability of soil hydraulic properties in water budget modeling
复制标题
水收支模型中土壤水力特性空间变异的影响
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
J. Stolzy
中科院分区：
文献类型：
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作者：
A. Peck;R. Luxmoore;J. Stolzy
即使在单一土壤类型中，流域或田地范围内的土壤特性也存在明显的空间变异性。一个地区土壤水特征的空间变化是根据平均特性和尺度异质性的假设来模拟的（Philip，1967）。模型中使用模拟的土壤水特征和代表森林植被的其他数据来模拟田纳西州东部部分流域四月和七月平均天气的水收支。假设该地区的降水量是均匀的，在模拟的几个月内，即使是渗透性最低的土壤也没有径流。土壤水分条件的空间变异对蒸散量的影响很小。土壤剖面中的水储存发生变化，使得根区以外的排水通量在整个模拟区域趋于均匀。假设土壤的特征微观长度在一个区域内呈正态分布，并建立了根据多个土壤样品的保留曲线和导水率计算平均土壤水特征的方程。用平均土壤水特征模拟的水预算的组成部分与整个空间可变土壤单元的模拟行为非常一致。这一结果并不意味着其他分布函数和土壤-植物-天气组合也有类似的一致性，但所开发的方法可用于研究这些问题。
There is appreciable spatial variability of soil properties on the scale of a watershed or a field even in a single soil type. The spatial variation of soil water characteristics in an area was simulated from average properties and the assumption of scale heterogeneity (Philip, 1967). Simulated soil water characteristics and other data representing forest vegetation were used in a model to simulate water budgets over part of a watershed in eastern Tennessee for average April and July weather. Precipitation was assumed to be uniform over the area, and there was no runoff even from the least permeable soil during the months simulated. The spatial variability of soil water conditions had only a small effect on evapotranspiration. Water storage in the soil profile changed, so that the drainage flux beyond the root zone tended to become uniform throughout the area simulated. The characteristic microscopic length of the soil was assumed to be normally distributed in an area, and equations were developed for calculating average soil water characteristics from the retention curves and hydraulic conductivities of a number of soil samples. Components of the water budgets simulated with average soil water characteristics were in excellent agreement with the simulated behavior of the spatially variable soil unit as a whole. This result does not imply similar agreement for other distribution functions and soil-plant-weather combinations, but the methodology developed may be applied to investigate these problems.