Depressional storage for Markov-Gaussian surfaces.
Depressional storage for Markov-Gaussian surfaces.
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DOI：
10.1029/wr026i009p02235
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发表时间：
1990-09
影响因子：
5.4
通讯作者：
Chi-Hua Huang;J. Bradford
中科院分区：
文献类型：
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作者：
Chi-Hua Huang;J. Bradford
降雨过程，如入渗、径流、土壤侵蚀和结皮形成，在一定程度上受到洼地储存和地表粗糙度的影响。如果表面形貌已知，就可以计算其潜在的凹陷储量。本文的目的是将量化表面粗糙度的统计参数与凹陷储存联系起来。利用激光扫描仪对毫米网格数字化的地形数据集进行分析，发现土壤粗糙度可以通过马尔可夫-高斯（M-G）型随机过程进行量化。采用蒙特卡罗模拟程序，从模拟的M-G表面求出平均积水特性。发现洼地储存是两个M-G参数、两个样本长度尺度和坡度的函数。马尔可夫参数为全局方差（σ2）和相关长度尺度(L)，样本长度尺度为网格间距（Δx）和边长（Ls）。经过适当的缩放后，所有存储函数都分解为两个非维度关系：(1)零斜率存储作为相对样本长度尺度的函数，(2)存储作为缩放后的斜率的函数。当L = 0时，模拟曲面服从随机高斯模型，无量纲存储仅是缩放斜率的函数。利用M-G型统计数据的数字化高程数据集计算出的存储量与模拟表面得到的结果吻合良好。
Processes during rain events, such as infiltration, runoff, soil erosion, and crust formation, are influenced in part by depressional storage and surface roughness. If the surface topography is known, its potential depressional storage can be calculated. The objective of this paper was to relate the statistical parameters for quantifying surface roughness to depressional storage. Analysis of topographic data sets digitized at millimeter grids by a laser scanner showed that soil roughness can be quantified by a Markov-Gaussian (M-G) type random process. A Monte Carlo simulation procedure was used to find the mean ponding characteristics from simulated M-G surfaces. Depressional storages were found to be functions of two M-G parameters, two sample length scales, and the slope steepness. The Markov parameters are the global variance (σ2) and the correlation length scale (L), and the sample length scales are grid spacing (Δx) and side length (Ls). After proper scaling, all storage functions collapsed into two nondimensional relationships: (1) storage at zero slope as a function of relative sample length scale, and (2) storage as a function of scaled slope. When L = 0, simulated surfaces followed the random Gaussian model and the nondimensional storage was only a function of scaled slope. Storages calculated from digitized elevation data sets with M-G type statistics agreed well with results obtained from simulated surfaces.