一维马尔可夫链模拟黑河中游流域土壤质地垂向变异

CORC > 水土保持研究所 > 中国科学院水利部水土保持研究所 > 水保所知识产出(1956-2013)

	一维马尔可夫链模拟黑河中游流域土壤质地垂向变异
	李丹凤 ; 邵明安
刊名	农业工程学报
	2013
卷号	29 期号:05 页码:71-10
关键词	土壤 soils 质地 textures 模型 models 马尔可夫链 Markov-chain 转移概率矩阵 transition probability matrix 随机模拟 stochastic simulation 质地剖面 textural
其他题名	One-dimensional Markov chain simulation of vertical change of soil
中文摘要	黑河中游地区土壤剖面砂、黏层次相间排列的特点及部分区域剖面中出现的不透水层对土壤中的水分运动和溶质迁移具有重要影响。该研究调查了黑河中游100km2区域内土壤剖面的质地分层情况,运用一维嵌入马尔可夫链模型模拟该地区的土壤质地剖面。研究表明,研究区土壤剖面共出现砂土、壤质砂土、砂质壤土、壤土、黏质壤土、粉黏壤土和粉黏土7种质地类型,层次厚度呈对数正态分布。粉黏土未在表层土壤出现,而砂土在表层出现的概率明显高于其余质地类型,剖面某一质地层之下多出现细粒含量比其高的下一质地类型。剖面上相邻两质地层之间的转移具有明显的马尔可夫链特征(简称马氏性),且马氏链是平稳的。一维嵌入马尔可夫链模型能够较好地描述研究区土壤质地层次的垂向变化,剖面主要的质地层次组合为:砂—壤、壤—砂、壤—黏、黏—壤。对土壤质地剖面的定量模拟,可以为开展该区域土壤水循环、转化和溶质迁移等相关研究提供参考。
英文摘要	In the Linze County, located in the middle reaches of the Heihe River, northwest China, the geomorphic types include alluvial-proluvial plain, plain of denudation, and desert grassland in the fringe of an oasis. The main landscapes of this region are composed of desert, oasis farmland and wetland, all of which distribute irregularly and patchily. The differentiation of soil textures was observed both horizontally and vertically. In a vertical direction, sand and clay layers in soil usually sandwich each other, even when there are some impermeable layers in some profiles. The heterogeneity of soil profile textures with depth significantly influences water movement and solute transport. In this study, all 2,000 soil samples were collected with a 5-cm diameter auger to a depth of 300 cm at 100 points in an area of 100 km2. After being taken into a laboratory and having been wind-dried, the soil mechanical composition was measured using a Malvern Laser particle size analyzer. Then the vertical change of soil textural layers was analyzed, and a MC-LN (Markov chain- lognormal distribution) model was constructed to simulate the soil textural profiles. Results showed that there were seven soil textural types occurring in the study area, namely, sand, loamy sand, sandy loam, loam, clay loam, silty clay loam and silt clay, respectively. Compared with the non-occurrence of silty clay layers in the surface soil, another six types of textural layers all occurred in the surface soil of the study area, while sand layers occurred with a much higher probability than the others. The layer thickness of each textural type in the study area was characterized as a lognormal distribution, with relatively thick sand and silty clay loam layers, and relatively thin sandy loam, loam and clay layers. For a certain textural type, layers occurred beneath it were mainly the two types which adjoined it, especially the one which contained more fine particles. The uncertainty analysis of soil textural layer transitions indicated that the formation of loamy sand layers was much strongly dependent on the lower layers, whereas the clay loam layers had a key effect on the formation of the upper layers. Loamy sand and loam layers had a relative high probability to have sandy loam layers as upper layers, while silty clay loam layers had relative high probability to occur as upper layers of both clay loam and silty clay layers. None of the seven textural layers had the same combinations of upper and lower layers simultaneously. Markov characteristics and the stability of the vertical change of textural layers were verified by χ2 test using the TPMs of the entire samples, the subintervals and the sub-regions. A one-dimensional MC-LN model could quantitatively describe the vertical change of textural layers. The simulated TPM approached to the measured TPM, and the simulated layer thickness of each textural type was close to the measured value. The main combinations of textural layers along each profile were sand-loam, loam-sand, loam-clay, and clay-loam. Quantitative description of soil textural profiles will benefit further study on water cycles, transformation and solute transfer in soil profiles. This, in turn, will serve to improve the water use efficiency、the relieve and the salinization of the study area.
语种	中文
公开日期	2014-10-20
内容类型	期刊论文
源URL	[http://ir.iswc.ac.cn/handle/361005/5545]
专题	水土保持研究所_水保所知识产出(1956-2013)
推荐引用方式 GB/T 7714	李丹凤,邵明安. 一维马尔可夫链模拟黑河中游流域土壤质地垂向变异[J]. 农业工程学报,2013,29(05):71-10.
APA	李丹凤,&邵明安.(2013).一维马尔可夫链模拟黑河中游流域土壤质地垂向变异.农业工程学报,29(05),71-10.
MLA	李丹凤,et al."一维马尔可夫链模拟黑河中游流域土壤质地垂向变异".农业工程学报 29.05(2013):71-10.