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A New Nomograph for Estimating Erodibility Factor (K) in Some Soils of the Semi-Arid Regions in Northwest of Iran  [cached]
A Vaezi,H Bahrami,H Sadeghi,M Mahdian
Journal of Science and Technology of Agriculture and Natural Resources , 2009,
Abstract: Proper evaluation of soil erodibility factor is very important in assessment of soil erosion. In this study, soil erodibility factor (K) was assessed in a zone, 900 km2 in area in Hashtrood, located in a semi-arid region in north west of Iran. Soil erodibility factor was measured at the unit plots under natural rainfall events in 36 different lands in the study area from March 2005 to March 2007. Results indicated that the measured soil erodibility factor K is on average 8.77 times lower than the nomograph-based values in the study area. To achieve a new nomograph, correlation between measured soil erodibility and soil physicochemical properties was studied. Based on the results, soil erodibility factor negatively correlated with coarse sand, clay, organic matter, lime, aggregate stability and permeability, while its correlation with very fine sand and silt was positive. Results of principal component analysis of soil properties and multi-regression analysis showed that the soil erodibility factor is significantly (R2 = 0.92, P < 0.001) related to soil permeability, aggregate stability, lime and coarse sand. A new nomograph with a R2 of 92% was developed based on these properties to easily estimate soil erodibility factor in the study area. The soil erodibility factor can be reliably estimated using the nomograph in all regions with the soil and rain properties similar to those in the study area.
Vincenzo Bagarello,Costanza Di Stefano,Vito Ferro,Giordano Giuseppe
Journal of Agricultural Engineering , 2009, DOI: 10.4081/jae.2009.3.7
Abstract: The soil erodibility factor, K, of the Universal Soil Loss Equation (USLE) is a simple descriptor of the soil susceptibility to rill and interrill erosion. The original procedure for determining K needs a knowledge of soil particle size distribution (PSD), soil organic matter, OM, content, and soil structure and permeability characteristics. However, OM data are often missing and soil structure and permeability are not easily evaluated in regional analyses. The objective of this investigation was to develop a pedotransfer function (PTF) for estimating the K factor of the USLE in Sicily (south Italy) using only soil textural data. The nomograph soil erodibility factor and its associated first approximation, K’, were determined at 471 sampling points distributed throughout the island of Sicily. Two existing relationships for estimating K on the basis of the measured geometric mean particle diameter were initially tested. Then, two alternative PTFs for estimating K’ and K, respectively, on the basis of the measured PSD were derived. Testing analysis showed that the K estimate by the proposed PTF (eq.11), which was characterized by a Nash-Suttcliffe efficiency index, NSEI, varying between 0.68 and 0.76, depending on the considered data set, was appreciably more accurate than the one obtained by other existing equations, yielding NSEI values varying between 0.21 and 0.32.
A review of soil erodibility in water and wind erosion research

SONG Yang,LIU Lianyou,YAN Ping,CAO Tong,

地理学报 , 2005,
Abstract: Soil erodibility is an important index to evaluate the soil sensitivity to erosion. The research on soil erodibility is a crucial tache in understanding the mechanism of soil erosion. Soil erodibility can be evaluated by measuring soil physiochemical properties, scouring experiment, simulated rainfall experiment, plot experiment and wind tunnel experiment. We can use soil erosion model and nomogram to calculate soil erodibility. Many soil erodibility indices and formulae have been put forward. Soil erodibility is a complex concept, it is influenced by many factors, such as soil properties and human activities. Several obstacles restrict the research of soil erodibility. Firstly, the research on soil erodibility is mainly focused on farmland; Secondly, soil erodibility in different areas cannot be compared sufficiently; and thirdly, the research on soil erodibility in water-wind erosion is very scarce. In the prospective research, we should improve method to measure and calculate soil erodibility, strengthen the research on the mechanism of soil erodibility, and conduct research on soil erodibility by both water and wind agents.
Ayoubi, S.A,M. H. Alizadeh
Revista Sociedade & Natureza , 2005,
Abstract: Soil erodibility is one of the key factors on some sediment and soil erosion models such as USLE, MUSLE, RUSLE, AUSLE (USLE modified in LS factor) and MMF and represents like K factor and is function of particle distribution, organic mater, soil structure and ermeability. Traditional methods do not take spatial variability and estimate precision of variables in to consideration and amount of them are constant across the whole of soil series .This study was performed to assess spatial variability of soil erodibility and its relevant variables at MEHR watershed from Khorasan province, in northern Iran. Interested network was designed by 110 samples like nested- systematic with distance about 50, 100, 250 and 500 meter across the study area by preparing point map at GIS. Sampling points were identified in field by an Global Positioning system. Soil sampling was done at depth of 0-5cm of ground surface and permeability was studied at depth of 5-30 cm. Some soil properties such as particle distribution and organic mater were measured at laboratory. Particle size distribution was determined by Hydrometer method and Organic matter was measured by wet oxidation approach. Then spatial analysis was done. Variography analysis on soil attributes according to soil erodibility, showed that Gaussian, exponential and spherical models were the most models to predict spatial variability of soil parameters. The range of spatial dependencies was changed from 320 to 3200 m. Soil attribute maps prepared by kriging technique using models parameters. Then soil attributes were composed by Wischmeier (1978) formula in Illwis media to calculate K factor. Amount of soil erodibility changed from 0.13 to 0.91 that it's maximum and minimum was identified in east and southwest of studiedarea. Soil spatial variability pattern, is similar to silt pattern due to high effect of silt on soil rodibility, Also that is partially confirmed with geology map, indicated which soil erodibility attribute controlled by parent material. High amount of soil erodibility in southwest area of given study area showed need to more attention for conservation the soil and control erosion.
Abandoned Smolník mine (Slovakia) – a catchment area affected by mining activities
Lintnerová, Otília,?ottník, Peter,?oltés, Stanislav
Estonian Journal of Earth Sciences , 2008,
Abstract: Smolník is a historical Cu-mining area that was exploited from the 14th century to 1990. The Smolník mine was definitively closed and flooded in 1990–1994. Acid mine drainage discharging from the flooded mine (pH = 3.83, Fe = 542 mg/l, SO42– = 3642 mg/l, Cu = 1880 μg/l, Zn = 9599 μg/l, As = 108 mg/l) acidified and contaminated the Smolník Creek water, which transported pollution into the Hnilec River catchment. The Smolník mine waste area has been used as a model area to document pollution of waters, stream sediments, and soils by metals and other toxic elements. Major goals of this complex study were to document creek water transport of the main pollutants (Fe, sulphates, Cu, Al, As, etc.) in the form of suspended solids, to investigate elements mobility in common mine waste (rock and processing waste heaps and tailing impoundment) and in the soil on the basis of neutralization and leach experiments. Different methodologies and techniques for sampling and chemical and mineralogical characterization of samples were used and checked to evaluate environmental risk of this abandoned mine area.
月壤及模拟月壤微观结构的研究  [PDF]
岩土力学 , 2012,
Abstract: 为了对比研究月壤与模拟月壤的微观结构,介绍了月壤的形成作用过程和5种基本颗粒类型;通过真实月壤照片,对月壤微观结构进行了分析;利用火山灰为模拟月壤主体材料,对其成分进行了检测;对模拟月壤的火山灰颗粒进行了显微图像分析试验。结果表明,月壤存在胶结物微观颗粒,胶结物颗粒具有分支的组织形态和封闭的气泡,并且有金属铁珠存在;火山灰所含的主要成分及含量与月壤相似,经过粉碎的火山灰试样棱角较为明显,其纵横比峰值略小,稍显长条状,但与月壤比较相近,而复杂度因子则略有欠缺,说明颗粒还不够粗糙和多棱
k均值聚类引导的遥感影像多尺度分割优化方法  [PDF]
测绘学报 , 2015, DOI: 10.11947/j.AGCS.2015.20130497
Abstract: 针对不同尺度地物的分割需求,提出了一种k均值聚类引导的多尺度分割优化方法。首先对原始影像进行小尺度分割和k均值聚类,然后利用k均值聚类结果引导对象合并,在合并过程中利用Otsu阈值方法自动选择k均值聚类的影响因子,最终得到适应不同尺度地物的分割结果。以FNEA多尺度分割方法为例,利用模拟数据和真实的GeoEye-1影像数据进行相关试验,目视和定量评价表明本文方法能够得到适宜不同尺度地物的高质量分割结果。
月壤静力学特性的离散元模拟  [PDF]
吉林大学学报(工学版) , 2008,
Abstract: 以典型月壤的物理力学性质为参照标准,采用颗粒流程序PFC3D对月壤静力学特性进行了离散元模拟研究。通过离散元模拟三轴试验反复调整颗粒细观参数,建立了月壤离散元接触力学模型;描述了月面探测车辆行驶下的月壤承压特性模型与剪切特性模型;从月面探测车辆的行驶观点出发,模拟压板试验,得出了载荷沉降关系;通过模拟履带板试验得出了剪切应力位移关系。最后,计算出了月壤的变形模量K为1635kN/mn+2、变形指数n为1.22,剪切变形模量k为1.35cm。结果表明,模拟试验值与模型预测趋势一致。
Variation of Soils Erodibility in Mbe Agropastoral Area in Relation with Land Utilization, Central Cameroon  [PDF]
Boukar Atougour, Simon Djakba Basga, Elisabeth Yaboki, Jean Pierre Temga, Jean Pierre Nguetnkam
Open Journal of Soil Science (OJSS) , 2019, DOI: 10.4236/ojss.2019.912017
Abstract: The study of the soils from Mbé and Wack is carried out in the framework of the knowledge of soils from the Adamawa Region of Cameroon and their erodibility was investigated using erodibility indices obtained through physico-chemical data. Eleven topsoils (0 - 20 cm) samples were collected on different land use and their susceptibility to erosion was assessed. The water dispersible clay (34.92 - 121.75 gkg−1), the clay dispersion ratio (0.45 - 0.84) and the dispersion ratio (0.75 - 0.89) were high in the studied soils while the clay aggregation (13.16 - 42.27gkg−1) and the clay flocculation index (0.16 - 0.55) were low to moderate indicating their high erodibility. The soils under natural vegetation, more clayey, displayed the highest amount of water dispersible clay while cropped soils recorded the smaller ones. Globally, in cropped soils, those under cereals displayed the highest clay dispersion indices than those under tubers. This suggests that tubers cropping practices in studied soils enhance their erodibility. Statistical analyses revealed that amorphous Al and Fe are elements which limit soils erodibility while K+ and \"\" promote soils particles dispersion. Sustainable management of these soils will consist on limiting runoff through agricultural practices such as direct seedling and orienting tillage perpendicularly to slope gradient.
Determining and Mapping Soil Erodibility Factor (Case Study: Yamchi Watershed in Northwest of Iran)  [PDF]
Rasool Imani, Hoda Ghasemieh, Mohammad Mirzavand
Open Journal of Soil Science (OJSS) , 2014, DOI: 10.4236/ojss.2014.45020

Among Universal Soil Erosion Equation (USLE) factors (R, K, L, S and P), Soil Erodibility Factor (K) is one of the most important and key factors which determines soil particles resistance to be detachment by water erosion (rainfall and/or runoff) forces. In fact, K factor is the rate of soil loss per rainfall erosion index unit and affected by 6 parameters including soil primary particles (silt, sand and clay), organic matter content and also permeability and structure of soil. The USLE nomograph is one of the most rapid and common methods for calculating K factor based on mentioned parameters. In this study, 38 samples of surface soil (0 - 15 cm) were collected from Yamchi watershed and the percentage of silt, sand, clay and organic matter content were determined in soil laboratory. Also textures of soil samples were determined to choice soil permeability and structure class codes based on United States Department of Agriculture (USDA) published information. Using USLE nomograph equation, K factor was calculated for each soil sample and based on kriging interpolation method, soil erodibility factor (K) map was constructed for entire study area which average soil erodibility factor and average standard error of interpolated map were 0.442 and 0.0076 t·ha·h·ha-1·Mj-1·mm-1, respectively.

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