scholarly journals An aerodynamic approach in soil hydraulic conductivity estimation for investigating soil erosion degree

2015 ◽  
Vol 367 ◽  
pp. 66-71
Author(s):  
V. Sergey ◽  
S. Vyacheslav
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Erosion ◽  
European Russia ◽  
New Method ◽  
East European Plain ◽  
Soil Porosity ◽  
New Approach ◽  
Soil Hydraulic Conductivity ◽  
East European ◽  
Zonal Soils

Abstract. We propose a new method for determining the degree of erosion for zonal soils of the East European Plain. This new approach uses soil porosity and filtration to determine a coefficient of aerodynamic similarity. We evaluated the degree of soil erosion on ranges of the major zonal soils of the eastern part of European Russia by applying this new method. Based on these data, we developed a diagnostic scale to determine the extent of soil erosion in this area.

Spatial and temporal features of soil erosion in the forest-steppe zone of the East-European Plain

2011 ◽  
Vol 44 (7) ◽  
pp. 794-801 ◽  
Author(s):  
V. N. Golosov ◽  
A. N. Gennadiev ◽  
K. R. Olson ◽  
M. V. Markelov ◽  
A. P. Zhidkin ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Steppe Zone ◽  
East European Plain ◽  
Forest Steppe ◽  
East European ◽  
Temporal Features

scholarly journals New transient method for determining soil hydraulic conductivity function

2016 ◽  
Vol 53 (8) ◽  
pp. 1332-1345 ◽  
Author(s):  
A.K. Leung ◽  
J.L. Coo ◽  
C.W.W. Ng ◽  
R. Chen
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Column ◽  
Water Flow Rate ◽  
Numerical Differentiation ◽  
New Method ◽  
Transient Method ◽  
Soil Hydraulic Conductivity ◽  
Conductivity Function ◽  
Soil Hydraulic ◽  
Boundary Flux

The instantaneous profile method (IPM) is a transient method for measuring a soil’s hydraulic conductivity function (SHCF), which relates soil hydraulic conductivity with suction. In the existing interpretation method of the IPM, boundary flux during testing must be known to integrate instantaneous profiles of water content for obtaining the water flow rate. However, it is usually difficult and expensive to measure a boundary flux and if not known, assumptions that may not be easily justified (especially in the field condition) have to be made. In this study, a new method is proposed so that boundary flux does not need to be measured, controlled or assumed during a test. The new method is evaluated through (i) hypothetical column tests using transient seepage analyses and (ii) five case studies. The new method is capable of determining an SHCF with good accuracy. Normalized root-mean-square deviation (NRMSD) for the old and new methods is less than 5% and 10%, respectively. The accuracy of the new method can be increased substantially (i.e., NRMSD <5%) when the spacing of sensors installed along a soil column is reduced. Closer sensor spacing reduces error propagation due to numerical differentiation of instantaneous profiles of hydraulic head for determining hydraulic gradient.

A multilayer soil approach for seepage process analysis in earthen levees

2021 ◽  
Author(s):  
Bianca Bonaccorsi ◽  
Tommaso Moramarco ◽  
Leonardo Valerio Noto ◽  
Silvia Barbetta
Keyword(s):  
Hydraulic Conductivity ◽  
Water Table ◽  
Groundwater Level ◽  
Process Analysis ◽  
The Body ◽  
Soil Parameters ◽  
New Approach ◽  
Soil Hydraulic Conductivity ◽  
Water Head ◽  
Soil Hydraulic

&lt;p&gt;Earthen levees protect flood-prone areas during severe flood events. In most cases, however, flooding is the result of the collapse of the embankments due to the seepage through and under the levee body. The description of the seepage line is difficult mainly because of the uncertainty on the hydraulic parameters, first of all the soil hydraulic conductivity. Barbetta et al. (2017) proposed a practical method for the seepage analysis based on the Marchi&amp;#8217;s equation for the estimation of the probability of occurrence of the levee seepage which provides a vulnerability index under the assumption that the groundwater level coincides with the ground. Recently, the method has been tested also considering the groundwater level below the ground pointing out that such a condition has a high impact on the levee vulnerability to seepage. However, it does not consider the interactions between seepage process in the levee body and in the foundation.&lt;/p&gt;&lt;p&gt;In this context, this work proposes a new approach for the analysis of the infiltration line through the body and the foundation, considering a multilayer soil and assuming a different soil hydraulic conductivity for each layer. The new equation is obtained starting from the continuity equation and the flow equation.&lt;/p&gt;&lt;p&gt;The saturation line estimated through the Marchi&amp;#8217;s equation and the one derived through the new multilayer model equation are compared. The analysis is first addressed to identify a threshold of the ratio between water head and water table beyond which the Marchi&amp;#8217;s equation is no longer applicable. Indeed, the Marchi&amp;#8217;s equation is valid when the river water head is lower than the water table. Different values of these two variables are analyzed and a threshold ratio equal to 0.57 is identified.&lt;/p&gt;&lt;p&gt;Furthermore, the levee vulnerability to seepage estimated with the two approaches is compared and the levee is found more vulnerable when the new approach is applied. The results indicate that the difference between the two vulnerability approaches decreases as the distance between the groundwater table and the ground level tends to zero. The proposed approach is an attempt to quantify the seepage probability with more realistic levees characteristics, hydraulic and soil parameters.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Barbetta, S., Camici, S., Bertuccioli, P., Palladino, M. R., &amp; Moramarco, T. 2017. Refinement of seepage vulnerability assessment for different flood magnitude in national levee database of Italy. Hydrology Research, 48(3), 763&amp;#8211;775. https://doi.org/10.2166/nh.2017.101.&lt;/p&gt;

Geographical features of forest vegetation reflected at the level of the lower-rank syntaxa (evidence from the Russian part of the Upper Dnieper basin)

2017 ◽  
pp. 94-108 ◽  
Author(s):  
Yu. A. Semenishchenkov
Keyword(s):  
Forest Vegetation ◽  
East European Plain ◽  
Early 20Th Century ◽  
Suggested Approach ◽  
Central European ◽  
Classification Schemes ◽  
East European ◽  
Lower Rank ◽  
Geographical Variations ◽  
European Part Of Russia

Phytogeographical features of forest vegetation at the level of lower-rank syntaxa were being discussed in literature since the early 20th century (Cajander, 1903; Sukachev, 1926; Braun-Blanquet, 1964; Kral et al., 1975; Kleopov, 1990; Bulokhov, 2003; Ellenberg, 2009), however, phytocoenologists still have no uniform interpretation and geographical maintenance of lower classification units. Forest vegetation of the European part of Russia is well studied according to Braun-Blanquet approach with association as a system of geographical subassociations. The paper offers the approaches to the reflection of geographical variations of the natural forest vegetation in the basin of the Upper Dnieper (central part of the East European Plain) at the level of lower-rank syntaxa The xeromesophytic oak woods in the basin of the Upper Dnieper belong to the East European ass. Lathyro nigri–Quercetum roboris Bulokhov et Solomeshch 2003. Floristic differentiation of this association from the similar Central European ass. Potentillo-Quercetum is given. These two associations have large blocks of geographically significant differential species that does not allow to consider them as a part of one association. The suggested approach allows to define the chorological content of units of lower syntaxonomical ranks and make regional classification schemes comparable to each other.

A New Approach for the Analysis of Mixture Toxicity Data

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2345-2348 ◽  
Author(s):  
C. N. Haas
Keyword(s):  
Quantitative Analysis ◽  
Mixture Toxicity ◽  
New Method ◽  
Metal Exposure ◽  
Positive Interactions ◽  
Toxicity Data ◽  
Data Set ◽  
New Approach ◽  
Negative Interactions

A new method for the quantitative analysis of multiple toxicity data is described and illustrated using a data set on metal exposure to copepods. Positive interactions are observed for Ni-Pb and Pb-Cr, with weak negative interactions observed for Ni-Cr.

scholarly journals Eastern Europe’s “Transitional Industry”?: Deconstructing the Early Streletskian

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
R. Dinnis ◽  
A. Bessudnov ◽  
N. Reynolds ◽  
T. Devièse ◽  
A. Dudin ◽  
...  
Keyword(s):  
Modern Human ◽  
East European Plain ◽  
Upper Palaeolithic ◽  
Radiocarbon Dates ◽  
East European ◽  
Archaeological Material ◽  
Younger Age ◽  
Layer V ◽  
Precise Relationship ◽  
Early Upper

AbstractThe Streletskian is central to understanding the onset of the Upper Palaeolithic on the East European Plain. Early Streletskian assemblages are frequently seen as marking the Neanderthal-anatomically modern human (AMH) anthropological transition, as well as the Middle-to-Upper Palaeolithic archaeological transition. The age of key Streletskian assemblages, however, remains unclear, and there are outstanding questions over how they relate to Middle and Early Upper Palaeolithic facies. The three oldest Streletskian layers—Kostenki 1 Layer V, Kostenki 6 and Kostenki 12 Layer III—were excavated by A. N. Rogachev in the mid-20th century. Here, we re-examine these layers in light of problems noted during Rogachev’s campaigns and later excavations. Layer V in the northern part of Kostenki 1 is the most likely assemblage to be unmixed. A new radiocarbon date of 35,100 ± 500 BP (OxA- X-2717-21) for this assemblage agrees with Rogachev’s stratigraphic interpretation and contradicts later claims of a younger age. More ancient radiocarbon dates for Kostenki 1 Layer V are from areas lacking diagnostic Streletskian points. The Kostenki 6 assemblage’s stratigraphic context is extremely poor, but new radiocarbon dates are consistent with Rogachev’s view that the archaeological material was deposited prior to the CI tephra (i.e. >34.3 ka BP). Multiple lines of evidence indicate that Kostenki 12 Layer III contains material of different ages. Despite some uncertainty over the precise relationship between the dated sample and diagnostic lithic material, Kostenki 1 Layer V (North) therefore currently provides the best age estimate for an early Streletskian context. This age is younger than fully Upper Palaeolithic assemblages elsewhere at Kostenki. Other “Streletskian” assemblages and Streletskian points from younger contexts at Kostenki are briefly reviewed, with possible explanations for their chronostratigraphic distribution considered. We caution that the cultural taxon Streletskian should not be applied to assemblages based simply on the presence of bifacially worked artefacts.

scholarly journals New Method for Generating New Families of Distributions

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 726
Author(s):  
Lamya A. Baharith ◽  
Wedad H. Aljuhani
Keyword(s):  
Exponential Distribution ◽  
Real Data ◽  
Rate Function ◽  
New Method ◽  
Likelihood Method ◽  
Alpha Power ◽  
Unknown Parameters ◽  
Failure Rate Function ◽  
New Approach ◽  
Numerical Studies

This article presents a new method for generating distributions. This method combines two techniques—the transformed—transformer and alpha power transformation approaches—allowing for tremendous flexibility in the resulting distributions. The new approach is applied to introduce the alpha power Weibull—exponential distribution. The density of this distribution can take asymmetric and near-symmetric shapes. Various asymmetric shapes, such as decreasing, increasing, L-shaped, near-symmetrical, and right-skewed shapes, are observed for the related failure rate function, making it more tractable for many modeling applications. Some significant mathematical features of the suggested distribution are determined. Estimates of the unknown parameters of the proposed distribution are obtained using the maximum likelihood method. Furthermore, some numerical studies were carried out, in order to evaluate the estimation performance. Three practical datasets are considered to analyze the usefulness and flexibility of the introduced distribution. The proposed alpha power Weibull–exponential distribution can outperform other well-known distributions, showing its great adaptability in the context of real data analysis.

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