Search results for "Soils"
showing 10 items of 157 documents
Fluorine speciation in topsoils of three active volcanoes of Sicily (Italy)
2008
Fluorine is one of the many environmental harmful elements released by volcanic activity. The content of total oxalate-extractable and water-extractable fluorine was determined in 96 topsoils of three active volcanic systems of southern Italy (Mt Etna, Stromboli and Vulcano). Total fluorine (F) content (F TOT) ranges from 112 to 7,430 mg kg−1, F extracted with oxalate (F OX) ranges from 16 to 2,320 mg kg−1 (2–93% of F TOT) and F extracted with distilled water ( $$ F_{{{\text{H}}_{{\text{2}}} {\text{O}}}} $$ ) ranges from 1.7 to 159 mg kg−1 (0.2–40 % of F TOT). Fluorine in the sampled topsoils derives both from the weathering of volcanic rocks and ashes and from the enhanced deposition due t…
Repercussion of anthropogenic landscape changes on pedodiversity and preservation of the pedological heritage
2013
Over a period of time people have lived in and with their surrounding landscapes and for several thousand years transformed the soilscapes and the vegetation into cultural landscape types important for their economy and to meet their needs (Richter 2007, Ellis 2011, Hjelle 2012). The sustainable provision of goods and services depends critically on managing soils without damaging the natural soilscapes and the related natural resources. To support the transition towards sustainable development, science needs to understand how land-use change affects the environment and how this, in turn, feeds back into human livelihood strategies or infl uences the vulnerability of the environment (Rounsev…
Exploring methanotrophic activity in geothermal soils from Pantelleria Island (Italy)
2012
Methane is released to the atmosphere by a wide number of natural (geological and biological) and anthropogenic sources, and is the second most important greenhouse gas after CO2. Microbial oxidation in soils by methanotrophic bacteria contributes to the removal of CH4 from the atmosphere and methanotrophic activity was also detected in volcanic/geothermal areas where degassing of endogenous gases occurs. Our aim is to describe the methanotrophs at the main exhalative area of Le Favare site at Pantelleria Island, where high CH4 consumption (up to 950 ng/g/ per h) was measured. Total soil bacterial diversity was analysed by TTGE of amplified 16S rRNA genes and the diversity of proteobacteria…
Simple soil water balance model (R function)
2022
This R function models the soil water balance (SWB) for two soil layers based on relatively simple assumptions. It is a simple method to calculate actual evapotranspiration, downward water flux (leaching), and upward water flux (or capillary rise) from two soil layers and the net flux between the two soil layers. The necessary input data comprises the change in soil water storage between two time steps per soil layer (e.g. from repeated volumetric soil water content measurements), potential evapotranspiration, precipitation, and the percentage of roots in the top soil layer. The soil water balance model is described in detail in Leimer et al. (2014). It is based on a soil water balance mode…
Characterization of gas flow through low-permeability claystone: laboratory experiments and two-phase flow analyses
2014
For the characterization of gas migration through a low-permeability clay host rock for deep underground repositories, a comprehensive understanding of the relevant phenomena of gas and fluid flow through low-permeability clay is required. The National Cooperative for the Disposal of Radioactive Waste (Nagra) in Switzerland has developed a comprehensive programme to characterize gas flow in low-permeability Opalinus Clay through laboratory tests and detailed numerical analyses for developing appropriate constitutive models. Laboratory tests were performed on cores by two different laboratories, the Laboratory for Soil Mechanics at EPFL and the Department of Geotechnical Engineering and Geos…
La resistenza di interfaccia calcestruzzo poroso-terreni a grana fina per il consolidamento di pendii mediante trincee drenanti profonde
2022
Le trincee drenanti profonde rappresentano uno dei metodi più efficaci per la mitigazione del rischio da frana, in pendii con falda idrica. Esse sono realizzate mediante pannelli o pali secanti. Il riempimento è costituito di calcestruzzo poroso o materiale granulare. Se le trincee sono adeguatamente “innestate” nel terreno stabile e il materiale di riempimento ha sufficiente resistenza e rigidezza come il calcestruzzo poroso, si ha ulteriore in-cremento di resistenza a taglio per effetto shear keys, oltre a quello derivante dalla riduzione delle pressioni in-terstiziali. L’incremento di resistenza è dovuto sia alla resistenza all’interfaccia calcestruzzo–terreni sia a quella intrinseca del…
Modelling landslides in unsaturated slopes subjected to rainfall infiltration using material point method
2016
This paper presents a dynamic fully coupled formulation for saturated and unsaturated soils that undergo large deformations based on material point method. Governing equations are applied to porous material while considering it as a continuum in which the pores of the solid skeleton are filled with water and air. The accuracy of the developed method is tested with available experimental and numerical results. The developed method has been applied to investigate the failure and post-failure behaviour of rapid landslides in unsaturated slopes subjected to rainfall infiltration using two different bedrock geometries that lie below the top soil. The models show different failure and post-failur…
A physical model for the interaction between unsaturated soils and retaining structures
2020
Temporary and permanent retaining structures interact with soils that are usually in unsaturated conditions. In this work, a 1g-scale physical model is presented to investigate the interactions between retaining walls and unsaturated soils. The physical model is equipped with a water-filled hydraulic cylinder connected to a pressure-volume controller to measure the horizontal component of the later earth thrust and high capacity tensiometers to measure soil matric suction. A system of low-friction linear guideways has been installed at the base of the wall-model. The failure surface is observed through a 3 cm thick glass wall on one side of the container. A series of images are acquired dur…
Magnetic Susceptibility in the Soils Along Communication Routes in the Town of Opole
2019
Magnetic susceptibility measurements were taken in eight selected streets of Opole, with diversified vehicle traffic intensity. The experiment surfaces were marked on every street, with two separate zones: A – a strip directly adjacent to the road and B – a strip 1 m away from the road edge. The carried out research indicated considerable influence of communication-generated pollution, with simultaneous influence of other local emission sources. The relation of magnetic anomalies was indicated, which may be the result of ferromagnetic materials aggregation, originating mainly from combustion processes. The road structure, including the surface condition, the main construction material and s…
Diuron mobility through vineyard soils contaminated with copper
2005
International audience; The herbicide diuron is frequently applied to vineyard soils in Burgundy, along with repeated treatments with Bordeaux mixture (a blend of copper sulfate and calcium hydroxide) that result in elevated copper concentrations. Cu could in principle affect the fate and transport of diuron or its metabolites in the soil either directly by complexation or indirectly by altering the populations or activity of microbes involved in their degradation. To assess the effect of high Cu concentrations on diuron transport, an experiment was designed with ten undisturbed columns of calcareous and acidic soils contaminated with 17–509 mg kg−1 total Cu (field-applied). Grass was plant…