Search results for "soils"

Evaluación del riesgo en humedales costeros mediterráneos de la presencia de contaminantes químicos orgánicos = Evaluation of the risk in Mediterrane…

2008

El rápido incremento de la población urbana ha traído asociado una intensa presión en el medioambiente circundante. Actualmente, la franja costera en la mayoría de países europeos es el área que ha experimentado un mayor desarrollo socioeconómico. Algunas pinceladas obtenidas de distintas fuentes dan una idea global de la importancia del crecimiento demográfico de estas zonas. Hoy en día, 3 mil millones de personas –alrededor de la mitad de la población mundial- viven a menos de 200 kilómetros de la costa. Dos quintas partes de las ciudades con poblaciones de entre 1 y 10 millones están localizadas cerca de la costa. En Bélgica, Portugal y España, la densidad de población en los 10 kilómetr…

Zanieczyszczenie wielopierścieniowymi węglowodorami aromatycznymi (WWA) gleb zalanymi wodami powodziowymi

2008

Changes in physicochemical properties of soils in the area affected by lime industry

2016

Lime and cement industry belongs to the best developed branches of industry in Opole Voivodeship. The plants are located in eastern and central part of the province, in the vicinity of the city of Opole and the towns of Krapkowice and Strzelce Opolskie due to the location of the resources of calcareous raw materials (limestones and marls).The impact of lime and cement industry on the natural environment, especially soils, was studied by many authors, but these works do not concern the Province of Opole, which is one of the main centers of lime and cement industry in Poland for centuries. The article is an attempt to show changes in physicochemical properties of soils being under long lastin…

Gamma-radioactive contamination in the area of Lesisko Reserve

2004

Evolution des paysages Sahélines au cours des six dernières décennies dans la région de Niamey : de la disparition de la brousse tigrée à l'encroutem…

2010

In the Sahel, the rapid increase of the population during the last decades and the climate variation lead to an important environmental degradation. This work aims to measure the impacts of the human pressure on ecosystem during the six last decades. A diachronic cartography of a 100 km² area close to Niamey was done with aerial photographs (1950 and 1975) and GPS measurements (2009). Results showed that the tiger bush vegetation was completely cleared between 1950 and 2009 while the fallow decreases from 7 % to 1 %. In the sandy valley, the increase of cultivated fields from 20,7 % (1950) to 69,4 % (1975) favoured wind and water erosions which allowed surface soil crusting. Between 1975 an…

Rainwater-induced leaching of selenium, arsenic and vanadium from Etnean volcanic soils

2009

Active volcanoes emit considerable amounts of contaminants such as As, Se and V. Mount Etna is the biggest volcano of Europe and an excellent geochemical site to study water-soil processes. Due to its volcanic activity, the rainwater has a strong compositional gradient, both in time and space. At present, the behaviour of trace elements in the soils around Mt Etna is poorly understood. To determine the influence of the rainwater pH on the potential mobilization of geogenic pollutants, batch experiments have been performed with synthetic rainwater for 25 soils collected along the flanks of the volcano. Our results show that: i) The maximum concentrations in the leaching solutions are higher …

Inhibition of denitrification and N2O emission by urine-derived benzoic and hippuric acid

2006

Abstract Hippuric acid (HA) in cattle urine acts as a natural inhibitor of soil N2O emissions. As HA concentration varies with diet, we determined critical HA levels. We also tested the hypothesis that the inhibition occurs because the HA breakdown product benzoic acid (BA) inhibits denitrification rates. During a 64-day incubation, we quantified emissions from artificial urine varying in HA, BA and glycine (Gly) concentrations, added to a sandy pasture soil. Increasing HA concentration from 0.4 to 5.6 mmol kg−1 soil significantly decreased the average N2O flux by 54%. At 3.9 mmol kg−1 soil, denitrification levels were 50% reduced for BA as compared to Gly. We conclude that HA inhibits both…

ESTIMATING SOIL PARTICLE-SIZE DISTRIBUTION FOR SICILIAN SOILS

2009

The soil particle-size distribution (PSD) is commonly used for soil classification and for estimating soil behavior. An accurate mathematical representation of the PSD is required to estimate soil hydraulic properties and to compare texture measurements from different classification systems. The objective of this study was to evaluate the ability of the Haverkamp and Parlange (HP) and Fredlund et al. (F) PSD models to fit 243 measured PSDs from a wide range of 38 005_Bagarello(547)_33 18-11-2009 11:55 Pagina 38 soil textures in Sicily and to test the effect of the number of measured particle diameters on the fitting of the theoretical PSD. For each soil textural class, the best fitting perf…

Labile nitrogen, carbon, and phosphorus pools and nitrogen mineralization and immobilization rates at low temperatures in seasonally snow-covered soi…

2006

Surface mineral horizons from four ecosystems sampled in the northwestern Italian Alps were incubated at −3 and +3°C to simulate subnivial and early thaw period temperatures for a seasonally snow-covered area. The soil profiles at these sites represent extreme examples of management, grazed meadow (site M) and extensive grazing beneath larch (site L) or naturally disturbed by avalanche and colonized by alder (site A) and the expected forest climax vegetation beneath fir (site F). Changes in labile pools of nitrogen (N) and phosphorus (P) were active at all sites at both temperatures during 14 days of laboratory incubation. Ammonium was the dominant inorganic form of total dissolved N (TDN),…

Role of land set-up systems on soil (physicochemical) conditions

2020

Land reclamation and drainage networks represent one of the most ancient human modifications of the Italian soilscape, where tailored land set-up systems were developed in agro- and forestecosystems in three millennia of man’s activity. Most of once manually maintained land settings are currently scarcely working or even disappeared because of the cost needed for their maintenance and the advent of mechanization that have simplified the field organization. The scarce attention to the soil experienced in the last decades, has accelerated soil erosion and flooding events, which entailed high costs in terms of money and human lives, but also caused reduction of soil thickness, water holding ca…