Search results for "Soils."
showing 10 items of 150 documents
Is land-use change a cause of loss of pedodiversity? The case of the Mazzarrone study area, Sicily
2011
Anthropogenic soils created ex novo by land-us e change in large scale farming are, from a pedogenetic point of view, catastrophic events that bring the soils to time zero and change the natural pattern of the soilscape, remarkably, in some cases. The qu antitative aspects of pedodiversity of a soilsc ape in South-East Sicily, where some types of soils, in recent decades, have suffered a consistent reduction due to the transformations by large scale farming, are considered. The evolution of pedodiversity over a 53-year period (1955 to 2008 ) is examined using a dedicated statistical method and a space – time model based on Markov analysis and cellular autom ata in order to predict the evolu…
Post-fire hydrological response and suspended sediment transport of a terraced Mediterranean catchment
2017
In July 2013, a wildfire severely affected the western part of the island of Mallorca (Spain). During the first three post-fire hydrological years, when the window of disturbance tends to be more open, the hydrological and sediment delivery processes and dynamics were assessed in a representative catchment intensively shaped by terracing that covered 37% of its surface area. A nested approach was applied with two gauging stations (covering 1.2 km2 and 4.8 km2) built in September 2013 that took continuous measurements of rainfall, water and sediment yield. Average Suspended Sediment Concentration (1,503 mg l-1) and the maximum peak (33,618 mg l-1) were two orders of magnitude higher than tho…
Impacts of thinning of a Mediterranean oak forest on soil properties influencing water infiltration
2017
[EN] In Mediterranean ecosystems, special attention needs to be paid to forest¿water relationships due to water scarcity. In this context, Adaptive Forest Management (AFM) has the objective to establish how forest resources have to be managed with regards to the efficient use of water, which needs maintaining healthy soil properties even after disturbance. The main objective of this investigation was to understand the effect of one of the AFM methods, namely forest thinning, on soil hydraulic properties. At this aim, soil hydraulic characterization was performed on two contiguous Mediterranean oak forest plots, one of them thinned to reduce the forest density from 861 to 414 tree per ha. Th…
Testing different approaches to characterize Burundian soils by the best procedure
2011
Abstract The Beerkan Estimation of Soil Transfer parameters (BEST) procedure seems attractive for soil hydraulic characterization but it has received little testing so far. The objective of this investigation was to test BEST with different application approaches for some soils in Burundi, where there is the need of using simple methods to characterize soils. Most (14) of the 19 sampled sites had a clay soil texture whereas texture ranged from silty clay to loam in the other cases. On average, the fitting ability of both the particle size distribution (PSD) model (mean relative error, Me ( E r ) = 2.0%) and the cumulative infiltration model ( Me ( E r ) = 2.3%) was good according to recomme…
The evaluation of urban soils aimed at the sustainability of plants in public and private flowerbeds
2020
The authors report the survey of some flowerbeds located in the city of Palermo with the aim of assessing the sustainability of the plants and the interventions to be implemented, i.e. cutting or transfer of plants, to achieve a sustainable green. In the case in which it is possible to insert other plants in the flowerbeds, it is recommended to elaborate a project using programs that allow to have a preview of the spaces available for the new plants. This work is methodological and is aimed at creating a green that can achieve the functional objectives in relation to the site where it is located (sustainability in all aspects) and at low management costs with no or almost no irrigation prac…
Bridging Mediterranean cultures in the International Year of Soils 2015: A documentary exhibition on irrigation techniques in water scarcity conditio…
2017
The paper presents the activity performed at the University of Brescia by students and researchers, belonging to different Mediterranean cultures and different disciplines, to prepare a documentary exhibition on irrigation techniques in water scarcity conditions, on the occasion of the International Year of Soils 2015. Traditional irrigation techniques were identified as a key aspect of soil conservation and agricultural practices, to build living and autopoietic ecosystems, also in adverse climatic conditions, and to adapt to climatic changes. Being a structural source of ecosystem survival, and being based on long-lasting observation of the climate and of the environment, they have deep r…
Fabric evolution and the related swelling behaviour of a sand/bentonite mixture upon hydro-chemo-mechanical loadings
2015
This experimental study investigates the swelling behaviour of an 80/20 sand/bentonite mixture and the associated fabric evolution under different hydro-chemo-mechanical loadings. Free and confined swelling tests are performed on specimens compacted to different dry densities and wetted with different pore fluids. Controlled suction confined swelling tests are performed to determine the suction–swelling pressure relationship for two different densities. An extensive microstructural characterisation is performed to relate the observed swelling behaviour to the evolution of the different pore networks during wetting. Based on the microstructural analysis, an expression is proposed to determi…
Rock decay phenomena and collapse processes in the “Latomiae del Paradiso” in Syracuse (Sicily)
2014
The Latomiae (origin: Greek latomia, from laas, las stone plus –tomia tomy ) del Paradiso in Syracuse are Magna Graecia rock quarries, located in the coastal areas of Southern Italy and internationally renowned for their impressive environment. The few historical technical records do not help clarify the events that led to their current configuration since a series of instability phenomena occurred due to decay processes over time. Through a geotechnical back-analysis, this work highlights the failure phenomena, which may have led to the current configuration of the easterly side of the Latomiae del Paradiso. The back-analysis process was carried out by means of numerical modelling, support…
Coupled hydro-mechanical analysis of compacted bentonite behaviour during hydration
2021
Abstract This study analyses the response of compacted bentonites upon hydration based on a coupled hydro-mechanical elasto-plastic framework. As an alternative to multi-porosity interpretation, the framework was selected based on the experimental evidence of adsorbed water behaviour in bentonites and the volumetric response at saturated states, apparently independent of its initial state. Based on these premises, a water retention model was formulated using an explicit distinction between adsorbed water and free water, enabling the postulation of the water properties and behaviour depending on its state. In order to effectively account for the transition between unsaturated to saturated st…
Urban growth (1956-2012) and soil sealing in the metropolitan area of Valencia (Eastern Spain)
2019
[EN] The aim of this study is to understand the urban growth dynamics from the mid-1950s to 2012 in the Metropolitan Area of Valencia, eastern Spain, and its impact on soils. The study area is a very interesting example of the many changes in land use and land cover in the landscape of Mediterranean alluvial plains. The analysis of urban growth was based on photo interpretation of aerial photographs and GIS based methodology. At a detailed scale (1:10,000), results show that there has been a highly dynamic process produced by the extent of land developed as urban area. In 1956 only 3,441 hectares (9.3% of the overall study area) were occupied by urban use. In 2012 the total sealed surface w…