Search results for "soil water"
showing 10 items of 840 documents
Bypass flow, salinization and sodication in a cracking clay soil
2004
Abstract In Sicily, the increasing scarcity of good-quality waters is spreading irrigation with saline–sodic waters, thus enhancing the risk of soil secondary salinization and sodication. Sustainable management strategies are urgently needed in Sicily to prevent extent of salinization and sodication, thus preserving soil quality. Since irrigation is performed in cracking soils using irrigation systems involving high application rates, bypass flow of water and solutes occurs during irrigation. The objectives of this paper were (i) to investigate the process of Na–Ca exchange and subsequent salinization/sodication during bypass flow and (ii) to explore possibilities of using cyclic strategies…
Application of the SWAP model to predict impact of climate change on soil water balance in a Sicilian vineyard
2012
In Sicily, the increasing scarcity of quality water is leading to irrigation with saline water in soils having a considerable susceptibility to salinization and degradation. In this paper, water flow and solute transport in a Sicilian irrigated soil was simulated by using the SWAP model, and the simulated results compared to measured values of soil moisture and salinity. The investigation was carried out in a vineyard located in Sicily (Mazara del Vallo, Trapani Province) within the framework of the Project: Evolution of cropping systems as affected by climate change (CLIMESCO). The soil hydraulic parameters were obtained by inverse method based on multi-step outflow experiments. The result…
Properties and erosional response of soils in a degraded ecosystem in Crete (Greece)
2013
To study desertification processes relating to soil erosion, a climatological and altitudinal gradient from south to north was selected in Crete (Greece) and four locations were selected along the gradient. At the locations precipitation ranged from 1400 mm/year at the highest location to 400 mm/year at the lowest. All locations are affected by the actual land use: intensive grazing, small controlled fires, and abandoned agricultural terraces. Representative soil profiles were described in the field and analyzed in the laboratory, and rainfall simulation experiments in the field measured soil erosion over different soil surfaces and land uses. Data on physical and chemical properties were o…
Application of Magnetic Susceptibility Measurements for Identification of Technogenic Horizons in Soil Profiles on the Example of the Vistula River C…
2017
Studies on magnetic properties of soils have been recently applied in the soil environment quality monitoring in relation to basic physical and chemical properties. However, the issue of distribution of ferrimagnetic materials in particular genetic soil horizons, especially in altered soils, has not yet been considered in environmental studies. The main subject of the research was to evaluate a potential of magnetic susceptibility measurements as implements for supporting the soil classification through indication of particular distinctive genetic horizons in the soil profile. The study objects were soils whose formation was strictly conditioned by hydrotechnical regulations in the area of …
Using Static and Dynamic Indicators to Evaluate Soil Physical Quality in a Sicilian Area
2013
Both capacitive indicators derived from the water retention curve and dynamic measurements of the flow-weighted mean pore radius, R0, were used to assess the soil physical quality of two agricultural areas (cropland and olive orchard) and two natural areas (grassland and managed woodlot plantation) potentially subject to soil degradation. The overall idea of the study was to investigate whether a dynamic indicator quantitatively derived from hydraulic conductivity measurements could be used to supplement the traditionally applied capacitive indicators retrieved from water retention measurements. According to the available criteria, only the surface layer of the cropland site showed optimal …
Climate changes' effects on vegetation water stress in Mediterranean areas
2010
Many recent studies have demonstrated that CO(2) increase is driving the climate in Mediterranean areas towards important changes, mainly represented by a temperature increase and a contemporaneous rainfall reduction. Starting from this premise, the primary aim of the present study is to investigate the effects of potential climatic changes on vegetational stress in Mediterranean ecosystems. Particular attention is here focussed only on the plants' water stress in water controlled ecosystems, mainly related to soil water balance. The interactions among climate, soil and vegetation are evaluated numerically by means of an ecohydrological model. In this work, different future climatic scenari…
The Impact of Climatic Change and Land Use on the Hydrological Response of Mediterranean Soils; a Study along a Climatological Gradient in Crete (Gre…
1995
Abstract To help understand the impact of Climatic Change on the soils of the Mediterranean area, measurements of physical soil properties were carried out in a mountain zone in Crete (Greece), following a climatological gradient. Four experimental slopes were chosen, south facing and situated on limestone lithology. Soil hydrological properties including infiltration, runoff and sediment concentration, were measured and the percentage of waterstable microaggregation in the soil was calculated and used as an indicator of soil degradation. It was found that as well as climate, soil properties were highly affected by the extensive land use of the area, intensive grazing by goats and small sca…
The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period
2008
Abstract Hillslopes are thought to be most susceptible to enhanced surface runoff and erosion immediately following wildfire due to removal of protective vegetation and litter cover, and in many cases a fire-induced reduction in soil wettability. This enhanced susceptibility declines as vegetation and litter layer recover. For logistical reasons, however, few studies have been able to examine the responses of burnt terrain immediately following burning and little is therefore known about the effect of the wettable ash layer that often covers the ground until it is redistributed or removed by wind or water erosion. Here we quantify the effects of ash and needle cast ground cover on surface r…
Shrubland as a soil and water conservation agent in Mediterranean-type ecosystems
2015
John Thornes found that shrubland was a key factor in the control of soil erosion on Mediterranean hillsides. His research inspired many scientists to investigate the impact of shrubland changes and management in semi-arid ecosystems. An example of Professor Thornes’ scientific influence is the experiment carried out on the El Teularet–Sierra de Enguera experimental station since 2003 which showed erosion rates on a 30-year-old abandoned orchard with dense vegetation cover of Ulex parviflorus and Cistus albidus and a 20-year-old fire-affected maquia with Quercus coccifera, Pistacia lentiscus and Juniperus oxycedrus. The measurements demonstrated that the shrubs help create more stable soil …
Response of water and nutrient fluxes to improvement fellings in a tropical montane forest in Ecuador
2009
Abstract Management of natural forests might be one option to reduce the high deforestation rate in Ecuador. We therefore evaluated the response of water and nutrient cycles in a natural tropical montane forest to improvement fellings with the aim of favoring economically valuable target trees which will later be harvested with additional ecosystem impacts not considered here. The study was conducted at ca. 1900–2200 m above sea level in the south Ecuadorian Andes on the east-exposed slope of the east cordillera. In June 2004, one of two paired ca. 10-ha large catchments was thinned by felling 10.2% of the initial basal area (dbh ≥ 10 cm) on 30% of the catchment. The stems remained in situ.…