Search results for " Erosion"
showing 10 items of 356 documents
No-Till Soil Organic Carbon Sequestration Patterns as Affected by Climate and Soil Erosion in the Arable Land of Mediterranean Europe
2022
No-tillage (NT) has been considered an agronomic tool to sequester soil organic carbon (SOC) and match the 4p1000 initiative requirements of conservative soil management. Recently, some doubts have emerged about the NT effect on SOC sequestration, often because observations and experimental data vary widely depending on climate and geographic characteristics. Therefore, a suitable SOC accounting method is needed that considers climate and morphology interactions. In this study, the yearly ratio between SOC in NT and conventional tillage (CT) (RRNT/CT) collected in a previous study for flat (96 samples) and sloping (44 samples) paired sites was used to map the overestimation of SOC sequestra…
Testing a spatially distributed sediment delivery model (SEDD) in a forested basin by cesium-137 technique
2005
The aim of the paper is to validate the sediment delivery distributed (SEDD) model for estimating hillslope sediment yield estimates using net soil erosion values obtained by the cesium-137 technique. The cesium-137 technique provides spatially-distributed measurements useful to verify the predictive capability of a distributed sediment yield model. The application of the cesium-137 technique requires a calibration procedure to convert measurements of 137Cs inventories to estimates of net soil erosion rates. Rainfall and sediment yield data from 1978 to 1994 in a small Calabrian basin forested with eucalyptus trees, were initially used to calibrate, at mean annual temporal scale, the SEDD m…
Sediment delivery processes and chemical transport in a small forested basin
2005
Recent reaserch has directed attention to the properties of the eroded material because of its influence in deposition phenomena and in carrying capacity of pollutant materials
Rill flow velocity and resistance law: A review
2022
Rills caused by runoff concentration on erodible hillslopes generally have very irregular longitudinal profiles and cross-section shapes. Rill erosion directly depends on the hydraulics of flow within the rills which may differ greatly from that in larger and regular channels like streams or rivers. At first, in this paper, a review of the two different approaches to estimate rill flow velocity, based on flow regime and flow resistance laws, is presented. Recent advances in measurements of rill geometry by the three-dimensional photo-reconstruction (3D-PR) technique, which allows one to obtain a Digital Terrain Model (DTM) by low-altitude aerial and terrestrial photogrammetry, are also disc…
Theoretical advancements on a recently proposed method to measure rainfall energy
2022
Soil erosion induced by rainfall is mainly due to the rainfall impact besides the consequent surface runoff. Rainfall kinetic energy is the most used variable to represent its erosivity. The latter represents the weathering attitude to erode soil and is a fundamental variable of the erosion process. Consequently, precise measurements of rainfall erosivity have to perform to develop a reliable prediction model of the erosive phenomenon. Currently, impact energy can be reliably measured only by disdrometers. These instruments measure the Drop Size Distribution (DSD) which, joined with the raindrop falling velocity, allow to calculate, by integration, the impact kinetic energy. However, disdro…
Testing the Universal Soil Loss Equation-MB equation in plots in Central and South Italy
2019
Planning soil conservation strategies requires predictive techniques at event scale because a large percentage of soil loss over a long-time period is due to relatively few large storms. Considering runoff is expected to improve soil loss predictions and allows relation of the process-oriented approach with the empirical one, furthermore, the effects of detachment and transport on soil erosion processes can be distinguished by a runoff component. In this paper, the empirical model USLE-MB (USLE-M based), including a rainfall-runoff erosivity factor in which the event rainfall erosivity index EI30 of the Universal Soil Loss Equation (USLE) multiplies the runoff coefficient QR raised to an ex…
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…
Applying the RUSLE and ISUM in the Tierra de Barros Vineyards (Extremadura, Spain) to Estimate Soil Mobilisation Rates
2020
Spain is one of the largest wine producers in the world, with Extremadura (south-west Spain) being its second-largest producing region after Castilla La Mancha. Within Extremadura, the most traditional and productive viticulture region is the Tierra de Barros, which boasts an annual production of 3×
Understanding tungsten erosion during inter/intra-ELM periods in He-dominated JET-ILW plasmas
2021
Tungsten erosion was quantified during inter/intra-ELM periods in He-dominated JET-ILW plasmas by optical emission spectroscopy. The intra-ELM tungsten sputtering in helium plasmas, which dominates the total W source, prevails by a factor of about 4 over inter-ELM sputtering in the investigated ELM frequency range from 90 Hz-120 Hz. He ions are mainly responsible for the W erosion during the ELMs in He plasmas. The strong in/out asymmetry of the ELM-induced W erosion is observed in He plasmas even at high ELM frequencies beyond 100 Hz. In Ohmic/L-mode plasmas and during the H-mode inter-ELM plasma phases both He2+ and Be2+ ionic species are major contributors to the W erosion. Their contrib…