Search results for " Erosion"
showing 10 items of 356 documents
Morphological Similarity of Channels: From Linear Erosional Features (Rill, Gully) to Alpine Rivers
2017
The geometric characteristics of incised features such as channels, rills, ephemeral gully, gully, represent the erosional transport regime and the fluvial dynamic equilibrium, and thus it is critical for the understanding of the long-term evolution of natural, agricultural, and anthropogenic landscapes. This paper examines the morphological similarity of channelized erosion in two different environments such as Alpine landscapes and cultivated hillslopes. The first dataset comprises six rivers in the Italian Alps, three in the Carnia region and three in the Dolomites, where erosion is mainly the effect of discharges with high sediment loads or landslides and debris flows. The agricultural …
Overview of the JET results
2015
Since the installation of an ITER-like wall, the JET programme has focused on the consolidation of ITER design choices and the preparation for ITER operation, with a specific emphasis given to the bulk tungsten melt experiment, which has been crucial for the final decision on the material choice for the day-one tungsten divertor in ITER. Integrated scenarios have been progressed with the re-establishment of long-pulse, high-confinement H-modes by optimizing the magnetic configuration and the use of ICRH to avoid tungsten impurity accumulation. Stationary discharges with detached divertor conditions and small edge localized modes have been demonstrated by nitrogen seeding. The differences in…
Policies can help to apply successful strategies to control soil and water losses. The case of chipped pruned branches (CPB) in Mediterranean citrus …
2018
[EN] There is a need to devise management strategies that control soil and water losses in agriculture land to allow the design of proper policies to achieve sustainability. It is the responsibility of scientists to work with other actors to co-construct strategies that will lead to sustainable land-use policies. Using chipped pruned branches (CPB) as mulch can be a viable option because they represent local (in situ) organic material that can restore soil nutrient and organic matter. This research assesses: i) the perception of farmers towards different types of management strategies and CPB's costs; ii) the biomass yield of citrus branches and the impact of CPB on soil properties; iii) ho…
MoSi2 laser cladding—elaboration, characterisation and addition of non-stabilized ZrO2 powder particles
2003
International audience; The cladding process using laser beam radiation comprises different operational regimes, depending on the involved lasers (usually CO2 or Nd:YAG) and materials. A series of experiments has been carried out to investigate Nd:YAG laser cladding using MoSi2 powder. Procedures and operating parameters for producing clad layers has been developed and their properties evaluated. The feasibility of the laser cladding technique, using a high power Nd:YAG laser, by projecting MoSi2 powder on steel substrate was demonstrated. The results indicate a low density of cracks, elevated powder catchment efficiency (between 65 and 90%) and hardness values around 1200–1300 HV. Our goal…
The Permeable Concrete: A Low Energy Consumption Solution for Deep Draining Trenches
2018
The reduction of pore water pressures is one of the very effective measures to improve the stability conditions of marginally stable water-bearing slopes or to stabilise landslides. For this purpose the trench drains have been used long since. Like filling material of deep trenches the permeable concrete can be effectively employed. It presents relatively high hydraulic conductivity, filtering capacity in order to prevent the internal erosion of the soil in which the trench drain is installed, enough residual hydraulic conductivity after possible clogging, sufficient shear strength after a short curing time to avoid the instabilisation of adjacent previously built panels or piles. Results o…
A new shoreline change assessment approach for erosion management strategies
2022
Shoreline evolution studies are fundamental to assess the rate of beach accretion or retreatment. In the last years, researchers developed many methods with several techniques belonging to different disciplines and backgrounds. Nowadays, the Shoreline Change Analysis (SCA) is the most widespread method to assess shoreline evolution. In fact, the SCA is needed to perform management strategies able to respond to current erosion or potential future erosion problems. This paper presents a new approach using an automatic method for SCA with accuracy and speed improvements. Indeed, in the framework of the management of coastal erosion and to develop an adaptation plan to coastal hazards it is nec…
Análisis de la evolución de la línea de costa entre Alcossebre y Orpesa a partir de fotografía aérea (1956-2015)
2019
[ES] El artículo presenta un análisis de la evolución de la línea de costa entre Alcossebre y Orpesa, a partir de fotografías aéreas y ortofotografías, entre 1956 y 2015. La digitialización de 12 líneas de costa ha permitido calcular los cambios netos y máximos, así como la tasa de cambio entre los diferentes años. Los resultados muestran una costa recesiva, con una gran variabilidad espacio-temporal. Conviven sectores con crecimiento sostenido provocado por la acción antrópica (deriva arriba de los espigones y regeneraciones de playa) o causas naturales (prominencias costeras), con otros claramente erosivos (deriva abajo de espigones). Además, el análisis de las isobatas del estrán sumergi…
Electroplated Ni/Ni-Co multilayer coatings for higher corrosion-erosion resistance
2019
Erosion-corrosion behaviour of hierarchical structured hydrophobic nickel-cobalt coating, obtained by electrodeposition, was assessed. In situ electrochemical measurements were carried out to study the corrosion resistance and stability during erosion tests. The electrochemical behaviour was related to surface hydrophobicity and its hierarchical structure nature as well as its modification. The pure Ni showed the lowest erosion-corrosion resistance. A smoothing of the hierarchical structure and thus a reduction the hydrophobicity was highlighted. On the other hand, Ni-Co coating even if associated to a lower electrochemical stability showed a more stable hierarchical structure also at high …
A modified applicative criterion of the physical model concept for evaluating plot soil erosion predictions
2015
Abstract In this paper, the physical model concept by Nearing (1998. Catena 32: 15–22) was assessed. Soil loss data collected on plots of different widths (2–8 m), lengths (11–44 m) and steepnesses (14.9–26.0%), equipped in south and central Italy, were used. Differences in width between plots of given length and steepness determined a lower data correlation and more deviation of the fitted regression line from the identity one. A coefficient of determination between measured, M , and predicted, P , soil losses of 0.77 was representative of the best-case prediction scenario, according to Nearing (1998). The relative differences, Rdiff = ( P − M ) / ( P + M ), decreased in absolute value a…
Dye-tracer technique for rill flows by velocity profile measurements
2020
Abstract Water flow on hillslope soil surface supplies energy which is required to detach soil particles, to transport and deposit sediments, therefore flow velocity is a key variable related to hillslope hydrodinamics of soil erosion processes. Among the different methods available for measuring velocity of shallow interrill and rill flow, the trace technique is widely used. Trace technique is applied by adding a material (salt, magnetic material, water isotope, floating object) and then measuring the speed of the material to travel a known distance from the injection point. When flow velocity is measured using a dye-tracing method, the mean velocity is calculated by multiplying the measur…