Search results for " sistema."

USLE-based models: perspectives and limitations in soil erosion modelling

2020

Water soil erosion is a process of detachment and transport of soil particles due to rainfall and runoff and causes the landform modeling on earthʹs surface. The acceleration of soil erosion process through anthropogenic perturbation has severe impacts on soil which becomes qualitatively poor for crop establishment and growth. Planning soil conservation strategies requires prediction technologies of soil loss over a long‐time period. The Universal Soil Loss Equation (USLE), and its revised versions, are widely tested and applied in different environments throughout the world. At present, the USLE continues to be the most applied model for estimating soil loss and still represents the best c…

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…

Measuring the USLE soil erodibility factor in the unit plots of Sparacia (southern Italy) experimental area

2022

The Universal Soil Loss Equation (USLE) is still widely used to predict soil loss by water erosion and to establish soil conservation measures. In this model, the soil erodibility factor K accounts for the susceptibility of the soil to be eroded due to the detachment and transport processes operated by the erosive agents. According to the USLE scheme, the K factor should be measured on unit plots, i.e., bare plots of given length (22 m) and steepness (9%) tilled along the maximum slope direction, but there is little evidence that there ever existed an actual unit plot between the plots used to develop the USLE. Given the difficulty in collecting sufficient data to adequately measure K, the …

Compost Amendment Impact on Soil Physical Quality Estimated from Hysteretic Water Retention Curve

2022

Capacity-based indicators of soil physical quality (SPQ) and pore distribution parameters were proposed to assess the effects of compost amendment but their determination was limited to desorption water retention experiments. This study also considered the pore size distribution obtained from adsorption experiments to establish the effectiveness of compost amendment in modifying the physical and hydrological attributes of a sandy loam soil. Repacked soil samples with different compost to soil ratios, r, were subjected to a wetting–drying cycle, and the water retention data were fit to the van Genuchten model to obtain the pore volume distribution functions. The soil bulk density was m…

Apporto di sostanza organica e nutrienti dalle banquettes di Posidonia oceanica (L.) Delile verso agroecosistemi mediterranei.

2011

Mapping soil water content under sparse vegetation and changeable sky conditions: comparison of two thermal inertia approaches

2013

A critical analysis of a thermal inertia approach to map surface soil water content on bare and sparsely vegetated soils by means of remotely sensed data is reported. The study area is an experimental field located in Barrax, Spain. In situ data were acquired within the Barrax 2011 research project. An advanced hyperspectral scanner airborne imager provides images in the visible/near-infrared and thermal infrared bands. Images were acquired both in day and night times by the Instituto Nacional de Técnica Aeroespacial between 12th and 13th of June 2011. The scene covers a corn irrigation pivot surrounded by bare soil, where a set of in situ data have been collected both previously and simult…