Search results for "sistema"

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…

Relaciones suelo-vegetación en una toposecuencia del Escudo Guayanés, Venezuela

2014

El Escudo Guayanés es uno de los territorios más antiguos del planeta; tiene millones de años sometido a procesos de lixiviación y erosión que dejan suelos oligotróficos. El objetivo de este trabajo fue hacer la caracterización de los parámetros físicos y químicos de los suelos, en diferentes comunidades boscosas de la Reserva Forestal Imataca, e identificar ciertas relaciones entre los componentes edáficos y las especies que allí se presentan. Se realizó un inventario de todos los individuos mayores a 10cm dap (diámetro a la altura del pecho) en 15 parcelas (1ha); en cada una de esas parcelas se evaluaron cuatro sub-parcelas de sotobosque (100m²) para contabilizar todas las espermatofitas;…

Los bienes comunes en el pensamiento de Stefano Rodotà

2021

El trabajo se ha desarrollado en el marco del proyecto de investigación BICOM. Bienes comunes: articulación cívica y jurídica (CAMUAM, SI/PJI/2019- 00474), codirigido por Ricardo Cueva y Luis Lloredo. También se ha participado con el proyecto Vulnus (INV-IGU159- 2021).

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…

ANCESTRALITY OR MORPHOLOGICAL CONVERGENCE IN THE MOLLISSIMA AND ITALICA GROUPS OF SILENE IN THE WESTERN MEDITERRANEAN BASIN

2010

Dis-misure e dis-valori del danno all'ambiente fluviale: un approccio socio-sistemico

2013

Si espone qui la sperimentazione di un metodo di analisi e valutazione del danno ispirato all’approccio sociologico di N. Nuhmann (1990), che definisce l’ambiente per differenza rispetto ai processi comunicativi che informano il sistema sociale e quindi il danno ambientale come difetto della comunicazione tra sub-sistemi. In questa logica la valutazione del risarcimento è stata condotta con riferimento al rapporto verticale tra unità inquinanti e supporto naturale e orizzontale tra i diversi sub-sistemi che comunicano “sull’ambiente”. Il caso studiato riguarda le immissioni di inquinanti in un bacino idrico siciliano da tempo sotto osservazione anche da parte della Comunità Europea a causa …