Search results for "forest"

VALUTAZIONE DELLA TOLLERANZA ALLO STRESS SALINO DI DUE SPECIE DA TAPPETO ERBOSO TRATTATE CON APPLICAZIONI FOGLIARI DI GLICINBETAINA ( OSMOREGOLATORE …

2011

Assessing the performance of a large-scale irrigation system by estimations of actual evapotranspiration obtained by Landsat satellite images resampl…

2019

Abstract Remote sensing techniques allow monitoring the Earth surface and acquiring worthwhile information that can be used efficiently in agro-hydrological systems. Satellite images associated to computational models represent reliable resources to estimate actual evapotranspiration fluxes, ETa, based on surface energy balance. The knowledge of ETa and its spatial distribution is crucial for a broad range of applications at different scales, from fields to large irrigation districts. In single plots and/or in irrigation districts, linking water volumes delivered to the plots with the estimations of remote sensed ETa can have a great potential to develop new cost-effective indicators of irr…

Estimation of actual evapotranspiration of Mediterranean perennial crops by means of remote-sensing based surface energy balance models

2009

Abstract. Actual evapotranspiration from typical Mediterranean crops has been assessed in a Sicilian study area by using surface energy balance (SEB) and soil-water balance models. Both modelling approaches use remotely sensed data to estimate evapotranspiration fluxes in a spatially distributed way. The first approach exploits visible (VIS), near-infrared (NIR) and thermal (TIR) observations to solve the surface energy balance equation whereas the soil-water balance model uses only VIS-NIR data to detect the spatial variability of crop parameters. Considering that the study area is characterized by typical spatially sparse Mediterranean vegetation, i.e. olive, citrus and vineyards, alterna…

Run duration effects on the hydrodynamic properties of a loam soil estimated by steady-state infiltration methods

2020

Steady-state methods for the analysis of single-ring infiltration data are commonly applied. However, the duration of an infiltrometer experiment is often established quite subjectively based on the assumption that in general infiltration stabilizes rather quickly in the field. For a loam soil, the effect of the duration of a beerkan run on sorptivity, S, and saturated hydraulic conductivity, Ks, was tested by using the BEST (Beerkan Estimation of Soil Transfer parameters)-steady method and SSBI (Steady version of the Simplified method based on a Beerkan Infiltration run) method for data analysis. The standard experiment, based on a total of 15 water volumes each establishing an initial pon…

Management scenarios optimizing irrigation with saline water in cracking clay soils.

2006

Management scenarios aimed at optimizing irrigation in a Sicilian vineyard characterized by a cracking clay soil irrigated with saline water were explored for seven soil profiles (Baglio 1–Baglio 7), by using the simulation model soil-water-atmosphere-plant environment (SWAP), which accounts for shrinkage and cracking. Accurate prediction of water content, u, was obtained for the seven profiles by expressing the soil hydraulic properties according to the Brutsaert retention equation coupled with the hydraulic conductivity model proposed by Gardner (B-G model). A satisfactory prediction of the electrical conductivity of saturated extract (ECsat) was obtained using for the dispersivity (Ldis)…

Plant Response to Saline-Water Irrigation in a Sicilian Vineyard

2012

This chapter presents results of a 3-year field investigation in a vineyard located in Sicily (Mazara del Vallo, Trapani) within the framework of the Project “Evolution of cropping systems as affected by climate change” (CLIMESCO). Soil-plant responses to two saline irrigation waters were determined by measuring soil hydrological characteristics, soil salinity, crop transpiration and stomatal conductance in field plots of a Sicilian vineyard. The results proved that crop transpiration (T r) and stomatal conductance (G s) were significantly affected by soil salinity conditions, expressed by electrical conductivity of soil saturation extract (ECe). Significant reductions in T r and G s were f…

Monitoring soil salinization as a strategy for preventing land degradation: a case study in Sicily

2008

Assessing Effects of Temperature Change on Four Limonium Species from Threatened Mediterranean Salt-Affected Habitats

2018

[EN] Evaluation of tolerance to temperatures in the germination stage is an important tool to foresee the possible effect of global warming. Moreover, establishing germination protocols for endemic and threatened species is most interesting for restoration and management plans that focus on habitat conservation. Seed germination was analysed in four species of the genus Limonium (L. virgatum, L. narbonense, L. girardianum and L. santapolense) growing in two saline habitats on the eastern coast of the Iberian Peninsula. The study aim was to compare responses of seed germination to different temperature regimes. Seeds were collected in two protected areas, `L¿Albufera de Valencia¿ (province o…

Improvement of BEST (Beerkan Estimation of Soil Transfer parameters) method for soil hydraulic characterization

Interpreting and modeling soil hydrological processes require the determination of the soil hydraulic characteristic curves, i.e. the relationships between volumetric soil water content, pressure head, and hydraulic conductivity. Using traditional methods to determine these properties is expensive and time consuming. Haverkamp et al. (1996) pioneered a specific method for soil hydraulic characterization known as the “Beerkan method”. An improved version of this methodology, called the Beerkan Estimation of Soil Transfer parameters (BEST) procedure, was developed by Lassabatère et al. (2006) to simplify soil hydraulic characterization. BEST considers certain analytic formulae for hydraulic c…

Dissipative scaling of step-pool features

2021

Abstract This paper focuses on the dissipative similarity of step-pool units at rill, flume and stream scale. This investigation is carried out using recent advances in open channel flow resistance, applications of close-range photogrammetry to rill erosion, available published data on step-pool features in flumes and streams and a new dataset of measurements in fixed bed step-pool rills. A theoretically-based equation for calculating the Darcy-Weisbach friction factor obtained by integration of a power velocity profile is presented. The scale factor Γ of this power velocity profile, which is included in the flow resistance equation, was previously calibrated (Eq. 10) for mobile bed rills w…