Search results for "forest"
showing 10 items of 3780 documents
Patent number PA2010 A 000023: Sistema biocompatibile di supporto per la piantumazione di organismi vegetali in ambiente marino
2010
Il brevetto consiste in un sistema a basso impatto ambientale, realizzato interamente in bioplastica, per il fissaggio sul fondo marino in forma rapida ed efficace di organismi vegetali, allo scopo di garantirne l'attecchimento e la crescita, assecondandone la dinamica naturale di sviluppo.
Determining the appropriate timing of the next forest inventory: incorporating forest owner risk preferences and the uncertainty of forest data quali…
2017
Key message The timing to conduct new forest inventories should be based on the requirements of the decision maker. Importance should be placed on the objectives of the decision maker and his/her risk preferences related to those objectives. Context The appropriate use of pertinent and available information is paramount in any decision-making process. Within forestry, a new forest inventory is typically conducted prior to creating a forest management plan. The acquisition of new forest inventory data is justified by the simple statement of “good decisions require good data.” Aims By integrating potential risk preferences, we examine the specific needs to collect new forest information. Meth…
Caratteristiche dei boschi della Sicilia.
2011
La superficie forestale della Sicilia, inventariata secondo le definizioni di “bosco” e “altre aree boscate” della FAO (FRA 2000), comprende formazioni molto diversificate in termini di composizione floristica del soprassuolo, della sua densità e struttura, del suo sviluppo potenziale, dell’origine, del grado di naturalità e della coltura praticata. Le categorie inventariali riconducono le diverse formazioni forestali entro insiemi relativamente omogenei in termini di copertura arborea e arbustiva, sviluppo potenziale e, nel caso degli impianti di arboricoltura, di particolare forma gestionale.
Scour on alluvial bed downstream of grade-control structures
2004
This paper describes an approach for predicting local scour downstream of grade control structures. The developed analysis applies the incomplete self-similarity (ISS) theory for deducing some physically based dimensionless groups controlling the geometrical pattern of the scour profile. The scour measurements available in the literature in conjunction with numerous unpublished data allow a multiregressive calibration of the ISS relationships. The experimental sample includes different bed grain-size distributions and scales of the erosive phenomenon. The results prove that the ratio between the upstream water head and the weir height is able to explain the measurements of scour depth carri…
Investigating the Performance of Enhanced Permeable Groins in Series
2020
The enhanced permeable groin is a novel eco-friendly and cost-effective technique for bank protection and restoration of meander bends. The behavior of bed deformations due to the distance between the structures has to be studied to design enhanced permeable groins in series properly. In this study, scour morphologies around enhanced permeable groins in series, characterized by four different distances and located in a 180°
The paradox of the alien plant Leucaena leucocephala subsp. glabrata (Rose) S. Zárate in Sicily: another threat for the native flora or a valuable re…
2020
With this contribution, an updated picture of the rapid expansion of Leucaena leucocephala subsp. glabrata in Sicily is provided. On the one hand, this is a quite worrying sign, as this woody species figures among the world’s worst invasive alien species. On the other hand, the species shows interesting potential for production purposes (for wood, biomass and for feeding livestock), also considering its nitrogen fixation ability. Consequently, the two opposite options to cope with this species, i.e. cultivation and control/eradication, should accurately take into account the possible uses as well as its invasive behaviou.
Roughness effect on the correction factor of surface velocity for rill flows
2021
Flow velocity is one of the most important hydrodynamic variables for both channelized (rill and gullies) and interrill erosive phenomena. The dye tracer technique to measure surface flow velocity Vs is based on the measurement of the travel time of a tracer needed to cover a known distance. The measured Vs must be corrected to obtain the mean flow velocity V using a factor αv = V/Vs which is generally empirically deduced. The Vs measurement can be influenced by the method applied to time the travel of the dye-tracer and αv can vary in different flow conditions. Experiments were performed by a fixed bed small flume simulating a rill channel for two roughness conditions (sieved soil, gravel)…
A Comprehensive Check of Usle-Based Soil Loss Prediction Models at the Sparacia (South Italy) Site
2020
At first, in this paper a general definition of the event rainfall-runoff erosivity factor for the USLE-based models, REFe = (QR)b1(EI30)b2, in which QR is the event runoff coefficient, EI30 is the single-storm erosion index and b1 and b2 are coefficients, was introduced. The rainfall-runoff erosivity factors of the USLE (b1 = 0, b2 = 1), USLE-M (b1 = b2 = 1), USLE-MB (b1 ≠ 1, b2 = 1), USLE-MR (b1 = 1, b2 ≠ 1), USLE-MM (b1 = b2 ≠ 1) and USLE-M2 (b1 ≠ b2 ≠ 1) can be defined using REFe. Then, the different expressions of REFe were simultaneously tested against a dataset of normalized bare plot soil losses, AeN, collected at the Sparacia (south Italy) site. As expected, the poorest AeN predict…
Comparing Beerkan infiltration tests with rainfall simulation experiments for hydraulic characterization of a sandy-loam soil
2017
[EN] Saturated soil hydraulic conductivity, K-s, data collected by ponding infiltrometer methods and usual experimental procedures could be unusable for interpreting field hydrological processes and particularly rainfall infiltration. The K-s values determined by an infiltrometer experiment carried out by applying water at a relatively large distance from the soil surface could however be more appropriate to explain surface runoff generation phenomena during intense rainfall events. In this study, a link between rainfall simulation and ponding infiltrometer experiments was established for a sandy-loam soil. The height of water pouring for the infiltrometer run was chosen, establishing a sim…
Evidence de l'adaptation des communautés microbiennes sédimentaires de rivière à la minéralisation du diuron: influence du ruissellement et de l'éros…
2010
International audience; Purpose Surface runoff and erosion are major drivers of pesticide transport from soils to rivers draining vineyard watersheds. A recent study showed that applications of diuron on vineyards and diuron dispersal could lead to microbial adaptation to diuron biodegradation from treated soils to the receiving hydrosystem. Given the limited knowledge on microbial adaptation to pesticide degradation in aquatic environments, we conducted a microcosm study designed to assess the impact of runoff and erosion processes on the adaptation of riverine-sediment microbial communities to diuron mineralization. Materials and methods The experimental laboratory set-up consisted in aqu…