Source shape and data analysis procedure effects on hydraulic conductivity of a sandy-loam soil determined by ponding infiltration runs

2017

Performing ponding infiltration runs with non-circular sources could represent a good means to sample completely an area of interest. Regardless of the shape of the source, predicting the expected reliability of the collected data by infiltrometers should facilitate soil hydraulic characterisation and also allow a more conscious use of the field data. The influence of the shape of the infiltration source (i.e., circular or square) and the analysis procedure of the steady-state infiltration data on the saturated hydraulic conductivity, Ks, of a sandy-loam soil was tested in this investigation. Circular and square surfaces sampled with the pressure infiltrometer (PI) yielded similar estimates…

Endovascular management of the deep venous thrombosis: A new challenging role for the endovascular specialist in 2020

2020

Over the last years, the endovascular approach to the management of the acute and chronic deep vein thrombosis (DVT) has gained more and more attention from the scientific community. DVT is the third most common cardiovascular disease after coronary heart disease and stroke, with classic treatment based on anticoagulation. Recent evidences have highlighted the risk of postthrombotic syndrome as high as 30%-50% in proximal ilio-femoral lesions, with irreversible clinical symptoms and impact on the quality of life of the population. Since 2000s, the new concept of thrombus removal in the acute phase has been supported by the introduction of different techniques based on the endovascular ablat…

Isoerosivity and erosion risk map for Sicily

1991

This paper reviews simplified methods for evaluating the rainfall erosivity index and proposes two relationships for estimating the annual value of Wischmeier's rainfall erosivity index at sites equipped with recording and non-recording raingauges. For the Sicilian region, the FAO index was also found to represent the erosion risk. A regional relationship to estimate the standard deviation of the annual erosivity index is proposed. The isoerosivity map is plotted by using 41 values of the rainfall erosivity index calculated by Wischmeier's procedure and 128 values estimated according to a relationship proposed by the authors. Finally, for each of 169 sites, an erosion risk index is calculat…

Response to ‘comment on “predicting event soil loss from bare plots at two Italian sites”’

2014

In this paper, a response to the comment by Dr. Kinnell on “Predicting event soil loss from bare plots at two Italian sites”’ (Bagarello et al., Catena 109, 96–102, 2013) is provided.

Testing the shape-similarity hypothesis between particle-size distribution and water retention for Sicilian soils

2012

Application of the Arya and Paris (AP) model to estimate the soil water retention curve requires a detailed description of the particlesize distribution (PSD) but limited experimental PSD data are generally determined by the conventional sieve-hydrometer (SH) method. Detailed PSDs can be obtained by fitting a continuous model to SH data or performing measurements by the laser diffraction (LD) method. The AP model was applied to 40 Sicilian soils for which the PSD was measured by both the SH and LD methods. The scale factor was set equal to 1.38 (procedure AP1) or estimated by a logistical model with parameters gathered from literature (procedure AP2). For both SH and LD data, procedure AP2 …

Transplacental permeability of heavy metals in relation to newborn sex - evidence from the neurodevelopment project

2023

Introduction: Gender medicine is an innovative medical approach that studies how some biological variables are influenced by the male or female sex and gender. This issue is under debate because it characterizes the impact of tailored or individual medicine. In this scenario, the aim of this study is to study the correlation between heavy metal exposure and pathologies of neurodevelopment, according to the sex of newborns. In particular, this is an observational study under the name of the Neurosviluppo Project, involving 217 mother-child couples. Material and methods: The correlation with phenotype small for gestational age and congenital malformations were studied, but above all we focuse…

INDAGINE SULL’ IDROREPELLENZA DEL SUOLO DI UNA PINETA ARTIFICIALE MEDITERRANEA

2016

Nell’indagine è stata caratterizzata l’idrorepellenza del suolo di una pineta artificiale Mediterranea utilizzando sia il tradizionale Water Drop Penetration Time (WDPT) test che due indici desunti da esperimenti di infiltrazione condotti con il MiniDisk Infiltrometer (MDI). In particolare, il Repellency Index (RI) è stato calcolato come rapporto tra i valori di sorptività misurati con etanolo e acqua, mentre il Water Repellency Cessation Time (WRCT) è stato ricavato utilizzando l’informazione acquisita nella fase idrofobica e in quella idrofila del processo di infiltrazione con acqua. Tutti gli indici hanno inequivocabilmente indicato che la lettiera di Pinus pinaster è altamente idrofobic…

A simple field method to measure the hydrodynamic properties of soil surface crust

2013

The hydraulic resistance of the surface crust was determined by a combination of two infiltrometric techniques: first, a surface measurement of steady-state infiltration rate is conducted by a mini-disk tension infiltrometer (MDI); then, the surface crust is removed, its thickness is measured, and a ponded infiltration test is performed at the same site. The Beerkan Estimation of Soil Transfer parameters (BEST) method is applied to estimate the hydraulic properties of the underlying soil provided the particlesize distribution and the bulk density are known. Under the assumption of a unit gradient of hydraulic head below the soil crust, the pressure head at the interface crust-soil is derive…

Sediment delivery processes and the spatial distribution of caesium-137 in a small Sicilian basin

1998

The sediment delivery processes occurring in a small Sicilian basin are modelled using the spatially distributed SEDD model recently proposed by Ferro and Minacapilli. The model is applied by using soil data (grain-size distribution, organic matter content, etc.) of 129 samples uniformly distributed over the study area and compiling the available information (topographic map, soil data, etc.) into a Geographical Information System. Finally, the predictive capability of the distributed sediment delivery approach is tested experimentally using the caesium-137 measurement technique. The comparison between calculated sediment yield and the corresponding measured caesium-137 loss is used to vali…

Testing infiltration run effects on the estimated water transmission properties of a sandy-loam soil

2016

Abstract Testing factors influencing determination of soil water transmission properties by an infiltrometer method helps better interpretation of the collected data and allows the development of appropriate sampling strategies for the intended use of the data. These factors include the soil water content at the start of the experiment, the height from which water is poured onto the soil surface, and the duration of the infiltration run. A sandy-loam soil was sampled with the BEST (Beerkan Estimation of Soil Transfer parameters) procedure of soil hydraulic characterization and two heights of pouring of water (0.03 and 1.5 m) under three different initial soil water content, θ i (0.12 ≤ θ i …

A test of the Beerkan Estimation of Soil Transfer parameters (BEST) procedure

2014

Abstract The Beerkan Estimation of Soil Transfer parameters (BEST) procedure is attractive for a simple soil hydraulic characterization but testing the ability of this procedure to estimate soil properties is necessary. The BEST predictions were compared with soil water retention and hydraulic conductivity data measured in the laboratory and the field, respectively, at ten Sicilian field sites. Provided that BEST yielded physically possible scale parameters of the soil characteristic curves in most of the four replicated infiltration runs at a site, the measured water retention was satisfactorily predicted (i.e., not statistically significant differences between measurements and predictions…

Effect of plot size on measured soil loss for two Italian experimental sites

2011

The objective of this investigation was to determine empirically the plot width and length effects on runoff volume, Ve, soil loss, Ae, and sediment concentration, Ce, by using data collected, at the temporal scale of the erosive event, on bare plots differing in width (2 to 8 m) and length (11 to 22 m) for two Italian stations (Masse, Umbria; Sparacia, Sicily). Mean results differed by a maximum factor of 1.6 for Ve, 1.8 for Ae and 1.2 for Ce when plots differing in width were compared and by a maximum factor of 1.4 for Ve, 1.2 for Ae and 1.3 for Ce when comparison between plot lengths was conducted. Differences between two plot widths or two plot lengths were not statistically significant…

Testing soil water repellency in a Sicilian area two years after a fire

2019

The water drop penetration time (WDPT) technique was applied in 2018 to check persistence of soil water repellency (SWR) in a Sicilian mountain area affected by a wildfire on June 2016. A total of four sites, that were severely water repellent immediately after burning, were sampled. Depending on the site, wettable soil conditions, less SWR and maintenance of a noticeable SWR were detected two years later. At the site showing a near-constant SWR, WDPTs were particularly high in the top soil layer (0-0.03 m) and they appreciably decreased more in depth. Signs of decreasing SWR in drier soil conditions and in association with coarser soil particles were also detected at this site. High gradie…

A simplified approach to estimate water retention for Sicilian soils by the Arya-Paris model

2014

Application of the Arya and Paris (AP) model to estimate the soil water retention curve requires a detailed description of the particle-size distribution (PSD) because the scale factor a, relating the pore length of an ideal soil to that of the natural one, depends on the particle size distribution parameters. For a dataset of 140 Sicilian soils that were grouped in five texture groups, the logistic and linear models were applied to evaluate a, and the water retention values predicted by the AP model were compared with the measured ones. Using the parameters proposed by Arya et al. (1999), the two models yielded similar unsystematic root mean error of estimate (RMSEu). Therefore, their pote…

Estimating the USLE soil erodibility factor in Sicily, South Italy

2012

The Universal Soil Loss Equation (USLE) is used by professionals and technicians to predict soil loss by water erosion and to establish soil conservation measures. One of the key elements of the USLE is the K factor, which is a measure of the soil erodibility. Given the difficulty in collecting sufficient data to adequately measure K, early in the USLE's history the soil erodibility nomograph method was developed to allow estimation of K based on standard soil properties. Since the nomograph approach was developed based on a small number of soils in the United States, it is necessary for other contexts to check the nomograph's ability to predict the soil's true erodibility. Considering that…

Evaluation of Green Roof Ageing Effects on Substrate Hydraulic Characteristics

2020

The vegetated substrate of green roofs may undergo various chemical and physical changes with time. Minidisk infiltrometer (MDI) tests were conducted to assess the short-term variations of the near-saturated hydraulic conductivity, K0, in the extensive green roof test plot established at the University of Palermo. Sampling was repeated four times: before planting (Age 0) and then after four months (Age 1), seven months (Age 2) and ten months (Age 3). A total of 144 infiltration tests were conducted at two pressure heads, h0 = −3 cm and h0 = −0.5 cm and infiltration data analysed by the Zhang (Soil Science Society of America Journal 61(4):1024–1030, 1997) model. Both K-3 and K-0.5 underwent …

An assessment of the Beerkan method for determining the hydraulic properties of a sandy loam soil

2014

Abstract Establishing the ability of the Beerkan Estimation of Soil Transfer parameters (BEST) procedure to reproduce soil properties is necessary for specific soil types. In this investigation, the BEST predictions for a sandy loam soil were compared with water retention data obtained by a standard laboratory method and with the saturated soil hydraulic conductivity, K s , obtained by both the Wu et al. (1999) method, applied to the BEST infiltration data, and the Simplified Falling Head (SFH) technique. When the original BEST-slope algorithm with the infiltration constants fixed at β = 1.9 and γ = 0.79 was applied, the agreement between the predicted and the measured retention data was sa…

ESTIMATING SOIL PARTICLE-SIZE DISTRIBUTION FOR SICILIAN SOILS

2009

The soil particle-size distribution (PSD) is commonly used for soil classification and for estimating soil behavior. An accurate mathematical representation of the PSD is required to estimate soil hydraulic properties and to compare texture measurements from different classification systems. The objective of this study was to evaluate the ability of the Haverkamp and Parlange (HP) and Fredlund et al. (F) PSD models to fit 243 measured PSDs from a wide range of 38 005_Bagarello(547)_33 18-11-2009 11:55 Pagina 38 soil textures in Sicily and to test the effect of the number of measured particle diameters on the fitting of the theoretical PSD. For each soil textural class, the best fitting perf…

Predicting unit plot soil loss in Sicily, south Italy

2008

Predicting soil loss is necessary to establish soil conservation measures. Variability of soil and hydrological parameters complicates mathematical simulation of soil erosion processes. Methods for predicting unit plot soil loss in Sicily were developed by using 5 years of data from replicated plots. At first, the variability of the soil water content, runoff, and unit plot soil loss values collected at fixed dates or after an erosive event was investigated. The applicability of the Universal Soil Loss Equation (USLE) was then tested. Finally, a method to predict event soil loss was developed. Measurement variability decreased as the mean increased above a threshold value but it was low als…

Using Static and Dynamic Indicators to Evaluate Soil Physical Quality in a Sicilian Area

2013

Both capacitive indicators derived from the water retention curve and dynamic measurements of the flow-weighted mean pore radius, R0, were used to assess the soil physical quality of two agricultural areas (cropland and olive orchard) and two natural areas (grassland and managed woodlot plantation) potentially subject to soil degradation. The overall idea of the study was to investigate whether a dynamic indicator quantitatively derived from hydraulic conductivity measurements could be used to supplement the traditionally applied capacitive indicators retrieved from water retention measurements. According to the available criteria, only the surface layer of the cropland site showed optimal …

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…

Testing alternative erosivity indices to predict event soil loss from bare plots in Southern Italy

2009

Methods for predicting unit plot soil loss for the ‘Sparacia’ Sicilian (Southern Italy) site were developed using 316 simultaneous measurements of runoff and soil loss from individual bare plots varying in length from 11 to 44 m. The event unit plot soil loss was directly proportional to an erosivity index equal to (QREI30)1·47, being QREI30 the runoff ratio (QR) times the single storm erosion index (EI30). The developed relationship represents a modified version of the USLE-M, and therefore it was named USLE-MM. By the USLE-MM, a constant erodibility coefficient was deduced for plots of different lengths, suggesting that in this case the calculated erodibility factor is representative of a…

Statistical check of USLE-M and USLE-MM to predict bare plot soil loss in two Italian environments

2018

The USLE-M and the USLE-MM estimate event plot soil loss. In both models, the erosivity term is given by the runoff coefficient, QR, times the single-storm erosion index, EI30. In the USLE-MM, QREI30is raised to an exponent b1> 1 whereas b1= 1 is assumed in the USLE-M. Simple linear regression analysis can be applied to parameterize both models, but logarithmically transformed data have to be used for USLE-MM. Parameterizing the USLE-MM with nonlinear regression of untransformed data could be a more appropriate procedure. A statistical check of the two suggested models (USLE-M and USLE-MM), considering two alternative parameterization procedures for the USLE-MM, was carried out for the Mass…

Predicting event soil loss from bare plots at two Italian sites

2013

Abstract Including runoff in USLE-type empirical models is expected to improve plot soil loss prediction at the event temporal scale and literature yields encouraging signs of the possibility to simply estimate runoff at these spatial and temporal scales. The objective of this paper was to develop an estimating procedure of event soil loss from bare plots (length = 11–44 m, slope steepness = 14.9–16.0%) at two Italian sites, i.e. Masse, in Umbria, and Sparacia, in Sicily, having a similar sand content (5–7%) but different silt (33% at Sparacia, 59% at Masse) and clay (62% and 34%, respectively) contents. A test of alternative erosivity indices for the Masse station showed that the best perf…

DETERMINING THE SATURATED HYDRAULIC CONDUCTVITY OF A LOAM SOIL WITH DIFFERENT INFILTROMETER TECHNIQUES

2015

The saturated soil hydraulic conductivity, Ks, is one of the most important soil hydraulic properties since it controls many hydrological processes. This hydrodynamic parameter depends on soil texture and structure and it is very difficult to measure. Infiltrometer techniques are becoming very popular to determine Ks in the field but testing alternative approaches is necessary for specific soil types. For a loam soil, the estimated Ks values with six infiltrometer techniques were compared. The so-called BEST procedure of soil hydraulic characterization, the pressure infiltrometer (PI), single head experiments with both the tension infiltrometer (TI) and the mini disk infiltrometer (MDI), th…

Testing a Simplified Approach to Determine Field Saturated Soil Hydraulic Conductivity

2013

Abstract Interpreting and simulating hydrological processes need a large number of field saturated soil hydraulic conductivity, Kfs , data that should be collected with simple and rapid field experiments. A Simplified method based on a Beerkan Infiltration run (SBI method) was recently developed and tested successfully on Burundian soils. With the SBI method, a cylinder is inserted to a short depth into the soil and the infiltration time of a few small volumes of water repeatedly applied at the surface of the confined soil is measured. Calculating Kfs needs the slope of the linearized cumulative infiltration vs. time relationship and an estimate of the so called α* parameter. In this invest…

Discussion of “Soil Water Retention Characteristics of Vertisols and Pedotransfer Functions Based on Nearest Neighbor and Neural Networks Approaches …

2013

Il rito musicale del Lazzaro nelle comunità arbëreshe di Sicilia. Con CD-ROM

2016

Questo volume è dedicato al rito del “Lazzaro” nei cinque centri siciliani siculo-albanesi. Si tratta di una tradizione di origine orientale che caratterizza fortemente il venerdì che precede la Domenica delle Palme (ricorrenza detta, nel mondo bizantino, Venerdì di Lazzaro). Il rito è incentrato su un canto in arbëresh che narra l’episodio evangelico della resurrezione di Lazzaro. Il canto è eseguito in due differenti contesti: nelle chiese arbëreshe di rito bizantino può essere intonato una prima volta al termine della Liturgia dei Presantificati, sebbene ciò non sia previsto nelle rubriche dei libri liturgici; in un secondo momento viene eseguito per le strade, dove ha luogo il rito musi…

Misure dell’erodibilità del suolo a scala di parcella nell’area sperimentale di Sparacia

2012

Verifiche sperimentali della USLE a scala di parcella in Sicilia

2008

Un criterio per la determinazione della tolleranza della perdita di suolo

2014

Caratterizzazione delle precipitazioni ai fini erosivi - Analisi dei dati di letteratura

2007

6. Processi di Trasporto nel Suolo

2012

assente - capitolo di libro

Analisi delle distribuzioni dimensionali delle gocce di pioggia acquisite mediante un disdrometro ottico

2007

Calibrazione della tecnica TDR per il monitoraggio del contenuto d'acqua in esperimenti condotti su colonne di suolo

2007

MISURA DELL’ERODIBILITA’ DEL SUOLO NELLE PARCELLE SPERIMENTALI DI SPARACIA, IN SICILIA

2010

Nell’indagine è stata effettuata una determinazione sperimentale del fattore di erodibilità del suolo, K, della USLE basata sulle misure effettuate nel suolo argilloso di Sparacia. Il valore medio annuo del suddetto fattore, misurato su parcelle di lunghezza, , comprese tra 11 e 44 m, è risultato decrescente con . La stima indiretta del fattore di erodibilità è risultata del 46% inferiore rispetto alla misura effettuata nella parcella di riferimento, lunga cioè 22 m, e si è attestata su un valore intermedio tra le misure di K ottenute nelle parcelle di 33 e 44 m. Un simile effetto di scala è stato riconosciuto anche con riferimento ai valori annui e a quelli stagionali del fattore di erod…

Approfondimenti su alcune tecniche infiltrometriche per la misura delle conducibilità idraulica del suolo saturo

2010

Nella memoria vengono approfonditi alcuni aspetti della misura in campo della conducibilità idraulica del suolo saturo, Kfs, con tecniche infiltrometriche. In primo luogo, è stata determinata la frequenza degli insuccessi con una prova del tipo Two- Ponding-Depth effettuata con l’infiltrometro ad anello singolo (PI). La suddetta frequenza è risultata più elevata in due suoli franco-argillosi (40%) che in uno franco-sabbioso (25%). Un contenuto idrico iniziale elevato ha costituito una possibile causa di fallimento della misura. L’esclusione dal data set delle prove che hanno fornito valori del parametro * ricadenti al di fuori del range 1-100 m-1 è risultata ininfluente solo nel caso in cu…

Verifica applicativa di tre modelli di stima dell’erosione idrica mediante il concetto di modello fisico

2014

Twenty years of scientific activity at Sparacia experimental area. Quaderni di Idronomia Montana 33

2016

The main purpose of this booklet is to give to the participants to the Palermo’s Conference of the EU COST ACTION ES1306 - CONNECTING EUROPEAN CONNECTIVITY RESEARCH - CONNECTEUR a general idea of the scientific activity that was carried out in the past 20 years on the basis of the data collected at the Sparacia experimental station for soil erosion measurement, in Sicily, South Italy. The booklet includes a presentation of the experimental site, a description of the applied methods and procedures for measuring soil erosion processes at the Sparacia experimental area, and an illustration of the developed methodologies for predicting soil erosion from plots, small basins, rills and gullies. I…

Confronto funzionale di differenti strategie di caratterizzazione idraulica del suolo

2008

Misura della conducibilità idraulica del suolo con l’infiltrometro a depressione a dischi concentrici

2008

Variabilità delle misure parcellari di perdita di suolo nell'area sperimentale di Sparacia

2008

Stima dell'erosione idrica parcellare in due siti sperimentali italiani

2011

La carta dell'erosione potenziale del territorio siciliano

2005

Metodi transitori per la misura in campo della conducibilità idraulica del suolo

2005

Verifica sperimentale della tecnica LD per la determinazione della distribuzione granulometrica

2011

Funzioni di pedotrasferimento per la determinazione della curva di ritenzione idrica dei suoli siciliani

2009

Il ricorso alle funzioni di pedotrasferimento (PTF) rende possibile una stima relativamente agevole delle caratteristiche di ritenzione idrica del suolo. Una riproduzione accurata delle misure per un’area di interesse presuppone però l’accertamento delle prestazioni delle PTF esistenti ed, eventualmente, lo sviluppo di PTF alternative. Utilizzando 217 curve di ritenzione misurate in Sicilia, nell’indagine è stata dapprima verificata l’applicabilità di alcune delle più diffuse PTF disponibili in letteratura. Tale verifica ha evidenziato che i risultati migliori competono alle PTF che includono, tra le variabili indipendenti, la densità apparente del suolo. Poiché tale proprietà fisica non se…

Metodo di calibrazione per la misura del contenuto d’acqua di un suolo mediante tecnica TDR

2005

Effect of laboratory procedures on the integrity of a sandy-loam soil sample for bi-directional measurement of saturated hydraulic conductivity

2011

Practical and validated methods to measure anisotropy of saturated, Ks, or field-saturated, Kfs, soil hydraulic conductivity on a single soil sample are still lacking. The objective of this investigation was to test factors affecting anisotropy measured in a sandy-loam soil by the constant-head laboratory permeameter and the modified cube method. The ratio, RK, between the conductivity results obtained with a long (6 h) and a short (0.5 h) duration run varied from a minimum of 0.29 to a maximum of 0.88 with the considered experimental procedure, differing by both the employed constant-head device (Mariotte bottle, siphon) and the initial soil water content (unsaturated, saturated). Maximum …

Predicting the water retention characteristic of Sicilian soils by pedotransfer functions.

2008

Approfondimenti sul Cube Method per la misura della conducibilità idraulica del suolo

2005

Studi applicativi per la realizzazione della carta dell'erosione potenziale del territorio siciliano e del relativo sistema informativo territoriale

2004

Verifica del concetto di modello fisico in due stazioni di misura dell’erosione parcellare

2012

Monitoraggio della perdita di suolo nell'area sperimentale di Sparacia

2005

Simplified estimation of field saturated soil hydraulic conductivity from ponded infiltration data

2013

Simple and reasonably rapid experiments are desirable to conduct a spatially distributed determination of field-saturated soil hydraulic conductivity, Kfs, that is a highly variable soil property. Bagarello et al. (2012) recently developed a simplified approach to estimate Kfs that is based on a ponded field infiltration experiment. A cylinder is inserted to a short depth into the soil, so to produce a minimal disturbance of the porous medium, and the infiltration time of a few small volumes of water repeatedly applied at the surface of the confined soil is measured. Calculating Kfs needs to determine the slope of the linearized cumulative infiltration vs. time relationship, the ring radius…

INFLUENCE OF PARTICLE-SIZE DISTRIBUTION MEASUREMENT METHOD ON THE PREDICTION OF SOIL WATER RETENTION CURVE

2013

Application of the Arya and Paris (AP) model to estimate the soil water retention curve requires detailed particle-size distributions (PSD) that can be obtained by fitting a continuous model to traditional sieve-hydrometer (SH) data or using the laser diffraction (LD) method. The AP model was applied to 40 Sicilian soils for which PSD was measured by both SH and LD methods. The scale factor  was set equal to 1.38 (procedure AP1) or estimated by a logistic model with parameters gathered from literature (procedure AP2). To simplify application of the AP model, a relationship for estimating a soil-specific  value from clay content was developed (procedure OPT). For both SH and LD data, proce…

Una nuova stazione sperimentale per il monitoraggio della produzione di sedimenti nell'area sperimentale di Sparacia

2005

COMMUNITY DETECTION IN TRIPARTITE NETWORKS OF UNIVERSITY STUDENT MOBILITY FLOWS

2021

The purpose of this study is to explore how the multimode network approach can be used to analyse network patterns derived from student mobility flows. We define a tripartite network based on a three-mode data structure, consisting of Italian provinces of residence, universities and fields of study, with student exchanges representing the links between them. A comparison of algorithms for detecting communities from tripartite networks based on modularity optimization is provided, revealing relevant information about the phenomenon under analysis over time. The findings are applied to a real dataset containing micro-level longitudinal information on Italian university students’ careers.

Effetto della dimensione dell'anello sulla conducibilità idraulica del suolo saturo misurata con la tecnica SFH

2009

Nel lavoro è stata esaminata la relazione tra la conducibilità idraulica del suolo saturo, Kfs, misurata in campo con la tecnica Simplified Falling Head (SFH) e la dimensione della superficie campionata con una singola prova. L’indagine è stata condotta in un suolo franco-sabbioso ed in uno franco-limoso, esplorando la medesima superficie complessiva (0.71 m2) con anelli di diametro compreso tra 0.15 e 0.30 m. Nel suolo franco-sabbioso, le misure di Kfs effettuate con gli anelli piccoli sono risultate significativamente più elevate di quelle ricavate con gli anelli grandi. In particolare, i valori medi hanno mostrato una discrepanza di un fattore 1.7 e il ricorso agli anelli piccoli ha dete…

Un nuovo modello distribuito per la stima della produzione di sedimenti

2008

Using static and dynamic indicators to evaluate soil physical quality in a Sicilian area

2016

Both capacitive indicators derived from the water retention curve and dynamic measurements of the flow-weighted mean pore radius, R0, were used to assess the soil physical quality of two agricultural areas (cropland and olive orchard) and two natural areas (grassland and managed woodlot plantation) potentially subject to soil degradation. The overall idea of the study was to investigate whether a dynamic indicator quantitatively derived from hydraulic conductivity measurements could be used to supplement the traditionally applied capacitive indicators retrieved from water retention measurements. According to the available criteria, only the surface layer of the cropland site showed optimal …

Impact of reforestations with exotic and native species on water repellency of forest soils

2017

Forest duff layer is usually water repellent due to the hydrophobic organic compounds resulting from degradation of tree tissues. Transition from hydrophobic to wettable conditions, or vice versa, is largely controlled by water content. The objective of this investigation was to assess the influence of soil moisture on the degree of soil water repellency (WR) in exotic and native tree forests. Occurrence of WR was investigated by the water drop penetration time (WDPT) and the ethanol percentage (EP) tests. Sampling was conducted in the forest soils of two exotic species (Pinus pinaster, P, and Eucaliptus camaldulensis, E), used in the past for reforestation, and two native species (Quercus …

Influenza della tecnica di misura della distribuzione granulometrica sulla stima della curva di ritenzione idrica del suolo

2011

Le distribuzioni granulometriche ottenute sia con il tradizionale metodo per stacciatura-sedimentazione (SH) che con il metodo della diffrattometria laser (LD) sono state utilizzate per determinare le curve di ritenzione idrica di 40 suoli siciliani attraverso modello di Arya e Paris (AP). La curve di ritenzione idrica determinate con il metodo SH sono risultate più accurate di quelle ottenute dal metodo LD. Fra le differenti procedure applicative utilizzate, i risultati migliori si sono ottenuti utilizzando per ciascun suolo un valore del parametro  determinato attraverso una procedura di ottimizzazione. Infine, è stata proposta una relazione tra il parametro  e il contenuto in argilla c…

Elementi di Idrologia del Suolo

2008

Contenuto idrico del suolo, Potenziale dell'acqua nel suolo, Moto della acqua nel suolo