Critical analysis of the thermal inertia approach to map soil water content under sparse vegetation and changeable sky conditions

The paper reports a critical analysis of the thermal inertia approach to map surface soil water content on bare and sparsely vegetated soils by means of remotely sensed data. The study area is an experimental area located in Barrax (Spain). Field data were acquired within the Barrax 2011 research project. AHS airborne images including VIS/NIR and TIR bands were acquired both day and night time by the INTA (Instituto Nacional de Tecnica Aeroespacial) between the 11 th and 13 rd of June 2011. Images cover a corn pivot surrounded by bare soil, where a set of in situ data have been collected previously and simultaneously to overpasses. To validate remotely sensed estimations, a preliminary prox…

Geostatistical techniques for runoff mapping: an application to Sicily, Italy

The availability of reliable and long time series of runoff data is fundamental for most of the hydrological analyses and for the assessment and the management of water resources even in condition of global climatic change. However, hydrologic data sets are often characterized by a short duration and also suffer from missing data values, mainly due to malfunctioning of gauging stations for a specific period. In order to overcome this problem and obtain long and continuous runoff time series, different models and methods have been previously developed and proposed. While some models, used to extent the streamflow record, are conceptual, empirical, regressive models based on the rainfall inpu…

Riduzione delle perdite apparenti. Analisi sperimentale e modellistica dell'UFR

Stima da remoto delle caratteristiche evapotraspirative e di umidità del sistema suolo-vegetazione di un impianto viticolo su morfologia complessa

Obiettivo della ricerca è la messa a punto di tecniche di elaborazione d’immagini telerilevate al fine di analizzare le caratteristiche evapotraspirative e di umidità del sistema suolo-vegetazione. La valutazione di tali grandezze è, infatti, di notevole interesse poiché consente alle aziende viticole di ottimizzare i processi di produzione nonché la qualità del prodotto. L’evapotraspirazione effettiva del sistema suolo-vegetazione (ETa) è stata stimata mediante l’applicazione del SEBAL (Surface Energy Balance Algorithm for Land), un modello di bilancio energetico facente uso d’immagini telerilevate nel campo riflessivo ed emissivo dello spettro. Il modello, implementato nella versione Moun…

CONFRONTO TRA UN MODELLO DINAMICO ED UNO STAZIONARIO NELLA VALUTAZIONE DELLE PERDITE REALI ED APPARENTI DI UNA RETE DI DISTRIBUZIONE

Nel presente articolo è stato applicato un modello dinamico di simulazione idraulica delle reti di distribuzione per la valutazione delle perdite idriche reali ed apparenti. Sono stati sviluppati uno modello di domanda al nodo che simula i serbatoi privati ed un modulo per la stima delle perdite apparenti. Le perdite reali sono state modellate attraverso una relazione generale che esprime la portata effluente dalla perdita come una funzione della pressione. I risultati ottenuti sono stati confrontati con le stime modellistiche basate su di un approccio stazionario.

Monitoring Mediterranean marine pollution using remote sensing and hydrodynamic modelling

Human activities contaminate both coastal areas and open seas, even though impacts are different in terms of pollutants, ecosystems and recovery time. In particular, Mediterranean offshore pollution is mainly related to maritime transport of oil, accounting for 25% of the global maritime traffic and, during the last 25 years, for nearly 7% of the world oil accidents, thus causing serious biological impacts on both open sea and coastal zone habitats. This paper provides a general review of maritime pollution monitoring using integrated approaches of remote sensing and hydrodynamic modeling; focusing on the main results of the MAPRES (Marine pollution monitoring and detection by aerial survei…

EFFETTI DELLE VARIAZIONI CLIMATICHE SULLA VEGETAZIONE IN AMBIENTE MEDITERRANEO

PUMP AS TURBINE (PAT) IN INTERMITTENT DISTRIBUTION NETWORKS

A hydraulic model was performed in order to evaluate potential energy recovery resulting by the use of centrifugal pump as turbines (PAT) in the water distribution network characterized by the presence of private tanks. The model integrates the Enhanced Global Gradient Algorithm (EGGA) (Todini [1], Giustolisi et al. [2]), with a pressure driven model (Criminisi et al. [3]) that entails a more realistic representation of the influence of the private tanks filling and emptying process in the network behaviour. The model was applied to real case study: a district metered area in Palermo (Italy). Namely three different scenarios were analyzed and compared with the actual scenario (Scenario 0 - …

Distrettualizzazione di una rete idrica per mitigare l’iniqua distribuzione delle risorse idriche in condizioni di scarsità

Multicriteria performance analysis of an integrated urban wastewater system for energy management

AbstractThe optimization and management of an integrated urban wastewater system is a complex problem involving many processes and variables. The possible control options are defined by several management strategies that may differently impact the economic, operational or environmental performance of the system. The present paper aims to contribute to the environmental and energy sustainability of urban wastewater systems by means of a multicriteria performance analysis. The paper begins with a complete analysis of the system performance in several fields of interest (energy, environment, quality of service, operation, economy and financial resources), and it highlights the management stren…

La qualità nel monitoraggio di variabili meteoclimatiche

Caratterizzazione della rugosità e dell’umidità del suolo tramite dati radar multifrequenza e multipolarizzazione

Mapping phycocyanin cells density of Planktothrix rubescens in freshwater reservoirs

A weather monitoring system for the study of precipitation fields, weather, and climate in an urban area

The possibility to study the precipitation dynamics with advanced and specific tools is an important task of the research activity addressing the understanding, the modeling, and the managing of rainfall events. Over the last years, the hydrology laboratory of the Department of Civil, Environmental, Aerospace Engineering, and Materials (DICAM) at the University of Palermo, has installed several instruments for the monitoring and the study of precipitation within the urban area of Palermo (Italy). The main instrument of this system is the X-band weather radar, which allows monitoring the precipitation fields with high resolution in space and time. This instrument is supported by a rain gauge…

Stagnone di Marsala lagoon, Sicily

Reti per il monitoraggio meteoclimatico

Sviluppo di un sistema di monitoraggio per lo studio delle dinamiche meteorologiche nell'area urbana di Palermo.'

A critical analysis of three remote sensing-based actual evapotranspiration assessment methods over sparse crops agricultural areas

During last two decades the increasing availability of remotely sensed acquisitions in the thermal infrared part of the spectrum has encouraged hydrologist community to develop models and methodologies based on these kind of data. The aim of this paper is to compare three methods developed to assess the actual evapotranspiration spatial distribution by means of remote sensing data. The comparison was focused on the differences between the "single" (SEBAL) and "two" source (TSEB) surface energy balance approaches and the S-SEBI semi-empirical method. The first assumes a semiempirical internal calibration for the sensible heat flux assessment; the second uses a physically based approach in or…

Estimation of the time lag occurring between vegetation indices and aridity indices in a Sicilian semi-arid catchment

The evolution of drought phenomena in a Sicilian semi-arid catchment has been analyzed processing both remote sensing images and climatic data for the period 1985-2000. The remote sensing dataset includes Landsat TM and ETM+ multispectral images, while the climatic dataset includes monthly rainfall and air temperature. The results have been specifically discussed for areas where it is possible to neglect agricultural activities and vegetation growth is only influenced by natural forcing. The main outcome of this study is the quantification of the time lag between the remote sensing retrieved vegetation indices and the aridity indices (AIs) calculated from climatic data. Moreover the obtaine…

On the Influence of Spatial Resolution on Submerged Vegetation Mapping Using Satellite Images

Monitoring marine water quality of Sicily by means of remotely sensed imagery

Within the framework of the GEOGRID research project, a semi-automatic computational chain has been implemented in order to map the time evolution of marine water quality, around Sicily island, by means of satellite images. To this aim a set of MODIS (TERRA and AQUA) multispectral images has been acquired. An automatic system to georeference and calibrate the images has been implemented. All the procedures to map clorophill-a, total suspended solids and turbidity come from the literature, whereas models parameters have been calibrated by means of in situ measurements.

Strategic Master Plans

The MEDIWAT Project (Sustainable management of environmental issues related to water stress in Mediterranean Islands) aims to provide innovative and sustainable technical, operational and managerial solutions for tackling problems caused by water resources-quality worsening and shortage in the Mediterranean insular context. The project brings together partners from six Mediterranean islands: Sicily, Cyprus, Corsica were considered large islands because of their area and hydrological behavior. Conversely Crete, Malta and Balearic Islands were considered small islands. A detailed analysis of current and future conditions relating to freshwater availability, quality and use has been carried ou…

ANALISI DEL PROCESSO DI CONSUMO ISTANTENEO DI SINGOLE UTENZE RESIDENZIALI CON IL MODELLO DI POISSON AD IMPULSI RETTANGOLARI

A Comparison between Heuristic, Statistical and Data-driven Methods in Landslide Susceptibility Assessment: an Application to the Briga and Giampilieri Catchments

Susceptibility assessment concerning the estimation of areas prone to landslide is one of the most useful approach in the analysis of landslide hazard. Over the last years, in an attempt to find the best approach to evaluate landslide susceptibility, many methods have been developed. Among these, the heuristic, the statistical, and the data-driven approaches are very widespread, and they all are based on the concept that the conditions which led to landslide movements in the past will control the probability of movement occurrence in the future. This study presents an assessment of landslide susceptibility in which models of the three different methodologies, such as the heuristic approach,…

Flow and turbulence characteristics in the presence of a discontinuous ligulate seagrass prairie

Uncertainty analysis in sewer system performance evaluation

Elaborazione di una mappa di suscettibilità delle aree in frana a scala di bacino

Le frane costituiscono uno tra i più pericolosi e dannosi eventi naturali. Negli ultimi decenni si sono succeduti numerosi eventi catastrofici che hanno provocato, oltre a danni ingenti, anche numerosi morti e dispersi. Per questo motivo cresce sempre di più l’esigenza di fornire ai pianificatori e gestori del territorio strumenti di supporto per la valutazione del pericolo da frana. In questo contesto, negli ultimi anni sono stati sviluppati nuovi approcci per la valutazione della propensione di un’area a produrre scivolamenti, basandosi sulla correlazione tra i fattori innescanti e le occorrenze di scivolamenti. Nel presente lavoro viene presentata una mappa di suscettibilità creata attra…

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

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…

Monitoring Water Surface and Level of a Reservoir Using Different Remote Sensing Approaches and Comparison with Dam Displacements Evaluated via GNSS

Remote sensing allowed monitoring the reservoir water level by estimating its surface extension. Surface extension has been estimated using different approaches, employing both optical (Landsat 5 TM, Landsat 7 ETM+ SLC-Off, Landsat 8 OLI-TIRS and ASTER images) and Synthetic Aperture Radar (SAR) images (Cosmo SkyMed and TerraSAR-X). Images were characterized by different acquisition modes, geometric and spectral resolutions, allowing the evaluation of alternative and/or complementary techniques. For each kind of image, two techniques have been tested: The first based on an unsupervised classification and suitable to automate the process, the second based on visual matching with contour lines…

Critical Analysis Of Remote Sensing Techniques To Monitor Coastal Water Quality-Related Parameters

Carenza idrica: conseguenze in ambiente urbano

DETERMINAZIONE DELLE CARATTERISTICHE OTTICHE DI VEGETAZIONE SOMMERSA TRAMITE METODO MONTE CARLO

Si presentano i risultati di una ricerca volta alla determinazione della risposta spettrale della vegeta-zione sommersa mediante simulazioni stocastiche, con l’obiettivo di porre in risalto il range d’applicabilità (in termini di profondità e di lunghezza d’onda) delle tecniche di monitoraggio della vegetazione sommersa a partire da dati telerilevati. Per fare ciò è stato sviluppato e implementato un codice di calcolo che permette di ricostruire, mediante simulazioni stocastiche, la firma spettrale di oggetti posti sul fondale, una volta note le caratteristiche ottiche degli oggetti stessi e della colonna d’acqua. La flessibilità del modello di calcolo implementato ha inoltre permesso di es…

Analysis of the Impact of the intermittent distribution by modelling the network filling processes.

Use of differential SAR interferometry for detecting and measuring ground displacement due to a extensive landslide near Niscemi (Sicily, Italy)

Comparing actual evapotranspiration and plant water potential on a vineyard

Agricultural water requirement in arid and semi-arid environments represents an important fraction of the total water consumption, suggesting the need of appropriate water management practices to sparingly use the resource. Furthermore the quality and quantity of some crops products, such as grape, is improved under a controlled amount of water stress. The latter is related, on a side to actual evapotranspiration (ET) through water demand, on the other side to plant water content through leaf water potential. Residual energy balance approaches based on remote sensing allow to estimate the spatial distribution of daily actual ET at plant scale, representing an useful tool to detect its spati…

Monitoraggio di frane attivate da precipitazione a supporto di un Early Warning System: Progetto SESAMO

Analisi di storm tracking nell’area urbana di Palermo attraverso dati di pioggia ad alta risoluzione

La conoscenza della distribuzione spaziale e temporale delle piogge di breve durata, nonché la loro cinematica, sono alcuni tra i fattori più importanti che stanno alla base dell’approssimazione dei modelli di trasformazione afflussi-deflussi nei bacini urbani. L'incertezza dovuta alla variabilità spaziale della pioggia può influenzare, ad esempio, le performance dei modelli di drenaggio urbano. Un'adeguata conoscenza della variabilità spaziale e temporale delle precipitazioni può essere considerata un passo fondamentale per un'esatta interpretazione dei processi idrologici di base che avvengono nei sistemi di drenaggio urbano durante gli eventi di pioggia intensi. L'analisi di tali informa…

Confronto tra evapotraspirazione effettiva e potenziale idrico fogliare da dati telerilevati e micrometeorologici

Comparison of potential vs. actual vegetation status by means of distributed hydrological bilance model and remore sensing data

Evaluation of the Water Scarcity Energy Cost for Users

Abstract: In systems experiencing water scarcity and consequent intermittent supply, users often adopt private tanks that collect water during service periods and supply users when the service is not available. The tank may be fed by gravity or by private pumping stations depending on the network pressure level. Once water resources are collected, the tank can supply users by gravity if it is located on the rooftop or by additional pumping if underground. Private tanks thus increase the energy cost of the water supply service for users by introducing several small pumping structures inside the network. The present paper aims to evaluate this users’ energy cost for different private tank con…

Meteorological monitoring networks

Utilizzo della termografia per l’individuazione dell’infestazione da punteruolo rosso, la ricerca scientifica sul punteruolo rosso e gli altri fitofagi delle palme in Sicilia

Un modello per il riempimento delle reti di distribuzione idrica in presenza di turnazione del servizio

MODELLING RUNOFF WITH A CONCEPTUAL MODEL BASED ON INTEGRATION OF TOPOGRAPHIC INDEX IN A PROBABILITY DISTRIBUTED MODEL

Applicazione a 5 bacini siciliani di una procedura integrata per lo studio della propagazione delle onde di piena mediante modellazione bidimensionale e uso di cartografia digitale

La maggiore difficoltà per l’applicazione dei modelli numerici alla simulazione delle onde di piena in alvei naturali consiste nella acquisizione dei dati topografici e in una opportuna discretizzazione spaziale del dominio di calcolo. L’uso di modelli monodimensionali comporta la necessità di assegnare un orientamento prefissato alle sezioni di calcolo, di definire la geometria delle sezioni in base alla cartografia digitale, di tornare alla rappresentazione bidimensionale per la restituzione dei risultati. L’uso di mesh triangolari non strutturate e di metodologie numeriche incondizionatamente stabili consente di realizzare una modellazione bidimensionale che, oltre a produrre risultati m…

Utilizzo degli l-moments per l’analisi regionale delle portate di piena in Sicilia. Atti del XXX Convegno di Idraulica e Costruzioni Idrauliche.

Optical properties of Sicilian lakes during a Cyanophycea Planktothrix rubescens algal bloom

In December 2006 blooms of Planktothrix rubescens were found in the reservoir Prizzi in Sicily. Planktothrix is a genus of filamentous alga comprising approximately 6 species, between these the P. rubescens is sadly famous since this organism produces microcystins which are powerful hepatotoxins. Firstly found in Europe in 1825 on Geneva lake, recently (2006) those algae has been find out in Pozzillo, Nicoletti e Ancipa reservoirs (Enna Province), as well as in Prizzi (Palermo Province) and Garcia reservoirs (Trapani Province). Toxins produced by those bacteria (usually called microcystine LR-1 and LR-2) are highly toxic since they can activate oncogenes cells causing cancer pathologies on …

Hydrodynamic measurements in a shallow lagoon

Analisi del processo di consumo istantaneo di singole utenze residenziali con il modello di Poisson ad impulsi rettangolari

Coherent flow and turbulence structures in fragmented meadows of the mediterranean seagrass posidonia oceanica

EHSMu: a new conceptual model for hourly discharge simulation under ecohydrological framework in urban area

A parsimonious conceptual lumped model is presented here with the aim of simulating hourly discharge in urban areas. The EHSMu (EcoHydrological Streamflow Model for urban areas) is able to reproduce the discharge at the outlet of an urban drainage system and, at the same time, soil moisture dynamics and evapotranspirative fluxes over vegetated areas within an urban catchment. In urban areas, rain falling over impervious surfaces is directly transferred towards the drainage system in a time depending on the catchment characteristics, and drainage network geometry. If the rain falls over pervious and vegetated areas the runoff generation is driven by soil moisture content, which in turn is li…

Power sensitivity analysis of multi-frequency, multi-polarized, multi-temporal SAR data for soil-vegetation system variables characterization

Abstract: The knowledge of spatial and temporal variability of soil water content and others soil-vegetation variables (leaf area index, fractional cover) assumes high importance in crop management. Where and when the cloudiness limits the use of optical and thermal remote sensing techniques, synthetic aperture radar (SAR) imagery has proven to have several advantages (cloud penetration, day/night acquisitions and high spatial resolution). However, measured backscattering is controlled by several factors including SAR configuration (acquisition geometry, frequency and polarization), and target dielectric and geometric properties. Thus, uncertainties arise about the more suitable configurati…

Effects of rainfall events on the evapotranspiration retrieved by an energy balance model

An alternative way to map the actual evapotranspiration (ET) spatial distribution at daily scale is the application of residual surface energy balance models to satellite images that are characterised by high temporal frequency and moderate spatial resolution, like those acquired by the MODIS sensors on board of TERRA and AQUA platforms. Within this research the well-known SEBAL model has been applied on an area located in the southern part of Sicily (Imera Meridionale catchment) using four images acquired between the 27th of March and the 11th of April 2007. The catchment extends for about 2000 km2 and includes both mountains and hill areas: the first are located in the northern part (the …

Processing hyperspectral mivis data in order to monitor submerged vegetation in shallow water

Flow resistance of a very dense Posidonia oceanica grassland in shallow water

Future Climate Forcings and Olive Yield in a Mediterranean Orchard

The olive tree is one of the most characteristic rainfed trees in the Mediterranean region. Observed and forecasted climate modifications in this region, such as the CO2 concentration and temperature increase and the net radiation, rainfall and wind speed decrease, will likely alter vegetation water stress and modify productivity. In order to simulate how climatic change could alter soil moisture dynamic, biomass growth and fruit productivity, a water-driven crop model has been used in this study. The numerical model, previously calibrated on an olive orchard located in Sicily (Italy) with a satisfactory reproduction of historical olive yield data, has been forced with future climate scenar…

Regional frequency analysis of extreme precipitation in Sicily

Analisi e previsione dei consumi urbani attraverso l’applicazione di modelli a rete neurale

Quality management in meteoclimatic variables monitoring

EHSM: a new conceptual model for daily streamflow simulation under ecohydrological framework

A parsimonious conceptual lumped model is presented here with the aim of simulating daily streamflow in semi-arid areas. The model is able to reproduce surface and sub-surface runoff, soil moisture dynamics and evapotranspirative fluxes, averaged over a basin starting from daily time series of rainfall and temperature and from the initial value of soil. The rainfall is partioned in two components: the first, which interests a totally impermeable area, is routed directly on a superficial linear reservoir, while the second passes through permeable soil. If the rainfall input exceeds the soil storage capacity, which is a function of soil moisture at that specific time, this saturation excess i…

Stima dell’evapotraspirazione effettiva tramite modelli di bilancio energetico superficiale e immagini telerilevate

Analisi economica degli interventi distribuiti di gestione dei deflussi urbani

L’applicazione degli interventi distribuiti di gestione dei deflussi urbani è stata effettuata finora in maniera piuttosto disomogenea in Europa ed in particolare in Italia, probabilmente anche in seguito alle difficoltà legate alla valutazione dell'efficienza idraulica ed economica di tali interventi. Obiettivo del presente lavoro è quello di analizzare l’aspetto economico di alcune BMP per quanto riguarda sia i costi di realizzazione sia quelli di manutenzione, nell’ottica della valutazione dell'efficienza delle BMP e delle problematiche relative alla implementazione di sistemi di drenaggio nel contesto della pianificazione territoriale. Attraverso la classificazione, la descrizione e l’a…

Progetto di un sit-web per la fruizione dei beni archeologici ed ambientali dell'isola di Mothia

Strategies investigation in using artificial neural network for landslide susceptibility mapping: application to a Sicilian catchment

Susceptibility assessment of areas prone to landsliding remains one of the most useful approaches in landslide hazard analysis. The key point of such analysis is the correlation between the physical phenomenon and its triggering factors based on past observations. Many methods have been developed in the scientific literature to capture and model this correlation, usually within a geographic information system (GIS) framework. Among these, the use of neural networks, in particular the multi-layer perceptron (MLP) networks, has provided successful results. A successful application of the MLP method to a basin area requires the definition of different model strategies, such as the sample selec…

Prevention of marine pollution from oil spill: The activities of MAPRES project

Soil moisture limiting olive orchard evapotranspiration

Two years of field data concerning soil moisture dynamics and water vapor fluxes over a rainfed olive orchard in Sicily are presented here in order to understand how climate, seasonality, water availability and farming practices drive evapotranspiration in such a peculiar Mediterranean vegetation. Soil moisture has been measured in two different points characterized by a uniformly sandy soil and at multiple depths up to 1.2 m. The observed dynamics are driven by rainfall inputs, which are frequent during the winter season and rare during the growing season, and by vegetation uptakes, which deplete the water stored in the soil. The top layers soil moisture status is much more time dependent …

Analisi evolutiva della distribuzione della vegetazione sommersa in una laguna per mezzo di dati iperspettrali MIVIS

Critical analysis of empirical ground heat flux equations on a cereal field using micrometeorological data

The rate at which the net radiation is transferred to the soil as ground heat flux varies with surface characteristics. Surface energy balance algorithms use empirical relationships taking into account the effects of the canopy cover to insulate the soil through vegetation indexes, the soil capacity to absorb incoming net radiation via the albedo, and the surface temperature promoting the energy transfer. However empirical relationships are often dependent on local conditions, such as the soil humidity and vegetation type. Ground heat flux assumes a minimum value in case of full canopy cover and a maximum value for dry bare soil. Aim of the present research is the critical analysis of some …

Development of a regional flood frequency analysis using L-Moments approach for gauged and ungauged catchments of Sicily. Atti del International Workshop on Hydrological Extremes “Observing and modelling exceptional floods and rainfalls”.

Produttività dell’ulivo e dinamiche di umidità del suolo

Affidabilita’ e analisi di incertezza nelle scale di deflusso di corsi d’acqua con caratteristiche di forte variabilità

Spatial distribution of temperature trends in Sicily

Climate change resulting from the enhanced greenhouse effect is expected to have great impacts on hydrological cycle and consequently on ecosystems. The effects of climate variability have direct implications on water management, as water availability is related to changes in temperature and precipitation regimes. At the same time, this kind of alterations drives ecological impacts on flora and fauna. For these reasons, many studies have been carried out to investigate the existence of some tendency in temperature and/or precipitation series in different geographic domains. In order to verify the hypothesis of temperature increase in Sicily (Italy), temperature data from about 80 spatially …

CAMBIAMENTI CLIMATICI E EROSIONE IDRICA: UN’APPLICAZIONE AL BACINO DEL COMUNELLI, SICILIA

INFLUENCE OF POSIDONIA OCEANICA MEADOW DENSITY ON FLOW RESISTANCE IN SHALLOW WATERS

Aquatic vegetation considerably affects circulation in water bodies with influence increasing as the depth decreases. On the other hand, increasing use of mathematical circulation models for management of coastal sea waters, lagoons and marshes requires determination of such effects and in particular of flow resistance. A typical plant of inshore sandy beds, less than 40 m deep, in the Mediterranean Sea is Posidonia oceanica, which is constituted by a tuft of very thin and flexible ribbon-like leaves about 1 cm wide and up to 1.5 m long. This plant forms meadows with areal density usually ranging between 500 and 1000 plants/m2. Because of its characteristics, Posidonia oceanica constitutes …

Mediterranean Maritime Pollution: The Role Of Remote Sensing To Monitor And Mitigate

A paradigm of extreme rainfall pluvial floods in complex urban areas: the flood event of 15 July 2020 in Palermo (Italy)

Abstract. In the last years, some regions of the Mediterranean area are witnessing a progressive increase in extreme events, such as urban and flash floods, as a response to the increasingly frequent and severe extreme rainfall events and their ground effects, which are often exacerbated by ever-growing urbanization. In such a context, the traditional defense of urban areas, which are usually based on urban drainage systems designed without regard to the impacts of urbanization and climate change on natural systems, may not be sufficient to deal with the risk deriving from the occurrence of such events. This study focuses on a very recent and particularly intense urban flood that occurred i…

Caratterizzazione dei processi di siccità e di desertificazione su scala regionale

Le perdite apparenti nelle reti di distribuzione: implementazione di un modello numerico

INFLUENZA DELLA DENSITÀ DI UN PRATO DI POSIDONIA OCEANICA SULLA RESISTENZA AL MOTO IN ACQUE BASSE

L’impiego di modelli di circolazione per la gestione di acque costiere, quali lagune, paludi, ecc., richiede la valutazione degli effetti della vegetazione acquatica, i quali crescono al diminuire della profondità idrica. Una pianta tipica dei fondi sabbiosi sotto costa del Mar Mediterraneo è la Posidonia oceanica, la quale per le sue caratteristiche (ciuffi di foglie nastriformi molto flessibili e lunghe fino a 1,5 m) costituisce una particolare scabrezza, poiché al crescere della velocità della corrente le foglie si incurvano sempre più fino ad adagiarsi sul fondo. Nella presente memoria si rielaborano tutti insieme i dati sperimentali di due precedenti indagini degli scriventi, riguardan…

Procedures for historical data characterization

Soil Water Content Assessment: Critical Issues Concerning the Operational Application of the Triangle Method

Knowledge of soil water content plays a key role in water management efforts to improve irrigation efficiency. Among the indirect estimation methods of soil water content via Earth Observation data is the triangle method, used to analyze optical and thermal features because these are primarily controlled by water content within the near-surface evaporation layer and root zone in bare and vegetated soils. Although the soil-vegetation-atmosphere transfer theory describes the ongoing processes, theoretical models reveal limits for operational use. When applying simplified empirical formulations, meteorological forcing could be replaced with alternative variables when the above-canopy temperatu…

CONFRONTO TRA DIVERSE TECNICHE DI INTERPOLAZIONE DI DATI DI PRECIPITAZIONE E TEMPERATURA PER LA CREAZIONE DI DATASET DI SERIE STORICHE MENSILI COMPLETE DI VARIABILI CLIMATICHE

Tecniche di analisi spaziale per la ricostruzione delle serie storiche di dati climatici

USING A X-BAND WEATHER RADAR FOR AN URBAN AREA EARLY WARNING SYSTEM AND THE STUDY OF PRECIPITATION DYNAMICS.

The development and availability of X-band radar instruments occurred in the last years, provides the scientific community of an important tool for the study, the characterization and the operational usage of detailed precipitation information. The hydrology laboratory of the Department of Civil, Environmental, Aerospace Engineering, and Materials (DICAM) at the University of Palermo, has installed a X-band weather radar in the urban area of Palermo (Italy) along with a set of advanced auxiliary instruments that help on exploiting the precipitation information. A raingauge network of 18 tipping bucket gauges spread over the observed area is available for the calibration of precipitation map…

Indagine sulla vulnerabilità alla desertificazione mediante l’utilizzo di dati termopluviometrici e telerilevati

The Stagnone di Marsala, western Sicily

Development of a regional flood frequency analysis using L-Moments approach for gauged and ungauged catchments of Sicily

Tecniche GIS per il calcolo del bilancio idrologico delle acque superficiali

Sprectroradiometric characteristics of inland water bodies infestated by Oscillatoria rubescens algae

In December 2006 blooms of Oscillatoria rubescens were found in the reservoir Prizzi in Sicily. Oscillatoria is a genus of filamentous alga comprising approximately 6 species, between these the O. rubescens is sadly famous since this organism produces microcystins which are powerful hepatotoxins. Firstly found in Europe in 1825 on Geneva lake, recently (2006) those algae has been find out in Pozzillo, Nicoletti e Ancipa reservoirs (Enna Province), as well as in Prizzi (Palermo Province) and Garcia reservoirs (Trapani Province). Toxins produced by those bacteria (usually called microcystine LR-1 and LR-2) are highly toxic since they can activate oncogenes cells causing cancer pathologies on …

Caratterizzazione della vegetazione mediante immagini NOAA-AVHRR e modellistica idrologica

On the Use of the Eddy Covariance Latent Heat Flux and Sap Flow Transpiration for the Validation of a Surface Energy Balance Model

Actual evapotranspiration is assessed via surface energy balance at an hourly rate. However, a robust estimation of daily evapotranspiration from hourly values is required. Outcomes of surface energy balance are frequently determined via measures of eddy covariance latent heat flux. Surface energy balance can be applied on images acquired at different times and spatial resolutions. In addition, hourly actual evapotranspiration needs to be integrated at a daily rate for operational uses. Questions arise whether the validation of surface energy balance models can benefit from complementary in situ measures of latent heat flux and sap flow transpiration. Here, validation was driven by image ac…

On the processing of field spectroradiometric data for remote sensing mapping of submerged vegetation in coastal zones and lagoon environments

Surface soil humidity retrieval using remote sensing techniques: a triangle method validation

Soil humidity plays a key-role in hydrological and agricultural processes. In the rainfall-runoff processes the knowledge of its spatial distribution is fundamental to accurately model these phenomena. Furthermore in agronomy and agricultural sciences, assessing the water content of the root zone is required in order to optimize the plant productivity and to improve the irrigation systems management. Despite the importance of this variable the in situ measurements techniques based on Time Domain Reflectometry (TDR) or on the standard thermo-gravimetric methods, are neither cost-effective nor representative of its spatial and temporal variability. Indirect estimations via Earth Observation (…

Basin-Scale Water Resources Assessment in Oklahoma under Synthetic Climate Change Scenarios Using a Fully Distributed Hydrologic Model

Climate change resulting from the enhanced greenhouse effect is expected to have significant implications for the hydrological cycle. Several studies have pointed out the importance of basin-scale investigations for determining regional impacts on water resources, including the effects of floods and droughts. In this study, a fully distributed hydrologic model is used to assess the potential impacts of climate change on water availability in a basin in Oklahoma United States . With this aim, the hydrologic model was applied for current conditions as well as under the hypotheses of climate variations represented by scenarios consistent with a climatic trend analysis generated using a stochas…

Mappatura della vegetazione sommersa mediante immagini multispettrali telerilevate da satellite

Comparative Analysis Between Actual and Potential Evapotranspiration in a Sicilian Semi-Arid Catchment

Ricostruzione delle curve di durata mediante un nuovo approccio ecoidrologico

Le curve di durata delle portate forniscono un importante sintesi dei processi idrologici più rilevanti occorrenti a scala di bacino. Sebbene vengano tipicamente ottenute a partire dalle osservazioni idrometriche, uno dei temi più rilevanti in idrologia è proprio la loro ricostruzione anche in bacini non strumentati. A tal proposito sono stati sviluppati negli ultimi anni svariati approcci teorici, alcuni dei quali meritano particolare attenzione per la loro semplicità di applicazione e accuratezza dei risultati mostrati. La curva di durata viene spesso disaggregata in due componenti: una componente veloce di deflusso superficiale ed una componente lenta di deflusso subsuperficiale. Un rece…

Telerilevamento di aree archeologiche mediante dati iperspettrali MIVIS” (Remote sensing of archaelogical areas using hyperspectral MIVIS data)

The aim of this study is to examine the relationship between physical parameters and the spatial distribution of buried archaeological structures, using data acquired by the airborne hyperspectral sensor mivis in the visible, near infrared and thermal infrared wavelengths. The study areas are the territories of Halaesa, an important city in the Hellenistic-Roman period, and the Punic city of Mozia in Sicily. The influence of buried structures on thermal-radiative behaviour has been investigated using three parameters: Normalized Difference Vegetation Index (ndvi), thermal inertia, and Thermal Balanced Gradient. These techniques are shown to be particularly effective in identifying surface p…

Spatial distribution of temperature trends in Sicily

Modelling flows duration curves in Mediterranean river basins through an ecohydrological approach

The flow duration curve, representing the relationship between magnitude and frequency of streamflows in a basin, provides an important synthesis of the relevant hydrological processes occurring at the basin scale. It is typically obtained from field observations and, since most of the geographical areas of the world still lack suitable streamflow observations, its reconstruction in ungauged river basins is certainly an open and relevant issue in the hydrological literature. Different theoretical approaches have been developed in recent years, and in particular, a novel ecohydrological framework has provided considerable results. The aim of this study is to test with field data, a recent an…

Velocity profiles and water levels measurements in a shallow coastal lagoon

A Decision Support Tool for Water and Energy Savingin the Integrated Water System

Abstract In the last decades, a growing attention on energy saving associated with water resources usage and leakages reduction has been recorded at both national and international level. Scientific research has focused on implementation of several methodologies aimed at the understanding of energy transformation processes occurring in the integrated water system. The main concern is then identifying energy impacts associated to each macro-area of integrated water system, such as collection, treatment and distribution, and analysing the potential interactions between them. Unfortunately, only overall energy consumptions are usually available at national level. The main objective of the pape…

SESAMO: An integrated framework for gathering, managing and sharing environmental data

ICT systems are widely adopted for environmental management, but existing solutions address limited tasks and compose a plethora of heterogeneous tools, which impose a great additional effort on the operators. This work presents SESAMO, a novel framework to provide the operators with a unique tool for gathering, managing and merging environmental and territorial data. SESAMO uses WSNs for providing pervasive monitoring of environmental phenomena and exploits a multi-tier infrastructure in order to integrate data coming from heterogeneous information sources.

Creazione di un database per l’applicazione di modelli empirici di analisi di dissesto idrogeologico da precipitazione nel territorio Siciliano.

La previsione di fenomeni di dissesto idrogeologico è uno strumento essenziale di supporto alle decisioni per una corretta pianificazione del territorio. Tra tali fenomeni quelli franosi possono assumere dimensioni particolarmente rilevanti. Il fattore scatenante più ricorrente nella gran parte dei casi di frane documentate e’ costituito dalle precipitazioni. La letteratura scientifica propone diverse metodologie di analisi volte a fornire strumenti di pre-allarme in vista di un evento meteorico critico o di derivazione di mappe tematiche delle aree a maggiore suscettibilità franosa. I modelli empirici per la derivazione di soglie pluviometriche critiche di innesco risultano tra i più utili…

Analysis of the energetic flows through the sebal application to the assessment of the actual evapotranspiration in a Napa Valley vineyard California (USA).

The use of water resources is constantly growing in agriculture industry and the reduction of the this resource is due by both anthropogenic and climate factors. Under this perspective it is necessary to develop monitoring systems able to forecast the consumption of water. The knowledge of the actual water demand of a crop is therefore strategic for the rational use of resources and to improve the quality of the crop production. Recent applications of remote sensing in agriculture provide a valuable contribution to release this purpose, besides the integration of remotely sensed data with measures retrieved by meteorological stations allows the development of models able to estimate the act…

Masonry structures subjected to tsunami loads: Modeling issues and application to a case study

Abstract Tsunamis are among the most dangerous natural disasters for coastal areas experiencing tsunami hazard. One of the major concerns in the assessment of strategies for the risk mitigation is to estimate vulnerability of structures and infrastructures. However, reliable approaches for the evaluation of the structural capacity under tsunami loads are nowadays not always available for all the types of structures, especially masonry. On this aim, the paper deals with the modeling issues of 3D masonry structures subjected to tsunami loads and the effect on the structural behavior of different modeling approaches. First, a brief state of the art on the available studies is presented regardi…

Comparison of Potential VS actual vegetation status by means of distributed hydrologic balance model and remote sensing data

Determinazione dell’umidità del sistema suolo-vegetazione mediante tecniche di remote sensing: una verifica del metodo triangolare

Modelling analysis of distribution network filling process during intermittent supply

The paper presents the modeling results of the filling process of a water distribution network subjected to intermittent supply. The local tanks built by users for reducing their vulnerability to intermittent supply increase user water demand at the beginning of the service period and the time required for completely fill the network. Such a delicate process is responsible of the inequalities taking part among users. Users located in advantaged positions can receive water resources soon after the beginning of the service period while disadvantaged users have to wait until the network is full. Such an highly dynamic process requires ad-hoc models to be developed in order to obtain reliable r…

Detection of a reservoir water level using shape similarity metrics

The matching between reservoirs’ water edge and digital elevation model’s (DEM) contour lines allowed determining the water level at the acquisition date of satellite images. A preliminary study was conducted on the Castello dam (Magazzolo Lake), between Alessandria della Rocca and Bivona (Agrigento, south-Italy). The accuracy assessment of the technique was than evaluated from the comparison between classified and reference objects using similarity metrics about the shape, theme, edge and position, through the plugin STEP of open source software GIS. Moreover, an independent GIS technique was implemented to evaluate the water level, based on a distances’ array between existing contour line…

Coastal zone water quality: Calibration of a water-turbidity equation for MODIS data

AbstractA nephelometric turbidity algorithm has been specifically calibrated for coastal waters in Sicily. To this purpose, intensive field campaigns were performed in July, August and September 2008. Measurements were collected in situ in three different gulfs. Statistical analysis suggests that field data should be spatially grouped but temporally separated; hence, new calibration parameters have been proposed.Turbidity retrieved by applying the algorithm using literature coefficients and the ones calibrated in situ are shown and compared. The comparison demonstrated that a specific calibration was necessary for quantitatively monitoring turbidity in Sicilian gulfs.

Trend analysis of climatic indexes in Sicily

Planejamento existente e propostas para melhoria de gestao em Manaus

Urban drainage analysis for flooding mitigation

Olive yield as a function of soil moisture dynamics

This study introduces a water-driven crop model aiming to quantitatively link olive yield to climate and soil moisture dynamics using an ecohydrological approach. A mathematical model describing soil moisture, evapotranspiration and assimilation dynamics of olive orchards is developed here. The model is able to explicitly reproduce two different hydroclimatic phases in Mediterranean areas: the well-watered conditions in which evapotranspiration and assimilation assume their maximum values and the real conditions where the limitations induced by soil moisture availability are taken into account. Annual olive yield is obtained by integrating the carbon assimilation during the growing season, …

Vegetation index retrieval by coupling optical and SAR images

Monitoring spatial and temporal variability of Vegetation Indices (VIs) is important to manage land and water resources, with significant impact on the sustainability of modern agriculture Although algorithms based on optical data give accurate products, cloud cover dramatically reduces the temporal resolution of these outputs. The launch of new Synthetic Aperture Radar (SAR) constellations such as COSMO-Skymed opened new opportunities to develop agro-hydrological applications. Indeed, these satellites may represent a suitable source of data for operational applications due to their high spatial and temporal resolutions (10 m in StripMap PingPong acquisition mode, best revisit time with 4 s…

Modelli di previsione del consumo idrico istantaneo

In condizioni di scarsità delle risorse intervenire sulla domanda o sull'offerta

Implementation of a numerical model for the evaluation of potential apparent losses in a distribution network

Misure di velocità e livelli nello Stagnone di Marsala

Misure termografiche da pallone aerostatico per la diagnosi precoce di attacchi da punteruolo rosso delle palme

GIS AND REMOTE SENSING IN HYDROLOGY: SELECTED PRACTICAL APPLICATIONS

Caractèrisation des processus de seècheresse et de désertification à l'échelle régionale

A composite indicator for water meter replacement in an urban distribution network

In water supply management, volumetric water meter are typically used to measure users' consumption. With water meters, utilities can collect useful data for billing, assess the water balance of the system, and identify failures in the network, water theft and anomalous user behaviour. Despite their importance, these instruments are characterised by intrinsic errors that cause so-called apparent losses. The complexity of the physical phenomena associated with metering errors in aging water meters does not allow meter replacement to be guided by single parameters, such as the meter age or the total volume passed through the meter. This paper presents a meter replacement strategy based on a c…

ADCP velocity profiles analisys in the Castellammare gulf

Velocity profiles have been collected in three points within the Castellammare gulf at around 1500 m far from the coastline. This area is characterized by the presence of an aquaculture farm that positioned 5 floating cages in this zone. The impact of this activity on the environment strictly depends on the currents and water exchange. The general aim of this research is the characterization of the circulation characteristics of this area. The analysis of the free surface oscillations shows the typical behaviour of tide forcing, with high minima and maxima during the night, due to the higher moon attraction during these hours compared with the morning hours. A prevalent current direction fr…

Comparison between storm tracking analysis techniques in urban area based on high resolution raingauge data

Experimental and modeling analysis of an apparent losses reduction device

GIS AND REMOTE SENSING IN HYDROLOGY: SELECTED PRACTICAL APPLICATIONS. Proceedings of the ECO-GEOWATER conference - GIS for International river basin management.

Integrazione di dati telerilevati in modelli idrologici: pre-elaborazione di immagini riprese da sensori aviotrasportati CASI ed ATM

ANALISI DEI TREND DI INDICI CLIMATICI IN SICILIA

L’INFLUENZA DELLA MORFOLOGIA SULLA DISTRIBUZIONE DELLE PIOGGE INTENSE

Le precipitazioni intense costituiscono uno dei principali pericoli naturali perché sono all’origine di processi, come innesco di frane o piene improvvise, che possono rappresentare una grave minaccia per la vita umana. Il problema di determinare la variazione spaziale delle precipitazioni intense e in particolare, di indagare sulle relazioni che intercorrono tra queste e la morfologia del territorio, è molto importante soprattutto per gli studi connessi alla realizzazione di efficienti sistemi di allerta e di allarme. Tuttavia la variabilità delle piogge intense con la morfologia è scarsamente studiata in idrologia. In questo lavoro si intende affrontare l’argomento a scala regionale, assu…

The use of the Specht distributed hydrologic balance model for an analysis of vegetation state

Analisi frattale dei reticoli idrografici estratti automaticamente da DEM

Effect of DEM resolution and threshold area on the hydrologic response at catchment scale

Analisi multitemporale delle relazioni tra parametri produttivi e indice di vegetazione in viticoltura

L’efficacia degli interventi agronomici dipendono dalla capacità di programmazione in termini di tempo e intensità di intervento. Questultimi aspetti possono essere calibrati tramite una corretta conoscenza delle caratteristiche produttive e qualitative dei parametric di campo e della loro variabilità nel tempo e nello spazio. La viticoltura di precisione fornisce un supporto valido alla definizione della variabilità di campo e temporale dei parametric vegetative e produttivi. Questo lavoro sintetizza due anni di viticoltura di precisione in Sicilia, nelle campagne agronomiche consotte nel 2012 e 2013 in due aziende vitivinicole “Tenute Rapitalà” e “Donnafugata”. L’indice di vegetazione nor…

Uncertainty in urban flood damage assessment due to urban drainage modeling and depth – damage curve estimation

Spatial interpolation methods based on the use of elevation data

On the influences of vegetation biomass on COSMO-Skymed X-band

The knowledge of spatial and temporal variability of land cover is important to manage water resources for yield forecasting, water stress prediction, irrigation water management and flood protection. Cloud cover dramatically reduces the temporal resolution of optical data thus limiting their operational use; in addition, the spatial resolution is often inadequate for applications in heterogeneous areas. On the other hand, algorithms based on Synthetic Aperture Radar (SAR) implemented to retrieve vegetation parameters are not yet fully validated. New SAR missions (COSMO-Skymed and Terrasar-X) may represent a suitable source of data for operational uses due to the high spatial and temporal r…

Basin-scale water resources assessment in a sicilian basin under climate change scenarios using the conceptual model TOPDM

Climate change resulting due to the greenhouse effect is expected to have great implications for hydrological cycle and for existing surface and groundwater resources systems. The effects of climate variability and climate change have to be fully considered in current water management and planning, since water availability, quality and streamflow are very sensitive to changes in temperature and precipitation regimes. International literature proposes several models, attempting to assess accurately the available water resources under stationary and changing climatic conditions at different spatial and temporal scales. In order to assess the potential impacts of climate change on surface and …

MODELLAZIONE DELLA QUALITÀ DELLE ACQUE NEI RICETTORI IN TEMPO DI PIOGGIA

Controllo dell’inquinamento delle acque meteoriche e qualità dei corpi idrici ricettori: l’esperienza del bacino Nord di Palermo

TECNICA LS-PIV PER IL MONITORAGGIO DEI CORSI D’ACQUA NATURALI: UN APPROCCIO NUMERICO PER L’INDIVIDUAZIONE DI SETUP SPERIMENTALI OTTIMALI

Nuove tecniche per il monitoraggio ambientale, come le tecniche LS-PIV (Large-Scale Particle Image Velocimetry) e PTV (Particle Tracking Velocimetry), consentono una più speditiva e sicura acquisizione di misure di velocità nei corsi d’acqua. L’impiego di tecniche basate sull’elaborazione di immagini presenta infatti numerosi vantaggi che permettono di superare alcune criticità tipiche di approcci tradizionali (es. misure non invasive, low-cost, possibili anche in circostanze avverse e in real-time). Il recente sviluppo di tali tecniche è progredito di pari passo con la crescente disponibilità di sensori digitali sempre più performanti ed economici. Nonostante la grande disponibilità anche …

Reti Neurali per la Realizzazione di Mappe di Suscettibilità per il Rischio Frana

La valutazione della suscettibilità al dissesto rimane uno degli approcci più utilizzanti e più efficaci per l'analisi della pericolosità da frana. Come noto, la correlazione tra il fenomeno fisico ed i fattori predisponenti sulla base degli eventi accaduti in passato è il punto chiave di tale analisi. I metodi statistici, uniti con le tecnologie GIS, si sono rilevati in questi anni tra gli strumenti più idonei e più efficaci per la valutazione e la modellazione di tale correlazione. Tuttavia, questi metodi richiedono spesso ipotesi restrittive circa la distribuzione statistica dei dati che spesso non vengono rispettate. Per tale motivo si sono anche sviluppate metodologie alternative basat…

Time Series Analysis of Climatic Vegetation Data in the Oreto Watershed in Sicily

Analisi dei trend climatici in Sicilia

Tecnica Differenziale Interferometrica per l’individuazione di un dissesto: il caso della frana di Niscemi

Telerilevamento di aree archeologiche mediante dati iperspettrali MIVIS

The aim of this study is to examine the relationship between physical parameters and the spatial distribution of buried archaeological structures, using data acquired by the airborne hyperspectral sensor MIVIS in the visible, near infrared and thermal infrared wavelengths. The study areas are the territories of Halaesa, an important city in the Hellenistic-Roman period, and the Punic city of Mozia in Sicily. The influence of buried structures on thermal-radiative behaviour has been investigated using three parameters: Normalized Difference Vegetation Index (NDVI), thermal inertia, and Thermal Balanced Gradient. These techniques are shown to be particularly effective in identifying surface p…

Le fanerogame marine in Sicilia

Pumps as turbines (PATs) in water distribution networks affected by intermittent service

A hydraulic model was developed in order to evaluate the potential energy recovery from the use of centrifugal pumps as turbines (PATs) in a water distribution network characterized by the presence of private tanks. The model integrates the Global Gradient Algorithm (GGA), with a pressure-driven model that permits a more realistic representation of the influence on the network behaviour of the private tanks filling and emptying. The model was applied to a real case study: a District Metered Area in Palermo (Italy). Three different scenarios were analysed and compared with a baseline scenario (Scenario 0 – no PAT installed) to identify the system configuration with added PATs that permits th…

Modifications in Water Resources Availability Under Climate Changes: A Case Study in a Sicilian Basin

Climate variability due to the greenhouse effect has important implications on hydrological processes and water resources systems. Indeed, water availability, quality and streamflow are very sensitive to changes in temperature and precipitation regimes whose effects have to be fully considered in current water management and planning. International literature proposes several models, attempting to assess accurately the available water resources under stationary and changing climatic conditions at different spatial and temporal scales. In order to assess the potential impacts of climate change on surface and groundwater resources water availability in a Southern area of Italy, a conceptual h…

Analisi dell'influenza della risoluzione del DEM e dell'area di soglia sulla risposta idrologica a scala di bacino

Un sistema integrato di telerilevamento e modellistica idrodinamica per il monitoraggio delle praterie a Posidonia oceanica

Assessing Urban System Vulnerabilities to Flooding to Improve Resilience and Adaptation in Spatial Planning

Fluvial, pluvial and coastal flooding are the most frequent and costly natural hazard. Cities are social hubs and life in cities is reliant on a number of services and functions such as housing, healthcare, education and other key daily facilities. Urban flooding can cause significant disruption to these services and wider impacts on the population. These impacts may be short or long with a variably spatial scale: urban systems are spatially distributed and the nature of this can have significant effects on flood impacts. From an urban-planning perspective, measuring this disruption and its consequences is fundamental in order to develop more resilient cities. Whereas the assessment of phys…

Valutazione delle perdite idriche apparenti legate all’errata misurazione dei consumi residenziali

Gestione delle emergenze da incendi boschivi: un sistema di supporto alle decisioni in ambiente GIS

Il presente studio è finalizzato alla definizione di un insieme di modelli decisionali e di procedure per la gestione a livello pre-operativo e operativo delle risorse antincendio boschivo disponibili nel territorio regionale siciliano. Per raggiungere tali obiettivi è stata messa a punto una struttura concettuale per la definizione di un sistema di supporto alle decisioni in grado di coadiuvare i responsabili della gestione delle emergenze alle diverse scale territoriali. La sintesi dello studio è costituita dall'implementazione di un prototipo relativo ad un modulo decisionale, atto a supportare le decisioni per la dislocalzione in tempo reale di uomini e mezzi, con riferimento ad un'area…

Applicability of a displaced-beam laser scintillometer in a sparse tall Mediterranean vegetation

Recent studies showed that the sensible heat flux (H) measured with an array of eddy-correlation system has an high spatial and temporal variability over sparse tall vegetation, such as olive trees, whereas H determined with a displaced-beam laser scintillometer (DBLS) appeared to behave more stable. In this study, the results are shown of two field experiments performed over an olive tree plantation in Sicily in 2007 and 2008, in order to investigate the applicability of a DBSL in combination with remote sensing techniques for the actual evapotranspiration assessment. In 2007 the laser beams was closer to the top of the canopy than in 2008. Various aspects of the scintillation method will …

Flow resistance ofPosidonia oceanicain shallow water

Management of coastal waters and lagoons by mathematical circulation models requires determination of the hydraulic resistance of submerged vegetation. A plant typical of sandy coastal bottoms in the Mediterranean Sea is Posidonia oceanica, which is constituted by very thin and flexible ribbon-like leaves, about 1 cm wide and up to 1.5 m long, and usually covers the bottom with a density of 500-1000 plants/ m2. From the hydraulic viewpoint, P. oceanica constitutes a particular roughness, because, as the velocity increases, the leaves bend more and more until they lie down on the bottom. Although P. oceanica is widespread, in the technical literature it is difficult to find indications about…

A post-fire analysis of vegetation dynamics in semi-forested areas using multi-temporal remote sensing imagery

Controllo dell'inquinamento delle acque meteoriche e qualità dei corpi idrici ricettori

EHSM: UN NUOVO MODELLO CONCETTUALE PER LA SIMULAZIONE DEL DEFLUSSO GIORNALIERO

Il controllo distribuito dei deflussi meteorici in ambiente urbano: le esperienze brasiliane ed italiane, le problematiche e le prospettive. Atti del VIII Simpósio Ítalo Brasileiro de Engenharia Sanitária e Ambiental, VIII SIBESA

Influenza della imperfetta conoscenza delle precipitazioni sulla risposta incerta di modelli afflussi- deflussi concettuali non distribuiti

Un modello energetico-idrologico per la stima distribuita dell’evapotraspirazione alla scala di bacino: prime applicazioni

Turbidity analysis in Sicilian coastal zones by means of remote sensing images and spectroradiometric measurements

Water turbidity has a wide range of variability both spatially and temporally. Rivers transport sediments to the river mouth following a seasonal behaviour and occasionally during flood events (Doxaran et al., 2006; Pribble et al., 2001). Once in the sea, sediments are spatially driven by currents, and re-suspended by waves from the bottom, changing water turbidity in the tidal and sub-tidal zones (Cloern et al., 1989; Uncles et al., 2002; Wolanski & Spagnol, 2003). Moreover human activities such as transport and dredging occasionally and locally influence turbidity magnitude and distribution (Schoellhamer, 1996). In recent years the pollution of the maritime environment suggests that only …

Analisi comparativa di modelli euristici e statistici spaziali nella derivazione della suscettibilità da colate rapide di fango e detrito.

La suscettibilità da frana può essere definita come la propensione di una determinata area all’innesco di movimenti di massa, in relazione alle caratteristiche intrinseche dei terreni di copertura e del substrato, delle caratteristiche morfologiche ed alla maggiore esposizione nei confronti degli agenti climatici. Nel corso degli anni sono stati sviluppati vari metodi per valutare la suscettibilità, basati su approcci sia di tipo deterministico che statistico. Tutti i metodi si basano su poche assunzioni fondamentali secondo cui la franosità è controllata da leggi meccaniche che possono essere determinate in modo empirico, statistico o deterministico. Scopo del presente lavoro è quello di v…

I grandi sistemi idrici in Sicilia

Utilizzo degli L-Moments per l’analisi regionale delle portate di piena in Sicilia.

Soil Water Content Diachronic Mapping: An FFT Frequency Analysis of a Temperature–Vegetation Index

Among the indirect estimation approaches of soil water content in the upper layer of the soil, the &ldquo

Mapping the annual runoff data in Sicily using a geostatistical approach

The availability of reliable and long time series of runoff data is fundamental for most of the hydrological analyses and for the assessment and the management of water resources even in condition of global climatic change. However, hydrologic data set are often characterized by a short duration and also suffer from missing data values, mainly due to malfunctioning of gauging stations for a specific period. In order to overcome this problem and obtain long and continuous runoff time series, different models and methods have been previously developed and proposed. While some models, used to extent the streamflow record, are conceptual, empirical, regressive models based on the rainfall input…

Use of L-moments approach for regional flood frequency analysis in Sicily, Italy

Extremely great floods are among environmental events with the most disastrous consequences for the entire world. Estimates of their return periods and design values are of great importance in hydrologic modeling, engineering practice for water resources and reservoirs design and management, planning for weather-related emergencies, etc. Regional flood frequency analysis resolves the problem of estimating the extreme flood events for catchments having short data records or ungauged catchments. This paper analyzes annual maximum peak flood discharge data recorded from more than 50 stream flow gauging sites in Sicily, Italy, in order to derive regional flood frequency curves. First these data…

Water and Energy Saving in Urban Water Systems: The ALADIN Project

The ALADIN project was aimed at contributing to environmental and energy sustainability of the urban water system by means of a decision support tool able to allow an evaluation of the energy impact related to each different macro-sectors of urban water cycle highlighting the main energy flows and to assess the system energy balance and identify the possible energy-efficient solutions. Moreover the tool suggests the most efficient actions in reducing water losses. In the present paper the main features of the developed tool are presented. (C) 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.

Integrazione di tecniche GIS e dati telerilevati per il bilancio idrologico del suolo

Utilizzo di modelli lineari generalizzati nella derivazione di mappe di suscettibilità per il rischio idrogeologico

L’analisi statistica basata sulla correlazione tra cause e occorrenze, costituisce uno degli approcci più utilizzati in letteratura scientifica per la valutazione delle aree propense a produrre dissesti idrogeologici. Tra questi, il dissesto da frana rappresenta uno tra i più pericolosi e dannosi eventi naturali che negli ultimi anni hanno particolarmente colpito tutto il territorio nazionale. Il presente lavoro si pone come obiettivo quello di valutare l’efficienza di un modello statistico multivariato per la determinazione di mappe di suscettibilità al rischio idrogeologico, basandosi sulla correlazione tra fattori innescanti e occorrenze. Tra i modelli statistici presenti in letteratura …

Actual evapotranspiration assessment in a sparse tall Mediterranean crops

Planktothrix rubescens in freshwater reservoirs: remote sensing potentiality for mapping cell density

Planktothrix rubescens is sadly famous for producing microcystins (MCs), which are powerful hepatotoxins. During the winter 2005/06, P. rubescens has been found in the Pozzillo, Nicoletti, Prizzi and Garcia reservoirs, Sicily; in 2008 it was also detected in SS. Trinita di Delia and Castello reservoirs. Indeed, during periods of low shortwave irradiance such as winter, when light weakly penetrates water column and the water cools, P. rubescens filaments float up to the surface, forming red-colored blooms. Ancillary meteorological measurements highlighted low air temperatures between two frosts in December 2007 and February 2008, with a simultaneous reduction in the incoming total solar radi…

Reservoir monitoring using satellite SAR and GNSS: a case study in southern Italy

Recently, it has been demonstrated that it is possible to relate water levels of a reservoir with its dam displacements. Water levels were determined via remote sensing, while dam displacements were measured via Global Navigation Satellite System (GNSS). Results have shown that displacements and water levels are correlated.Water levels at the Magazzolo reservoir in southern Italy were firstly retrieved using two remote sensing approaches: by visual matching between the reservoir shoreline and contour lines, and by evaluating the surface extent via unsupervised classification to estimate the water levels with an area/depth relation. Dam displacements were measured using GPS receivers on the …

Un confronto tra stime di evapotraspirazione effettiva basate su dati telerilevati in sistemi agricoli e condizioni di stress idrico

Comparison of sensible and latent heat fluxes computed by a surface energy balance algorithm and measured eddy covariance fluxes across rainfall events

Definition of performance indicators for urban water distribution systems in drought conditions

Regional frequency analysis of extreme precipitation in Sicily, Italy

In condizioni di scarsità delle risorse intervenire sulla domanda o sull’offerta

The role of urban growth, climate change, and their interplay in altering runoff extremes

Changes in climate and urban growth are the most influential factors affecting hydrological characteristics in urban and extra-urban contexts. The assessment of the impacts of these changes on the extreme rainfall–runoff events may have important implications on urban and extra-urban management policies against severe events, such as floods, and on the design of hydraulic infrastructures. Understanding the effects of the interaction between climate change and urban growth on the generation of runoff extremes is the main aim of this paper. We carried out a synthetic experiment on a river catchment of 64 km2to generate hourly runoff time series under different hypothetical scenarios. We impos…

Evaluation of different InSAR multi-baseline construction methods over a dam in southern Italy

Monitoring dam displacements using different techniques allows an evaluation of their structural behaviour over time. In this study, dam displacements (for the Castello dam, Agrigento, Italy) have been investigated using different Interferometric Synthetic Aperture Radar (InSAR) techniques exploiting a freely available dataset from the EU Copernicus Sentinel-1 SAR built by the European Space Agency (ESA). The dataset includes Sentinel 1A (S1A) images acquired in dual-polarization and Interferometric Wide (IW) swath using the Terrain Observation with Progressive Scans SAR (TOPSAR) mode. Three main Multi-Baseline Construction methods based on the identification of Persistent Scatterers (PS) h…

Effetti di urbanizzazione e cambiamenti climatici sui deflussi a scala di bacino

Fra le pressioni di natura antropica agenti sui bacini idrografici, particolare rilevanza hanno sia la progressiva perdita di suoli naturali in favore di suoli poco, o per nulla, permeabili (es. strade, edifici, parcheggi, etc.) che la regimazione e regolazione dei deflussi sulla rete di drenaggio naturale mediante interventi idraulici. In particolare, l’ultima relazione sullo stato dell’ambiente europeo a cura dell’Agenzia Europea dell’Ambiente (AEA, 2010) considera l’impermeabilizzazione dei bacini naturali come uno dei maggiori processi di degrado del suolo. L’aumento del grado di urbanizzazione dei bacini naturali, inteso come aumento della frazione impermeabile del suolo derivante dell…

Derivation of a Distributed Unit Hydrograph Integrating GIS and Remote Sensing

The paper describes the results of a study based on the integration of remote sensing and geographical information system techniques to evaluate a distributed unit hydrograph model linked to an excess rainfall model for estimating the streamflow response at the outlet of a watershed. Travel time computation, based on the definition of a distributed unit hydrograph, has been performed, implementing a procedure using (1) a cell-to-cell flow path through the landscape determined from a digital elevation model (DEM); and (2) roughness parameters obtained from remote sensing data. This procedure allows the taking into account of the differences, in terms of velocity, between the hillslopes and t…

Monitoring displacements of an earthen dam using GNSS and remote sensing

This paper shows the results of a scientific research in which a GNSS continuous monitoring system for earth-dam deformations has been developed, then, deformations have been related with reservoir water surface and level. The experiment was conducted near Bivona (Sicily, Italy), on the Castello dam (Magazzolo Lake). On the top of the dam three control points were placed and three GNSS permanent stations were installed. The three stations continuously transmitted data to the control centre of the University of Palermo. The former has been determined using freely available satellite data (specifically Landsat 7 SLC-Off) collected during the whole study period (DOYs 101 to 348 2011). Issues r…

EFFECTS OF DATA GAP ON THE CAPABILITY TO DETECT TREND IN HYDROCLIMATOLOGICAL TIME SERIES

In the last decades the growing concerns about the existence of global climatic changes push many researchers to use different trend test in order to identify whether monotonic trends exist in hydroclimatological time series such as temperature, precipitation, and streamflow. Unfortunately, these time series often suffer from missing data values mainly due to malfunctioning of gauge for specific time periods. Starting from this premise, the main target of our work is to investigate the effect of data gap in a time series on the results provided by the most used trend test: the nonparametric Mann–Kendall statistical test. Firstly, different synthetic time series characterized by different si…

Stagnone di Marsala Lagoon, western Sicily.

An integrated information system for the acquisition, management and sharing of environmental data aimed to decision making

This paper reports the first results of the Project SESAMO - SistEma informativo integrato per l’acquisizione, geStione e condivisione di dati AMbientali per il supportO alle decisioni (Integrated Information System for the acquisition, management and sharing of environmental data aimed to decision making). The main aim of the project is to design and develop an integrated environmental information platform able to provide monitoring services for decision support, integrating data from different environmental monitoring systems (including WSN). This ICT platform, based on a service-oriented architecture (SOA), will be developed to coordinate a wide variety of data acquisition systems, based…

FOTOGRAMMETRIA CONVENZIONALE E SENSORE AD IM-MAGINI “CASI”: APPLICAZIONI ALLA MAPPATURA DELLA VEGETAZIONE SOMMERSA

Obiettivo della ricerca è stato quello di testare l’applicabilità delle tecniche che fanno uso di dati te-lerilevati (multispettrali e da aerofotogrammetria convenzionale) da piattaforma aerea per il monito-raggio delle praterie di Posidonia oceanica. L’analisi multitemporale ha permesso di monitorare l'e-voluzione del “limite superiore” delle praterie sommerse evidenziando l'impatto della pressione an-tropica sulla componente biotica fotoautotrofa dell'ecosistema marino costiero. Dallo studio è emer-so che l'analisi dei dati telerilevati da aereo fornisce un contributo essenziale all’indagine del pae-saggio vegetale a media e piccola scala, consentendo sia un monitoraggio periodico di vast…

Early warnings of Rhynchophorus ferrugineus infestation of Phoenix canariensis: a proximity thermal sensing approach

Phoenix canariensis represents one of the most relevant ornamental plants within Mediterranean environment. In the last few years the infestation of a curculio coleopteron, namely the Rhynchophorus ferrugineus, caused a widespread decimation of these palms. Unluckily damages caused by the insect are evident only in the advanced phase of the disease making futile almost any plant treatment. Early warning of this disease may represents the only way to setup efficient actions to fight the coleopteron in trees where it takes over, thus limiting its spreading in contiguous palms. This research aims to achieve the former result by processing: i) short and long-wave images of the crown acquired du…

A paradigm of extreme rainfall pluvial floods in complex urban areas: the flood event of 15 July 2020 in Palermo (Italy)

Abstract. In the last few years, some regions of the Mediterranean area have witnessed a progressive increase in extreme events, such as urban and flash floods, as a response to the increasingly frequent and severe extreme rainfall events, which are often exacerbated by the ever-growing urbanization. In such a context, the urban drainage systems may not be sufficient to convey the rainwater, thus increasing the risk deriving from the occurrence of such events. This study focuses on a particularly intense urban flood that occurred in Palermo (Italy) on 15 July 2020; it represents a typical pluvial flood due to extreme rainfall on a complex urban area that many cities have experienced in rece…

CONTROLLO DELL’INQUINAMENTO DELLE ACQUE METEORICHE E QUALITÀ DEI CORPI IDRICI RICETTORI: L’ESPERIENZA DEL BACINO NORD DI PALERMO

USING HIGH RESOLUTION RAINGAUGE DATA FOR STORM TRACKING ANALYSIS IN THE URBAN AREA OF PALERMO, ITALY

This paper presents a comparative analysis between rain-gauge storm tracking techniques in order to achieve a better knowledge of the rainfall dynamics over an urbanized area. The temporal and spatial distribution and kinematics of short term rainfall are recognized as one of the most important reasons in error production in rainfall-runoff on urban catchments. The uncertainty due to rainfall variability can greatly affect urban drainage modeling performance and reliability thus reducing the confidence of operators in their results. Modeling representations of urban catchments and drainage systems are commonly adopted for surface flooding forecasting and management and an adequate knowledge…

A diachronic analysis of estuarine turbidity due to a flood following an extreme rainfall event

During floods following rainfall events characterized by long return period, rivers bring to their mouths the higher concentration of sediments. This paper deals with a qualitative assessment of coastal water and turbidity load in estuarine waters as a consequence of an intense rainfall event occurred on the 16t h and 17 th September 2003 in the eastern part of Sicily. Although empirical relationships to estimate turbidity using remote sensing can be found in literature, however models parameters need to be calibrated through in situ measures acquired via intensive field campaigns. The algorithm used within this research was calibrated using field data acquired during three periods in 2008 …

Time series analysis of climate and vegetation variables in the Oreto watershed (Sicily, Italy)

Procedure di caratterizzazione dei dati storici

Laboratory Measurements of Flow and Turbulence in Discontinuous Distributions of Ligulate Seagrass

Turbulent flow characteristics were investigated in laboratory flume studies of a ligulate plant canopy interrupted by a gap representing discontinuities observed in seagrass prairies. The reliability of velocity measurements obtained using an acoustic Doppler velocimeter within the canopy was shown using specifically designed experiments. In relatively fast flow (mean velocity 5.5 cm s−1), the mean flow profile was logarithmic above the canopy, had an inflection point near its top, and uniformly low values within it. Within the gap, a recirculation cell formed. Reynolds stress maxima were approximately coincident with the mean flow inflection point. Quadrant analysis revealed an ejection-d…