ADATTAMENTO E APPLICAZIONE DI UN MODELLO MICROSCOPICO DI SIMULAZIONE DEL TRAFFICO PER IL PROGETTO DI ROTATORIE

Negli ultimi decenni la mobilità ed il traffico sono diventati temi di grande attualità. L’auto è diventata il mezzo preferenziale per fasce di mercato sempre più vaste, a causa dei cambiamenti subiti dalla domanda di trasporto non solo in termini quantitativi, ma anche riguardo alla sua struttura temporale e spaziale. Tutto questo non è stato accompagnato da una corretta pianificazione dei sistemi di trasporto, che sarebbe servita per giungere ad un equilibrio territoriale e di ripartizione modale, con la conseguenza di portare le strade ai limiti della capacità con sempre più frequenti e maggiori fenomeni di congestione peggiorando così le prestazioni delle reti stesse. Le congestioni che si possono verificare hanno una forte caratterizzazione temporale, infatti sono fenomeni che si presentano in particolari momenti del periodo di osservazione. Per esempio se analizziamo delle situazioni relative ad intersezioni che si trovano nei pressi di edifici scolastici vedremo che la maggiore affluenza si avrà all’orario di ingresso e di uscita degli studenti dalla struttura scolastica. Ci sono molti altri esempi che potrebbero essere proposti come quello dei centri commerciali, o come la riduzione della capacità della strada a causa di un incidente o di un cantiere presente sulla carreggiata. Per una giusta valutazione di questi fenomeni sono necessari degli strumenti adeguati che oltre a collocare spazialmente il fenomeno valutino i suoi effetti nel tempo, considerando il momento di inizio e la sua evoluzione con il passare del tempo e con il modificarsi delle condizioni di traffico. Per questo si sta sempre più diffondendo l’utilizzo di modelli di assegnazione dinamica del traffico o modelli DTA (Dynamic Traffic Assignment), quali strumenti analitici per la simulazione e l’analisi quantitativa dei fenomeni caratteristici di una rete di trasporto. Con i metodi di simulazione tradizionali nati agli inizi degli anni ’50, ci si basa sull’ipotesi di stazionarietà intraperiodale. Si valuta cioè la domanda di trasporto,assunta in termini di valore medio nel periodo considerato, su un intervallo sufficientemente lungo tale da poter considerare le condizioni come stazionarie. Questo comporta che non possano essere considerati tutti quei fenomeni dinamici che caratterizzano le reti congestionate: la propagazione del ritardo a ritroso, la formazione di code e la loro evoluzione e dissipazione, gli effetti di un incidente sulla rete stradale, la variazione della domanda nel tempo e le prestazioni della rete nel caso di fenomeni eccezionali come per esempio l’evacuazione di alcune aree a causa di calamità naturali. Chiaramente fenomeni di questo tipo non possono essere studiati in termini di valori medi, perché proprio la variabilità della domanda e di altre caratteristiche porta alla formazione di ulteriori fenomeni di congestione. Facendo un esempio, basta pensare ad una rete sulla quale in un particolare momento del periodo di osservazione abbiamo che la domanda supera quella che è la capacità dell’infrastruttura; questo comporta che vi siano dei rallentamenti ed in alcuni casi anche l’arrestarsi dei veicoli, ma se il valore della domanda rilevato durante tutto il periodo di osservazione viene valutato in termini medi, non mettiamo in luce il fenomeno che porta alla situazione critica prima descritta. Quindi l’obiettivo dei modelli dinamici è proprio di considerare la variazione del flusso nel tempo per rilevare le situazioni di criticità che sarebbero altrimenti non evidenziabili con l’utilizzo di strumenti statici

The Rock Mass Quality Index (RQI): a quantitative tool for the quality evaluation of near-surface rock masses

The knowledge of rock masses behaviour is an important information in various fields such as civil engineering, land use planning and hazard/risk zoning. Different rock mass classification methods, initially aimed at assisting underground excavations (Hoek, 2007), are widely used nowadays for preliminary design procedures (Bieniawski, 1989; Hoek, 2007), like the RMR (Bieniawski, 1976) and the Q (Barton et al., 1974) and their modifications. These methods incorporate geological, geomechanical and geometric parameters in order to obtain a quantitative estimation of the rock mass quality, but, on the other hand, their implementation is time-consuming. Despite the dominance of these two methods, further rock mass classifications systems have been proposed in the last decades and, among these, the Geological Strength Index (GSI) classification system is currently widely used as it allows to estimate the strength of rock mass through empirical semiquantitative evaluation (Hoek, 1994; Cai et al., 2004), based on both rock mass structure and condition of the joints (Hoek et al., 1995). Estimating the GSI is straightforward and fast, but it comes at the cost of a certain degree of subjectivity. Moreover, the index does not adequately account for the lithology of the rock mass matrix. Hence, for the above reasons, these classification methods are not fully suitable to collect rock mass data over wide scale areas for engineering geological mapping. The Rock mass Quality Index (RQI, Disperati et al., 2016; Mammoliti et al., 2018) is a rock mass classification system developed for cartographic purposes and it is based on the systematic fieldwork measurement and processing of sets of the Schmidt hammer rebound values (R). Each representative rock mass outcrop is analysed by collecting ca. 20 R values at the 15-25 nodes of a regular grid conceived to investigate the typical features of the rock mass. This allows to perform statistical analyses and to calculate the RQI, a quantitative indicator of the global strength and quality of the rock mass. In the last decade, a dataset of ca 1100 outcrops sites spreading over a large area (ca. 12000 km2) were acquired in Tuscany (Italy), according to different lithology, weathering, jointing conditions. The dataset consists of both RQI measurements and GSI estimations for the main different lithological groups (flysch, limestones, marls, magmatic rocks and schists) of the Northern Apennines (Italy), as well as the laboratory determinations of the Slake Durability Index (Id2; Franklin & Chandra, 1974) obtained by testing representative outcrop rock samples. The large dataset has allowed to analyse the correlation among RQI, GSI and Id2 and to perform an in-depth critical analysis of the relationships among RQI, lithology, rock mass structure, as well as the suitability of the RQI as reference index for engineering geological mapping of near-surface rock mass quality

Joint Probabilities of Storm Surge, Significant Wave Height and River Discharge Components of Coastal Flooding Events. Utilising statistical dependence methodologies & techniques.

In this Report, the possibility of utilizing joint probability methods in coastal flood hazard component calculations is investigated, since flood risk is rarely a function of just one source variable but usually more of two or three variables such as river discharge, storm surge, wave etc. Joint probability values provide the likelihood of source variables taking high values simultaneously and resulting to a situation where flooding may occur. This report focuses on data preparation, parameter selection and methodology application. The source variable-pairs presented here, which include enough information for calculations, are: (i) surge & wave, (ii) surge & discharge and (iii) wave & discharge. The analysis is focused over 32 river ending (RIEN) points that have been selected to cover a variety of coastal environments along European riverine and estuary areas. In the absence of coincident long-term measurements, the methodology of simulating data observations by modelling was adapted resulting to a set of hindcasts for the three source variables (surge, wave height and discharge). Storm surge hindcasts were performed by utilising the hydrodynamic model Delft3D-Flow that was forced by wind and pressure terms from ECMWF ERA-Interim reanalysis. In a similar way, wave hindcasts were generated by utilizing the latest version of ECMWF ECWAM wave (stand-alone) model, forced by neutral wind terms from ERA-Interim. For the construction of river discharge hindcasts the LISFLOOD model – developed by the floods group of the Natural Hazards Project of the Joint Research Centre (JRC) – was employed. Validation of hindcasts was made over the RIEN point of river Rhine (NL) where coincident observations were available. Considering the physical driver complexity behind interactions among surge, wave height and discharge variables, hindcasts were found to perform quite well, not only simulating observation values over the common interval of interest, but also in resolving the right type and strength of both correlations and statistical dependencies. Results are presented by means of analytical tables and detailed maps referring to both correlation and dependence (chi) values being estimated over RIEN points. In particular, dependencies coming from such analytical tables can be used in an easy way to calculate the joint return period for any combined event by inserting chi in a simple formula containing the individual return periods of source variables. It is then straightforward to estimate the joint probability value as the inverse of the joint return period. Overall, the highest values of (strong / very strong) correlations and dependencies were found between surges and waves mainly over North Sea and English Channel with (such combined) events to take place on the same day (zero-lag mode). Moderate to well category dependencies were found for most sea areas, also on a zero-lag mode. In the case of surge and river discharge, moderate to well category values were found in most cases but not in a zero-lag mode as in surge & wave case. It became clear that in order to achieve such (relatively high) values, a considerable lag time interval of a few days was required with surge clearly leading discharge values. For the case of wave and river discharge, well to strong category values were found but once more mostly in non-zero lag mode indicating the necessity of a considerable lag time interval for dependence to reach such (well / strong) values with wave distinctly leading discharge values.JRC.G.2-Global security and crisis managemen

MINDED-FBA: An Automatic Remote Sensing Tool for the Estimation of Flooded and Burned Areas

This paper presents the MINDED-FBA, a remote-sensing-based tool for the determination of both flooded and burned areas. The tool, freely distributed as a QGIS plugin, consists of an adaptation and development of the previously published Multi Index Image Differencing methods (MINDED and MINDED-BA). The MINDED-FBA allows the integration and combination of a wider diversity of satellite sensor datasets, now including the synthetic aperture radar (SAR), in addition to optical multispectral data. The performance of the tool is evaluated for six case studies located in Portugal, Australia, Pakistan, Italy, and the USA. The case studies were chosen for representing a wide range of conditions, such as type of hazardous event (i.e., flooding or fire), scale of application (i.e., local or regional), site specificities (e.g., climatic conditions, morphology), and available satellite data (optical multispectral and SAR). The results are compared in respect to reference delineation datasets (mostly from the Copernicus EMS). The application of the MINDED-FBA tool with SAR data is particularly effective to delineate flooding, while optical multispectral data resulted in the best performances for burned areas. Nonetheless, the combination of both types of remote sensing data (data fusion approach) also provides high correlations with the available reference datasets. The MINDED-FBA tool could represent a new near-real-time solution, capable of supporting emergency response measures

Engineering geological mapping of near-surface rock mass quality of folded and thrusted arenaceous flysch units in the Northern Apennines (Italy)

The regionalized knowledge of the quality of near-surface rock masses is an important tool for land management/planning, as well as for guiding further in-depth studies aimed at landslide and earthquake risk assessment and civil engineering planning. The characterization of heterogeneous rock masses like flysch units represents a relevant challenge to engineering geologists due to the complex structure of these materials, which results from both their depositional context and tectonic history. Flysches are widespread all over the Apennines chain and their mechanical characterization is a difficult task given the occurrence of intercalation of layers with different lithology and strength. Moreover, the complexity of the thrust and fold tectonic framework makes the regional distribution of these characters difficult to predict. The aim of this work is to provide a method to map the near-surface rock masses quality for an arenaceous flysch widely cropping out in the outer Northern Apennines (Torrente Carigiola Formation, Aquitanian; Bettelli et al., 2002). This formation is mapped in both the geological map of the Regione Toscana (Italy) at the scale of 1:10,000 and the geological sheet “252 – Barberino di Mugello” (Bettelli et al., 2002) of the Italian Geological Map at the scale of 1:50,000 (CARG). It is made up by intercalated arenaceous (A) and pelitic (P) layers characterized by variable A/P ratio. The rock mass quality is evaluated by estimating, for a set of representative rock outcrops, the Rock Mass Quality Index (RQI; Disperati et al. 2016; Mammoliti et al. 2018). This index results from the analysis of both systematic Schmidt hammer rebound measurements (R) acquired at the nodes of a regular grid (ca. 20 R measurements for ca. 15-25 nodes) and the determination of the unit weight for representative outcrop rock samples. For the same outcrops, also the A/P ratio and bedding attitude are determined. The results show a positive linear correlation between RQI and the A/P ratio, confirming that the latter parameter is an important feature controlling the rock mass strength. This correlation is used to assess the distribution of both parameters within a set of geological cross sections traced normal to the regional structures trend (main thrusts and km-scale folds). Then, the structural features available from the literature geological maps allow us to extrapolate both the RQI and A/P ratio from the profiles to the map scale. Finally, a further set of the same rock outcrop data acquired after the above-described modelling procedure is used to check the accuracy of the method

Weathering Effects on Engineering Geological Properties of Trachydacitic Volcanic Rocks from the Monte Amiata (Southern Tuscany, Italy)

Variability in lithology and weathering degree affects physical and mechanical properties of rocks. In this study, we investigated the relationships between weathering degree and engineering geological properties of trachydacitic volcanic rocks from Monte Amiata (central Italy) by coupling field and laboratory analyses. We collected in situ Schmidt hammer tests in the field. We evaluated weathering quantifying the percentage of secondary minerals through thermal analysis in the laboratory. We also determined dry density (rd), specific gravity of solids (Gs), porosity (n) and two-dimensional (2D) porosity as resulted from scanning electron microscopy investigations. The results of our study indicate a negative linear correlation between Schmidt hammer rebound values and secondary mineral percentage. This correlation provides a tool to quantitatively estimate the deterioration of rock uniaxial compressive strength (UCS) as weathering increases. Moreover, thermal analysis turned out to be a quantitative and reproducible method to evaluate weathering degree of magmatic rocks

Una tecnica per la geolocalizzazione di host Internet basata su crowdsourcing e dispositivi mobili

Il rilevamento della posizione geografica di un host Internet è un argomento di studio particolarmente interessante per le molteplici applicazioni, sia in ambito di ricerca che in ambito commerciale. Negli studi condotti fino ad oggi sono stati utilizzati sistemi dedicati per il sondaggio e il rilevamento della posizione degli host, ottenendo buoni risultati nelle regioni del mondo dove questi sistemi sono presenti (tipicamente Europa e Nord America). In questa tesi viene presentato un nuovo approccio al problema basato sull'utilizzo di dispositivi mobili connessi a reti wireless, utilizzando i dati raccolti in crowdsourcing dal progetto Portolan. Analizzando i dati collezionati in due anni di attività è stato elaborato un metodo di geolocalizzazione che tenesse conto delle limitazioni imposte dall'uso di dispositivi mobili. L'obiettivo è disporre di una quantità di sonde superiore di vari ordini di grandezza rispetto ai precedenti metodi, specialmente nelle zone del mondo dove le reti di ricerca non sono ancora sviluppate

The mapping of stands of Parana pine (Araucaria angustifolia (Bert.) O. Ktze) in the forest of south-west Parana State (Brazil) using computer-aided analysis of Landsat MSS data

This study examines the value of Landsat data for mapping stands of Parana Pine (Araucaria angustifolia (Bert.) 0. Ktze) in the natural forests of southern Parana State, Brazil. This species is economically the most important forest tree in southern Brazil and estimation of its reserves and the rate of exploitation are important. Two forest areas were selected for detailed studies. For one area (Quedas do Iguacu) Landsat data in both computer compatible tape (CCT) and transparency format was used. No aerial photographs were available but an existing forest map was used as ground truth.For the second area (Mangueirinha) Landsat CCTs and aerial photographs were available. From the latter a forest cover type map was produced and used as ground truth. Additionally some field checking was undertaken.For the Quedas do Iguacu area visual qualitative temporal analyses were carried out on the products generated from transparencies of six different Landsat scenes. On these Parana Pine stands could be recognized in the MSS bands 6 and 7 and in colour composites generated from the MSS bands 4, 5 and 7. For a selected subarea a supervised computer classification using CCT data was tested success-fully for mapping both mature Parana Pine stands and reforestation areas. A supervised classification using transparencies of MSS bands 5 and 7 that were scanned and digitized by microdensitometer successfully mapped Parana Pine stands but failed to discriminate reforestation areas.For the Mangueirinha area CCTs of Landsat imagery acquired in spring and in winter were used for mapping Parana Pine stands. Both visual and computer classification methods were employed. For the latter, a small area of Parana Pine stands with two different crown densities (as ascertained from study of aerial photographs) was selected. Different combinations of MSS bands were tested using supervised and unsupervised classifications. The results showed that using a supervised classification combinations of MSS bands 5 and 7 were most effective, but that only dense stands of Parana Pine could be mapped accurately. The spring imagery yielded better discrimination than that acquired in winter

O uso do ultraleve para a obtenção manual de fotografias aéreas (35mm) verticais e inclinadas

Acervo transferido da AG para CF 2001Tese (professor titular) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Departamento de Silvicultura e ManejoInclui referências: p. 115-118Resumo: A presente pesquisa analisa o uso de ultraleves "biplace" para a tomada manual de fotos aéreas (35 mm) verticais e inclinadas. A pesquisa está dividida em três partes. A primeira parte relata a obtenção de fotos aéreas com uma câmara 35 mm, equipada com lente de 50 mm. Duas áreas loca lizadas no município de Tijucas do Sul foram selecionadas. A respectiva fotointerpretação foi desenvolvida visando o reconhecimento de espécies florestais. Para o sobrevoo foi usado o ultraleve "biplace side-by-side" FLYER G T, de segunda geração. A área urbana de Tijucas do Sul foi fotografada apenas uma vez, enquanto que um capão florestal, de oito hectares, foi fotografado em três datas diferentes e em escalas diferentes. Da área urbana, foram apresentadas fotos verticais e inclinadas caracterizando diversas espécies florestais. Do capão florestal, foram mostrados desenhos esquemáticos de 22 copas de árvores. A segunda parte da pesquisa testa um clinômetro e um intervalômetro eletrônicos, desenvolvidos para a técnica de fotos aéreas usando câmaras 35 mm e 70 mm. O clinômetro proporciona a obtenção de fotos com até quarenta e cinco graus de inclinação. O intervalômetro permite acionar, de modo programável ou manual, duas câmaras 35 mm. Dois suportes manuais foram construídos. Em um suporte era instalado uma câmara 35 mm e o clinômetro eletrônico. No outro eram instalados duas câmaras, o clinômetro e o intervalômetro eletrônicos. Ambo s os suportes foram testados, com êxito, em voo com o ultraleve modelo FENIX, de terceira geração, para a tomada das fotos aéreas verticais e inclinadas. A terceira parte da pesquisa analisa cinco diferentes ultraleves, três "biplace side-by-side" (FENIX, MICROLEVE ML 300 e FLYER) e dois "biplace tandem" (FOX II e CHALLENGER), quanto ao modo, a p o s ição e o espaço disponíve l para a tomada das fotos aéreas. Neles, a câmara ou o suporte pode ser posicionada manualmente fora da aeronave propiciando fotos verticais ou inclinadas ou então simplesmente mantendo a câmara próxima do rosto, resultando fotos inclinadas ou panorâmicas (laterais ou frontais). Todos os ultraleves testados propiciam a tomada de fotos verticais e inclinadas, mas apresentam restrições quanto às fotos panorâmicas. O ultraleve, desenvolvido para lazer e recreio, pode ser usado para a tomada manual de fotos aéreas, com câmaras de pequeno formato, de áreas de pequena extensão, nas quais a utilização do avião e câmaras aerofotogramétricas são inviáveis economicamente.Abstract: The present research analysis the microlight biplace in order to acquire hand-held 35 mm vertical or oblique aerial photographs. The research has three parts. The first part describes the acquisition of 35 mm aerial photos using a camera with 50 mm lens. Two different areas located in the city of Tijucas do SuI were selected. It was developed the photointerpretation related to the mapping of individual trees. The flight was done using the second generation microlight FLYER GT. The urban area of Tijucas do SuI was photographed only once, while the forest area ("capão florestal"), with 8 hectares, was covered three times, resulting surplus aerial photographs in different scales. For the urban area, it is presented vertical and oblique photos showing different forest trees species. For the "capão florestal", it is showed drawnings of 22 crown trees based on the vertical photos. The second part of the research tested a clinometer and a intervalometer electronics, built for the small format technique using 35 and 70 mm cameras. The clinometer allows the acquisition of oblique aerial photos with until 45 degrees. The intervalometer allows to shot, either in manual or programmed ways, two different 35 mm cameras. Two different hand-held camera mounts were built. In one mount was installed· one 35 mm camera and the clinometer. In another mount, it was installed two 35 mm cameras, the clinometer and the intervalometer. The two mounts were successfully tested during flights done by the third generation microlight FENIX, for the acquisition of vertical and oblique aerial photos. The third part of the research evaluate five different microlights, 'three biplace side-by-side (FENIX, MICROLEVE ML 300, FLYER) and two biplace tandem (FOX II and CHALLENGER), related with the way and the available space to hand-held a 35 mm camera to acquire aerial photos. In those microlights, the camera and or the mount can be hand-held outside the aircraft for the acquisition of vertical or oblique photos, or the photographer can hold the camera, closed to the face, resulting oblique or panoramic photos (acquired by side or by front). With all the microlights tested it was possible to acquire vertical or oblique photos, but it presented also some restrictions related with panoramic photos. The microlight, built for fun and hobby, can be used to acquire 35 mm aerial photos of small areas, in which the use of airplane and conventional photogrammetric cameras are impractical due the high cost