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

A 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

Using very high resolution (VHR) imagery within a GEOBIA framework for gully mapping: An application to the Calhoun Critical Zone Observatory

Gully erosion is a form of accelerated erosion that may affect soil productivity, restrict land use, and lead to an increase of risk to infrastructure. Accurate mapping of these landforms can be difficult because of the presence of dense canopy and/or the wide spatial extent of some gullies. Even where possible, mapping of gullies through conventional field surveying can be an intensive and expensive activity. The recent widespread availability of very high resolution (VHR) imagery has led to remarkable growth in the availability of terrain information, thus providing a basis for the development of new methodologies for analyzing Earth’s surfaces. This work aims to develop a geographic object-based image analysis to detect and map gullies based on VHR imagery. A 1-meter resolution LIDAR DEM is used to identify gullies. The tool has been calibrated for two relatively large gullies surveyed in the Calhoun Critical Zone Observatory (CCZO) area in the southeastern United States. The developed procedure has been applied and tested on a greater area, corresponding to the Holcombe’s Branch watershed within the CCZO. Results have been compared to previous works conducted over the same area, demonstrating the consistency of the developed procedure

The classification of submerged vegetation using hyperspectral MIVIS data

The aim of this research is to use hyperspectral MIVIS data to map the Posidonia oceanica prairies in a coastal lagoon (Stagnone di Marsala). It is approximately 12 km long and 2 km wide and is linked to the open sea by two shallow openings. This environment is characterised by prairies of phanerogams, the most common of which is Posidonia oceanica, an ideal habitat for numerous species of fish, molluscs and crustaceans. A knowledge of the distribution of submerged vegetation is useful to monitor the health of the lagoon. In order to classify the MIVIS imagery, the attenuation effects of the water column have been removed from the signal using Lyzenga’s technique. A comparison between classifications using indices obtained using band pairs from only the first spectrometer, and using band pairs of the first and second spectrometers, shows that the best classification is obtained from some indices derived from the first spectrometer. Field controls carried out in July 2002 were used to determine the training sites for the supervised classification. Twelve classes of bottom coverage were obtained from the classification, of which four are homogeneous and eight are mixed coverage. The methodology applied demonstrates that hyperspectral sensors can be used to effectively map submerged vegetation in shallow waters

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 of rainfall spatial and temporal variability should be considered as a fundamental step for a robust interpretation of the physical processes that take part in urban areas during intense rainfall events. The starting basis of such studies is usually given by a network of high resolution raingauges disseminated inside and around the examined urban area. One of the raingauge techniques used is based on simulating the storm motion by visualizing the sequence of the rainfall patterns obtained using rain-gauge data and on spatial correlation. The storm speed and direction are obtained using the rain-gauge method by tracking the advance of the maximum rainfall intensity in time and space. A second method is based on the identification, for each gauge, of the time of occurrence of some significant features such the time of onset of a storm or the time of peak. A third method is based on the classical idea of spacetime autocorrelation function; This function describes the way in which the correspondence between the rainfall patterns at two points in space-time reduces as the distance between two points is increased. The analysis has been carried out on the basis given by high resolution rainfall data collected over Palermo urban area (Italy). The urban area has a surface of around 30 km2 and it is mainly distributed on North West – South East direction. The monitoring network is made of 10 tipping bucket raingauges. Bucket volume is equivalent to 0.1 mm rainfall. Raingauges have been uniformly distributed over the urban areas allocating them mainly over public buildings and school in order to allow for easy access. The network has been put in place in January 2006 and it is still working. Data is monthly collected by the operator that also provide for clock synchronization and ordinary maintenance and cleaning. An accurate analysis of the results of this comparison between the techniques has been carried out and, since the city of Palermo is not covered by any meteorological radar, the analysis of storm dynamics will allow to create a system monitoring hydrometeorological conditions which operates on time basis using the information coming from the raingauge network as forecast triggers

Effetto combinato di cambiamenti climatici ed urbanizzazione sugli estremi di portata

Il termine “cambiamento idrologico” (hydrological change) è spesso utilizzato per sintetizzare quell’insieme di alterazioni della risposta idrologica dei bacini indotte da fattori naturali o antropici. ll ruolo fondamentale di tali alterazioni nel determinare fenomeni di dissesto ha stimolato l’International Association of Hydrological Scienses (IAHS) a dedicare la decade scientifica 2013-2022 (denominata “Phanta Rhei”) ai cambiamenti idrologici e all’analisi dei diversi fattori perturbanti. I cambiamenti climatici e l’urbanizzazione sono fra i fattori antropici perturbanti più influenti e, allo stesso tempo, più diffusi a livello globale. Il cambiamento climatico è stato abbondantemente studiato in passato, con chiare evidenze di trend sugli estremi (es. Burn et al., 2011; Arnone et al., 2013) e con numerosi esempi attestanti i possibili cambiamenti idrologici indotti (es. Wang and Alimohammadi, 2012; Francipane et al., 2015; Chiarelli et al., 2016; Pumo et al. 2016). Molto più recente è l’analisi degli effetti dell’urbanizzazione sulla risposta idrologica dei bacini (es. Salvadore et al., 2015). Il processo di urbanizzazione è associato a una perdita di “superfici permeabili” (suoli naturali), con conseguente impoverimento dei processi d’infiltrazione, alterazione ai sistemi di drenaggio naturale e ai processi di trasferimento (alterazione dei percorsi idrici e delle velocità di deflusso). La valutazione dell’impatto di tali perturbazioni sulle portate di picco durante eventi estremi, può risultare particolarmente utile nel definire e orientare efficaci politiche di pianificazione urbana e gestione di eventi di inondazione, nonché in attività di verifica delle infrastrutture idrauliche esistenti e di progettazione di quelle future. L’obiettivo di questo lavoro è quello di investigare gli effetti dell'interazione delle suddette perturbazioni sugli eventi estremi di deflusso. A tale scopo, è stato ideato un esperimento numerico, applicato ad un piccolo bacino fluviale, che ha permesso di generare e confrontare serie temporali di deflusso orario sotto diversi ipotetici scenari di cambiamento. Gli scenari, generati attraverso l’uso combinato di un modello di cambiamento di uso del suolo opportunamente implementato e di un modello di generazione di serie climatiche già esistente (Fatichi et al., 2011), descrivono situazioni estreme sia in termini di espansione delle aree urbane che in termini di variazioni (aumento o diminuzione) della precipitazione media annua (MAP). Nella creazione degli scenari climatici si è anche tenuto conto di un aumento della temperatura media, e, a parità di MAP, sono state create diverse configurazioni, caratterizzate da diversa frequenza e/o l’intensità media degli eventi di pioggia. La risposta idrologica del bacino ai vari scenari è stata riprodotta mediante il tRIBS (Ivanov et al., 2004), un modello idrologico, fisicamente basato e distribuito, in grado di simulare, con alta risoluzione temporale, anche le diverse componenti di deflusso. I risultati mostrano un’alta sensibilità degli indicatori della risposta idrologica utilizzati alle variazioni delle caratteristiche di pioggia. In termini di deflusso totale, gli effetti dei cambiamenti climatici sembrano essere prevalenti rispetto a quelli indotti dall’espansione urbana, anche se, a una maggiore frazione di suoli impermeabili, corrisponde un chiaro aumento della componente di scorrimento veloce, i cui effetti sul deflusso totale vengono parzialmente smorzati da una simultanea riduzione della componente di deflusso lento e profondo

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

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 recent years, especially in the Mediterranean region. A conceptual hydrological model and a 2D hydraulic model, particularly suitable for simulations in a very complex urban context, have been used to simulate the event. Results have been qualitatively validated by means of crowdsourced information and satellite images. The experience of Palermo, which has highlighted the urgent need for a shift in the way stormwater in urban settlements is managed, can be assumed to be a paradigm for modeling pluvial floods in complex urban areas under extreme rainfall conditions. Although the approaches and the related policies cannot be identical for all cities, the modeling framework used here to assess the impacts of the event under study and some conclusive remarks could be easily transferred to other, different urban contexts

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 phenomena caused by structures present in the top soil. Multicriterial analysis has been carried out to investigate the possible presence of buried linear structures, which are linked to these parameters. Results show good agreement with the distribution of known structures and archaeological sites identified by survey

Diet management, lifestyle factors and education needs by target attainment in Italian youth with type 1 diabetes from the Global TEENs study

Background and aims: TEENs is an international, cross-sectional observational study, conducted in 20 countries in order to assess T1D management and psychosocial parameters in 8-25-year-olds (y/o). Data on diet management, lifestyle factors and education needs by target HbA1c attainment from the Italian cohort are reported. Materials and methods: Data were collected at 23 centres by participant interview, medical record review and participant/parent survey from 1,009 Italian youth (46% female) in three age groups: 8-12 y/o (n=330), 13-18 y/o (n=490), and 19-25 y/o (n=189). HbA1c was measured uniformly using A1cNow™ with target HbA1c defined as <7.5% (58 mmol/mol) for ≤18 y/o (ISPAD) and <7% (53 mmol/mol) for >18 y/o (ADA). Results: Overall, 40% of participants met HbA1c targets. Measuring food intake based on experience was the most common method used by all age groups, followed by carbohydrate counting (Table). Of the participants who used carbohydrate counting, a higher percentage met target HbA1c than did not in all age groups, with a significant effect on target attainment due to carbohydrate counting compared with other methods observed in 13-18 y/o (p=0.035). Avoiding sugars was the least common method used in all age groups. Across all age groups, participants who did not undertake any exercise were numerically less likely to reach HbA1c target; on the contrary, participants who exercised 1-2 days/week were numerically more likely to reach HbA1c target. Performing exercise had a significant effect on target HbA1c attainment in 8-12 y/o (p=0.012). The majority of participants were in the underweight/normal body mass index (BMI) category in all age groups, with no clear pattern between BMI class and the proportion of patients reaching HbA1c target. Participants of all ages commonly requested education on diet, carbohydrate counting, how to manage T1D during illness, and how to manage blood glucose levels with exercise. Conclusion: Carbohydrate counting and exercising at least twice per week help to attain HbA1c target across all age groups. Assessment of lifestyle factors suggests that efforts targeting carbohydrate counting and exercise could promote successful health outcomes and help more patients with T1D to reach the recommended HbA1c target. Supported by: Sanof

Younger age at onset and sex predict celiac disease in children and adolescents with type 1 diabetes: an Italian multicenter study

OBJECTIVE— To estimate the prevalence of biopsy-confirmed celiac disease in Italian children and adolescents with type 1 diabetes and to assess whether age at onset of type 1 diabetes is independently associated with diagnosis of celiac disease. RESEARCH DESIGNANDMETHODS— The study group was a clinic-based cohort of children and adolescents with type 1 diabetes cared for in 25 Italian centers for childhood diabetes. Yearly screening for celiac disease was performed using IgA/IgG anti-gliadin and IgA anti-endomysium antibodies. RESULTS— Of the 4,322 children and adolescents (age 11.8 4.2 years) identified with type 1 diabetes, biopsy-confirmed celiac disease was diagnosed in 292 (prevalence 6.8%, 95% confidence interval [CI] 6.0 –7.6), with a higher risk seen in girls than in boys (odds ratio [OR] 1.93, 1.51–2.47). In 89% of these, diabetes was diagnosed before celiac disease. In logistic regression analyses, being younger at onset of diabetes, being female, and having a diagnosis of a thyroid disorder were independently associated with the risk of having diabetes and celiac disease. In comparison with subjects who were older than 9 years at onset of diabetes, subjects who were younger than 4 years at onset had an OR of 3.27 (2.20–4.85). CONCLUSIONS— We have provided evidence that 1) the prevalence of biopsy-confirmed celiac disease in children and adolescents with type 1 diabetes is high (6.8%); 2) the risk of having both diseases is threefold higher in children diagnosed with type 1 diabetes at age 4 years than in those age 9 years; and 3) girls have a higher risk of having both diseases than boys