Helminth communities of herons (Aves: Ardeidae) in southern Italy

The helminth communities of nine species of herons from southern Italy were studied and compared. Of 24 taxa found including seven digeneans, seven nematodes, six cestodes and four acanthocephalans, only five taxa were found in more than one heron species, and five of the 21 taxa that could be identified to species level were classified as 'heron specialists'. The total number of helminth species per heron species ranged from 1 in Botaurus stellaris to 9 in Ixobrychus minutus with infection levels generally low. A statistical comparison was carried out for herons with a sample size >. 5. At the infracommunity level, only I. minutus clearly differed from other heron species. Diversity parame…

Statistica degli estremi idrologici in Sicilia

Il carattere torrentizio di tutti i più importanti corsi d'acqua siciliani ha da sempre determinato esondazioni delle onde di piena e conseguenti allagamenti delle aree limitrofe provocando danni rilevanti. La valutazione delle piene e del rischio idrologico ad esse connesso può essere condotta secondo un approccio di tipo probabilistico attraverso il quale si determini una relazione tra la portata di piena di assegnata frequenza probabile ed il tempo di ritorno. In questo articolo sono richiamate le leggi di distribuzione di probabilità solitamente usate in idrologia, con particolare riferimento all'analisi probabilistica del valore massimo annuale della portata al colmo di piena e dell'al…

Risposta erosiva di un bacino percorso da incendio in ambiente mediterraneo

Helminth communities of loggerhead turtles (Caretta caretta) from Central and Western Mediterranean Sea: the importance of host's ontogeny.

We investigated the factors providing structure to the helminth communities of 182 loggerhead sea turtles, Caretta caretta, collected in 6 localities from Central and Western Mediterranean. Fifteen helminth taxa (10 digeneans, 4 nematodes and 1 acanthocephalan) were identified, of which 12 were specialist to marine turtles; very low numbers of immature individuals of 3 species typical from fish or cetaceans were also found. These observations confirm the hypothesis that phylogenetic factors restrict community composition to helminth species specific to marine turtles. There were significant community dissimilarities between turtles from different localities, the overall pattern being compat…

Helminth communities of owls (strigiformes) indicate strong biological and ecological differences from birds of prey (accipitriformes and falconiformes) in southern Italy.

We compared the helminth communities of 5 owl species from Calabria (Italy) and evaluated the effect of phylogenetic and ecological factors on community structure. Two host taxonomic scales were considered, i.e., owl species, and owls vs. birds of prey. The latter scale was dealt with by comparing the data here obtained with that of birds of prey from the same locality and with those published previously on owls and birds of prey from Galicia (Spain). A total of 19 helminth taxa were found in owls from Calabria. Statistical comparison showed only marginal differences between scops owls (Otus scops) and little owls (Athene noctua) and tawny owls (Strix aluco). It would indicate that all owl …

Changes in the hydrological response of two sicilian basins affected by fires

Stima dell'erosione idrica in due bacini siciliani mediante tecniche GIS

Parasite assemblages in the Western whip snakeHierophis viridiflavus carbonarius(Colubridae) from southern Italy

AbstractParasite assemblages of the Western whip snakeHierophis viridiflavus carbonariuswere investigated from the Calabria region in southern Italy. A total of 14 parasite taxa including 6 nematodes, 3 acanthocephalans, 2 cestodes, 2 digeneans and a single pentastomid was identified. Within the study area,H. v. carbonariusserves as the final host for seven species of helminths, of which only four (Hexametra quadricornis,Kalicephalus viperae,Paracapillaria sonsinoiandRenifer aniarum) can be considered as snake specialists, while one (Oswaldocruzia filiformis) is shared with other reptiles and amphibians, and two (Paradistomum mutabileandRhabdias fuscovenosa) with lizards. A large proportion…

Estimation of urban structural flood damages: the case study of Palermo

Abstract The estimation of flood damage is a fundamental step in the economic analysis of a flood control projects. In particular, frequency–damage functions, derived from the hydrologic, hydraulic and damage relationships, are one of the fundamental pieces of information upon which expenditure decisions are based. The aim of this study has been to develop an empirical frequency–damage relationship, obtained by means of detailed local studies, which could be a judgement tool for flood mitigation measures in strongly urbanised drainage areas. Monuments and other estates having a cultural or artistic significance have been specifically taken into account. The analysis has been carried out for…

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

Effects of forest fires on flood frequency curves in a Mediterranean catchment

The effect of land-use change on the flood frequency curve (FFC) in a natural catchment is analysed. To achieve this, a simple methodology for the derivation of FFCs in land-use change scenarios is proposed. The adopted methodology, using a stochastic model in Monte Carlo simulation of FFCs, was found to provide a useful framework for detecting changes in flood magnitudes in both pre- and post-fire conditions. In particular, the importance of the antecedent soil moisture condition in the determination of the flood frequency distribution was analysed. The analysis of FFCs for pre- and post-fire conditions shows an increase in the average value of Curve Number and a decrease in the catchment …

Hydroclimatological characterisation of extreme events in Sicilian region finalised to describe regional hydrological patterns and to predict flood regime in ungauged catchments.

Estimation of flood inundation probabilities using hydrodynamic indexes with uncertainty analysis

Applicability of hydrological similarities measures based on linkage between rain and flood regime for regional flood frequency analysis in Mediterranean catchment.

Analysis of the linkage between hydrological and climatic information finalised to descrive flood regime in Sicily.

DEFINIZIONE DI IDROGRAMMI SINTETICI PER LA REDAZIONE DI MAPPE DI PERICOLOSITA’ D’INONDAZIONE

Obiettivo di questo studio è la definizione di idrogrammi sintetici da utilizzarsi come input per la redazione di mappe di pericolosità d’inondazione; in particolare nel lavoro sono state messe a confronto tre diverse metodologie entrambe basate su tecniche di tipo stocastico. La prima prevede il calcolo degli idrogrammi di piena attraverso una procedura di tipo Monte Carlo generando tre elementi che caratterizzano gli idrogrammi: portata al colmo, volume di piena e forma dell’onda. La seconda riguarda la generazione di idrogrammi sintetici a partire dalla derivazione della curva di riduzione dei colmi di piena basata su forma inferenziale. Le procedure adottate non portano agli stessi risu…

Investigating reservoir sediment and watershed erosion using the WEPP model

Estimation of flood inundation probabilities using global hazard indexes based on hydrodynamic variables

In this paper a new procedure to derive flood hazard maps incorporating uncertainty concepts is presented. The layout of the procedure can be resumed as follows: (1) stochastic input of flood hydrograph modelled through a direct Monte-Carlo simulation based on flood recorded data. Generation of flood peaks and flow volumes has been obtained via copulas, which describe and model the correlation between these two variables independently of the marginal laws involved. The shape of hydrograph has been generated on the basis of a historical significant flood events, via cluster analysis; (2) modelling of flood propagation using a hyperbolic finite element model based on the DSV equations; (3) de…

DERIVAZIONE DI IDROGRAMMI DI PIENA ATTRAVERSO L’ACCOPPIAMENTO DI MODELLI STOCASTICI BIVARIATI DELLE PRECIPITAZIONI E E MODELLI AFFLUSSI - DEFLUSSI DISTRIBUTI

In questo studio viene presentata una procedura di tipo Monte Carlo per la derivazione delle curve di frequenza delle portate al colmo e dei volumi corrispondenti basata sull’accoppiamento di un modello di generazione delle forzanti pluviometriche tramite copule e un modello di trasformazione afflussideflussi di tipo distribuito. Tale procedura è stata applicata ad un caso di studio siciliano; i risultati ottenuti hanno mostrato la bontà del modello a riprodurre le statistiche complesse delle grandezze idrologiche a fronte di un basso numero di parametri modellistici e di un ridotto sforzo computazionale.

Un nuovo approccio per la determinazione del deflusso minimo vitale nei corsi d’acqua a carattere torrentizio.

INVESTIGATING RESERVOIR SEDIMENT AND CATCHMENT EROSION USING THE WEPP MODEL