Papers by giovanni callegari
Geofluids, 2021
In this study, the equivalent dose rate of natural radionuclides ( H T ) in 99 spring water and s... more In this study, the equivalent dose rate of natural radionuclides ( H T ) in 99 spring water and surface soil samples was determined using an alpha, beta, and gamma high sensitivity detector up within a Geiger-Muller tube and with an external probe NaI (Tl). The samples were collected in the Crati basin (southern Italy), and during sample collection, water quality parameters were detected in situ and at the University of Calabria laboratories. A Pearson correlation coefficient analysis was applied to identify and clarify the relationships between water physical-chemical properties and soil and water radioactivity. Results show that the mean H T for spring waters is 97.07 μSv/h. Furthermore, the mean H T for surface soils is 97.92 μSv/h, thus evidencing higher mean H T values than worldwide ones reported in a previous literature. Low correlation coefficients were detected between water H T and conductivity and pH. On the contrary, a reasonable correlation was found between H T in spri...
The fallout radionuclide caesium-137 ( l37 Cs) has been increasingly used in recent years to asse... more The fallout radionuclide caesium-137 ( l37 Cs) has been increasingly used in recent years to assess soil erosion and deposition at the catchment scale. However, the successful application of the l37 Cs approach depends heavily on the availability of reliable conversion models for converting measurements of 1 Cs redistribution to estimates of soil redistribution rates. This paper reports the results of a study aimed at validating the use of a theoretical conversion model to convert measurements of l37 Cs inventories on uncultivated soils to estimates of soil erosion rates. It is based on three small catchments located in Calabria, Southern Italy, for which measurements of sediment output are available. By comparing the estimates of net soil loss from the catchments derived from l37 Cs measurements with the measured sediment output, it is possible to assess the accuracy of the former estimates. The general corresp ondence between the measured sediment yields and the estimates of net s...
L'Indice di Funzionalita Fluviale viene introdotto in Italia nell'anno 2000 in una fase t... more L'Indice di Funzionalita Fluviale viene introdotto in Italia nell'anno 2000 in una fase transitoria molto importante e delicata nel settore della gestione nazionale del ciclo delle acque che prevedeva l'elaborazione dei piani di tutela delle risorse idriche da parte delle regioni italiane entro il 31/12/2003. Il Decreto Legislativo 152/99, confermato e rafforzato nelle sue linee generali dalla Direttiva Quadro sulle acque 2000/60/CE, propone un nuovo approccio metodologico per la determinazione dei livelli qualitativi dei corpi idrici superficiali al fine di raggiungere entro il 31/12/2015 un grado di qualita definito "buono" ai sensi della normativa europea. L'Agenzia per la Protezione dell'Ambiente e per i Servizi Tecnici (APAT) ha elaborato un nuovo metodo, l'Indice di Funzionalita Fluviale (I.F.F.) che, pur derivando sostanzialmente dal precedente indice il Riparian Channel and Enviromental Inventory (R.C.E.), introduce alcuni elementi valutativ...
Questo studio si propone di valutare lo stato di salute ecologica e la funzionalita ecosistemica ... more Questo studio si propone di valutare lo stato di salute ecologica e la funzionalita ecosistemica del bacino idrografico del fiume Crati attraverso l'applicazione della nuova versione dell'Indice di Funzionalita Fluviale (Siligardi et al., 2007) ai sensi del D.Lgs.152/99 e della Direttiva Quadro sulle acque 2000/60/CE. I risultati evidenziano il buon grado di funzionalita fluviale del bacino idrografico in esame sebbene alcuni tratti nella zona di deposito siano compromessi nelle loro componenti biotiche ed abiotiche a causa della presenza di numerose captazioni e derivazioni idriche utilizzate anche a scopo irriguo ed agricolo. L'applicazione del metodo consente di individuare le criticita ambientali emergenti alle quali la sensibilita politico-amministrativa puo porre rimedio se interviene in una direzione non piu antropocentrica ma ecosistemica, cosi come suggerito nel metodo proposto. Questa sperimentazione, in forma estesa, del metodo IFF in Calabria conferma la note...
Goldschmidt Abstracts, 2020
Land Degradation & Development, 2017
Over the last 50 years different approaches have been employed in order to predict environmental ... more Over the last 50 years different approaches have been employed in order to predict environmental risk due to soil erosion and to propose effective strategies to control erosion and sedimentation. The use of fallout radionuclides (FRNs), mainly caesium-137 (137 Cs) and excess lead-210 (210 Pb ex), proved to be very effective to complement existing traditional methods especially if a re-sampling strategy is employed. The re-sampling approach consists in repeating soil sampling and radionuclide measurements within the same site, following a known amount of time (generally 10 to 15 years). This strategy, in the light of the possibility to obtain independent estimates of soil erosion for different periods, allows to establish sediment budgets for different time windows. The use of sediment budgets represents an important tool to provide information on the catchment behaviour regarding the relationship between the sediment output at the catchment outlet and rates of sediment redistribution within the catchment. For this reason, this approach can provide important indications on possible change of sediment connectivity at catchment scale. The study reported here focuses on the W1 catchment (1.47 ha), located in Calabria, Southern Italy, for which long-term This article is protected by copyright. All rights reserved. measurements of sediment yield are also available. The W1 catchment supports a rangeland vegetation cover and no change in land use occurred during the last 100 years. The catchment was sampled for 137 Cs and 210 Pb ex analyses in 2001 and resampled in 2014 to provide estimates of soil erosion and deposition for different time windows. The role of uncertainty related to these estimates is also discussed and some guidelines for the application of 210 Pb ex as a soil erosion tracer are provided. The overall results provided by the measurements of sediment yield at the catchment outlet showed a general increase of soil erosion rates during the last 15-20 years. The estimates of sediment redistribution provided by the measurements of 210 Pb ex demonstrated that these results reflect an increase in sediment delivery ratio and also emphasized how the presence of some small depositional areas associated with the occurrence of high magnitude events determines the change in sediment connectivity at the catchment scale.
Journal of environmental radioactivity, Jan 27, 2016
In recent years, the fallout radionuclides caesium-137 ((137)Cs) and unsupported lead-210 ((210)P... more In recent years, the fallout radionuclides caesium-137 ((137)Cs) and unsupported lead-210 ((210)Pbex) have been successfully used to document rates of soil erosion in many areas of the world, as an alternative to conventional measurements. By virtue of their different half-lives, these two radionuclides are capable of providing information related to different time windows. (137)Cs measurements are commonly used to generate information on mean annual erosion rates over the past ca. 50-60 years, whereas (210)Pbex measurements are able to provide information relating to a longer period of up to ca. 100 years. However, the time-integrated nature of the estimates of soil redistribution provided by (137)Cs and (210)Pbex measurements can be seen as a limitation, particularly when viewed in the context of global change and interest in the response of soil redistribution rates to contemporary climate change and land use change. Re-sampling techniques used with these two fallout radionuclide...
Journal of Environmental Radioactivity, 2016
The need for reliable assessments of soil erosion rates in Serbia has directed attention to the p... more The need for reliable assessments of soil erosion rates in Serbia has directed attention to the potential for using 137 Cs measurements to derive estimates of soil redistribution rates. Since, to date, this approach has not been applied in southeastern Serbia, a reconnaissance study was undertaken to confirm its viability. The need to take account of the occurrence of substantial Chernobyl fallout was seen as a potential problem. Samples for 137 Cs measurement were collected from a zone of uncultivated soils in the watersheds of P cinja and South Morava Rivers, an area with known high soil erosion rates. Two theoretical conversion models, the profile distribution (PD) model and diffusion and migration (D&M) model were used to derive estimates of soil erosion and deposition rates from the 137 Cs measurements. The estimates of soil redistribution rates derived by using the PD and D&M models were found to differ substantially and this difference was ascribed to the assumptions of the simpler PD model that cause it to overestimate rates of soil loss. The results provided by the D&M model were judged to more reliable.
The basin management is steered towards a global approach where engineering and naturalistic tech... more The basin management is steered towards a global approach where engineering and naturalistic techniques complement each other, supporting the natural trend of continental waterways until a stable equilibrium longtime. In this sense, the river, regarded as “hydro-system”, extends from riverbed to bordering areas, known as peri-fluvial strips. This approach is particularly important in the morphological study of fluvial systems, located in anthropic areas. The fluvial morphology or, in other words, the whole of different shapes showed by rivers, develops on time under the action of different factors, human actions included, and it occurs as a “continuum” of structures without any boundaries between them. Mollard suggested in 1973 a morphological classification based on photo-interpretation that compares the linear forms with some factors as the solid transport at the bottom of rivers, the relationship between this kind of transport and the whole solid transport, the grain size and som...
Il lavoro si propone di analizzare le caratteristiche idrogeologiche e geochimiche di alcune sorg... more Il lavoro si propone di analizzare le caratteristiche idrogeologiche e geochimiche di alcune sorgenti, site nel bacino idrografico del torrente Beltrame nel territorio comunale di Chiaravalle Centrale (CZ, Italia). Il monitoraggio delle sorgenti attive, svolto dall’Istituto per i Sistemi Agricoli e Forestali del Mediterraneo (I.S.A.FO.M) del Consiglio Nazionale delle Ricerche (C.N.R.) - Sezione di Rende (CS, Italia) nel biennio 2008-2009, ha consentito di rilevare e misurare i principali parametri chimico-fisici e idrologici di tali emergenze per valutare il loro grado di potabilita e le relative caratteristiche idrodinamiche. Le analisi dei dati raccolti hanno evidenziato buone condizioni di potabilita ed hanno permesso di distinguere due gruppi di sorgenti caratterizzati da differenti velocita di deflusso e da ritardi di piena, rispetto ai valori di precipitazione, variabili tra uno e due mesi.
Land Degradation & Development, 2015
The sediment budget is a key concept and tool for characterizing the mobilization, transfer and s... more The sediment budget is a key concept and tool for characterizing the mobilization, transfer and storage of fine sediment within a catchment. Caesium-137 measurements can provide valuable information on gross and net erosion rates associated with sheet and rill erosion that can be used to establish the slope component of a catchment sediment budget. However, there is a need to validate the use of 137 Cs measurements for this purpose, because their reliability has sometimes been questioned. The study reported focuses on a small (3•04 ha) steepland (mean slope 37%) catchment in Southern Italy. It exploits the availability of information on the medium-term sediment output from the catchment provided by the construction of a reservoir at its outlet in 1978 and the existence of estimates of soil redistribution rates derived from 137 Cs measurements made on 68 replicate soil cores collected from the slopes of a substantial proportion of the catchment in 2001, to validate the use of 137 Cs measurements to construct the slope component of the catchment sediment budget. An additional 50 replicate soil cores were collected from the catchment slopes for 137 Cs analysis, to complement the data already available. Nine cores collected from the area occupied by the reservoir were used to estimate the mean annual sediment input to the reservoir. In the absence of evidence that the poorly developed channel system in the catchment was either a significant sediment source or sink, it was possible to directly compare the estimate of net soil loss from the catchment slopes (7•33 Mg ha À1 y À1) with the estimate of sediment output from the catchment provided by the reservoir deposits (7•52 Mg ha À1 y À1). Taking account of the uncertainties involved, the close agreement of the two values is seen as providing a convincing validation of the use of 137 Cs measurements to both estimate soil redistribution rates and as a basis for constructing the slope component of the sediment budget of a small catchment.
Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2015
In this study, an analysis of precipitation and temperature data has been performed over 67 serie... more In this study, an analysis of precipitation and temperature data has been performed over 67 series observed in a region of southern Italy (Calabria). At first, to detect possible trends in the time series, an analysis was performed with the Mann-Kendall non-parametric test applied at monthly and seasonal scale. An additional investigation, useful for checking the climate change effects on vegetation, has also been included analysing bioclimatic indicators. In particular, Emberger, Rivas-Martinez and De Martonne indices were calculated by using monthly temperature and precipitation data in the period 1916-2010. The spatial pattern of the indices has been evaluated and, in order to link the vegetation and the indices, different indices maps have been intersected with the land cover data, given by the Corine Land Cover map. Moreover, the temporal evolution of the indices and of the vegetation has been analysed. Results suggest that climate change may be responsible for the forest cover change, but, given also the good relationship between the various types of bioclimate and forest formations, human activities must be considered.
Questo studio si propone di valutare lo stato di salute ecologica e la funzionalita ecosistemica ... more Questo studio si propone di valutare lo stato di salute ecologica e la funzionalita ecosistemica del bacino idrografico del torrente Verri attraverso l’applicazione della nuova versione dell’Indice di Funzionalita Fluviale (IFF 2007). I risultati evidenziano il buon grado di funzionalita fluviale del bacino idrografico in esame sebbene alcuni tratti nella zona di deposito siano compromessi nelle loro componenti biotiche ed abiotiche a causa della presenza di numerose captazioni e derivazioni idriche utilizzate a scopo irriguo ed agricolo.
In numerosi problemi tecnici che si presentano nello studio delle piene fluviali riveste grande i... more In numerosi problemi tecnici che si presentano nello studio delle piene fluviali riveste grande importanza la previsione delle precipitazioni intense. I deflussi di piena si verificano infatti in conseguenza di eventi pluviometrici di forte intensità e si intuisce quindi come l’analisi delle caratteristiche di tali eventi abbia un’importanza fondamentale nello studio di diversi aspetti del fenomeno delle piene fluviali, in particolare nella valutazione delle portate di progetto, cioè di quei valori di portata da utilizzare nel proporzionamento di opere idrauliche. Questo lavoro ha come obiettivo la caratterizzazione delle precipitazioni intense nella parte settentrionale della regione Calabria, utili ai fini dell'applicazione dei metodi afflussi-deflussi per la determinazione indiretta degli idrogrammi di piena. La finalità operativa è quella di consentire la determinazione delle relazioni intensità-durata (curve di probabilità pluviometrica), in modo da poter stimare il valore ...
Hydrological Processes, 2013
Concern for the sustainability of the soil resource and for the detrimental impacts of fine sedim... more Concern for the sustainability of the soil resource and for the detrimental impacts of fine sediment on downstream river systems and aquatic ecosystems has directed attention to the need for information on the suspended sediment loads of rivers. However, traditional measurement programmes focus primarily on quantifying the sediment load at a catchment outlet. Such information, although useful, may be of limited value in establishing rates of soil degradation, because much of the sediment mobilized within a catchment may be deposited before reaching the catchment outlet. Furthermore, it may also be of limited value in the design and implementation of sediment management and control programmes, because this requires an understanding of the key sources of mobilized sediment, the transport pathways involved and the importance of storage within the catchment. Information on the sediment budget of a catchment must be seen as an increasingly important requirement. However, such information is difficult to obtain using conventional traditional monitoring techniques. Fallout radionuclides, including caesium-137 ( 137 Cs) and unsupported or excess lead-210 ( 210 Pb ex ), have been shown to offer considerable potential for use as sediment tracers in sediment budget investigations. They are able to provide distributed information on rates of soil and sediment redistribution within the catchment, which represents a valuable complement to information on sediment output. This contribution reports the results of a study aimed at exploring the use of both 137 Cs and 210 Pb ex measurements to establish the sediment budget for the small (1.39 km 2 ) forested Bonis catchment, located in southern Italy. The results confirm that 137 Cs and 210 Pb ex measurements can provide a valuable tool for quantifying both erosion and sediment redistribution within a catchment and therefore for establishing its sediment budget.
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Papers by giovanni callegari