1,720,999 research outputs found
Ricostruzione 3D dai dati di terreno : struttura del M. Misma, Sudalpino Centrale
No full textA 3D geological modelling methodology is briefly presented in this work. This procedure allows to reconstruct complex geological bodies using topographic and structural-geological data. The main constraints considered for the geological surfaces reconstruction are the geological cross-sections. GIS (Geographic Information System) tools and functions have been exploited for 2D data management, while gOcad® software for 3D modelling. The proposed methodology consists in three main steps: i) data acquisition; ii) data storage in a GIS; iii) 3D surface and volume reconstruction. This methodology has been applied for the 3D reconstruction of the Monte Misma anticline (Bergamo), localized in the thrust and fold systems of the frontal part of the Central Southern Alps. This 3D geological reconstruction allows to check and improve the geological interpretation of the buried surfaces. Moreover the geological surfaces and volumes definitions can be very useful in the different environment of the Earth Sciences (eg. oil exploration; numerical modelling; geophysical data processing, etc.)
The Use of the Weights-of-Evidence Modeling Technique to Estimate the Vulnerability of Groundwater to Nitrate Contamination
No full textThe occurrence of elevated nitrate (NO 3 - ) concentration in the aquifer of the Province of Milan (northern Italy) is related to both natural and anthropogenic variables. Using the weights-of-evidence modeling technique a specific vulnerability assessment has been performed. This study presents an evolution of previous applications of the proposed methodology as a consequence of an updating of the available database, in terms of data type, quality, and accuracy, and of a more specific and enhanced statistical controls onto the final results. A comparison between the spatial distribution of vulnerability classes and the frequency of occurrences of nitrate in wells shows a high degree of correlation, both for low and high nitrate concentration. Similar results may be evidenced considering the correlation between posterior probability classes and mean nitrate concentrations in wells located in each of these classes: a high R 2 value (0.99) and the agreement with the threshold concentration value used to define prior probability testifies a general good quality of results. Groundwater-specific vulnerability has been classified in terms of vulnerability classes and, according to the outcomes of the model, the density of population can be considered the most impacting source of nitrate. Mean annual irrigation and groundwater depth can be identified as influencing factors in the distribution of nitrate, while agricultural practice appears a negligible factor
Wildfire behaviour modelling for wildfire hazard characterization: an Earth Observation application
No full textThe study is intended as a contribution to the developement of a wildfire behaviour modelling methodology effective in wildfire hazard characterization on a local scale and providing an appropriate scientific information available in decision making processes for wildfire management. Satellite sensor technologies has been investigated in order to acquire updated and reliable input data with a suitable spatial and temporal resolution. The modelling methodology has been validated and calibrated to past events recorded in wildland fire databases of Umbria and Sardinia Regions. Afterwards, an heuristic local research method has been implemented to optimize the accuracy of the models and to estimate their predictive capacity
Fitosociologia, preferenze e mappatura floristica delle specie più appetite da Apis Mellifera e da altri apoidei
No full textL’alterazione dei paesaggi naturali e rurali del nord Italia, determinata dall’estesa urbanizzazione e dall’uso intensivo del suolo agricolo, ha portato a una riduzione delle specie nettarifere presenti con conseguente impoverimento delle risorse alimentari necessarie per la sopravvivenza degli apoidei. Si aggiunga inoltre che l’esistenza di barriere architettoniche determinate dagli insediamenti umani, e la riduzione nelle aree coltivate di siti di nidificazione per le specie selvatiche, rende spesso difficili gli spostamenti alla ricerca della fonte alimentare considerata. L’impatto di questi fattori è estremamente variabile a seconda che si tratti di Apis mellifera L. o di altri apoidei solitari o sociali. Nel caso di A. mellifera entrano in gioco numerosi fattori che implicano sia la sopravvivenza della colonia, sia la capacità produttiva in termini di miele prodotto.
Risulta quindi fondamentale l’analisi del territorio, supportata da studi fitosociologici, dall’utilizzo di banche dati dell’uso del suolo e dalla posizione degli apiari come indicatore “proxy” di idoneità territoriale per la realizzazione di mappe di idoneità finalizzate a verificare la potenzialità apistica dei territori circostanti gli alveari. Si evidenzia come tali mappe, ottenute con il supporto di Web & Mobile App e GIS, possano diventare strumento scientifico per lo studio e la progettazione degli interventi di miglioramento ambientale e per la gestione colturale a sostengo dell’ape da miele. Relativamente a quest’ultimo aspetto, si riportano i risultati di alcuni studi specifici effettuati su specie mellifere, potenzialmente utilizzabili in consociazione con altre colture e che possano supportare le api nei momenti di maggiori difficoltà. Nel panorama di ambienti fortemente antropizzati, gli orti botanici e i parchi urbani, sempre ricchi di numerose specie che si alternano nella fioritura per ottimizzare lo scopo estetico, possono risultare laboratori a cielo aperto per lo studio delle relazioni tra ambiente, specie fiorale, epoca di fioritura e relazione con gli apoidei, sia allevati che selvatici. Attraverso lo studio del network fiori-api è possibile individuare le specie botaniche più idonee a supportare sia A. mellifera sia altre specie di apoidei, tanto generalisti che specialisti. È possibile inoltre approfondire le relazioni che correlano le forme fiorali alle diverse specie di api presenti considerando l’interazione tra la morfologia/bioetologia dell’ape e le caratteristiche botaniche
Spatial and statistical assessment of factors influencing nitrate contamination in groundwater
No full textThe weights of evidence (WofE) modeling technique has been used to analyze both natural and anthropogenic factors influencing the occurrence of high nitrate concentrations in groundwater resources located in the central part of the Po Plain (Northern Italy). The proposed methodology applied in the Lodi District combines measurements of nitrate concentrations, carried out by means of a monitoring net of 69 wells, with spatial data representing both categorical and numerical variables. These variables describe either potential sources of nitrate and the relative ease with which it may migrate towards groundwater. They include population density, nitrogen fertilizer loading, groundwater recharge, soil protective capacity, vadose zone permeability, groundwater depth, and saturated zone permeability. Once conditional dependence problems among factors have been solved and validation tests performed, the statistical approach has highlighted negative and positive correlations between geoenvironmental factors and nitrate concentration in groundwater. These results have been achieved analysing the calculated statistical parameters (weights, contrasts, normalized contrasts) of each class by which each factor has been previously subdivided. This has permitted to outline: the overall influence each factor has on the presence/absence of nitrate; the range of their values mostly influencing this presence/absence; the most and least critical combination of factor classes existing in each specific zone; areas where the influence of impacting factor classes is reduced by the presence of not impacting factor classes. This last aspect could represent an important support for a correct land use management to preserve groundwater quality
Phytosociology, preferences and floristic mapping of the most appreciate species by Apis mellifera and other Apoidea
No full textThe alteration of natural and rural landscapes of northern Italy, caused by the broad urbanization and the intensive use of agricultural lands, has led to a reduction in the nectariferous species with the depletion of the food resources available and necessary for the survival of the bees. The existence of architectural barriers determined by human settlements, and the reduction in cultivated areas of nesting sites for wild bee species often alters and obstacles bee movements in the areas in search of the food source. The impact of these factors is extremely variable in relation to the bee-species studied, Apis mellifera L. or other social or solitary bees. In the case of A. mellifera, numerous factors should be considered and they imply both the survival of the colony and the productive capacity in terms of honey produced. The analysis of the territory is therefore fundamental, supported by phytosociological studies, use of databases related to land use and apiaries position as a proxy indicator of territorial suitability for the creation of maps aimed at verifying the potential beekeeping of the territories surrounding the hives. It is evident how these maps, obtained with the support of Web & Mobile App and GIS, become a scientific tool for the study and design of environmental improvement interventions and for crop management in support of the honey bees. With regard to this last aspect, the results of some specific studies on nectariferous species, potentially introduced in association with other crops to support bees in times of difficulty, are reported. Furthermore, in the panorama of highly anthropic environments, botanical gardens and urban parks, rich in numerous species that alternate blossoming period to improve the aesthetic purpose, can be used as open-air laboratories for the study of the relationships among bee-species, environment, floral species, and flowering. Through the study of the flower-bee network, it is possible to identify the most suitable species to support both A. mellifera and/or other species of Apoidea, both generalists and specialists. It is also possible to deepen the relationships that correlate the flower traits to the different species of bee present considering the interaction between the morphology/bioethology of the bee and the botanical characteristics
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