Search results for "Idrologia"
showing 10 items of 508 documents
Effetti di urbanizzazione e cambiamenti climatici sui deflussi a scala di bacino
2016
Fra le pressioni di natura antropica agenti sui bacini idrografici, particolare rilevanza hanno sia la progressiva perdita di suoli naturali in favore di suoli poco, o per nulla, permeabili (es. strade, edifici, parcheggi, etc.) che la regimazione e regolazione dei deflussi sulla rete di drenaggio naturale mediante interventi idraulici. In particolare, l’ultima relazione sullo stato dell’ambiente europeo a cura dell’Agenzia Europea dell’Ambiente (AEA, 2010) considera l’impermeabilizzazione dei bacini naturali come uno dei maggiori processi di degrado del suolo. L’aumento del grado di urbanizzazione dei bacini naturali, inteso come aumento della frazione impermeabile del suolo derivante dell…
DETERMINAZIONE DELLE CARATTERISTICHE OTTICHE DI VEGETAZIONE SOMMERSA TRAMITE METODO MONTE CARLO
2001
Si presentano i risultati di una ricerca volta alla determinazione della risposta spettrale della vegeta-zione sommersa mediante simulazioni stocastiche, con l’obiettivo di porre in risalto il range d’applicabilità (in termini di profondità e di lunghezza d’onda) delle tecniche di monitoraggio della vegetazione sommersa a partire da dati telerilevati. Per fare ciò è stato sviluppato e implementato un codice di calcolo che permette di ricostruire, mediante simulazioni stocastiche, la firma spettrale di oggetti posti sul fondale, una volta note le caratteristiche ottiche degli oggetti stessi e della colonna d’acqua. La flessibilità del modello di calcolo implementato ha inoltre permesso di es…
Using very high resolution (VHR) imagery within a GEOBIA framework for gully mapping: an application to the Calhoun Critical Zone Observatory
2019
AbstractGully erosion is a form of accelerated erosion that may affect soil productivity, restrict land use, and lead to an increase of risk to infrastructure. An 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 a 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 ge…
Object-based image analysis technique for gully mapping using topographic data at very high resolution (VHR)
2018
An accurate mapping of gullies is important since they are still major contributors of sediment to streams. Mapping gullies can be difficult because of the presence of dense canopy, which precludes the identification through aerial photogrammetry and other traditional remote sensing methods. Moreover, the wide spatial extent of some gullies makes their identification and characterization through field surveys a very large and expensive proposition. One cheaper and more expeditious way to detect gullies can be achieved in terms of morphological characteristics by the Digital Elevation Models (DEMs). The recent widespread availability of very high resolution (VHR) imagery, such as LIDAR data,…
On the influences of vegetation biomass on COSMO-Skymed X-band
2011
The knowledge of spatial and temporal variability of land cover is important to manage water resources for yield forecasting, water stress prediction, irrigation water management and flood protection. Cloud cover dramatically reduces the temporal resolution of optical data thus limiting their operational use; in addition, the spatial resolution is often inadequate for applications in heterogeneous areas. On the other hand, algorithms based on Synthetic Aperture Radar (SAR) implemented to retrieve vegetation parameters are not yet fully validated. New SAR missions (COSMO-Skymed and Terrasar-X) may represent a suitable source of data for operational uses due to the high spatial and temporal r…
A Decision Support Tool for Water and Energy Savingin the Integrated Water System
2015
Abstract In the last decades, a growing attention on energy saving associated with water resources usage and leakages reduction has been recorded at both national and international level. Scientific research has focused on implementation of several methodologies aimed at the understanding of energy transformation processes occurring in the integrated water system. The main concern is then identifying energy impacts associated to each macro-area of integrated water system, such as collection, treatment and distribution, and analysing the potential interactions between them. Unfortunately, only overall energy consumptions are usually available at national level. The main objective of the pape…
Critical analysis of thermal inertia approaches for surface soil water content retrieval
2013
The “thermal inertia” method to retrieve surface soil water content maps on bare or sparsely-vegetated soils is analysed. The study area is a small experimental watershed, where optical and thermal images (in day and night time) and in situ data were simultaneously acquired. The sensitivity of thermal inertia to the phase difference between incoming radiation and soil temperature is demonstrated. Thus, to obtain an accurate value of the phase difference, the temporal distance between thermographs using a three-temperature approach is evaluated. We highlight when a cosine correction of the temperature needs to be applied, depending on whether the thermal inertia formulation includes two gene…
ASSESSMENT OF THE WAVE ENERGY CONVERSION EFFICIENCY IN THE AEGADIAN ISLANDS
2016
The wave energy conversion efficiency surrounding an island group of Mediterranean Sea is estimated, a wave reanalysis dataset is used to characterize the offshore wave climate around Aegadian Islands and several numerical simulation of wave propagation are carried out. It is possible to convert the wave energy into electric energy and, at the same time, protecting the coastal areas from erosion
The relationship between precipitation depth and weather circulation patterns over Sicily
2019
Some weather circulation patterns (WPs) derived by the UK Met Office and defining a certain type of atmospheric circulation over Europe have been recently used to analyze the relationship of the regional UK precipitation and drought with respect to the atmospheric circulation over Europe (Richardson et al. 2018). In this study, we attempt to find out one or more relationships between precipitation depth and weather patterns over a non UK-centred domain, such as Sicily (Italy), which is characterized by a totally different climate as compared to the climate of UK. Since the island has been affected by many floods in the last years, occurred as a consequence of extreme rainfall events, it wou…
Olive yield as a function of soil moisture dynamics
2011
This study introduces a water-driven crop model aiming to quantitatively link olive yield to climate and soil moisture dynamics using an ecohydrological approach. A mathematical model describing soil moisture, evapotranspiration and assimilation dynamics of olive orchards is developed here. The model is able to explicitly reproduce two different hydroclimatic phases in Mediterranean areas: the well-watered conditions in which evapotranspiration and assimilation assume their maximum values and the real conditions where the limitations induced by soil moisture availability are taken into account. Annual olive yield is obtained by integrating the carbon assimilation during the growing season, …