Euro Mediterranean Center on Climate Changes

San Nicola da Crissa, Italy

Euro Mediterranean Center on Climate Changes

San Nicola da Crissa, Italy
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Mancosu N.,University of Sassari | Mancosu N.,Euro Mediterranean Center on Climate Changes | Snyder R.L.,University of California at Davis | Spano D.,University of Sassari | Spano D.,Euro Mediterranean Center on Climate Change
Journal of Irrigation and Drainage Engineering | Year: 2014

The goal of this study was to define procedures needed to make a Standardized Reference Evapotranspiration (ETos) zone map using daily climate data from full stations, having solar radiation, air temperature, wind speed, relative humidity, and from partial stations, having only temperature data. For partial stations, the ETos was estimated either by substitution of data from nearby full stations or by using a calibration factor and the Hargreaves-Samani equation estimate of reference evapotranspiration. The substitution method gave statistically better estimates of ETos than the calibration method. In addition, to improve the number and distribution of ETos estimates, three interpolation techniques were evaluated. Ordinary kriging provided better spatialization of ETos data than the inverse distance weighting and radial basis function. © 2014 American Society of Civil Engineers.

Kint V.,Catholic University of Leuven | Aertsen W.,Catholic University of Leuven | Fyllas N.M.,National and Kapodistrian University of Athens | Trabucco A.,Catholic University of Leuven | And 4 more authors.
Ecological Modelling | Year: 2014

To investigate the past forest-society interactions in the territory of the ancient city of Sagalassos, situated in the Taurus Mountains in Southwest Turkey, it is necessary to reconstruct forest composition and biomass through time. This paper focuses on modelling the natural vegetation dynamics in the area over the occurring gradient of biophysical site conditions under today's climate, as a first and essential stepping-stone towards this goal. GREFOS, a forest gap dynamics model developed for the North-Eastern Mediterranean Basin, was adapted to the bioclimatic conditions of the Taurus Mountains, adding effects of late frost on species regeneration and adjusting the fire module. The model was parameterized based on an extensive literature review and additional field measurements for the seven most important tree species in the study area (Pinus brutia, Pinus nigra, Cedrus libani, Abies cilicica, Quercus cerris, Quercus coccifera and Juniperus excelsa) resulting in the most complete and documented ecological traits matrix presently available for the studied species. Qualitative and semi-quantitative model validation indicates that simulated species presence, altitude ranges and basal area estimates correspond reasonably well to field observations or expected values based on literature and expert knowledge. Yet validation results also indicate some inaccuracies for simulation of P. nigra and J. excelsa at higher altitudes. Simulations are summarized in a conceptual model with four vegetation zones, which reflects literature and expert opinion, and is interpretable in terms of ecological processes and succession dynamics in the study area. It is concluded that the resulting model is able to realistically predict effects of fire and abiotic site conditions on natural vegetation development in different climate zones in the Taurus mountains. Further model development steps should aim to include important additional drivers of vegetation composition, such as climate change and land use. © 2014 Elsevier B.V.

Raposo J.R.,University of Coimbra | Cabiddu S.,Sardinia Forest Service CFVA | Viegas D.X.,University of Coimbra | Salis M.,University of Sassari | And 2 more authors.
International Journal of Wildland Fire | Year: 2015

Results from a laboratory-scale investigation of a fire spreading on the windward face of a triangular-section hill of variable shape with wind perpendicular to the ridgeline are reported. They confirm previous observations that the fire enlarges its lateral spread after reaching the ridgeline, entering the leeward face with a much wider front. Reference fire spread velocities were measured and analysed, putting in evidence the importance of the dynamic effect due to flow velocity and its associated horizontal-axis separation vortex strength without dependence on hill geometry. Similar parameters estimated from three forest fires compared favourably with the laboratory-scale measurements. © IAWF 2015.

Salis M.,University of Sassari | Salis M.,Euro Mediterranean Center on Climate Changes | Ager A.A.,U.S. Department of Agriculture | Finney M.A.,Rocky Research | And 3 more authors.
Natural Hazards | Year: 2014

We evaluated the spatiotemporal changes in wildfire regime and exposure in a fire-prone Mediterranean area (Sardinia, Italy) in relation to changes in ignition patterns, weather, suppression activities, and land uses. We also used wildfire simulations to identify fine-scale changes in wildfire exposure of important features on the island. Sardinia experienced a sharp reduction in fire number and area burned between the periods 1980-1994 and 1995-2009. Despite this decrease, losses and fatalities from wildfires continue. This suggests that localized areas and seasons of high wildfire risk persist on the island. Our analysis showed (1) a reduction in area burned (60,000-20,000 ha/year) and ignitions (3,700-2,600 fires/year), (2) an advance of 15 days for the fire season peak, (3) an increase in spring temperatures, and (4) an increase in fire exposure for WUI areas. Little change was noted for land use types and associated fuels. Most likely the reduction in fire activity may be due to a combination of social factors and suppression capabilities. On the other hand, simulation modeling suggested pockets of high wildfire exposure in specific places. The combined empirical analyses and simulation modeling provided a robust approach to understanding the spatiotemporal dynamics of wildfire risk on the island. © 2013 US Government.

PubMed | Water Resource Planning Sardinian Regional Water Authority ENAS, UNESCO-IHE Institute for Water Education, Euro Mediterranean Center on Climate Changes, National Technical University of Athens and 3 more.
Type: Journal Article | Journal: The Science of the total environment | Year: 2015

Many (semi-) arid locations globally, and particularly islands, rely heavily on reservoirs for water supply. Some reservoirs are particularly vulnerable to climate and development changes (e.g. population change, tourist growth, hydropower demands). Irregularities and uncertainties in the fluvial regime associated with climate change and the continuous increase in water demand by different sectors will add new challenges to the management and to the resilience of these reservoirs. The resilience of vulnerable reservoirs must be studied in detail to prepare for and mitigate potential impacts of these changes. In this paper, a reservoir balance model is developed and presented for the Pedra e Othoni reservoir in Sardinia, Italy, to assess resilience to climate and development changes. The model was first calibrated and validated, then forced with extensive ensemble climate data for representative concentration pathways (RCPs) 4.5 and 8.5, agricultural data, and with four socio-economic development scenarios. Future projections show a reduction in annual reservoir inflow and an increase in demand, mainly in the agricultural sector. Under no scenario is reservoir resilience significantly affected, the reservoir always achieves refill. However, this occurs at the partial expenses of hydropower production with implications for the production of renewable energy. There is also the possibility of conflict between the agricultural sector and hydropower sector for diminishing water supply. Pedra e Othoni reservoir shows good resilience to future change mostly because of the disproportionately large basin feeding it. However this is not the case of other Sardinian reservoirs and hence a detailed resilience assessment of all reservoirs is needed, where development plans should carefully account for the trade-offs and potential conflicts among sectors. For Sardinia, the option of physical connection between reservoirs is available, as are alternative water supply measures. Those reservoirs at risk to future change should be identified, and mitigating measures investigated.

Metzger M.J.,University of Edinburgh | Brus D.J.,Wageningen University | Bunce R.G.H.,Estonian University of Life Sciences | Carey P.D.,University of Cambridge | And 6 more authors.
Ecological Indicators | Year: 2013

There is growing urgency for integration and coordination of global environmental and ecological data and indicators required to respond to the 'grand challenges' the planet is facing, including climate change and biodiversity decline. A consistent stratification of land into relatively homogenous strata provides a valuable spatial framework for comparison and analysis of ecological and environmental data across large heterogeneous areas. We discuss how statistical stratification can be used to design national, European and global biodiversity observation networks. The value of strategic ecological survey based on stratified samples is first illustrated using the United Kingdom (UK) Countryside Survey, a national monitoring programme that has measured ecological change in the UK countryside for the last 35 years. We then present a design for a European-wide sampling design for monitoring common habitats, and discuss ways of extending these approaches globally, supported by the recently developed Global Environmental Stratification. The latter provides a robust spatial analytical framework for the identification of gaps in current monitoring efforts, and systematic design of new complementary monitoring and research. Examples from Portugal and the transboundary Kailash Sacred Landscape in the Himalayas illustrate the potential use of this stratification, which has been identified as a focal geospatial dataset within the Group on Earth Observation Biodiversity Observation Network (GEO BON). © 2012 Elsevier Ltd. All rights reserved.

Arcucci R.,University of Naples Federico II | Arcucci R.,Imperial College London | D'Amore L.,University of Naples Federico II | D'Amore L.,Euro Mediterranean Center on Climate Changes | Carracciuolo L.,National Research Council Italy
Proceedings of the 2015 International Conference on High Performance Computing and Simulation, HPCS 2015 | Year: 2015

We present an innovative approach for solving Four Dimensional Variational Data Assimilation (4D-VAR DA) problems. The approach we consider starts from a decomposition of the physical domain; it uses a partitioning of the solution and a modified regularization functional describing the 4D-VAR DA problem on the decomposition. We provide a mathematical formulation of the model and we perform a feasibility analysis in terms of computational cost and of algorithmic scalability. We use the scale-up factor which measure the performance gain in terms of time complexity reduction. We verify the reliability of the approach on a consistent test case (the Shallow Water Equations). © 2015 IEEE.

Arcucci R.,University of Naples Federico II | Arcucci R.,Euro Mediterranean Center on Climate Changes | D'Amore L.,University of Naples Federico II | D'Amore L.,Euro Mediterranean Center on Climate Changes | And 3 more authors.
International Journal of Parallel Programming | Year: 2016

We introduce a decomposition of the Tikhonov Regularization (TR) functional which split this operator into several TR functionals, suitably modified in order to enforce the matching of their solutions. As a consequence, instead of solving one problem we can solve several problems reproducing the initial one at smaller dimensions. Such approach leads to a reduction of the time complexity of the resulting algorithm. Since the subproblems are solved in parallel, this decomposition also leads to a reduction of the overall execution time. Main outcome of the decomposition is that the parallel algorithm is oriented to exploit the highest performance of parallel architectures where concurrency is implemented both at the coarsest and finest levels of granularity. Performance analysis is discussed in terms of the algorithm and software scalability. Validation is performed on a reference parallel architecture made of a distributed memory multiprocessor and a Graphic Processing Unit. Results are presented on the Data Assimilation problem, for oceanographic models. © 2016 Springer Science+Business Media New York

Costa-Saura J.M.,University of Sassari | Martinez-Vilalta J.,CREAF | Martinez-Vilalta J.,Autonomous University of Barcelona | Trabucco A.,University of Sassari | And 5 more authors.
Perspectives in Plant Ecology, Evolution and Systematics | Year: 2016

Despite growing evidence of changes in plant functional traits (FT) along environmental gradients, the way they shape species niches (i.e. how they alternatively influence the limits, width and environmental optimums of species niche) remains only partially understood. Thus, Species Distribution Models were developed and evaluated using distribution data from the Spanish Forest Inventory for 21of the most common Mediterranean woody species, and used to derive different environmental characteristics of species niche, which were then correlated against species-specific values of 14 FT and combinations of relatively orthogonal FT. Species leaf traits, and in particular Specific Leaf Area (SLA), were highly correlated with species niche characteristics regarding aridity (especially with the more arid limit). Hydraulic traits, i.e. the water potential at which a species loses 50% of xylem hydraulic conductivity due to cavitation (PLC50), and species hydraulic safety margins (SM), were better correlated with species aridity niche optimums. Overall, the best model fits, particularly regarding species' optimum and maximum aridity limit, were obtained when SLA and hydraulic traits (either PLC50 or SM) were used in combination. The study shows how in the Mediterranean region a single trait may be able to explain broad differences in species distributions, but also that the coordination of relatively independent traits achieves a more accurate representation of their environmental limits, particularly at the dry end of the species' range. The approach used in this study relies on the physiological limits of a species and, to a certain extent, on the mechanisms behind them, adding robustness and accuracy to predict species distribution and mortality under climate change scenarios. © 2016 Elsevier GmbH.

PubMed | University of Lleida, CNR Institute for Biometeorology, Euro Mediterranean Center on Climate Change, University of Sassari and 3 more.
Type: | Journal: Risk analysis : an official publication of the Society for Risk Analysis | Year: 2016

We used simulation modeling to assess potential climate change impacts on wildfire exposure in Italy and Corsica (France). Weather data were obtained from a regional climate model for the period 1981-2070 using the IPCC A1B emissions scenario. Wildfire simulations were performed with the minimum travel time fire spread algorithm using predicted fuel moisture, wind speed, and wind direction to simulate expected changes in weather for three climatic periods (1981-2010, 2011-2040, and 2041-2070). Overall, the wildfire simulations showed very slight changes in flame length, while other outputs such as burn probability and fire size increased significantly in the second future period (2041-2070), especially in the southern portion of the study area. The projected changes fuel moisture could result in a lengthening of the fire season for the entire study area. This work represents the first application in Europe of a methodology based on high resolution (250 m) landscape wildfire modeling to assess potential impacts of climate changes on wildfire exposure at a national scale. The findings can provide information and support in wildfire management planning and fire risk mitigation activities.

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