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1
Vukotic, B. y M. M. Cirkovic. "On the timescale forcing in astrobiology". Serbian Astronomical Journal, n.º 175 (2007): 45–50. http://dx.doi.org/10.2298/saj0775045v.
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We investigate the effects of correlated global regulation mechanisms, especially Galactic gamma-ray bursts (GRBs), on the temporal distribution of hypothetical inhabited planets, using simple Monte Carlo numerical experiments. Starting with recently obtained models of planetary ages in the Galactic Habitable Zone (GHZ), we obtain that the times required for biological evolution on habitable planets of the Milky Way are highly correlated. These results run contrary to the famous anti-SETI anthropic argument of Carter, and give tentative support to the ongoing and future SETI observation projects.
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Masse-Dufresne, Janie, Paul Baudron, Florent Barbecot, Marc Patenaude, Coralie Pontoreau, Francis Proteau-Bédard, Matthieu Menou, Philippe Pasquier, Sabine Veuille y Benoit Barbeau. "Anthropic and Meteorological Controls on the Origin and Quality of Water at a Bank Filtration Site in Canada". Water 11, n.º 12 (28 de noviembre de 2019): 2510. http://dx.doi.org/10.3390/w11122510.
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At many bank filtration (BF) sites, mixing ratios between the contributing sources of water are typically regarded as values with no temporal variation, even though hydraulic conditions and pumping regimes can be transient. This study illustrates how anthropic and meteorological forcings influence the origin of the water of a BF system that interacts with two lakes (named A and B). The development of a time-varying binary mixing model based on electrical conductivity (EC) allowed the estimation of mixing ratios over a year. A sensitivity analysis quantified the importance of considering the temporal variability of the end-members for reliable results. The model revealed that the contribution from Lake A may vary from 0% to 100%. At the wells that were operated continuously at >1000 m3/day, the contribution from Lake A stabilized between 54% and 78%. On the other hand, intermittent and occasional pumping regimes caused the mixing ratios to be controlled by indirect anthropic and/or meteorological forcing. The flow conditions have implications for the quality of the bank filtrate, as highlighted via the spatiotemporal variability of total Fe and Mn concentrations. We therefore propose guidelines for rapid decision-making regarding the origin and quality of the pumped drinking water.
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Fiorucci, Matteo, Salvatore Martino, Francesca Bozzano y Alberto Prestininzi. "Comparison of Approaches for Data Analysis of Multi-Parametric Monitoring Systems: Insights from the Acuto Test-Site (Central Italy)". Applied Sciences 10, n.º 21 (29 de octubre de 2020): 7658. http://dx.doi.org/10.3390/app10217658.
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This paper deals with monitoring systems to manage the risk due to fast slope failures that involve rock masses, in which important elements (such as infrastructures or cultural heritages, among the others) are exposed. Three different approaches for data analysis were here compared to evaluate their suitability for detecting mutual relations among destabilising factors, acting on different time windows, and induced strain effects on rock masses: (i) an observation-based approach (OBA), (ii) a statistics-based approach (SBA) and (iii) a semi-empirical approach (SEA). For these purposes, a test-site has been realised in an abandoned quarry in Central Italy by installing a multi-parametric monitoring sensor network on a rock wall able to record strain effects induced by natural and anthropic forcing actions (like as temperature, rainfall, wind and anthropic vibrations). The comparison points out that the considered approaches allow one to identify forcing actions, responsible for the strain effects on the rock mass over several time windows, regarding a specific size (i.e., rock block dimensional scale). The OBA was more suitable for computing the relations over short- to medium time windows, as well as the role of impulsive actions (i.e., hourly to seasonal and/or instantaneous). The SBA was suitable for computing the relations over medium- to long time windows (i.e., daily to seasonal), also returning the time lag between forcing actions and induced strains using the cross-correlation statistical function. Last, the SEA was highly suitable for detecting irreversible strain effects over long- to very long-time windows (i.e., plurennial).
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Bogunovic, Igor, Sebastiano Trevisani, Paulo Pereira y Vesna Vukadinovic. "Mapping soil organic matter in the Baranja region (Croatia): Geological and anthropic forcing parameters". Science of The Total Environment 643 (diciembre de 2018): 335–45. http://dx.doi.org/10.1016/j.scitotenv.2018.06.193.
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Mathé, V., A. Meunier y F. Lévêque. "Anthropic acceleration of a natural clay mineral reaction in marshland soils (Atlantic Coast, France)". Clay Minerals 42, n.º 1 (marzo de 2007): 1–12. http://dx.doi.org/10.1180/claymin.2007.042.1.01.
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AbstractSoil clay minerals in recent natural polders react on a human timescale in response to local environmental conditions. With increasing age, the mineral reaction leads to the dissolution of the chlorite component and a composition change of the different illite-smectite mixed-layer minerals (I-S MLMs): i.e. smectite layer content decreases and illite content increases. The process of oxidation, which is proven by magnetic susceptibility to trigger clay mineral reaction, changes the mineralogical composition of the sediment above the redox front. The mineral changes appear to be a non-linear function of time. In natural conditions the process lasts >1000 y. However, anthropoic forcing such as artificial drainage accelerates the oxidation reaction to complete the whole process in a few tens of years.
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Balbus, Steven A. "Dynamical, biological and anthropic consequences of equal lunar and solar angular radii". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 470, n.º 2168 (8 de agosto de 2014): 20140263. http://dx.doi.org/10.1098/rspa.2014.0263.
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The nearly equal lunar and solar angular sizes as subtended at the Earth is generally regarded as a coincidence. This is, however, an incidental consequence of the tidal forces from these bodies being comparable. Comparable magnitudes implies strong temporal modulation, as the forcing frequencies are nearly but not precisely equal. We suggest that on the basis of palaeogeographic reconstructions, in the Devonian period, when the first tetrapods appeared on land, a large tidal range would accompany these modulated tides. This would have been conducive to the formation of a network of isolated tidal pools, lending support to A. S. Romer's classic idea that the evaporation of shallow pools was an evolutionary impetus for the development of chiridian limbs in aquatic tetrapodomorphs. Romer saw this as the reason for the existence of limbs, but strong selection pressure for terrestrial navigation would have been present even if the limbs were aquatic in origin. Since even a modest difference in the Moon's angular size relative to the Sun's would lead to a qualitatively different tidal modulation, the fact that we live on a planet with a Sun and Moon of close apparent size is not entirely coincidental: it may have an anthropic basis.
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Stríkis, Nicolás Misailidis y Pedro Carlos Stríkis. "ANTHROPOCENE: A BRIEF DISCUSSION OF ANTHROPIC INFLUENCE FROM A PERSPECTIVE OF THE GEOCHEMICAL EVOLUTION OF SURFACE RESERVOIRS AND BIOLOGICAL INSIGHTS / ANTROPOCENO: UMA BREVE DISCUSSÃO DA INFLUÊNCIA ANTRÓPICA NA PERSPECTIVA DA EVOLUÇÃO GEOQUÍMICA DOS RESERVATÓRIOS SUPERFICIAIS TERRESTRES E DA BIODIVERSIDADE". Journal of Sedimentary Environments 3, n.º 3 (25 de septiembre de 2018): 194–204. http://dx.doi.org/10.12957/jse.2018.38763.
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Currently the extension of human activities allows us to characterize the human being as a geological and biological forcing, capable of generating significant alterations both in the geochemical composition of the main reservoirs of the Earth surface and in biodiversity. Substantial variations of the atmosphere composition as well as of sedimentary constituents deposited in lacustrine environments and in coastal zones allow to easily identifying the anthropic influence on Terrestrial ecosystems. However, the nature of a forcing does not characterize the beginning of a new geological interval, but the extension of its expression on the Earth system. These issues raise a vigorous debate that seeks to understand not only how the human affects the planet, but also how much we can change surface geochemistry and biological activity. In this context, the search for a marker of Anthropogenic effects in geological materials is an important criterion for determining the Anthropocene as a new geological event on the planet. This paper proposes a brief discussion of the scale about environmental changes due to the anthropic action on the planet surface and its signature in the biogeochemical reservoirs with a view to presenting a suggestion for the beginning of the Anthropocene. Finally, we ponder the fact that we are not the first biological forcing to change the surface of the planet, but without doubt, we are the first forcing that has a moral dimension. ResumoA magnitude e extensão das atividades humanas permite-nos considerar o Homem como uma forçante geológica e biológica, capaz de originar alterações significativas tanto na composição geoquímica dos principais reservatórios da superfície Terrestre quanto na biodiversidade. Variações substanciais da composição da atmosfera, bem como de constituintes sedimentares depositados em ambientes lacustres e em zonas costeiras, permitem identificar facilmente a influência antrópica nos ecossistemas terrestres. No entanto, a natureza de um forçamento não caracteriza o início de um novo intervalo geológico, mas a extensão da sua expressão no sistema terrestre. Essas questões levantam um debate vigoroso que busca entender não apenas como o homem afeta o planeta, mas também o quanto podemos mudar a geoquímica da superfície Terrestre e a atividade biológica. Neste contexto, a busca por um marcador de efeitos antropogênicos em materiais geológicos é um importante critério para a determinação do Antropoceno como um novo evento geológico no planeta. Este trabalho, propõe uma breve discussão da escala sobre mudanças ambientais devido à ação antrópica sobre a superfície do planeta e sua assinatura nos reservatórios biogeoquímicos com o objetivo de apresentar uma sugestão para o início do Antropoceno. O Homem não é o primeiro forçador biológico a mudar a superfície do planeta, mas é, sem dúvida, a primeira força com dimensão moral.
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D’Orefice, Maurizio, Piero Bellotti, Tiberio Bellotti, Lina Davoli y Letizia Di Bella. "Natural and Cultural Lost Landscape during the Holocene along the Central Tyrrhenian Coast (Italy)". Land 11, n.º 3 (25 de febrero de 2022): 344. http://dx.doi.org/10.3390/land11030344.
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Landscape evolution over the last 8000 years in three areas located along Tuscany, Latium, and Campania coasts (central Tyrrhenian) has been deduced through a morphological, stratigraphical, and historical approach considering the physical evolution and human activity. Between 8000 and 6000 yr BP, the Sea Level Rise (SLR) dominated and, near the river mouths, inlets occurred. In the Tuscany area, Mt. Argentario was an island and to SE of the Ansedonia promontory a lagoon occurred. The areas were covered by a dense forest and the human influence was negligible. Between 6000 and 4000 yr BP, humans organized settlements and activities, and a general coastline progradation occurred. A tombolo linked Mt. Argentario to the mainland. In the Tiber and Campania areas, coastal lakes and a strand plain developed. Between 4000 and 3000 yr BP, near Mt. Argentario, two tombolos enclosed a wide lagoon. At the SE of the Ansedonia promontory, the lagoon split into smaller water bodies. In the Tiber and Campania areas, delta cusps developed. The anthropogenic presence was widespread and forests decreased. During the last 3000 years, anthropic forcing increased when the Etruscans and Romans changed the territory through towns, salt pans, and ports. After the Roman period, natural forcing returned to dominate until the birth of the Italian State and technological evolution.
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Simonetti, Irene y Lorenzo Cappietti. "Influence of Inlets Morphology and Forcing Mechanisms on Water Exchange between Coastal Basins and the Sea: A Hindcast Study for a Mediterranean Lagoon". Journal of Marine Science and Engineering 10, n.º 12 (6 de diciembre de 2022): 1929. http://dx.doi.org/10.3390/jmse10121929.
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A numerical model, validated with field measurements, was applied to comparatively reconstruct the hydrodynamics of a eutrophic coastal lagoon in a set of scenarios over the last two centuries. The effect of major morphological changes on the water exchange with the open sea and water residence time is evaluated. The results show that the number and morphology of the lagoon inlets are crucial in determining the volume of water exchanged with the sea, the water transport timescales, and the extent of poorly circulated stagnant areas with poor flushing potential, which are areas where anoxic crises might develop. When all the relevant forcing mechanisms on the hydrodynamics are considered, great variability of the water residence time is found in the different historical scenarios, with values varying between 83 and 305 days. The effect of anthropic actions on the system hydrodynamics was quantitatively evaluated, consolidating the background knowledge to support the present and future management of this environmental system.
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Simoniello, T., M. Lanfredi, M. Liberti, R. Coppola y M. Macchiato. "Estimation of vegetation cover resilience from satellite time series". Hydrology and Earth System Sciences Discussions 5, n.º 1 (28 de febrero de 2008): 511–46. http://dx.doi.org/10.5194/hessd-5-511-2008.
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Abstract. Resilience is a fundamental concept for understanding vegetation as a dynamic component of the climate system. It expresses the ability of ecosystems to tolerate disturbances and to recover their initial state. Recovery times are basic parameters of the vegetation's response to forcing and, therefore, are essential for describing realistic vegetation within dynamical models. Healthy vegetation tends to rapidly recover from shock and to persist in growth and expansion. On the contrary, climatic and anthropic stress can reduce resilience thus favouring persistent decrease in vegetation activity. In order to characterize resilience, we analyzed the time series 1982–2003 of 8 km GIMMS AVHRR-NDVI maps of the Italian territory. Persistence probability of negative and positive trends was estimated according to the vegetation cover class, altitude, and climate. Generally, mean recovery times from negative trends were shorter than those estimated for positive trends, as expected for vegetation of healthy status. Some signatures of inefficient resilience were found in high-level mountainous areas and in the Mediterranean sub-tropical ones. This analysis was refined by aggregating pixels according to phenology. This multitemporal clustering synthesized information on vegetation cover, climate, and orography rather well. The consequent persistence estimations confirmed and detailed hints obtained from the previous analyses. Under the same climatic regime, different vegetation resilience levels were found. In particular, within the Mediterranean sub-tropical climate, clustering was able to identify features with different persistence levels in areas that are liable to different levels of anthropic pressure. Moreover, it was capable of enhancing reduced vegetation resilience also in the southern areas under Warm Temperate sub-continental climate. The general consistency of the obtained results showed that, with the help of suited analysis methodologies, 8 km AVHRR-NDVI data could be useful for capturing details on vegetation cover activity at local scale even in complex territories such as that of the Italian peninsula.
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Simoniello, T., M. Lanfredi, M. Liberti, R. Coppola y M. Macchiato. "Estimation of vegetation cover resilience from satellite time series". Hydrology and Earth System Sciences 12, n.º 4 (30 de julio de 2008): 1053–64. http://dx.doi.org/10.5194/hess-12-1053-2008.
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Abstract. Resilience is a fundamental concept for understanding vegetation as a dynamic component of the climate system. It expresses the ability of ecosystems to tolerate disturbances and to recover their initial state. Recovery times are basic parameters of the vegetation's response to forcing and, therefore, are essential for describing realistic vegetation within dynamical models. Healthy vegetation tends to rapidly recover from shock and to persist in growth and expansion. On the contrary, climatic and anthropic stress can reduce resilience thus favouring persistent decrease in vegetation activity. In order to characterize resilience, we analyzed the time series 1982–2003 of 8 km GIMMS AVHRR-NDVI maps of the Italian territory. Persistence probability of negative and positive trends was estimated according to the vegetation cover class, altitude, and climate. Generally, mean recovery times from negative trends were shorter than those estimated for positive trends, as expected for vegetation of healthy status. Some signatures of inefficient resilience were found in high-level mountainous areas and in the Mediterranean sub-tropical ones. This analysis was refined by aggregating pixels according to phenology. This multitemporal clustering synthesized information on vegetation cover, climate, and orography rather well. The consequent persistence estimations confirmed and detailed hints obtained from the previous analyses. Under the same climatic regime, different vegetation resilience levels were found. In particular, within the Mediterranean sub-tropical climate, clustering was able to identify features with different persistence levels in areas that are liable to different levels of anthropic pressure. Moreover, it was capable of enhancing reduced vegetation resilience also in the southern areas under Warm Temperate sub-continental climate. The general consistency of the obtained results showed that, with the help of suited analysis methodologies, 8 km AVHRR-NDVI data could be useful for capturing details on vegetation cover activity at local scale even in complex territories such as that of the Italian peninsula.
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Sanches Ferreira, Nedilson, Dênis José Cardoso Gomes, Priscila dos Santos Ribeiro, Lianne Borja Pimenta y José Henrique Cattanio. "VULNERABILIDADE DO SOLO À EROSÃO HÍDRICA, REGIÃO HIDROGRÁFICA DO GUAÍBA-RS". REVISTA GEONORTE 13, n.º 41 (30 de junio de 2022): 191–210. http://dx.doi.org/10.21170/geonorte.2022.v.13.n.41.191.210.
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The population increase in recent years is triggering advances in land use inappropriately and under extreme climatic occurrence, it causes numerous natural disasters, among them soil erosion. The objective of this work is to analyze the vulnerability to soil water erosion in the Guaíba-RS Hydrographic Region. Estimated precipitation data (Global Precipitation Climatology Center) was used; land use (MapBiomas Project); declivity (National Institute for Space Research) and soil (Brazilian Agricultural Research Corporation) in map algebra to obtain the product of soil water erosion. The Guaíba hydrographic region showed stability in the north and southeast, however, extremely unstable areas were detected mainly in the central axis (east-west) with some points to the south. The erosive processes in the region are naturally motivated by declivity and soil, where precipitation is not a major factor in erosion, and this disaster is caused in some points by the anthropic forcing. The control of unstable areas through preservation of vegetation cover and reduction of agricultural progress is essential for the prevention of possible cases of erosion, socio-environmental and economic damage
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COPPOLA, ROSA, VINCENZO CUOMO, MARIAGRAZIA D'EMILIO, MARIA LANFREDI, MARGHERITA LIBERTI, MARIA MACCHIATO y TIZIANA SIMONIELLO. "TERRESTRIAL VEGETATION COVER ACTIVITY AS A PROBLEM OF FLUCTUATING SURFACES". International Journal of Modern Physics B 23, n.º 28n29 (20 de noviembre de 2009): 5444–52. http://dx.doi.org/10.1142/s0217979209063766.
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The role of vegetation cover within the processes that link land and atmosphere is of stringent interest for the correct modeling of Climate dynamics. Temporal and spatial correlation of the terrestrial coverage varies according to Climate and acts as a major forcing on it through changes in surface energy and water balance as well as in the carbon cycle. Recent studies have enhanced the actual and potential impact of this forcing on the radiative balance thus evidencing effects that are at least comparable to that due to all the anthropogenic greenhouse gases together. At now, observational studies on land cover dynamics are strongly in progress thanks to satellite data. The availability of continuous observations of the land surface can allow us to understand the correlation structure, both in time and in space, that characterizes the land cover activity. Satellites provide time series of photosynthetic activity measures that can be regarded as a succession of observations of a two-dimensional scalar field. We exploited the paradigm of fluctuating surfaces as a mechanic analogue for our problem. To capture vegetation cover characteristic time-scales, persistence properties were evaluated by analysing annual maps of NDVI-AVHRR time series and persistence probability was estimated by using the sing-time distribution methodology. The analysis performed for ecoregions of Italian and Greek territories evidenced signatures of short range persistence with characteristic time scales that depend on land cover, climate, and anthropic activities. Our results confirm that such an approach can provide a useful parameterisation for including vegetation into climate models as a dynamical component.
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Botter, Martina, Paolo Burlando y Simone Fatichi. "Anthropogenic and catchment characteristic signatures in the water quality of Swiss rivers: a quantitative assessment". Hydrology and Earth System Sciences 23, n.º 4 (8 de abril de 2019): 1885–904. http://dx.doi.org/10.5194/hess-23-1885-2019.
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Abstract. The hydrological and biogeochemical response of rivers carries information about solute sources, pathways, and transformations in the catchment. We investigate long-term water quality data of 11 Swiss catchments with the objective to discern the influence of major catchment characteristics and anthropic activities on delivery of solutes in stream water. Magnitude, trends, and seasonality of water quality samplings of different solutes are evaluated and compared across catchments. Subsequently, the empirical dependence between concentration and discharge is used to classify the solute behaviors. While the anthropogenic impacts are clearly detectable in the concentration of certain solutes (i.e., Na+, Cl−, NO3, DRP), the influence of single catchment characteristics such as geology (e.g., on Ca2+ and H4SiO4), topography (e.g., on DOC, TOC, and TP), and size (e.g., on DOC and TOC) is only sometimes visible, which is also because of the limited sample size and the spatial heterogeneity within catchments. Solute variability in time is generally smaller than discharge variability and the most significant trends in time are due to temporal variations of anthropogenic rather than natural forcing. The majority of solutes show dilution with increasing discharge, especially geogenic species, while sediment-bonded solutes (e.g., total phosphorous and organic carbon species) show higher concentrations with increasing discharge. Both natural and anthropogenic factors affect the biogeochemical response of streams, and, while the majority of solutes show identifiable behaviors in individual catchments, only a minority of behaviors can be generalized across the 11 catchments that exhibit different natural, climatic, and anthropogenic features.
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Valentini, R., A. Arneth, A. Bombelli, S. Castaldi, R. Cazzolla Gatti, F. Chevallier, P. Ciais et al. "A full greenhouse gases budget of Africa: synthesis, uncertainties, and vulnerabilities". Biogeosciences 11, n.º 2 (28 de enero de 2014): 381–407. http://dx.doi.org/10.5194/bg-11-381-2014.
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Abstract. This paper, developed under the framework of the RECCAP initiative, aims at providing improved estimates of the carbon and GHG (CO2, CH4 and N2O) balance of continental Africa. The various components and processes of the African carbon and GHG budget are considered, existing data reviewed, and new data from different methodologies (inventories, ecosystem flux measurements, models, and atmospheric inversions) presented. Uncertainties are quantified and current gaps and weaknesses in knowledge and monitoring systems described in order to guide future requirements. The majority of results agree that Africa is a small sink of carbon on an annual scale, with an average value of −0.61 ± 0.58 Pg C yr−1. Nevertheless, the emissions of CH4 and N2O may turn Africa into a net source of radiative forcing in CO2 equivalent terms. At sub-regional level, there is significant spatial variability in both sources and sinks, due to the diversity of biomes represented and differences in the degree of anthropic impacts. Southern Africa is the main source region; while central Africa, with its evergreen tropical forests, is the main sink. Emissions from land-use change in Africa are significant (around 0.32 ± 0.05 Pg C yr−1), even higher than the fossil fuel emissions: this is a unique feature among all the continents. There could be significant carbon losses from forest land even without deforestation, resulting from the impact of selective logging. Fires play a significant role in the African carbon cycle, with 1.03 ± 0.22 Pg C yr−1 of carbon emissions, and 90% originating in savannas and dry woodlands. A large portion of the wild fire emissions are compensated by CO2 uptake during the growing season, but an uncertain fraction of the emission from wood harvested for domestic use is not. Most of these fluxes have large interannual variability, on the order of ±0.5 Pg C yr−1 in standard deviation, accounting for around 25% of the year-to-year variation in the global carbon budget. Despite the high uncertainty, the estimates provided in this paper show the important role that Africa plays in the global carbon cycle, both in terms of absolute contribution, and as a key source of interannual variability.
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Pietrodangelo, A., R. Salzano, C. Bassani, S. Pareti y C. Perrino. "Composition, size distribution, optical properties, and radiative effects of laboratory-resuspended PM<sub>10</sub> from geological dust of the Rome area, by electron microscopy and radiative transfer modelling". Atmospheric Chemistry and Physics 15, n.º 22 (27 de noviembre de 2015): 13177–94. http://dx.doi.org/10.5194/acp-15-13177-2015.
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Abstract. In this work, new information has been gained on the laboratory-resuspended PM10 fraction from geological topsoil and outcropped rocks representative of the Rome area (Latium). Mineralogical composition, size distribution, optical properties and the surface radiative forcing efficiency (RFE) of dust types representing the compositional end members of this geological area have been addressed. A multi-disciplinary approach was used, based on chamber resuspension of raw materials and sampling of the PM10 fraction, to simulate field sampling at dust source, scanning electron microscopy/X-ray energy-dispersive microanalysis (SEM XEDS) of individual mineral particles, X-ray diffraction (XRD) analysis of bulk dust samples, building of number and volume size distribution (SD) from microanalysis data of mineral particles and fitting to a log-normal curve, and radiative transfer modelling (RTM) to retrieve optical properties and radiative effects of the compositional end-member dust samples. The mineralogical composition of Rome lithogenic PM10 varies between an end-member dominated by silicate minerals (from volcanics lithotypes), and one mostly composed of calcite (from travertine or limestones). Lithogenic PM10 with intermediate composition derives mainly from siliciclastic rocks or marlstones. Size and mineral species of PM10 particles of silicate-dominated dust types are tuned mainly by rock weathering and, to lesser extent, by debris formation or crystallization; chemical precipitation of CaCO3 plays a major role in calcite-dominated types. These differences are reflected in the diversity of volume distributions, either within dust types or mineral species. Differences are also observed between volume distributions of calcite from travertine (natural source; SD unimodal at 5 μm a.d.) and from road dust (anthropic source; SD bimodal at 3.8 and 1.8 μm a.d.). The volcanics and travertine dusts differently affect the single scattering albedo (SSA) and the asymmetry parameter (g) in the visible (VIS) and near-infrared (NIR) regions. The downward component of the bottom-of-atmosphere (BOA) solar irradiance simulated by RTM for an atmosphere where only volcanics (or only travertine dust) composes the aerosol, shows that the volcanics contribution to the solar irradiance differs significantly from that of travertine in the NIR region, while similar contributions are modelled in the VIS. The RFE (−293 W m−2 for volcanics and −139 W m−2 for travertine, at 50° solar zenith angle) shows that volcanics dust produces a stronger cooling effect at surface than travertine, as expected for more absorbing aerosols.
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Faccini, Francesco, Fabio Luino, Guido Paliaga, Anna Roccati y Laura Turconi. "Flash Flood Events along the West Mediterranean Coasts: Inundations of Urbanized Areas Conditioned by Anthropic Impacts". Land 10, n.º 6 (9 de junio de 2021): 620. http://dx.doi.org/10.3390/land10060620.
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Flash floods represent one of the natural hazards that causes the greatest number of victims in the Mediterranean area. These processes occur by short and intense rainfall affecting limited areas of a few square kilometers, with rapid hydrological responses. Among the causes of the flood frequency increase in the last decades are the effects of the urban expansion in areas of fluvial pertinence and climatic change, namely the interaction between anthropogenic landforms and hydro-geomorphological dynamics. In this paper the authors show a comparison between flood events with very similar weather-hydrological characteristics and the ground effects occurred in coastal areas of three regions located at the top of a triangle in the Ligurian Sea, namely Liguria, Tuscany and Sardinia. With respect to the meteorological-hydrological hazard, it should be noted that the events analyzed occurred during autumn, in the conditions of a storm system triggered by cyclogenesis on the Genoa Gulf or by the extra-tropical cyclone Cleopatra. The “flash floods” damage recorded in the inhabited areas is due to the vulnerability of the elements at risk in the fluvio-coastal plains examined. There are numerous anthropogenic forcings that have influenced the hydro-geomorphological dynamics and that have led to an increase in risk conditions.
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Biondo, Manuela, Carla Buosi, Daniele Trogu, Hannah Mansfield, Matteo Vacchi, Angelo Ibba, Marco Porta, Andrea Ruju y Sandro De Muro. "Natural vs. Anthropic Influence on the Multidecadal Shoreline Changes of Mediterranean Urban Beaches: Lessons from the Gulf of Cagliari (Sardinia)". Water 12, n.º 12 (20 de diciembre de 2020): 3578. http://dx.doi.org/10.3390/w12123578.
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Urban Mediterranean beaches are often characterized by a fragile and unstable equilibrium that can be easily altered by ongoing climate change and by the increase in human pressure. This may pose serious threats to the survival of beach systems that cannot accommodate these modifications. In this paper, the spatio-temporal shift of the shoreline was investigated along two urban beaches in the Gulf of Cagliari (Poetto and Giorgino; southern Sardinia, western Mediterranean Sea) across a time frame of 62 years (1954–2016). The Digital Shoreline Analysis System (DSAS) ArcGIS™ extension was used to extract different statistical parameters which allowed us to quantify the erosion and accretion rates. These data were further examined in relation to a number of anthropic and natural forcings in order to disentangle the factors controlling shoreline evolution. Eight sectors with interchanging net erosive and accretion trends were identified along the Poetto and Giorgino beaches. In six decades, some sectors of the two study sites appeared to have undergone great shoreline modification as a result of the intense anthropogenic activities impacting these coastal areas. The westernmost portions of both beaches were found to be the most vulnerable to erosion processes; such conditions were likely controlled by the interplaying of local hydrodynamics and by the intense coastal development which affected these sectors. The highest retreat rates (mean end point rate (EPR) = −0.51/year) were recorded in the western limit of Giorgino beach. Along the western limit of Poetto beach, EPR erosion rates (mean EPR = −2.92/year) considerably increased in the years after the artificial beach nourishment carried out in 2002, suggesting that the majority of the nourished material was lost offshore or partly redistributed along the beach. Coastal structures, urban development, river catchment modification, industrial and port activities, beach cleaning and touristic and recreational activities have been identified as the ongoing causes of coastal alteration. If these factors remain constant, under projected climate change scenarios, these beaches are at risk of further increased flooding and erosion. In this context, the application of DSAS appeared as an essential tool, supporting a monitoring system able to provide understanding and, potentially, predictions of the short- to long-term evolution of these beach systems.
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Caruso, Gabriella, Maria Grazia Giacobbe, Filippo Azzaro, Franco Decembrini, Marcella Leonardi, Stefano Miserocchi, Xiuyun Cao, Chunlei Song y Yiyong Zhou. "All-In-One: Microbial Response to Natural and Anthropogenic Forcings in a Coastal Mediterranean Ecosystem, the Syracuse Bay (Ionian Sea, Italy)". Journal of Marine Science and Engineering 10, n.º 1 (26 de diciembre de 2021): 19. http://dx.doi.org/10.3390/jmse10010019.
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Bacterial and phytoplankton communities are known to be in close relationships, but how natural and anthropogenic stressors can affect their dynamics is not fully understood. To study the response of microbial communities to environmental and human-induced perturbations, phytoplankton and bacterial communities were seasonally monitored in a Mediterranean coastal ecosystem, Syracuse Bay, where multiple conflicts co-exist. Quali-quantitative, seasonal surveys of the phytoplankton communities (diatoms, dinoflagellates and other taxa), the potential microbial enzymatic activity rates (leucine aminopeptidase, beta-glucosidase and alkaline phosphatase) and heterotrophic culturable bacterial abundance, together with the thermohaline structure and trophic status in terms of nutrient concentrations, phytoplankton biomass (as Chlorophyll-a), and total suspended and particulate organic matter, were carried out. The aim was to integrate microbial community dynamics in the context of the environmental characterization and disentangle microbial patterns related to natural changes from those driven by the anthropic impact on this ecosystem. In spite of the complex relationships between the habitat characteristics, microbial community abundance and metabolic potential, in Syracuse Bay, the availability of organic substrates differently originated by the local conditions appeared to drive the distribution and activity of microbial assemblage. A seasonal pattern of microbial abundances was observed, with the highest concentrations of phytoplankton in spring and low values in winter, whereas heterotrophic bacteria were more abundant during the autumn period. The autumn peaks of the rates of enzymatic activities suggested that not only phytoplankton-derived but also allochthonous organic polymers strongly stimulated microbial metabolism. Increased microbial response in terms of abundance and metabolic activities was detected especially at the sites directly affected by organic matter inputs related to agriculture or aquaculture activities. Nitrogen salts such as nitrate, rather than orthophosphate, were primary drivers of phytoplankton growth. This study also provides insights on the different seasonal scenarios of water quality in Syracuse Bay, which could be helpful for management plans of this Mediterranean coastal environment.
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Viola, F., L. V. Noto y D. Pumo. "Parametric uncertainty or hydrological changes?" Proceedings of the International Association of Hydrological Sciences 364 (16 de septiembre de 2014): 134–39. http://dx.doi.org/10.5194/piahs-364-134-2014.
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Abstract. The model calibration is the way of hydrologists for searching also a physical interpretation of complex interactions acting within a basin. Actually, it can be frequently noticed how model calibration performed on a given time-window may converge to a point in the parameter space that could be distant from another obtainable calibration of the model in the same basin but considering a different time window. Is that again parametric uncertainty or does the trajectory in the parametric space relate about to a slow hydrological basin change? This paper depicts a possible path for detecting changes' signatures in a streamflow time series. In particular, the paper seeks to draw a way to discern the random variability over different time-windows of the calibrated model parameters set from that induced by the variation in time of some boundary conditions and external forcings. To this purpose, we will refer to a conceptual lumped model for simulating daily streamflow, the EHSM (EcoHydrological Streamflow Model), and to a hypothetical case study. The selected hydrological model requires a total of seven parameters, some of which can be easily related to land use, while others rely on climate variables. The calibration of the EHSM parameters with regard to different time-windows and the analysis of potential impacts of the anthropic variation in land use and/or climatic variability on the calibrated parameters set, will support our investigation.
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Foti, Giandomenico, Giuseppe Barbaro, Giuseppina Chiara Barillà y Pierluigi Mancuso. "Shoreline Changes Due to the Construction of Ports: Case Study—Calabria (Italy)". Journal of Marine Science and Engineering 11, n.º 12 (18 de diciembre de 2023): 2382. http://dx.doi.org/10.3390/jmse11122382.
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An important process that began in many Mediterranean countries in the last century, after the end of the Second World War, concerns the displacement of a large part of the population from inland to coastal areas, expanding many existing cities and building new ones. Following this expansion, some existing ports were expanded, and many new ports were built, mainly for commercial and tourist purposes. This strong anthropogenic pressure has modified not only the landscape but also the coastal dynamics, and significant shoreline erosion processes have often been observed, even at considerable distances from the ports. This paper analyzes shoreline changes due to the construction of ports in Calabria, based on geomorphological factors and wave forcings. Calabria is a region of Southern Italy, on the Mediterranean Sea, that is characterized by geomorphological, climatic, and anthropic peculiarities. In addition, other important effects caused by the construction of ports were also analyzed, such as shoreline advancement updrift, construction of coastal protection structures, siltation, and anthropogenic pressure. The main finding of this analysis is that coastal morphology plays a key role in the extent of shoreline changes due to the construction of ports. In fact, the greatest shoreline retreats were observed downdrifts of ports built in straight coastal areas. Furthermore, this analysis highlights that there is no direct correlation between wave climate and shoreline changes near the examined ports. The analysis described in this paper may be of interest both to the scientific field and to the planning and management of coastal areas. Furthermore, it is based on open-access data and was carried out using free software such as QGIS, so it is easily replicable and applicable in any coastal context.
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Napoli, Anna, Alice Crespi, Francesco Ragone, Maurizio Maugeri y Claudia Pasquero. "Variability of orographic enhancement of precipitation in the Alpine region". Scientific Reports 9, n.º 1 (16 de septiembre de 2019). http://dx.doi.org/10.1038/s41598-019-49974-5.
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Abstract Climate change impacts are non uniformly distributed over the globe. Mountains have a peculiar response to large scale variations, documented by elevation gradients of surface temperature increase observed over many mountain ranges in the last decades. Significant changes of precipitation are expected in the changing climate and orographic effects are important in determining the amount of rainfall at a given location. It thus becomes particularly important to understand how orographic precipitation responds to global warming and to anthropogenic forcing. Here, using a large rain gauge dataset over the European Alpine region, we show that the distribution of annual precipitation among the lowlands and the mountains has varied over time, with an increase of the precipitation at the high elevations compared to the low elevations starting in the mid 20 century and peaking in the 1980s. The simultaneous increase and peak of anthropogenic aerosol load is discussed as a possible source for this interdecadal change. These results provide new insights to further our understanding and improve predictions of anthropic effects on mountain precipitations, which are fundamental for water security and management.
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Regattieri, Eleonora, Giovanni Zanchetta, Ilaria Isola, Elena Zanella, Russell N. Drysdale, John C. Hellstrom, Andrea Zerboni et al. "Holocene Critical Zone dynamics in an Alpine catchment inferred from a speleothem multiproxy record: disentangling climate and human influences". Scientific Reports 9, n.º 1 (28 de noviembre de 2019). http://dx.doi.org/10.1038/s41598-019-53583-7.
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AbstractDisentangling the effects of climate and human impact on the long-term evolution of the Earth Critical Zone is crucial to understand the array of its potential responses to the ongoing Global Change. This task requires natural archives from which local information about soil and vegetation can be linked directly to climate parameters. Here we present a high-resolution, well-dated, speleothem multiproxy record from the SW Italian Alps, spanning the last ~10,000 years of the present interglacial (Holocene). We correlate magnetic properties and the carbon stable isotope ratio to soil stability and pedogenesis, whereas the oxygen isotope composition is interpreted as primarily related to precipitation amount, modulated at different timescales by changes in precipitation source and seasonality. During the 9.7-2.8 ka period, when anthropic pressure over the catchment was scarce, intervals of enhanced soil erosion are related to climate-driven vegetation contractions and occurred during drier periods. Immediately following the onset of the Iron Age (ca. 2.8 ka), by contrast, periods of enhanced soil erosion coincided with a wetter climate. We propose that the observed changes in the soil response to climate forcing were related to early anthropogenic manipulations of Earth’s surface, which made the ECZ more sensitive to climate oscillations.
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San Martín, Rodrigo, Catherine Ottlé y Anna Sörensson. "Fires in the South American Chaco, from dry forests to wetlands: response to climate depends on land cover". Fire Ecology 19, n.º 1 (2 de octubre de 2023). http://dx.doi.org/10.1186/s42408-023-00212-4.
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Abstract Background Wildfires represent an important element in the bio-geophysical cycles of various ecosystems across the globe and are particularly related to land transformation in tropical and subtropical regions. In this study, we analyzed the links between fires, land use (LU), and meteorological variables in the South American Chaco (1.1 million km2), a global deforestation hotspot and fire-exposed region that has recently attracted greater attention as the largest and one of the last tropical dry forests in the world. Results We found that the Dry Chaco (73% of the total area of Chaco) exhibits a unimodal fire seasonality (winter-spring), and the Wet Chaco (the remaining 23%) displays a bimodal seasonality (summer-autumn and winter-spring). While most of the burnt area (BA) was found in the Wet Chaco (113,859 km2; 55% of the entire BA), the Dry Chaco showed the largest fraction of forest loss (93,261 km2; 88% of the entire forest loss). Between 2001 and 2019, 26% of the entire Chaco’s forest loss occurred in areas with BA detections, and this percentage varies regionally and across countries, revealing potential connections to LU and policy. Argentina lost 51,409 km2 of its Chaco tree cover, surpassing the forest losses of Paraguay and Bolivia, and 40% of this loss was related to fire detections. The effect of meteorological fluctuations on fuel production and flammability varies with land cover (LC), which emerged as the principal factor behind BA. While wet areas covered with herbaceous vegetation showed negative correlations between BA and precipitation, some dry regions below 800 mm/year, and mostly covered by shrublands, showed positive correlations. These results reveal the two different roles of precipitation in (a) moisture content and flammability and (b) production of biomass fuel. Conclusions As fires and deforestation keep expanding in the South American Chaco, our study represents a step forward to understanding their drivers and effects. BA is dependent on LC types, which explains the discrepancies in fire frequency and seasonality between the Wet and Dry Chaco subregions. The links between fires and deforestation also vary between regions and between countries, exposing the role of anthropic forcing, land management, and policy. To better understand the interactions between these drivers, further studies at regional scale combining environmental sciences with social sciences are needed. Such research should help policy makers take action to preserve and protect the remaining forests and wetlands of the Chaco.
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Lewin, John y Tom O’Shea. "The shape-shifting form of UK floodplains: Fusing analysis of the territorially constructed with analysis of natural terrain processes". Progress in Physical Geography: Earth and Environment, 17 de marzo de 2023, 030913332311565. http://dx.doi.org/10.1177/03091333231156510.
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Physically, river floodplains have both the subdued morphology of natural terrain created as extreme discharges and sediments pass through catchment drainage systems and, to an increasing extent, the forms that arise from purposeful human constructions. Together, these direct out-of-channel inundation. As defined here, ‘territories’ and their humanly constructed physical forms have historically consumed or modified naturally created ‘terrains’ in a collection of actions that we summarize as ‘morphophagia’. A more inclusive physical geography is presented, adding-in explanations for the evolutionary phasing of humanly-generated, but environmentally functioning, physical forms in the UK in the Modern Era (since c.1500 CE). Floodplain developments here took place in five main episodes of historically-contingent accumulation: the Early Modern (c.1500–1780 CE) started with a framework of purposeful owned land, and then followed periods that can be related to Kondratieff global economic phases (c.1790–1840,1840–1900,1900–1947,1947–2000 CE). Three different groups of forcings operated: (1) the compartmentalizing and patched infill patterns set by territorial units, rights and developer ownerships; (2) the availability, motivations and timings for capital and labour investment; and (3) the evolving technical possibilities exploited by entrepreneurs and agents. Epistemic frameworks for broadening the analysis of coupled terrain and territory systems, exploring actuating social forces as much as their symptomatic physical outcomes, are discussed. Globally, there have been different forcings, timings and emplacement layouts operating at scales from local river reaches to city expansion and economic regions. As perceptions of environmental stasis now disintegrate, enthusiasm for reinvigorating economic growth, with further population increase and sprawling construction may, as in the past, discount the hazards of floodplain occupation. When and why risky anthropo-physical floodplain emplacements occur needs greater systematic understanding as social and economic initiatives are being considered.