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131.
dos Santos Janaína Cassiano Lyra Gustavo Bastos Abreu Marcel Carvalho de Oliveira-Júnior José Francisco Bohn Leonardo Cunha-Zeri Gisleine Zeri Marcelo 《Natural Hazards》2022,111(3):2531-2558
Natural Hazards - Desertification is a land degradation phenomenon with dire and irreversible consequences, affecting different regions of the world. Assessment of spatial climate susceptibility to... 相似文献
132.
133.
Dias Miguel Gustavo Festugato Lucas Batista Moreira Eclesielter Bellaver Corte Marina 《Geotechnical and Geological Engineering》2021,39(6):4649-4653
Geotechnical and Geological Engineering - Discussers offered comments to enhance results analysis. An alternative evaluation was proposed using the η/Biv index, where the Biv parameter, named... 相似文献
134.
Gustavo E. Romero † Diego F. Torres I. Andruchow Luis A. Anchordoqui Bennett Link † 《Monthly notices of the Royal Astronomical Society》1999,308(3):799-806
Based on Link & Epstein's study of temporal asymmetry of 631 gamma-ray bursts from the BATSE 3B catalogue, we identify the population of bursts with rising times that are longer than their decays, thus showing atypical profiles. We analyse their sky distribution, morphology, time–space clustering and other average properties and compare them with those associated with the bulk of the bursts. We show how most of the peculiar bursts analysed are consistent with recent fireball models, but a fraction of bursts (∼4 per cent of the total sample) appear to be inconsistent. 相似文献
135.
136.
Five exposed microtidal sandy beaches of North-eastern Buenos Aires (Argentina) were analysed to evaluate the influence of coastal dynamics on the abundance of the intertidal clams Donax hanleyanus and Mesodesma mactroides over a 1-year period. The physical characterisation of each beach was performed using 15 environmental variables and six morphodynamic indices. The population densities of both clam species were estimated by the number of individuals per strip-transect. Analysis of similarities revealed a significant multivariate environmental difference among beaches, which could be aggregated into a northern and a southern group. The former group was characterised by an intermediate morphodynamic state and by having, in general, high density values for both clam species. The latter was composed of beaches with an intermediate reflective state and showed, in general, low density values. Beach Index and Area showed the lowest temporal variation. Total density values, as well as density values of recruits and adults of D. hanleyanus and M. mactroides did not follow a north–south latitudinal gradient. Spatial and temporal fluctuations of density values were best explained by changes in individual physical variables rather than by changes in composite indices. 相似文献
137.
Veronica P. Bernardes Aline N. Sousa Camila H. Bernardo Gustavo M. Teixeira Rogério C. Costa Fernando L. Mantelatto Adilson Fransozo 《Marine Ecology》2020,41(5):e12605
This study was motivated by the data about a Rimapenaeus constrictus population from Ubatuba Bay, obtained in the 1990s, and by the establishment of a marine protected area (MPA) in the same region in 2008. We obtained comparable data about the distribution and abundance of this species collected 20 years apart, to evaluate the effectiveness of the MPA, for its preservation and possible changes in the populational profile. Biotic and abiotic data were obtained monthly, in September 1995–August 1996 (period 1 = 1ºP), and in September 2016–August 2017 (period 2 = 2ºP), from five transects within Ubatuba Bay. In total, 710 and 2,362 individuals were caught in the 1oP and 2oP, respectively. Despite this increase in abundance, aspects of the spatial distribution did not change substantially. The high abundance recorded at 5 m of depth was probably due to the creation of the MPA and to the accumulation of detritus at this depth. The high abundance seen in the transect sheltered from waves may be related to sediment heterogeneity, which was higher in this transect, and to the fact that this area is naturally protected from fisheries. In the 1ºP, the highest abundances were recorded in spring and summer, whereas in the 2ºP, they occurred in autumn and winter. This change may be explained by the entrance of the South Atlantic Central Water (SACW), which drives shrimps towards shallower areas. During the 2ºP, a fishing ban occurred in autumn (March 1st until May 31st), which is also when the SACW retreats and water temperature and salinity increase. These two factors combined may have been responsible for the increased shrimp abundance. In conclusion, both conservation practices (MPA and fishing ban) along with the existence of an area naturally protected from fisheries seem to have positively affected the population of R. constrictus, leading to an increase in abundance over the 20-year interval. 相似文献
138.
John J. Lyons Gregory P. Waite William I. Rose Gustavo Chigna 《Bulletin of Volcanology》2010,72(1):1-15
Fuego volcano, Guatemala is a high (3,800 m) composite volcano that erupts gas-rich, high-Al basalt, often explosively. It
spends many years in an essentially open vent condition, but this activity has not been extensively observed or recorded until
now. The volcano towers above a region with several tens of thousands of people, so that patterns in its activity might have
hazard mitigation applications. We conducted 2 years of continuous observations at Fuego (2005–2007) during which time the
activity consisted of minor explosions, persistent degassing, paroxysmal eruptions, and lava flows. Radiant heat output from
MODIS correlates well with observed changes in eruptive behavior, particularly during abrupt changes from passive lava effusion
to paroxysmal eruptions. A short-period seismometer and two low-frequency microphones installed during the final 6 months
of the study period recorded persistent volcanic tremor (1–3 Hz) and a variety of explosive eruptions. The remarkable correlation
between seismic tremor, thermal output, and daily observational data defines a pattern of repeating eruptive behavior: 1)
passive lava effusion and subordinate strombolian explosions, followed by 2) paroxysmal eruptions that produced sustained
eruptive columns, long, rapidly emplaced lava flows, and block and ash flows, and finally 3) periods of discrete degassing
explosions with no lava effusion. This study demonstrates the utility of low-cost observations and ground-based and satellite-based
remote sensing for identifying changes in volcanic activity in remote regions of underdeveloped countries. 相似文献
139.
Pablo García-Borboroglu P. Dee Boersma Valeria Ruoppolo Andréa Corrado-Adornes Raquel Velozo Gustavo Dutra Cláudia Carvalho-do-Nascimento Lupércio Barbosa 《Marine pollution bulletin》2010,60(10):1652-1657
Magellanic penguins migrate from Patagonia reaching northern Argentina, Uruguay, and southern Brazil on their winter migration, in parallel with the seasonal pulse of anchovy spawning. In 2008, Magellanic penguins went further north than usual. Many died and a few swam nearly to the Equator. Twelve groups surveyed 5000 km of coastline encountering 3371 penguins along the coast. Most penguins arrived in northern Brazil (68.4%) without petroleum (2933, 87%). Almost all penguins without petroleum were juveniles (2915, 99%) and 55% were alive when found. Penguins were dehydrated, anemic, hypothermic, and emaciated. Of the penguins with petroleum, 13% arrived in the southern half of Brazil, showing that petroleum pollution remains a problem along the SW Atlantic coast. The mortality occurred in the winter of 2008 when sea surface temperature were unusually cold perhaps reducing the prey for penguins. 相似文献
140.
Flood hazard mapping in Southern Brazil: a combination of flow frequency analysis and the HAND model 总被引:1,自引:1,他引:0
Gustavo Andrei Speckhann Roberto Fabris Goerl Janete Josina de Abreu Juan Antonio Altamirano Flores 《水文科学杂志》2018,63(1):87-100
The Itajaí River basin is one of the areas most affected by flood-related disasters in Brazil. Flood hazard maps based on digital elevation models (DEM) are an important alternative in the absence of detailed hydrological data and for application in large areas. We developed a flood hazard mapping methodology by combining flow frequency analysis with the Height Above the Nearest Drainage (HAND) model – f2HAND – and applied it in three municipalities in the Itajaí River basin. The f2HAND performance was evaluated through comparison with observed 2011 flood extent maps. Model performance and sensitivity were tested for different DEM resolutions, return periods and streamflow data from stations located upstream and downstream on the main river. The flood hazard mapping with our combined approach matched 92% of the 2011 flood event. We found that the f2HAND model has low sensitivity to DEM resolution and high sensitivity to area threshold of channel initiation. 相似文献