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161.
Pereira Rafael H. M. Andrade Pedro R. Vieira João Pedro Bazzo 《Journal of Geographical Systems》2023,25(3):453-466
Journal of Geographical Systems - The creation of the General Transit Feed Specification (GTFS) in the mid-2000s provided a new data format for cities to organize and share digital information on... 相似文献
162.
Avellaneda PM Englehardt JD Olascoaga J Babcock EA Brand L Lirman D Rogge WF Solo-Gabriele H Tchobanoglous G 《Marine pollution bulletin》2011,62(10):2157-2169
A relative risk assessment of biosolids disposal alternatives for cruise ships is presented in this paper. The area of study encompasses islands and marine waters of the Caribbean Sea. The objective was to evaluate relative human health and ecological risks of (a) dewatering/incineration, (b) landing the solids for disposal, considering that in some countries land-disposed solids might be discharged in the near-shore environment untreated, and (c) deep ocean disposal. Input to the Bayesian assessment consisted of professional judgment based on available literature and modeling information, data on constituent concentrations in cruise ship biosolids, and simulations of constituent concentrations in Caribbean waters assuming ocean disposal. Results indicate that human health and ecological risks associated with land disposal and shallow ocean disposal are higher than those of the deep ocean disposal and incineration. For incineration, predicted ecological impacts were lower relative to deep ocean disposal before considering potential impacts of carbon emissions. 相似文献
163.
Jaime A. Santos Pedro Chitas Isabel Lopes Carlos Sousa Oliveira Isabel Moitinho de Almeida João Carlos Nunes 《Soil Dynamics and Earthquake Engineering》2011
The Azores archipelago is located at the North America, Eurasia and Africa triple junction and shows seismicity and volcanism typical of an active plate boundary. Terceira Island has been affected by several damaging earthquakes being the 1980 January 1st event (M=7.2) the strongest in Azores during the last century. 相似文献
164.
José Maria Santos Luís Reino João Oliveira Paulo Pinheiro Pedro Raposo Almeida Rui Cortes Maria Teresa Ferreira 《Aquatic Sciences - Research Across Boundaries》2011,73(2):233-245
Knowledge of the distribution of species life stages at multiple spatial scales is fundamental to both a proper assessment
of species management and conservation programmes and the ability to predict the consequences of human disturbances for river
systems. The habitat requirements of three native cyprinid species—the Iberian barbel Barbus bocagei Steindachner, the Iberian straight-mouth nase Pseudochondrostoma polylepis (Steindachner), and the Northern straight-mouth nase Pseudochondrostoma duriense (Coelho)—were examined at 174 undisturbed or minimally disturbed sites in 8 river catchments across western Iberia, by modelling
occurrence and counts of species life stages at two spatial scales—large (regional) and instream (local)—using hurdle models.
All the life stages of the barbel showed a negative association with upstream high-gradient river reaches, whereas juvenile
P. duriense favoured such areas. Stream width and openness were negatively related with the occurrence of juvenile and small adult barbel,
but not with large adults. Juvenile nase, on the other hand, were found to be mainly confined to fast-flowing habitats with
high instream cover and coarser substrata. Advanced life stages of the barbel were mainly associated with the “pure” regional
and shared components, whereas the purely local attributes accounted for much of the model variation among nases, in particular
juveniles, and juvenile barbel. The results of this study are useful for setting or refining management goals, and highlight
the need to separately consider life stages when performing conservation-related studies of species distribution. 相似文献
165.
Milagrosa Aldana Vincenzo Costanzo-Álvarez Luis Gómez Carlos González Marisel Díaz Pedro Silva Myriam Rada 《Studia Geophysica et Geodaetica》2011,55(2):343-358
In this work we try to better characterise the shallow magnetic signature of hydrocarbon microseepage in oil fields from eastern
and western Venezuela. To get a better insight of the processes involved, we attempt to find out the main magnetic phases
responsible for the observed oil-related shallow magnetic anomalies. In this way, a new and alternative numerical approach
to decompose Isothermal Remagnetization (IRM) curves is introduced. The method is based on a Direct Signal Analysis (DSA)
of the IRM curve in order to identify the number and type of magnetic components. Representative wells from western (La Victoria)
and eastern (San Joaquín) Venezuelan fields are studied. The DSA approach, together with rock magnetic experimental results,
indicates that in the well from western Venezuela the main magnetic mineralogy associated to hydrocarbon microseepage is magnetite.
Conversely, in the well from eastern Venezuela, these MS anomalies are mainly caused by the presence of Fe-sulphides (i.e.
greigite). These results support the hypothesis of two different authigenic processes. For the well at the western field,
we propose that a net electron transfer from the organic matter, degraded by hydrocarbon gas leakage, should occur precipitating
Fe(II) magnetic minerals (e.g. magnetite). On the other hand, in the well of the eastern field, high concentrations of H2S
at shallow levels, might allow the formation of secondary Fe-sulphides. 相似文献
166.
Boris P. Koch Pedro W.M. Souza FilhoHermann Behling Marcelo C.L. CohenGerhard Kattner Jürgen RullkötterBarbara Scholz-Böttcher Rubén J. Lara 《Organic Geochemistry》2011,42(1):62-73
Mangroves are the dominant type of vegetation along many tropical coasts. Organic matter (OM) derived from mangrove leaf litter and root material is stored in sediments and is a major contributor to the amount and chemical composition of sedimentary OM. A set of organic biomarkers in sediments was applied as a palaeo-indicator for the Holocene dynamics of a mangrove Estuary (Rio Caeté, Pará, Brazil). Six sediment cores were collected perpendicular to the present coast line and analysed for triterpenols and sitosterol. The influence of microbial biomarker degradation was implemented from a previous study. Biomarker profiles were validated with pollen data and multivariate statistics to test whether these compounds were suitable indicators for the palaeo-vegetation. Sediments deposited up to 2 Ma BP showed biomarker assemblages similar to those of recent surface sediment. In two cores, the biomarker composition revealed a transition from marsh to mangrove vegetation. Taraxerol, germanicol and β-amyrin provided the most significant chemotaxonomical information and, especially in combination, served as reliable proxies for OM from Rhizophora mangle in northern Brazil. The maximum age of the mangrove system ranged between 1000 and 5100 yr depending on the topographic elevation of the drilling location. 相似文献
167.
Pedro Walfir M. Souza-Filho Waldir R. Paradella Suzan W.P. Rodrigues Francisco R. Costa José C. Mura Fabrício D. Gonçalves 《Estuarine, Coastal and Shelf Science》2011
This study assessed the use of multi-polarized L-band images for the identification of coastal wetland environments in the Amazon coast region of northern Brazil. Data were acquired with a SAR R99B sensor from the Amazon Surveillance System (SIVAM) on board a Brazilian Air Force jet. Flights took place in the framework of the 2005 MAPSAR simulation campaign, a German-Brazilian feasibility study focusing on a L-band SAR satellite. Information retrieval was based on the recognition of the interaction between a radar signal and shallow-water morphology in intertidal areas, coastal dunes, mangroves, marshes and the coastal plateau. Regarding the performance of polarizations, VV was superior for recognizing intertidal area morphology under low spring tide conditions; HH for mapping coastal environments covered with forest and scrub vegetation such as mangrove and vegetated dunes, and HV was suitable for distinguishing transition zones between mangroves and coastal plateau. The statistical results for the classification maps expressed by kappa index and general accuracy were 83.3% and 0.734 for the multi-polarized color composition (R-HH, G-HV, B-VV), 80.7% and 0.694% for HH, 79.7% and 0.673% for VV, and 77.9% and 0.645% for HV amplitude image. The results indicate that use of multi-polarized L-band SAR is a valuable source of information aiming at the identification and discrimination of distinct geomorphic targets in tropical wetlands. 相似文献
168.
Pedro N. Carvalho Pedro Nuno R. RodriguesRafael Evangelista M. Clara P. BastoM. Teresa S.D. Vasconcelos 《Estuarine, Coastal and Shelf Science》2011
Sediments are depositories of toxic substances such as organochlorine pesticides and there is a global need for their removal in contaminated environments. Studies that combine contaminated sediments and phytoremediation are relatively recent and their number has been increasing. This work aimed to investigate whether salt marsh plants (sea club-rush Scirpus maritimus, sea rush Juncus maritimus and sea purslane Halimione portulacoides) can favor DDT and metabolites remediation in estuarine environment. For this purpose the levels of DDT, DDE and DDD were compared in vegetated and non-vegetated sediments from an estuary in the North of Portugal (in-situ study) and from another in the South of Portugal (ex-situ study). Results obtained both in the in-situ study, involving S. maritimus and J. maritimus, and in the ex-situ study, involving H. portulacoides, indicated that these plants did not have a significant role in DDTs removal and/or degradation. Therefore, it seems that the tested plants cannot influence levels and distribution of DDTs in estuarine areas. 相似文献
169.
Recent structures in the Alboran Ridge and Yusuf fault zones based on swath bathymetry and sub-bottom profiling: evidence of active tectonics 总被引:2,自引:2,他引:0
The seafloor of the Alboran Sea in the western Mediterranean is disrupted by deformations resulting from convergence between
the African and Eurasian plates. Based on a compilation of existing and new multibeam bathymetry data and high-resolution
seismic profiles, our main objective was to characterize the most recent structures in the central sector, which depicts an
abrupt morphology and was chosen to investigate how active tectonic processes are shaping the seafloor. The Alboran Ridge
is the most prominent feature in the Alboran Sea (>130 km in length), and a key element in the Gibraltar Arc System. Recent
uplift and deformation in this ridge have been caused by sub-vertical, strike-slip and reverse faults with associated folding
in the most recent sediments, their trend shifting progressively from SW–NE to WNW–ESE towards the Yusuf Lineament. Present-day
transtensive deformation induces faulting and subsidence in the Yusuf pull-apart basin. The Alboran Ridge and Yusuf fault
zones are connected, and both constitute a wide zone of deformation reaching tens of kilometres in width and showing a complex
geometry, including different active fault segments and in-relay folds. These findings demonstrate that Recent deformation
is more heterogeneously distributed than commonly considered. A narrow SSW–NNE zone with folding and reverse faulting cuts
across the western end of the Alboran Ridge and concentrates most of the upper crustal seismicity in the region. This zone
of deformation defines a seismogenic, left-lateral fault zone connected to the south with the Al Hoceima seismic swarm, and
representing a potential seismic hazard. Newly detected buried and active submarine slides along the Alboran Ridge and the
Yusuf Lineament are clear signs of submarine slope instability in this seismically active region. 相似文献
170.
Relationships among environmental patterns and population size of the smut lizard Gallotia galloti galloti Oudart, 1839 (Sauria Lacertidae) were examined in the context of longer time-scale variability on a sandy beach and adjacent environments of Southeastern Tenerife. Seasonal and yearly patterns in the population size were likewise analyzed in relation to climatic and anthropic variables. Six sampling plots (coastal, sweet tabaiba, tuff, lava, sandy lava and crater) were selected following a perpendicular transect to the sandy fringe that extends from the beach toward the volcanic interior. Pitfall trapping was conducted from 1984 to 2005, and capture–mark–recapture technique and the Jolly–Seber method were used to estimate population sizes. The highest population size estimates were shown on the sandy lava plot and the neighboring lava plot, reaching values of about 3500 individuals ha−1 during the spring. The population was active almost the whole year, with seasonal patterns of activity from March to October. Seasonal temperature and population size patterns were correlated but the 'calima' episodes produced some disturbance. Gallotia galloti galloti was one of the most abundant lizards of all the species studied and its population size has not remained stable over the study period, probably because of the absence of predation and competition, and because of human interference and environmental instability. 相似文献