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81.
Hydroclimatology of the Upper Madeira River basin: spatio-temporal variability and trends 总被引:1,自引:0,他引:1
Jorge Molina-Carpio Jhan Carlo Espinoza Philippe Vauchel Josyane Ronchail Beatriz Gutierrez Caloir Jean-Loup Guyot 《水文科学杂志》2017,62(6):911-927
Rising in the Andes, the Madeira River drains the southwestern part of the Amazon basin, which is characterized by high geographical, biological and climatic diversity. This study uses daily records to assess the spatio-temporal runoff variability in the Madeira sub-basins. Results show that inter-annual variability of both discharge and rainfall differs between Andean and lowland tributaries. High-flow discharge variability in the Andean tributaries and the Guaporé River is mostly related to sea surface temperature (SST) in the equatorial Pacific in austral summer, while tropical North Atlantic (TNA) SST modulates rainfall and discharge variability in the lowlands. There also is a downward trend in the low-flow discharge of the lowland tributaries which is not observed in the Andes. Because low-flow discharge values at most lowland stations are negatively related to the SST in the tropical North Atlantic, these trends could be explained by the warming of this ocean since the 1970s.
EDITOR A. CastellarinASSOCIATE EDITOR A. Viglione 相似文献
82.
Luis Alberto Rojo Dora Marín Nestor Cardozo Alejandro Escalona Hemin Koyi 《Basin Research》2020,32(5):979-1004
Although the trajectory and geometry of clinoforms in different types of basins have been described in many studies, few studies discuss the influence of halokinesis on clinoforms in salt-related basins. In this study, we analyse the Lower Cretaceous clinoforms in the Tiddlybanken Basin, Norwegian Barents Sea to evaluate the impact of salt mobilization on the geometry and trajectory of clinoforms as well as its implications on sediment partitioning. To accomplish this objective, we use a multidisciplinary approach consisting of seismic and well-interpretation, 3D structural restoration, and forward stratigraphic modelling. The results show that salt mobilization affects prograding clinoforms by: (a) causing lateral variations in progradation rates, resulting in complex palaeogeography, (b) increasing slope angles, which affect the equilibrium of the clinoform profile and can trigger slope-readjustment processes and (c) producing lateral and temporal variations in accommodation space, leading to different clinoform trajectories, stacking patterns and reservoir distribution along the basin. Forward stratigraphic modelling shows that in salt-related basins and other tectonically active basins, the isolated use of conventional methods for clinoform analysis might lead to potential interpretation pitfalls such as misinterpretation of trajectories and overestimation of foreset angles, which can have negative consequences for exploration models. 相似文献
83.
José-María Montero-Lorenzo Beatriz Larraz-Iribas Antonio Páez 《Journal of Geographical Systems》2009,11(4):407-425
A vast majority of the recent literature on spatial hedonic analysis has been concerned with residential property values,
with only very few examples of studies focused on commercial property prices. The dearth of studies can be attributed to some
of the challenges faced in the analysis of commercial properties, in particular the scarcity of information compared to residential
transactions. In order to address this issue, in this paper we propose the use of cokriging and housing prices as ancillary
information to estimate commercial property prices. Cokriging takes into account the spatial autocorrelation structure of
property prices, and the use of more abundant information on housing prices helps to improve the accuracy of property value
estimates. A case study of Toledo in Spain, a city for which commercial activity stemming from tourism is one of the key elements
of the economy in the city, demonstrates that substantial accuracy and precision gains can be obtained from the use of cokriging. 相似文献
84.
A. Blanco A. Borghesi E. Bussoletti S. Nicolazzo A. M. Zambetta 《Astrophysics and Space Science》1976,41(2):447-474
Planck mean absorption cross-sections have been computed for spherical grains composed of graphite, iron, ice, olivine, amorphous quartz and a lunar silicate. Experimentally determined infrared optical constants have been used for all these materials. Ice mantle particles and planetesimal particles (iron core and olivine mantle) have also been considered with values of outer and inner radii covering a wide range of astrophysical conditions.The results given both graphically and in a tabular form are discussed and compared with those of other authors. The relationships of mantle and core properties are also critically discussed. 相似文献
85.
Optically bright and very cool AFGL carbon stars have been analyzed in order to find a common evolutionary sequence according to indications in this sense derived from papers which have treated only the first or the second group of stars separately.An apparent discrepancy existing between the stellar parameters has been overcome following an inverse procedure which provides these values by means of the shell parameters.The results seem to indicate that AFGL stars, whose variability nature is still unknown, should be Mira or Mira-like according to the values of their dust shell temperatures.Dust shell masses have been estimated for both samples of stars finding an inverse dependence with the effective temperature,M
d
T
*
–9.1
.This may be interpreted in terms of evolutionary sequence in the sense that the cooler the stars the larger their shell masses. 相似文献
86.
The granulites of the Juiz de Fora complex occur within thick basement thrust slices associated with the Pan-African shortening process in the central segment of the Ribeira belt. Five lithological units of the Intermediate tectonic domain of the belt can be identified on the basis of detailed geological mapping: a) orthogranulites, b) orthogneisses; c) kinzigite; d) intrusive garnet charnockite and e) amphibolite facies metasediments of probable Meso to Neoproterozoic age, correlated to the cover of the belt. Petrological data indicate high temperatures and intermediate to low lithostatic pressure conditions for the Paleoproterozoic granulite facies metamorphism. Textures and CO2-rich fluid inclusions are probably related to an IBC path. Geochemical data do not show relevant compositional change as a result of the granulite metamorphism. Two calc-alkaline suites and tholeiitic to alkaline basic rocks can be related to compressional and extensional settings, respectively. The overall composition of the granulites, the lack of substantial LILE depletion as well as the composition of the fluid inclusion points to granulitization process driven by CO2-rich fluids. Orthogranulites gave rise to banded gneisses as a result of the Pan-African retrograde metamorphism and intense deformation. The U and Th depletion detected in few rocks is possibly related with the hydrated conditions of the retrograde reactions. 相似文献
87.
Coastal fisheries are complex ecological and social systems, evolving in time with a shift from commercial towards recreational effort. We describe the coastal fisheries of Mallorca (W Mediterranean) and the management policies implemented to show the challenges faced at regional level to handle the different management tools used to conserve biodiversity and the social fabric in the coastal zone. Our example provides evidence of the complexity of fishing rights and how they can be adapted into practical fisheries management by combining fishing rights, open access recreational fishery, community-based management and biodiversity conservation. 相似文献
88.
Ivana Conceição de Araújo Pinho Johildo Salomão Figueiredo Barbosa Angela Beatriz de Menezes Leal Hervé Martin Jean-Jacques Peucat 《Journal of South American Earth Sciences》2011,31(2-3):312-323
The studied tonalitic and trondhjemitic granulites are located in the SSE granulitic domain of the São Francisco craton, Bahia, Brazil, where they represent most of the southern part of the Archean and Paleoproterozoic Itabuna-Salvador-Curaçá Block (ISCB). Chemically, the tonalitic and trondhjemitic granulites belong to a low-K calc-alkaline suite; their REE patterns are steep with strong LREE/HREE fractionation and no significant Eu anomaly. Garnet-bearing mafic granulites that occur as enclaves in the tonalitic and trondhjemitic granulites were derived from basalts and/or gabbros of tholeiitic affinity. Geochemical modelling showed that the tonalitic and trondhjemitic granulites were produced by moderate fractional crystallization of an assemblage of hornblende and plagioclase, with subordinate amounts of magnetite, apatite, allanite and zircon. The garnet-bearing mafic granulites would be the source of the magmas that generated these rocks. Partial melting left a residue made up of plagioclase, garnet, orthopyroxene and hornblende. 相似文献
89.
Spitidiscus is a widely-distributed Hauterivian genus that briefly invaded the Neuquén Basin, Argentina, in mid Hauterivian times, well after it first evolved in the west Tethyan area. Its appearance in Argentina is linked with a globally-significant mid Hauterivian sea-level rise. This is marked in the basin by a sharp facies change in the Agrio Formation, from non-marine sandstones of the Avilé Member to marine sediments, often laminated black shales, with Spitidiscus at the base of the overlying Agua de la Mula Member. Our extensive field work has shown that Spitidiscus occurs across the whole basin, where it is represented by two species, Spitidiscus riccardii Leanza and Wiedmann and Spitidiscus kilapiae sp. nov. For most of its vertical range Spitidiscus occurs alone, characterising the S. riccardii Zone. But at the top of its range it is joined by the first crioceratitid ammonites, their appearance marking the base of the Crioceratites schlagintweiti Zone. 相似文献
90.
Searching for traces of extinct and/or extant life on Mars is one of the major objectives for remote-sensing and in situ exploration of the planet. In previous laboratory works we have investigated the infrared spectral modifications induced by thermal processing on different carbonate samples, in the form of fresh shells and fossils of different ages, whose biotic origin is easily recognizable. The goal was to discriminate them from their abiotic counterparts. In general, it is difficult to identify biotic signatures, especially when the organisms inducing the carbonate precipitation have low fossilization potential (i.e. microbes, bacteria, archaea). A wide variety of microorganisms are implicated in carbonate genesis, and their direct characterization is very difficult to evaluate by traditional methods, both in ancient sedimentary systems and even in recent environments.In the present work we apply our analysis to problematic carbonate samples, in which there is no clear evidence of controlled or induced biomineralization. This analysis indicates a very likely biotic origin of the aragonite samples under study, in agreement with the conclusion previously reported by Guido et al. (2007) who followed a completely different approach based on a complex set of sedimentary, petrographic, geochemical and biochemical analyses. We show that our method is reliable for discriminating between biotic and abiotic carbonates, and therefore it is a powerful tool in the search for life on Mars in the next generation of space missions to the planet. 相似文献