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181.
La Gomera (Canary Islands, Spain) does not show water scarcity like other islands of the Archipelago. However, the study of its aquifers is paramount as nearly 60 % of the water supplies are covered with spring water. According to the currently accepted hydrogeological model, La Gomera presents an upper aquifer consisting of perched groundwater bodies. Below this hydrogeological unit, the General Saturated Zone or basal groundwater is placed. The model also establishes the presence of flows through them. Many perched groundwater bodies are located under Garajonay National Park where most of the springs are found. Therefore, if upper and lower aquifers are truly connected and new wells are built, the new extractions could affect Garajonay ecosystems. With the aim of identifying spring groups and related potential areas of water transfer, hydrochemical and statistical analyses (principal component analysis and cluster analysis) have been applied. This study shows the great compositional variability of groundwaters, precluding the identification of spring groups, hydrochemical patterns and, therefore, the transfer areas with no possibility of assessing the potential impact of a water demand increase on the Garajonay National Park ecosystems from the present data. Only the springs belonging to group II of the cluster analysis could indicate a transfer area. The lack of conclusive results could be due to: (1) great compositional variability of volcanic materials; (2) unequal influence of marine aerosols; (3) irregular distribution of rainfall; (4) different grades of soils development; and (5) the occurrence of partially disconnected water bodies giving as a result a complex hydrogeological system. 相似文献
182.
This paper presents the results of morphological and microclimatic surveys and speleothem analyses of ten karst caves located in different isles in Ha Long Bay, a famous tourist attraction in Vietnam. Characteristically, the caves have enormous entrances, roomy interiors, but short length, typical of karst caves in tropical climates. The cave microclimate was found to be significantly dependent on the outside atmosphere and human activities. There was a clear spatial variation in macro features and fabrics of speleothems from entrance (porous, microcrystalline) to rear (solid, macrocrystalline) of the caves. Microstructure analysis with the use of an environmental scanning electron microscope shows a gradual decrease of biological activity and microclimate instability from outside to the innermost parts of the caves are the causes for this spatial variation. Past and present deterioration of caves and speleothems directly due to tourist activities and vandalism has been observed. On the other hand, there are signs of speleothem regrowth in the caves where tourism has been stopped. This study has proved that caves and their speleothems in Ha Long Bay are highly dynamic and understanding of their environment requires immediate methodological attention. Based on the analytical results, it is recommended that regulation of visitor frequency and removal of lamp-flora are necessary for sustainable development of the show caves and their speleothems. 相似文献
183.
184.
Luis?PandoEmail author Javier?A.?Pulgar Manuel?Gutiérrez-Claverol 《Environmental Earth Sciences》2013,69(2):507-521
Within the TERENO initiative, four terrestrial observatories, collecting huge amounts of environmental data, are being set up since 2008. To manage, describe, exchange and publish these data, the distributed Spatial Data Infrastructure TEODOOR (http://www.tereno.net) was created. Each institution responsible for an individual observatory sets up its own local data infrastructure, which may communicate with each other to exchange data and metadata internally or to the public by OGC compliant Web services. The TEODOOR data portal serves as a database node to provide scientists and decision makers with reliable and well-accessible data and data products. Various tools like hierarchical search or Web-GIS functions allow a deeper insight into the different observatories, test sites and sensor networks. Sensor data can be queried and selected for measured parameters, stations and/or time periods, and can be visualized and downloaded according to a shared TERENO data policy. Currently, TEODOOR provides free access to data from more than 500 monitoring stations. 相似文献
185.
Oleg Malkov Mikhail Sachkov Boris Shustov Pavel Kaigorodov Francisco Javier Yáñez Ana Ines Gómez de Castro 《Astrophysics and Space Science》2011,335(1):323-327
We present scientific program construction principles and a time allocation scheme developed for the World Space Observatory—Ultraviolet
(WSO-UV) mission, which is an international space observatory for observation in UV spectral range 100–300 nm. The WSO-UV
consists of a 1.7 m aperture telescope with instrumentation designed to carry out high resolution spectroscopy, long-slit
low resolution spectroscopy and direct sky imaging. The WSO-UV Ground Segment is under development by Spain and Russia. They
will coordinate the Mission and Science Operations and provide the satellite tracking stations for the project. 相似文献
186.
187.
Isabel Egea-González Javier Ruiz Carlos Fernández Jean-Pierre Williams Álvaro Márquez Luisa M. Lara 《Planetary and Space Science》2012,60(1):193-198
Mercurian lobate scarps are interpreted to be the surface expressions of thrust faults formed by planetary cooling and contraction, which deformed the crust down to the brittle–ductile transition (BDT) depth at the time of faulting. In this work we have used a forward modeling procedure in order to analyze the relation between scarp topography and fault geometries and depths associated with a group of prominent lobate scarps (Santa Maria Rupes and two unnamed scarps) located in the Kuiper region of Mercury for which Earth-based radar altimetry is available. Also a backthrust associated with one of the lobate scarps has been included in this study. We have obtained best fits for depths of faulting between 30 and 39 km; the results are consistent with the previous results for other lobate scarps on Mercury.The so-derived fault depths have been used to calculate surface heat flows for the time of faulting, taking into account crustal heat sources and a heterogeneous surface temperature due to the variable insolation pattern. Deduced surface heat flows are between 19 and 39 mW m?2 for the Kuiper region, and between 22 and 43 mW m?2 for Discovery Rupes. Both BDT depths and heat flows are consistent with the predictions of thermal history models for the range of time relevant for scarp formation. 相似文献
188.
Kelsey D. Hargrove Michael S. Kelley Humberto Campins Javier Licandro Josh Emery 《Icarus》2012,221(1):453-455
We find a clear diversity in the 3 μm and 10 μm features of three Cybele asteroids: (107) Camilla, (121) Hermione, and (65) Cybele. (121) Hermione exhibits a “check-like” 3 μm feature, which may be attributed to OH-dominated minerals and (107) Camilla shows a rounded “bowl” like feature closer to that of (65) Cybele, which may be attributed to H2O-dominated minerals. The 10 μm features of these three asteroids are also different from each other. 相似文献
189.
Gateway cities have received much attention from urban geographers. In spite of outstanding contributions being made, we think that the concept needs to be revisited with regard to regional development implications. Bringing together research on global production networks (GPNs) and world cities, this article shows that gateway cities are critical for development in networks, generating impulses for peripheral locations by engaging them in processes of “strategic coupling.” Yet, gateway cities also concentrate segments of GPNs to the detriment of their hinterlands. We conceptualize gateway cities with the aid of five features: logistics and transport, industrial processing, corporate control, service provision and knowledge generation. Our concept allows for an understanding of cities in global and regional economic processes beyond corporate headquarters, corporate services and governance – that is, beyond the boundaries of existing research. It unsettles traditional understandings of strategic coupling and world cities, filling a lacuna on city–hinterland connections. 相似文献
190.
Javier Santos-González João A. Santos Rosa Blanca González-Gutiérrez José María Redondo-Vega Amelia Gómez-Villar 《自然地理学》2013,34(6):471-490
Fabric and grain-size analysis of eight deposits present in the Upper Sil River Basin palaeoglacial system of northwest Spain were used to interpret till types and to reconstruct the glacial paleoprocess history of this region. They are represented by lodgement, deformation, and melt-out tills. The first, representative of glacial advance stages, present cluster fabrics and are generally composed of poorly sorted and finer sediments. Melt-out and deformation tills, representative of stages of glacial stability followed by fast recession, present transitional to girdle fabrics and are composed of poorly sorted coarser sediments. In any case, multiple criteria, including lithological, clast-shape, or structural data, support these directional and grain-size observations. These sequences, most of them located in the snout area of the Sil palaeoglacier, are important in the reconstruction of glacial dynamics due to poor preservation of landforms related to the maximum glacial advance. This palaeoglacial system was formed by multiple tributaries and had an extension of over 450 km2, with the Sil paleoglacier being 51 km long during its maximum glacial advance. 相似文献