排序方式： 共有47条查询结果，搜索用时 15 毫秒
31.
32.
Timothy W. Collins Sara E. Grineski María de Lourdes Romo Aguilar 《Applied geography (Sevenoaks, England)》2009,29(3):448-461
The purpose of this paper is to present a geographic information system (GIS)-based method for mapping risk to environmental hazards. Framed by the hazards literature, the method has been developed to specifically overcome issues of data compatibility associated with transnational contexts. The approach is elaborated in reference to a project in which risk was spatially characterized, using a suite of biophysical and social indicators, for the Ciudad Juárez (Mexico)–El Paso (USA) metropolis. Results reveal clear spatial disparities in hazard vulnerability, both within and between the two cities, based on the differential allocation of selected risk factors. The case indicates that future international analyses will be advanced by the clear definition of concepts, the systematic mining of compatible variables, and the selection of valid risk indicators based on criteria that balance the need to incorporate contextual specificity with general comparability. 相似文献
33.
Shallow frontal deformation related to active continental subduction: structure and recent stresses in the westernmost Betic Cordillera 
下载免费PDF全文
下载免费PDF全文 Lourdes González‐Castillo Jesús Galindo‐Zaldívar Antonio Pedrera Francisco José Martínez‐Moreno Patricia Ruano 《地学学报》2015,27(2):114-121
The westernmost Betic Cordillera front is located along the arcuate alpine belt formed by the interaction of the Eurasian‐African plate boundary and the Alboran continental domain in between. Although classical geological data suggest that the western Cordillera front is inactive, recent GPS data show a westward–north‐westward motion of up to 3.4 mm a?1 with respect to the foreland. In addition, the increasing thickness of Guadalquivir sedimentary infill towards the Cordillera, and the rectilinear character of the front formed by soft sediments, suggest that the Cordillera is still active. Large ENE–WSW‐oriented open folds detected in the field, seismic reflection profiles and new audiomagnetotellurics data are consistent with active deformation. Fracture analysis in Quaternary deposits evidences recent NW–SE horizontal compression. The GPS motion and maximum stress orientation may be due to north‐westward tectonic collision of the westernmost Betic Cordillera, accommodated at depth by active continental subduction of the Iberian lithosphere. 相似文献
34.
35.
Jos A. Lpez-Sez Antonio Blanco-Gonzlez Lourdes Lpez-Merino M. Blanca Ruiz-Zapata Miriam Dorado-Valio Sebastin Prez-Díaz Ana Valdeolmillos Francesc Burjachs 《Quaternary International》2009,200(1-2):90
Correlations between ecological and cultural changes occurred during a short period between the end of Subboreal and the beginning of Subatlantic in the Amblés Valley (Ávila, central Spain) are analyzed, taking into account palaeopalynological and archaeological data. Plant dynamics from pollen analyses, both from archaeological sites and peat bogs, have been interpreted in relation to human settlements and the transformation of economic practices. These provided a comprehensive hypothesis on human/climate interactions at the beginning of the 1st millennium cal BC. There was an ecological crisis in the region that lasted for a century (ca. 850–760 cal BC). This was especially sharp due to both the geographical constraints of the area and its previous agrarian history. This event implied a sudden and abrupt climatic change from xeric and warm conditions (Subboreal) to more humid and cooler ones (Subatlantic). Environmental stress derived from climatic crisis could be an important factor in the explanation of the historical process, whose main consequences were both the origin of the Iron Age peasant villages and the end of the ‘dehesa’ type landscape. 相似文献
36.
37.
Jose I. Castillo-Manzano Lourdes López-Valpuesta Fernando Gonzalez Laxe 《Ocean & Coastal Management》2010,53(9):577-580
Spain’s port system was subjected to significant legislative reforms during the 1990s. Spanish Law 62/97 allowed regional governments to manage commercial ports, whereas the central government continued to control the main organisation in charge of the Spanish port system – the Spanish National Ports and Harbours Authority (SNPHA). This paper analyses the evolution of maritime traffic to measure the possible costs of political coordination between the SNPHA and the port authorities controlled by various political parties that rule regional governments. The findings point to coordination costs having a limited effect on the evolution of maritime traffic. 相似文献
38.
Berta Melndez Oliveros Raúl Martín Hernndez Lourdes Palacio Surez 《Journal of Atmospheric and Solar》2005,67(17-18):1706
The meridional propagation velocities of the ionospheric F2-region response to 268 geomagnetic storms are calculated. Ionospheric vertical sounding data of 1 h time resolution from several stations located in a longitude sector approximately centred along the great circle that contains both the geomagnetic poles and the geographic poles are used.Most meridional propagation velocities from high to low latitudes are less than 600 m/s. The smaller velocities are typical of global neutral meridional wind circulation and the larger are representative of traveling atmospheric disturbances.Simultaneous disturbances at several locations are more frequent during positive phases than during negative phases. Negative phase meridional propagation velocities associated with meridional neutral winds are less frequent in the southern hemisphere when compared with corresponding velocities observed in the northern hemisphere. This may be related to the fact that the distance between the geomagnetic pole and the equator is smaller in the northern hemisphere.Most negative phase onsets are within the 06–10 LT interval. For middle geomagnetic latitudes a “forbidden time interval” between 11 and 14 LT is present. The positive phase onsets show the “dusk effect”. 相似文献
39.
40.
Espíndola Juan Manuel De Lourdes Godinez Maria Espindola Victor Hugo 《Natural Hazards》2004,31(1):191-207
Popocatepetl volcano in Central Mexico entered its latest stage of activity in late 1994. Due to the nature of its eruptive history and its location in a heavily populated area, it constitutes the highest risk in the cuntry. For this reason the volcano is currently under continuous surveillance; yet the interpretation of the information is carried out mostly on empirical basis and an integrating working model is lacking, at the present. In this paper, models of elastic deformation and mass erupted are developed to estimate the mass erupted according to the observed deformation patterns. We present results obtained from input based upon a gravimetric model of the volcano's internal structure and reasonable physical parameters of the volcanic system. These results are helpful in the planning of deformation and gravimetric observations aimed to forecast a major eruption. 相似文献