La inflexión en el ciclo migratorio internacional en España : impacto y consecuencias demográficas

Estudi finançat per la Fundació Jaume BofillEl presente artículo analiza las consecuencias demográficas del cambio de tendencia de los flujos migratorios con origen y destino a España, dentro de la actual coyuntura de crisis económica global. El texto realiza un exhaustivo estudio de las entradas y las salidas de inmigrantes, diferenciando distintos colectivos, y ofreciendo datos desagregados por comunidades autónomas y su distribución por todo el territorio nacional. Los autores concluyen que si bien es cierto que las salidas de extranjeros han aumentado como consecuencia de la crisis, es difícil en estos momentos establecer su cuantía real y las características exactas de los colectivos afectados. Por último, se afirma que los efectos territoriales más significativos del cambio de ciclo migratorio se localizan en las comunidades del centro de la península y algunos sectores del litoral mediterráneo con mayor vinculación con el boom inmobiliario, mientras que en Cataluña y las comunidades autónomas del litoral cantábrico el desplome de los flujos de entrada ha sido de menor entidad

Perfil demográfico de la población extranjera en España

El año 2006 presenta tres novedades destacadas en materia de inmigración. La primera de ellas la constituye los más de cuatro millones de extranjeros empadronados a 1 de enero de 2006, datos que confi rman la consolidación del crecimiento experimentado en los últimos años y su papel creciente en la sociedad española, donde este colectivo representa un valor próximo al diez por ciento de la población. Esta cifra, menor que la resultante de sumar a la población extranjera a 1 de enero de 2005 las 682.000 entradas y las 48.000 salidas de extranjeros, nos conduce a la segunda de las novedades: la puesta en marcha del proceso administrativo de bajas por caducidad del Padrón Continuo prevista en el Reglamento de Extranjería, del que aún no disponemos de informaciones detalladas, pero que en los próximos años nos deparará una mayor convergencia con el otro registro principal de población extranjera: los permisos de residencia. Precisamente, esta última fuente logra, a 31 de diciembre de 2006, batir otra marca histórica, la barrera de los tres millones de permisos de residencia, resultado estrechamente ligado al proceso de normalización de trabajadores realizado en 2005, con 561.241 extranjeros regularizados, y a otros factores como reagrupación familiar que se deriva de esa regularización

"Ecualizador": un método integral para la decisión con múltiples objetivos

Se presenta un sistema soporte para la toma de decisión multiobjetivo en un espacio continuo, en el que se integraron métodos clásicos y una metodología que se ha denominado "ecualizador" por las facultades regularizadoras entre intereses respecto a objetivos. Esta permite que el decisor, partiendo desde una solución inicial, "navegue" dentro del espacio de los objetivos. Mediante aprendizaje sobre posibles intercambios entre objetivos y limitaciones del espacio factible, va deduciendo sus verdaderas preferencias hasta que el proceso converja en una solución completamente satisfactoria para el decisor. Esta metodología tiene especial aplicación en la gestión de recursos naturales, en especial los recursos hídricos. Se presenta una aplicación del sistema soporte desarrollado en el caso de la gestión de agua para riego en la cuenca del Guadalquivir

Improved modelling of the freshwater provisioning ecosystem service in water scarce river basins

[EN] Freshwater provisioning by the landscape contributes to human well-being through water use for drinking, irrigation and other purposes. The assessment of this ecosystem service involves the quantification of water resources and the valuation of water use benefits. Models especially designed to assess ecosystem services can be used. However, they have limitations in representing the delivery of the service in water scarce river basins where water management and the temporal variability of water resource and its use are key aspects to consider. Integrating water resources management tools represents a good alternative to ecosystem services models in these river basins. We propose a modelling framework that links a rainfall-runoff model and a water allocation model which allow accounting for the specific requirements of water scarce river basins. Moreover, we develop a water tracer which rebounds the value of the service from beneficiaries to water sources, allowing the spatial mapping of the service.The authors acknowledge the support of Universitat Politecnica de Valencia through its Support Programme for Research and Development. We also wish to thank Confederacion Hidrogr afica del Duero (belonging to the Spanish Ministry of Agriculture, Food and Environment) for the data provided in developing this study and the Spanish Ministry of Economy and Competitiveness for its financial support through the projects SCARCE (Consolider-Ingenio 2010 CSD2009-00065) and NUTEGES (CGL2012-34978). We also value the support provided by the European Community in financing the Seventh Framework Program projects DROUGHTR&SPI (FP7-ENV-2011, 282769), ENHANCE (FP7-ENV-2012, 308438), the H2020 project IMPREX (H2020-WATER-2014-2015, 641811), the grant WAMCD (EC-DG Environment No. 07.0329/2013/ 671291/SUB/ENV.C1) and the Life þ project LIFE ALBUFERA (LIFE12 ENV/ES/000685).Momblanch Benavent, A.; Andreu Álvarez, J.; Paredes Arquiola, J. (2017). Improved modelling of the freshwater provisioning ecosystem service in water scarce river basins. Environmental Modelling & Software. 94:87-99. https://doi.org/10.1016/j.envsoft.2017.03.033S87999

Managing water quality under drought conditions in the Llobregat River Basin

[EN] The primary effects of droughts on river basins include both depleted quantity and quality of the available water resources, which can render water resources useless for human needs and simultaneously damage the environment. Isolated water quality analyses limit the action measures that can be proposed. Thus, an integrated evaluation of water management and quality is warranted. In this study, a methodology consisting of two coordinated models is used to combine aspects of water resource allocation and water quality assessment. Water management addresses water allocation issues by considering the storage, transport and consumption elements. Moreover, the water quality model generates time series of concentrations for several pollutants according to the water quality of the runoff and the demand discharges. These two modules are part of the AQUATOOL decision support system shell for water resource management. This tool facilitates the analysis of the effects of water management and quality alternatives and scenarios on the relevant variables in a river basin. This paper illustrates the development of an integrated model for the Llobregat River Basin. The analysis examines the drought from 2004 to 2008, which is an example of a period when the water system was quantitative and qualitatively stressed. The performed simulations encompass a wide variety of water management and water quality measures; the results provide data for making informed decisions. Moreover, the results demonstrated the importance of combining these measures depending on the evolution of a drought event and the state of the water resources system. (C) 2014 Elsevier B.V. All rights reserved.The authors would like to thank the Spanish Ministry of Economy and Competitiveness for its financial support through the SCARCE (Consolider-Ingenio 2010 CSD2009-00065) and NUTEGES (CGL2012-34978) projects. We also value the support provided by the European Community's Seventh Framework Program in financing the SIRIUS (FP7-SPACE-2010-1, 262902), DROUGHT-R&SPI (FP7-ENV-2011, 282769) and ENHANCE (FP7-ENV-2012, 308438) projects. Moreover, we are grateful to the Catalan Water Agency for the data provided to develop this study.Momblanch Benavent, A.; Paredes Arquiola, J.; Munné, A.; Manzano, A.; Arnau Cosín, J.; Andreu Álvarez, J. (2015). Managing water quality under drought conditions in the Llobregat River Basin. Science of the Total Environment. 503-504:300-318. https://doi.org/10.1016/j.scitotenv.2014.06.069S300318503-50

Rate-dependent behaviour of fracture propagation in salt rock

This paper describes an on-going experimental and numerical modelling research project on salt rock specimens. The experimental part of the study consists of a number of Mode I fracture tests with the WST (Wedge-Splitting Test) configuration, which are performed at different loading rates and complemented by a series of standard uniaxial creep tests. The preliminary WST results show a greater mechanical fracture work accompanied with lower force peaks, for the slower tests. As a first attempt to represent the experimental results, an in-house Finite Element model has been used, which combines an inviscid discrete fracture approach with a Maxwell chain model for the continuum material. The simulations show a decrease of the mechanical work needed for opening the fracture and higher peak force, as foreseen by the ongoing experimental results, but not with the same intensity, which seems to indicate that work dissipation may not be caused eclusively by the bulk viscosity.This work was partially supported by research grants BIA2016-76543-R and PID-2020-117933RB-100 from MEC (Madrid), which include European FEDER funds, as well as grant SGR2017-1153 from Generalitat de Catalunya (Barcelona)The first author also acknowledges his FI scholarship (FI-AGAUR 2021) from Secretaria d’Universitats i Recerca de la Generalitat de Catalunya,which includes European Social Funds.Postprint (published version