Sunday, June 21, 2015

 

 



Soy un nuevo usuario

Olvidé mi contraseña

Entrada usuarios

Lógica Matemáticas Astronomía y Astrofísica Física Química Ciencias de la Vida
Ciencias de la Tierra y Espacio Ciencias Agrarias Ciencias Médicas Ciencias Tecnológicas Antropología Demografía
Ciencias Económicas Geografía Historia Ciencias Jurídicas y Derecho Lingüística Pedagogía
Ciencia Política Psicología Artes y Letras Sociología Ética Filosofía
 

rss_1.0 Recursos de colección

Digital.CSIC (75,985 recursos)
Repositorio institucional del Consejo Superior de Investigaciones Científicas. Digital.CSIC es un depósito de documentos digitales, cuyo objetivo es organizar, archivar, preservar y difundir en modo de acceso abierto la producción intelectual resultante de la actividad investigadora del CSIC.

(IRN) Artículos post-print

Mostrando recursos 1 - 20 de 158

1. Channel changes in the Jarama and Tagus rivers (central Spain) over the past 500 years - Uribelarrea, David; Pérez-González, Alfredo; Benito, Gerardo
Long-term channel changes of the Tagus and the Jarama Rivers in central Spain were studied in relation to variations in hydroclimatic factors, such as rainfall and flooding, and also with respect to human activities undertaken in their valleys. Data were taken from historical (1580–1823) and topographical (1877–1988) maps, as well as aerial photographs (1945–1999). The available hydroclimatic data consists of a series of monthly rainfall totals (1859–1994) and mean river flow values recorded at gauging stations (1911–1985). In addition, a historical flood record (1550–1947) was produced from documentary sources. Some of the data was incorporated into a geographical information system...

2. Influence of the calcination temperature of kaolin on the mechanical properties of mortars and concretes containing metakaolin - Mejía de Gutiérrez, R.; Torres, Trinidad José de; Vizcayno, Carmen; Castelló, Ricardo
The effect of healing, to temperatures between 400 and 1200ºC. on the dehydroxilation of kaolin and the pozzonanic activity of the resulting amorphons material were determined by a variety of analitical techniques. Mixtures of concrete containing variable ammounts of kaolin calented at 700ºC were analysed and the results compared with those for concrete samples containing two different types of imported metakaolin. As shown in this work. Colombian kaolin can be used effectively as a raw material to obtain a highly active product (metakaolin). The optimum heating temperature for the kaolin is between 700 and 800ºC.

3. A new taphonomic bioerosion in a Miocene lakeshore environment - Pesquero, María Dolores; Ascaso, Carmen; Alcalá, Luis; Fernández Jalvo, Yolanda
This study describes a new type of taphonomic alteration of fossil bone that occurred in a continental carbonate palaeolake environment at the reference Spanish Miocene site of Cerro de la Garita (Concud, Teruel). Scanning electron microscopy showed this type of alteration to be characterized by microtunnels that penetrate inward from the bone surface and by a branching-meandering arrangement of microchannels on the bone surface. These microtunnels had a highly electron dense inner wall, seen as a characteristic rim in transverse section. Microspheres were seen inside the microtunnels. Both this electron dense layer and these microspheres were found to be composed of calcium phosphate. These taphonomic modifications...

4. Assessing thermal interactions during laser cleaning by means of infrared thermal imaging - Gómez-Heras, Miguel; Sanz, Mikel; Álvarez de Buergo, Mónica; Oujja, Mohamed; Fort González, Rafael; Speranza, Mariela; Rios, Asunción de los; Ascaso, Carmen; Pérez Ortega, Sergio; Castillejo, Marta

5. Rainfall-runoff modelling and palaeoflood hydrology applied to reconstruct centennial scale records of flooding and aquifer recharge in ungauged ephemeral rivers - Benito, Gerardo; Botero, Blanca; Thorndycraft, V. R.; Rico, María Teresa; Sánchez Moya, Yolanda; Sopeña, Alfonso; Machado, María José; Dahan, O.
In this study we propose a multi-source data approach for quantifying long-term flooding and aquifer recharge in ungauged ephemeral rivers. The methodology is applied to the Buffels River, at 9000 km2 the largest ephemeral river in Namaqualand (NW South Africa), a region with scarce stream flow records limiting research investigating hydrological response to global change. Daily discharge and annual flood series (1965–2006) were estimated from a distributed rainfall-runoff hydrological model (TETIS) using rainfall gauge records located within the catchment. The model was calibrated and validated with data collected during a two year monitoring programme (2005–2006) at two stream flow stations,...

6. A Late Holocene palaeoflood record from slackwater flood deposits of the Llobregat river, NE Spain - Thorndycraft, V. R.; Benito, Gerardo; Rico, María Teresa; Sopeña, Alfonso; Sánchez Moya, Yolanda; Casas Planes, M. A.
The palaeofloods of the Llobregat River are the first to be reconstructed for any Spanish Mediterranean river basin. In total, 56 individual slackwater flood units were identified in eight valley side alcoves located along two study reaches, Pont de Vilomara and Monistrol de Montserrat. The majority of the deposits are fine sands or very fine sandy silts, with a variety of sedimentary structures identified, namely parallel laminations, climbing ripples (both in-phase and in-drift) and current ripples. The estimation of the palaeoflood discharges associated with these deposits, using the HEC-RAS onedimensional hydraulic model, has provided long-term data regarding flood magnitude within the catchment. Palaeofloods at Pont de Vilomara, radiocarbon...

7. The impact of late Holocene climatic variability and land use change on the flood hydrology of the Guadalentín River, southeast Spain - Benito, Gerardo; Rico, María Teresa; Sánchez Moya, Yolanda; Sopeña, Alfonso; Thorndycraft, V. R.; Barriendos, M.
The Guadalentín River, located in southeast Spain, is considered one of the most torrential rivers in Spain, as indicated by catastrophic events such as the 1879 flood that caused 777 fatalities in the Murcia region. In this paper, flood frequency and magnitude of the upper Guadalentín River were reconstructed using geomorphological evidence, combined with one-dimensional hydraulic modelling and supported by records from documentary sources at Lorca in the lower Guadalentín catchment. Palaeoflood studies were conducted along a 2.5-km reach located at the confluence of the Rambla Mayor (162 km2) and Caramel River (210 km2). These tributaries join at the entrance of a narrow bedrock canyon, carved...

8. Sandstone weathering processes damaging prehistoric rock paintings at the Albarracín Cultural Park, NE Spain - Benito, Gerardo; Machado, María José; Sancho, C.
The rock paintings in cliff-foot caves of the Albarracin Cultural Park are known as some of the most important evidences of the Levantine prehistoric art of Spain (8000–3000 BP). The paintings are on sandstone (Buntsandstein facies) of Triasic age, which may develop intense weathering. The analysis of the variables controlling the weathering indicate that salt and wetting-drying weathering are responsible for granular disintegration and flaking, which lead to rock painting deterioration.

9. River response to Quaternary subsidence due to evaporite solution (Gállego River, Ebro Basin, Spain) - Benito, Gerardo; Pérez-González, Alfredo; Gutiérrez, Francisco; Machado, María José
The stream terrace evolution of the Gállego river during the Quaternary was controlled by both climatic change and subsidence. Quaternary terrace deposits, overlying Tertiary clay and limestone, are between 2 and 5 m thick, whereas above evaporite formations the alluvial deposits may be as much as 110 m thick. Chronologically, the first period of alluvial thickening involved the stream terraces T2 (+ 105 m above the present thalweg), T3 (+ 95 m) and T4 (+ 85 m), which have been dated by paleomagnetic reversals as Matuyama (pre-780,000). The second subsidence period affected the deposits of the stream terrace T9 (+30),...

10. Paleoenvironmental Changes during the Last 4000 yr in the Tigray, Northern Ethiopia - Machado, María José; Pérez-González, Alfredo; Benito, Gerardo
In the Tigray region at the northern Ethiopian Highlands, paleoenvironmental reconstruction based on several infilled valley deposit sequences suggests that the past 4000 yr comprised three major wetter periods (ca. 4000–3500 yr B.P., 2500–1500 yr B.P., and 1000–960 yr B.P.), during which soils were formed, and two degradation episodes (ca. 3500–2500 yr B.P. and 1500–1000 yr B.P.), during which there was an increase of sediment yield from the slopes into the valleys. For the past 1000 yr, and in particular since the early 17th century, stratigraphic records together with historic chronicles suggest increasing aridity. Although difficulties arise in distinguishing between...

11. Geomorphological and sedimentological features in Quaternary fluvial systems affeced by solution-induced subsidence (Ebro Basin, NE-Spain) - Benito, Gerardo; Pérez-González, Alfredo; Gutiérrez, Francisco; Machado, María José
The Quaternary evolution and the morpho-sedimentary features of some of the most important rivers in Spain (Ebro and Tagus rivers among others) have been controlled by subsidence due to alluvial karstification of the evaporitic bedrock. The subsidence mechanism may range from catastrophic collapse to slow sagging of the alluvium by passive bending. In the Ebro Basin, the mechanisms and processes involved in karstic subsidence were studied through the analysis of present-day closed depressions as well as through old subsidence depressions (palaeocollapses and solution-induced basins) and associated deformations recorded in the Quaternary alluvial sediments. The Gállego–Ebro river system is presented as...

12. Combined palaeoflood and rainfall-runoff assessment of mountain floods (Spanish Pyrenees) - Rico, María Teresa; Benito, Gerardo; Barnolas, A.
This paper reports a comparative study of the use of palaeohydrological and hydrological techniques to estimate magnitude and frequency of floods applied to two high-gradient, small catchments located in the Spanish Central Pyrenees: the Arás basin, 18.6 km2; the Montardit basin, 15.2 km2. Palaeohydrological (palaeoflood) techniques, based on palaeostage indicators and the application of both Manning's equation and critical flow equation, were used to estimate discharge values corresponding to seven cross-sections of the Montardit stream. This method yielded discharges ranging from 7 to 112 m3 s−1. Palaeoflood and historical flood analyses indicated a greater frequency of high magnitude events for...

13. Combined palaeoflood and rainfall-runoff assessment of mountain floods (Spanish Pyrenees) - Rico, María Teresa; Benito, Gerardo; Barnolas, A.
This paper reports a comparative study of the use of palaeohydrological and hydrological techniques to estimate magnitude and frequency of floods applied to two high-gradient, small catchments located in the Spanish Central Pyrenees: the Arás basin, 18.6 km2; the Montardit basin, 15.2 km2. Palaeohydrological (palaeoflood) techniques, based on palaeostage indicators and the application of both Manning's equation and critical flow equation, were used to estimate discharge values corresponding to seven cross-sections of the Montardit stream. This method yielded discharges ranging from 7 to 112 m3 s−1. Palaeoflood and historical flood analyses indicated a greater frequency of high magnitude events for...

14. Palaeoflood record of the Tagus River (Central Spain) during the Late Pleistocene and Holocene - Benito, Gerardo; Sopeña, Alfonso; Sánchez Moya, Yolanda; Machado, María José; Pérez-González, Alfredo
Palaeoflood hydrology of the Tagus River (Central Spain) was reconstructed from slackwater deposits and palaeostage indicators in two canyon reaches located at El Puente del Arzobispo in the central part of the catchment (35,000 km2 in drainage area) and in Alcántara, at the lower part of the catchment (52,000 km2 in drainage area) near the Portuguese border. The palaeoflood record, with more than 80 flood events, shows clusters of floods at specific periods from 9440 to 9210 14Cyr BP (8540–8110 BC), 8500 to 8000 14Cyr BP (7500–7000 BC), 6750 14Cyr BP (5000 BC), 1200 to 950 14Cyr BP (AD 785–1205),...

15. Caesium-137 dating applied to slackwater flood deposits of the Llobregat River, NE Spain - Thorndycraft, V. R.; Benito, Gerardo; Walling, D. E.; Sopeña, Alfonso; Sánchez Moya, Yolanda; Rico, María Teresa; Casas Planes, M. A.
During a palaeoflood study of the Llobregat River (NE Spain), analysis of 137Cs was carried out on slackwater flood deposits to obtain an improved flood chronology for the most recent flood sediments. At the Monistrol study reach, 137Cs was measured in flood deposits preserved in valley side rock alcoves, with a range of 137Cs concentrations of 2.80–10.06 mBq/g measured. The 137Cs was associated with sediment mobilised from the upstream catchment by erosion and transported to the alcoves during floods. The onset of measured caesium activity in the sedimentary profiles permitted the deposits to be divided between those from floods that...

16. A long-term flood discharge record derived from slackwater flood deposits of the Llobregat River, NE Spain - Thorndycraft, V. R.; Benito, Gerardo; Rico, María Teresa; Sopeña, Alfonso; Casas Planes, M. A.; Sánchez Moya, Yolanda
Slackwater palaeoflood deposits were identified along two bedrock gorge study reaches of the Llobregat River, at Pont de Vilomara and Monistrol de Montserrat. The compiled palaeoflood record consists of two principal flood series: (a) a relatively complete record of low to high magnitude flood events from the last ca. 100 years and (b) evidence of the largest palaeoflood events that have occurred over the last ca. 2700 years. The longer term extreme palaeoflood record indicates that the discharge of the 1971 flood, the largest on record, was exceeded on at least eight occasions, with two periods of high magnitude flooding...

17. The palaeoflood record of the Gardon river, France: A comparison with the extreme 2002 flood event - Sheffer, N. A.; Rico, María Teresa; Enzel, Y.; Benito, Gerardo; Grodek, T.
A paleoflood study in the Gardon River gorge in southern France identified extreme floods larger than any modern or historically gauged flood. During the course of our study, an extreme flood on the 8–9th of September 2002 claimed the lives of 21 people and caused millions of Euros worth of damage to the towns and villages along the river. The magnitude of this flood was larger than any known historical flood on record,. However, there is evidence of greater magnitude flood events in the form of slack-water flood deposits preserved in caves elevated 17–19 m above the normal base flow,...

18. Reported tailings dam failures.A review of the European incidents in the worldwide context - Rico, María Teresa; Benito, Gerardo; Salgueiro, A. R.; Díez-Herrero, A.; Pereira, H.
A detailed search and re-evaluation of the known historical cases of tailings dam failure was carried out. A corpus of 147 cases of worldwide tailings dam disasters, from which 26 located in Europe, was compiled in a database. This contains six sections, including dam location, its physical and constructive characteristics, actual and putative failure cause, sludge hydrodynamics, socio-economical consequences and environmental impacts. Europe ranks in second place in reported accidents (18%), more than one third of them in dams 10–20 m high. In Europe, the most common cause of failure is related to unusual rain, whereas there is a lack...

19. Application of Correspondence Analysis in the Assessment of Mine Tailings Dam Breakage Risk in the Mediterranean Region - Salgueiro, A. R.; Garcia Pereira, Henrique; Rico, María Teresa; Benito, Gerardo; Díez-Herrero, A.
A new statistical approach for preliminary risk evaluation of breakage in tailings dam is presented and illustrated by a case study regarding the Mediterranean region. The objective of the proposed method is to establish an empirical scale of risk, from which guidelines for prioritizing the collection of further specific information can be derived. The method relies on a historical database containing, in essence, two sets of qualitative data: the first set concerns the variables that are observable before the disaster (e.g., type and size of the dam, its location, and state of activity), and the second refers to the consequences...

20. Floods from tailings dam failures - Rico, María Teresa; Benito, Gerardo; Díez-Herrero, A.
This paper compiles the available information on historic tailings dam failures with the purpose to establish simple correlations between tailings ponds geometric parameters (e.g., dam height, tailings volume) and the hydraulic characteristics of floods resulting from released tailings. Following the collapse of a mining waste dam, only a part of tailings and polluted water stored at the dam is released, and this outflow volume is difficult to estimate prior the incident. In this study, tailings’ volume stored at the time of failure was shown to have a good correlation (r2 = 0.86) with the tailings outflow volume, and the volume...

Página de resultados:
 

Busque un recurso