bluuebunny/crossref_metadata_2025 huggingface dataset:
Runoff generation on abandoned fields in the Central Ebro Basin. Results from modelling
Authors: Seeger M. , Ries J. B.
Published: May 2015

The results from several rainfall simulations performed on two abandoned fields of different ages in the Central Ebro Depression have been analysed by application of the physically based hydraulic model HILLFLOW 1D. The data gained by the simulations was used to parameterise the model. Afterwards, the runoff generation characteristics were determined by simulation of different rainfall intensities and different macroporosities of the soil. The young fallow land shows a minimum intensity for runoff generation of 6 mm h-1. An increase of the rainfall intensity leads rapidly to a growing runoff coefficient, being the value modelled for 30 mm h-1 nearly the same as the simulated one (40 mm h-1). Another con - clusion of the simulations and their modelling is the homogeneity of the soils on the young fallow land, with no macroporosity all over the profile. On the other hand, the rainfall simulations and the modelling on the old fallow land show a high variability of rainfall-runoff response patterns, strongly conditioned by the presence of macropores. They are distributed very irregularly throughout the soil of the old fallow land. In both cases, water infiltrates only little into the soil matrix, for that measures for enhancing soil hydraulic properties are needed.
The water balance of different soils on abandoned fields along a transect from the High Pyrenees to the Central Ebro Basin
Authors: Sauer T. , Ries J. B.
Published: May 2015

The water storage capacity of 10 typical soils on abandoned fields in five test areas along a transect from the High Pyrenees to the Central Ebro Basin is related to precipitation and potential evapotranspiration. The annual precipitation increases from 300 mm in the Central Ebro Depression to 1700 mm in the subalpine area, the potential evapotranspiration decreases from 920 mm to 650 mm. However in the High Pyrenees, months with a negative water balance are frequent. For a period of 6 years (1994-1999) the potential soil water balance was calculated on the base of physical soil properties and climatic data in daily intervals. The results show several periods with a very low content of plant available water in all test areas. They last for up to 8 months in the Central Ebro Basin and 2 weeks in the high mountain region. Beside grazing and soil erosion, the limitation of plant available water is a major reason for a slow vegetation succession on abandoned fields.
Runoff simulation in the Upper Oder catchment during the flooding event 1997 with a coupled atmospheric/ hydrological model
Authors: Mengelkamp H.-T. , Sutmüller J. , Zhao T.
Published: May 2015

Two alternative modes of the land-surface scheme SEWAB for the hydrological processes describe the two flood waves in the upper Oder catchment of the July 1997 flooding event with similar and reasonable accuracy. With the topographic index approach the peak value is slightly underestimated but correct in time while the reservoir concept shows a slight overestimation with a delay of one to two days. The interpolated observed and the simulated precipitation fields show remarkable differences in space and time. Consequently, the discharge also exhibits larger deviations.
Analysis of the severe flood of 13t-16th October 2000 in Piedmont (Italy)
Authors: Cassardo C. , Cremonini R. , Gandini D. , Paesano G. , Pelosini R. , Qian M. W.
Published: May 2015

During the 13th-16th of October 2000 a disastrous flood occurred in the whole Piedmont associated with heavy rainfall over the North-Western Alpine chain in successive episodes spanning the whole period. The event was originated by a Southern, strong and moist, upper flow established over North-Western Italy, associated at lower layers with an eastern rotation of the air flow and consequently strong convergence on the western Po Valley. The high temperature of the Mediterranean Sea caused a high rate of moisture enrichment of the air mass moving towards Piedmont. The most intense rainfall (values larger than 600 mm in 96 hours have been re ported) occurred over the mountainous regions, where the high temperatures forced the snow-rain threshold at very high altitudes. This event was one of the most intense events of the last 200 years in the Piedmont area. The majority of the basins suffered strong flood episodes; most of the mountainous portion of the basins and also part of the city of Turin down the Po Valley were seriously damaged by the strong rainfalls.
Effects of irrigation on water salinization in semi-arid environments. : A case study in Las Bardenas, Spain
Authors: Lasanta T. , Mosch W. , Pérez-Rontomé M. C. , Navas A. , Machín J. , Maestro M.
Published: May 2015

In this work, we analyse the salt and sediment load from an irrigation area located in a semi-arid environment in the Ebro Valley (Bardenas, Zaragoza). The results show higher solute and sediment load in the waters exiting the irrigation area compared to the inputs waters. Changes in the suspended load are very small, and most of the increase corresponds to soluble salts. During the period of irrigation, solute concentration is lower than during the non-irrigation periods because of higher dilution. However, the total load output during the irrigation periods is greater because the irrigation flows and returns are also higher.
Environmental impact of salinity by diffuse contamination on the water quality of the Arba River
Authors: Machín J. , Navas A.
Published: May 2015

Degradation of water quality of surface waters in the Ebro river basin constitutes an important environmental concern because of the increasing salinity trends observed in this region. A significant contribution to the salt load transported by the rivers is supplied by non-point sources from irrigation return flows. The Bardenas I irrigated area occupies 30000 ha in the semiarid central part of the Ebro valley. Return flows from this area have been monitored during the last decade. Since 1990, a total of 16 sampling points on return irrigation canals and another 6 sites along the Arba river, the natural drainage system of this area, have been sampled on a weekly/fortnightly basis. A high spatial variability in salinity levels has been found in the area, thus electrical conductivity varies from 0.3 to 10 dSm-1 depending on the irrigation period and on the soil types drained. The electrical conductivity in the Arba river increases from 0.3 to 4.7 dSm-1 from the inlet to the outlet of the Bardenas area. Therefore, the salt load supplied from the irrigation return flows amounts more than 50% of the total load transported by the Arba river. This river presents the highest salinity levels in the Ebro basin. Poor water quality due to high salinity determines restricted use for several purposes. In order to reduce this environmental impact, it is necessary to establish adequate management practices involving design of more water efficient uses to avoid further water quality deterioration.
Heavy metals and As transport under low and high flows in the River Guadiamar three years after the Aznalcóllar tailings dam failure : implications for river recovery and management
Authors: Turner J. N. , Brewer P. A. , Macklin M. G. , Hudson-Edwards K. A. , Coulthard T. J. , Howard A. J. , Jamieson H. E.
Published: May 2015

This paper presents work from an on-going research programme examining the recovery of the Guadiamar River following the April 1998 Aznalcóllar tailings dam failure. Analysis of heavy metal (Cd, Cu, Pb and Zn) and As in surface waters, valley floor alluvium, overbank and suspended sediments are compared between six study reaches downstream of the dam, over five sampling periods. The principal aims of the paper are to examine the distribution of contaminants in sediments and river waters and their delivery downstream under low and high flows, and the implications for river channel recovery and management three years after the tailings dam failure. Results from a survey of Guadiamar alluvium carried out in January 1999 showed that, although clean-up operations were largely successful in restoring the affected area to pre-spill conditions, sediments continued to exceed intervention thresholds for the region. Residual contaminant levels were highest near the spill source, with isolated ‘hotspots’of elevated contamination throughout the affected area, superimposed on a general downstream decline in concentrations. In terms of contaminant mobility, surface water samples taken in May 99, under very low flows, have dissolved Cd, Cu and Zn concentrations which fail EC directive thresholds for surface water abstraction. Element concentrations are significantly lower for waters in January 1999, when controlled discharge from the Agrio reservoir was taking place. Under high flow conditions, sediment-associated contaminant transport is dominant for all elements discussed, accounting for between 91% (Cu) and 99% (Pb) of export yields. This has lead to the remobilisation of significant quantities of contaminants, particularly Pb and Zn, during post-spill floods. Overbank deposits, however, show a fall in contaminant concentrations, following successive flood events. This has been due to sediment mixing of contaminated and “clean” material. Dilution has so far maintained contaminant concentrations below intervention threshold limits in the lower reaches, thereby offering a cautiously optimistic prognosis for the sensitive wetlands of Doñana.
Floods downstream the Yesa Reservoir, Spanish Pyrenees
Authors: López-Moreno J. I. , Beguería S. , García-Ruiz J. M.
Published: May 2015

This paper deals with the effects of the Yesa reservoir on the intensity and temporal distribution of floods in the Aragón River. The results confirm that the frequency of floods downstream the dam clearly decreased. The reduction mainly depended on two factors: i) the water storage level, and ii) the season of the year. Floods were very well controlled when the reservoir level was lower than 50%.
Interrelación nieve/geomorfología en la Sierra de Guadarrama : altas cuencas del Ventisquero de La Condesa y Vademartín
Authors: Andrés de Pablo N. , Palacios Estremera D.
Published: May 2015

La finalidad del presente trabajo es relacionar las formas del relieve con la distribución de la nieve y su permanencia sobre el suelo a lo largo del año en las altas cuencas del Ventisquero de la Condesa y Valdemartín. El área de estudio queda delimitada por las divisorias de dos torrentes, Condesa y Valdemartín, en el nacimiento del río Manzanares, donde la cumbre culminante es Cabeza de Hierro Menor (2.373 m, 40º 47' 56'' N y 3º 56' 10'' W) y la cota más baja queda aguas debajo de la confluencia de los dos arroyos (1.795 m, 40º 46' 32'' N y 3º 57' 15'' W). Para cumplir este objetivo, se han cartografiado las unidades geomorfológicas sobre al ortofoto digital de 1998 (CAM) y se han obtenido series temporales de mapas de la distribución de la nieve a partir de fotos semanales realizadas desde 1996 hasta 2004. Toda esta información se ha almacenado y tratado en un Sistema de Información Geográfica, el programa ArcGis. Con esta metodología se ha elaborado un mapa de permanencia de la nieve en el suelo para el periodo de estudio y se ha relacionado estadísticamente con el geomorfológico y con los principales datos topográficos de las cuencas: altitudes, pendientes y orientaciones. Los resultados indican que las áreas menos nivadas coinciden con las formas del relieve más antiguas. Cuando se supera el umbral de 219 días al año de permanencia de nieve en el suelo, la actividad geomorfológica nival se desencadena. En las últimas décadas, antiguos nichos nivales han cesado en su dinámica al descender el número de días de nieve en su suelo por debajo de ese umbral. Las incisiones torrenciales y la formación de canales por movimientos en masa crean nuevas áreas de acumulación nival.
Modificaciones climáticas y evolución de la cubierta vegetal en las áreas culminantes de la Sierra de Guadarrama (Sistema Central español) durante la segunda mitad del siglo XX : las altas cuencas del Ventisquero de La Condesa y de Valdemartín
Authors: Muñoz Jiménez J. , García Romero A.
Published: May 2015

Con el objeto de apreciar la relación entre las modificaciones climáticas recientes y los cambios apreciados en la cubierta vegetal de las áreas supraforestales del Sistema Central español se estudian dos pequeñas cuencas contiguas (La Condesa y Valdemartín) situadas en uno de los sectores más elevados de la Sierra de Guadarrama, muy cerca del Puerto de Navacerrada, donde existe un observatorio meteorológico perteneciente a la Red Principal que proporciona datos completos y fiables desde mediados del siglo XX. Se analiza mediante fotointerpretación la extensión de las seis facies principales que componen la vegetación dentro de las indicadas cuencas en los años 1957, 1972, 1984, 1991 y 1998 y se aprecia la correlación de los resultados obtenidos con la evolución de 18 parámetros climáticos a lo largo del período 1951-2000. El alto valor de los índices obtenidos y la básica analogía de las líneas de tendencia permite constatar que las dimensiones del área de las facies vegetales se ha modificado siguiendo el sentido y el ritmo de los cambios de los parámetros referentes a la temperatura y a la duración de la nieve. Se concluye así que la cubierta vegetal ha sido sensible a las variaciones climáticas acaecidas en el período analizado y ha respondido a ella reduciendo la extensión de los ventisqueros, de los pastizales higrófilos y de los matorrales abiertos y ampliando el área de los pastizales psicroxerófilos y de los matorrales densos.
Deglaciación reciente de Sierra Nevada : Repercusiones morfogénicas, nuevos datos y perspectivas de estudio futuro
Authors: Gómez Ortiz A. , Schulte L. , Salvador Franch F. , Palacios Estremera D. , Sanjosé Blasco J. J. , Atkinson Gordo A.
Published: May 2015

El Corral del Veleta (cabecera del glaciar del Guarnón, Sierra Nevada) albergó durante la Pequeña Edad del Hielo un pequeño glaciar. Su lenta desaparición, total a mediados del siglo XX, supuso la construcción del talud detrítico que se alinea al pie de la pared del Corral, al tiempo que la fosilización de los hielos glaciares residuales. En la actualidad, el talud evoluciona a partir de los materiales del derrumbe de la pared, afectados por procesos fríos (gelisolifluxión, crio-reptación, flujos, etc.) controlados por la duración del manto nival. De las formas elaboradas el incipiente glaciar rocoso es de las más interesantes. De éste, se controla su movimiento planar y vertical y temperatura interna del suelo. Los resultados obtenidos parecen avalar que el permafrost alpino en el que se asienta se encuentra en proceso de degradación.
El glaciar rocoso de Cerro Krund, Tierra del Fuego, Argentina
Authors: Redondo Vega J. M.
Published: May 2015

En la Sierra de Alvear, Tierra del Fuego, se ubica el Cerro Krund, que domina el complejo de esquí de Cerro Castor. En la vertiente Sur del Cerro Krund, a 900 m de altitud, se localiza un glaciar rocoso activo como atestiguan la presencia de hielo intersticial y de grietas en una pista de acceso que lo atraviesa de forma transversal. La zona está sometida a condiciones morfoclimáticas de tipo periglaciar que han sustituido a las glaciares desde la deglaciación iniciada en torno a 10-9 mil años B.P. La dinámica periglaciar y unas favorables condiciones morfoestructurales (fragmentación de la roca, extenso afloramiento al desaparecer el hielo glaciar) y tectónicas (elevada sismicidad de la región) son los factores que han favorecido la génesis del glaciar rocoso.
Procesos hidrológicos en una cuenca forestal del Sistema Central : cuenca experimental de Rinconada
Authors: Martínez Fernández J. , Ceballos Barbancho A. , Hernández Santana V. , Casado Ledesma S. , Morán Tejeda C.
Published: May 2015

In the present work we analyse the hydrological processes characterising a forested catchment on the northern face of the Sistema Central range. The Rinconada experimental catchment (at Rinconada de la Sierra, province of Salamanca), which has been running since autumn 1999, is mainly occupied by a dense forest of semi-deciduous oak (Quercus pyrenaica Willd.). It is equipped with different experimental devices (automatic meteorological and hydrological stations, a soil moisture measurement network, plots to monitor plant water dynamics, interception control networks) for the monitoring of the variables involved in the soil-water-plant-atmosphere system. The results of the analysis reveal the crucial role of the forest in the hydrological dynamics of the catchment. The catchment has a low capacity to generate runoff, above all during the period coinciding with the biological activity of the oaks. Factors such as low summer rainfall, high evapotranspiration, interception and water consumption by the trees mean that the catchment produces very little runoff, even though it is subject to subhumid climatic conditions. Also important is the fact that the saturated areas, even though occupying a very reduced percentage of the catchment, are determinant in the generation of the runoff from the majority of the events.
Evaluación de las consecuencias del fuego en quemas controladas mediante radiometría de campo
Authors: Montorio Llovería R. , Pérez Cabello F. , García Martín A. , Riva Fernández J. de la
Published: May 2015

Alteration of soil properties and destruction of vegetation cover are two important fire-induced consequences. At regional scale, remote sensing data appears suitable for monitoring post-fire processes. However, at ground-level, researchs about changes on reflectance values are necessary in order to know relationships between fire-induced environmental consequences and spectral reflectance values. In this way, measurements taken by means of field spectroradiometer provide useful information for describing these relationships. The main objective of this study is to characterize temporal patterns of reflectance values in an experimental fire and to analyze relationships between spectral reflectance values and fire-induced soils changes. A prescribed fire was carried out in two experimental plots and reflectance measurements were taken with a monthly frecuency by using a field spectro-radiometer. The collected data have shown that vegetation cover undergoes its greater change in the moment of fire, showing a stable behaviour after the fire in absence of recovery processes. On the other hand, soil is the cover with most important alterations in its behaviour from the post-fire situation due to the increase of erosion processes.
Territorios en transición : las transformaciones territoriales de la periferia de la ciudad de La Plata (Argentina)
Authors: Carut C.
Published: May 2015

The present work analyzes the transition territories that appear from the suburban dispersion process and that doesn’t have urban or rural characteristics, but they present signs in one or other according on their proximity to both spaces. The territorial organization process could have moments in the city construction cycle (creation and expansion, consolidation and strengthening, and standstill and retraction) which are representatives of transition morphologies. Since the incorporation of Milton Santos’s regimen and rupture concept, it is possible to appreciate the dynamism and fluctuation, which result are three subtypes of transition morphologies: suburban, “periurbano” in suburban process and “periurbano”.
Variación espacial de índices espectrales sobre áreas quemadas en Sudamérica
Authors: Opazo Saldivia S. , Rodríguez-Verdú F.
Published: May 2015

The present work is directed to the analysis of the variation of the spectral response shown in burnt areas of different South-America regions. The obtaining of the spectral information has been done using MODIS images (MCD43), within burnt area perimeters previously extracted by means of visual interpretation of higher spatial resolution images (Landsat and CBERS). The study has used two burnt area indices (NBR and BAI) and auxiliary information of vegetation and climate. Results shown that vegetation variables explain in a better way the indices variations in the different burnt areas. In general, it was observed that groups within more forested areas shown the highest values in the burnt area indices.
El proceso de filtración en los badlands del Este de la Península Ibérica : avances y retos
Authors: Cerdà A. , Bodí M. B.
Published: May 2015

Badlands are geomorphological miniature laboratories that contributed to the landforms and geomorphological processes studies. Infiltration is a key process in the hydrological cycle because it manages the volume of surface water and thus the erosive processes. Studying the process of infiltration into badlands gain insight on both, the process of infiltration and on badland geomorphology, and the results can be extrapolated to other areas where the high losses of soil and water must be controlled. This paper presents a review of the research regarding the infiltration in the badlands from experiments developed in the last two decades in the badlands of eastern Iberian Peninsula. The use of rainfall simulation experiments and cylinder infiltrometers measurements has provided relevant information to determine the effects of parent material, seasonality, time and geomorphological position on the process of infiltration, and then on the runoff generation and soil loss. Despite the lack of vegetation cover, and low soil development, the process of infiltration is highly complex in the badland surfaces because they generate macroporos from cracks that favor water infiltration and thus the piping developement. In the absence of vegetation, is the parent material through the surface morphology (cracks) the dominant factor in the processes of infiltration. Topographical position is key to understand the geomorphological processes in areas of badlands because the pediments behave as simple transmitters of water and sediment coming from the slopes because of its small infiltrabilidad and lack of cracks. Cracks also explain why the seasonality in the infiltration capacity of the regolith is high. Thus, the infiltration process in badlands is characterised by a highly seasonal, temporal and spatial variability which is key on the geomorphological processes behaviour.
Estado actual del conocimiento sobre la erosión por flujos concentrados en Navarra
Authors: Casalí J. , Giménez R. , Santisteban L. de , Campo M. A. , Álvarez Mozos J. , Goñi M. , Gastesi R.
Published: May 2015

There are few studies at a European level on concentrated flow erosion, especially with regard to gullies. In Spain, in particular, this information is still more limited. In this work, we have made a brief review of the current state of the knowledge on erosion in concentrated flows available in Navarre. For this purpose, the main results and conclusions of experimental studies carried out in different areas of the Navarre region in mini-basins and basins are presented. To locate the different experimental sites analysed, a pre-existent zone division of the territory, according to its erosive ambients, was used. In the central zone of Navarre and on a small scale, up to one hectare, the type of crop predominating (cereal and vines) seems to be a leading factor in erosion processes. So much so that the average erosion intensity per gullies and rills in vines is of around 2.5 kg m-2 year-1, that is, over double the most permissive values of soil loss tolerance. There are similarly important soil losses in cereals, especially from gullies, although the average loss values are below the tolerance threshold. In studies made on a larger scale, the complex topography and relief of the territory become highly significant factors in the control of these processes. For instance, two cerealist basins, apparently similar to each other, nevertheless show notable differences in sediment exportation: in one, the average annual production is of 1,800 kg ha-1 year-1, whereas in the other it is only 300 kg ha-1 year-1. In forested basins, however, the values are normally lower than those recorded in cerealist basins but they can sometimes exceed them, depending on the forest management carried out. The greatest erosion intensity is recorded during the winter since this is when, generally, the soils are almost bare and humid. Both the central and southern regions of Navarre are affected, sometimes seriously, by erosion in permanent gullies. To be specific, within Bardenas Reales de Navarra, the average intensity of the permanent gully head advance takes on values, depending on its different origin and typology, of between 3,000 to 94,000 kg ha-1 year-1. This paper also includes an extensive and critical review of the current definitions of the main phenomena involved in concentrated flow erosion.
Procesos de piping en la región de Murcia (Sureste de España)
Authors: Romero Díaz A. , Marín Sanleandro P. , Sánchez Soriano A.
Published: May 2015

The processes of sub superficial erosion or piping have a wide development in semiarid environment when the suitable characteristics for it happen. In the Region of Murcia 67 areas have been located where the presence of piping concerns a notable surface and whose evolution degree is very advanced. These areas often coincide with neogene-quaternary basins, of marly lithologie, and whose predominant soil use are old dryness culture fields, terraced and abandon today. In all the areas detailed morphologic studies have been realized and in 15 of them, soil samples at two depths (surface and 100 cm depth) were taken. Physic- chemist analysis have been carried out with the aim to study their characteristics and to establish possible formation reasons. From the morphologic point of view, the terraced importance stands out on having generated a hydraulic gradient and as the pipes depth usually coincides with the low terrace height. The results of the realized analyses show as the piping presence, in the majority of the areas, is linked to changes in the structure and soils texture at different depths (thinner textures in depth and lacking structure soils), and high exchangeable sodium percentage (superior at deeper levels) what favours the soil dispersion and the appearance of these processes. As practices of soil conservation, in areas with these characteristics, the terraced fields would be totally inadvisable, especially with high terraces, and its later abandon.
Identificación de zonas de erosión activa y áreas de riesgo mediante teledetección : un ejemplo en un paisaje de cárcavas sobre margas en el Pirineo Central Español
Authors: Alatorre L. C. , Beguería S.
Published: May 2015

The identification of eroded areas at catchment scale can be very useful for environmental planning and can help to reduce land degradation and sediment yield. In this paper remote sensing techniques are used to discriminate both eroded areas and erosion risk areas in a badlands landscape developed on Eocene marls, in the Ésera River catchment (Spanish Pyrenees). The spatial distribution, the scarce vegetal cover and the high erosion level let a good visual and digital discrimination of badlands, as opposed to other land covers and surfaces. A maximum likelihood supervised method was used to discriminate heavily eroded areas (badlands) from scarce or densely vegetated lands, by means of the spectral signature of bare soil. The classification distance was used to obtain thresholds for eroded areas and areas at risk. Two error statistics (sensitivity and specificity) where used to determine the most adequate threshold values. The resulting map shows that most areas at risk are located surrounding the badland areas.
Caracterización de la erosión en áreas acarcavadas en la Fm. Tudela (Bardenas Reales, Navarra)
Authors: Desir G. , Marín C.
Published: May 2015

At Bardenas Reales, erosion processes are due to hydric action and wind erosion. Climate, lithology and geomorphology are the main factors that control water erosion. Besides sediment yield by water, other forms exist to export material: mudslides and armoured mud balls. Clay material at high slopes and high dispersion index together with climate determine the presence of one type of erosion or another. On winter times, mudslides are developed while on summer high intensity storms provoke incision. Meanwhile armoured mud balls could coexist with both of them.
Erosión por cárcavas y barrancos en el área de viña del Alt Penedès-Anoia (NE España)
Authors: Martínez-Casasnovas J. A. , Ramos M. Concepción
Published: May 2015

The present research analyzes gully erosion processes in an area of the Alt Penedès and Anoia regions (Barcelona) at semi-detailed and detailed scales. For that, information technology methods (Geographic Information Systems and Remote Sensing) are developed and applied. The study area is located in the Vallès-Penedès Depression, where unconsolidated continental and marine Miocene deposits outcrop with a dense and deep gully network. The methods have allowed the location of gully erosion at regional scale and the determination of gully erosion rates in a sample area. The results reveal the importance of gully erosion, usually less studied than other erosion processes. The 15.2% of the region has been affected by gullies, with landscape units where the dissection reaches 31.9%. Gullies are active at present, with annual average rates of 576 ± 58 Mg ha-1 year-1, which indicates the importance of gully erosion processes in the production of sediments in the study area.
Influencia de los factores topográficos en los procesos de piping, Murcia (España)
Authors: Romero Díaz A. , Alonso Sarría F. , Sánchez Soriano A.
Published: May 2015

Usually, different mechanical, chemical or biological causes of piping development have been described, particularly those related to the hydraulic gradients and the presence of sodium into the soil. The main purpose of this paper is to analyze the topographic characteristicsof both the pipes and the agricultural plots where they appear, and to estimate the volume of sediment yield. Eight different zones, located in the Mula River basin, were studied. The slopes were terraced for cultivation and abandoned 30-40 years ago. 137 plots were selected for sampling, 71% of which showed piping processes. The results obtained show a concentration of pipes in certain areas. There is a high correlation between the volume of soil loss and the extent of piping; between the area affected by piping and the average length, depth and width of pipes; between the size of the plot and the degree of piping development; between the height of the terrace walls and the maximum depth of pipes; and, finally, between gradients and piping intensity. If topographic factors favour the presence of pipes, some plot levelling recommendations could be defined in order to minimize the risk of piping processes in the most susceptible areas.
Influencia de los procesos de piping en la evolución del modelado : Bardenas Reales (Navarra, España)
Authors: Desir G. , Marín C.
Published: May 2015

Piping processes are controlled by many interacting factors, such as dispersion index and sodium content, SAR and ESP, together with other important factors as cracking density, slope degree and climate. In the study area piping is linked to poor developed soils with high sodium contents which give raise to an intense regolith cracking that favours infiltration and finally piping. As the results show piping in this area can be separated in two different types depending on its genesis, one based on seepage processes, considered as a true type, and another due to tunnelling processes. From a distributional point of view piping is linked to two concrete situations: the massive intermediate levels of the intermediate Holocene filling sediments and the sediments deposited by gullies. In the tertiary materials, in general, it does not manage to develop. On Holocene materials pipes size and scale show a clear relationship among the level thickness, slope and hydraulic gradient, being the first one the principal bounding factor. Pipes developed on the lower laminated levels do not reach important depth due to the high number of discontinuities, generating centimetre-scale conduits that are always on duty to the drainage network. On gullies sediments piping are related to gullies margin evolution and headcut retreat. Pipes size and diameter are a direct function of gully dimensions and are inversely proportional to the proximity to gully scarp. Pipes are on a metric scale with a vertical pattern which development in depth is controlled by upper level thickness, since they are circumscribe to him.
Una nueva herramienta para evaluar la susceptibilidad de los suelos a los procesos de sufosión o piping : el pinhole test
Authors: Nadal-Romero E. , Verachtert E. , Maes R. , Poesen J.
Published: May 2015

Los procesos de piping o sufosión se han observado en paisajes naturales y antrópicos, en diferentes litologías y climas, y bajo diferentes usos del suelo y cubiertas vegetales. Sin embargo, a pesar de su importancia, no existe una metodología estándar que permita evaluar la susceptibilidad de los suelos a los procesos de sufosión o piping. El pinhole test, originalmente desarrollado por Sherard et al. en 1976 es un test empírico basado en la evaluación cualitativa y directa de la susceptibilidad de los suelos a la dispersión y a los procesos de piping o sufosión. Los objetivos de este trabajo son evaluar una metodología de trabajo, el pinhole test, y establecer recomendaciones y conclusiones acerca de la idoneidad de su uso, además de estudiar los efectos de diferentes gradientes hidráulicos, de la calidad del agua y del contenido de humedad del suelo en la respuesta hidrológica y sedimentológica. Los primeros ensayos se han realizado con el horizonte superficial Ap, de un suelo agrícola localizado en Heverlee (Bélgica central). Las pruebas se han realizado con diferentes contenidos de humedad, bajo 4 gradientes hidráulicos (50, 180, 380 y 1020 mm) y con dos calidades de agua (agua del grifo y agua destilada). Los resultados indican: (i) un aumento de la respuesta hidrológica (Qw) y de la respuesta erosiva (Qs) cuando se produce un incremento de gradiente hidráulico, (ii) una tendencia negativa (no significativa) entre el contenido de humedad y la respuesta hidrológica y erosiva, y (iii) una respuesta hidrológica y sedimentológica mayor en los experimentos realizados con agua destilada. Este estudio sugiere que el pinhole test es un método adecuado para evaluar de manera cuantitativa (Qw, Qs, tiempo de respuesta y el diámetro final del agujero) la susceptibilidad de los suelos u horizontes del suelo a los procesos de sufosión o piping. Para ello recomendamos (i) al menos el uso de dos gradientes hidráulicos contrastados (p.e. 180 y 1020 mm), (ii) el uso de agua destilada, y (iii) de diferentes contenidos de humedad
Besiberris glacigenic rock glacier (Central Pyrenees, Spain) : mapping surface horizontal and vertical movement (1993-2003)
Authors: Chueca Cía J. , Julián Andrés A.
Published: May 2015

A ten-year (1993-2003) geodetic survey was conducted at the Besiberris rock glacier, a tongue-shaped, glacigenic rock glacier, located in the eastern-central Spanish Pyrenees (42º35'48''N, 0º49'20''E). Displacement measurements were made on three traverse lines across the rock glacier and mapped by geostatistical kriging interpolation methods. Surface horizontal velocity increases from the head to the toe sectors (average values: traverse line A = 8.72 cm yr-1; line B = 10.65 cm yr-1; line C = 13.35 cm yr-1). Velocities are greater at the axis of the rock glacier compared to its lateral margins. In terms of vertical movement, the rock glacier has shown clear thinning of an ice-core. In all three traverse lines, surface lowering has been detected (average values: line A = 5.00 cm yr-1; line B = 7.10 cm yr-1; line C = 5.27 cm yr-1). This general lowering is interpreted as the adjustement of the rock glacier to the climatic amelioration (higher temperature, drier conditions and reduced snowfall) observed in the Pyrenean region since the end of the Little Ice Age and accentuated in the last few decades.
Distribución de glaciares rocosos relictos en la Cordillera Cantábrica
Authors: Gómez Villar A. , González-Gutierrez R. B. , Redondo-Vega J. M. , Santos-González J.
Published: May 2015

Se presenta la localización de 173 glaciares rocosos relictos (atendiendo a su forma en planta: de lengua, lobulados y complejos) en seis zonas de la Cordillera Cantábrica, establecidas según factores de tipo morfoestructural y/ o concentración de glaciares rocosos relictos. Se analiza cómo determinados elementos como la litología, pendiente y orientación, junto con las condiciones del relieve inicial y las características de los afloramientos rocosos (su fracturación), contribuyen a explicar el desarrollo y localización de estas formas periglaciares en la montaña cantábrica.
Dinámica superficial y estado actual del glaciar rocoso de la Madaleta Occidental (Pirineos)
Authors: González García M. , Serrano E. , Sanjosé Blasco J. J. , González Trueba J. J.
Published: May 2015

The Maladeta Occidental rock glacier is located in the Maladetas massif (Central Pyrenees). A geomorphologic analysis of detail, complemented by continuous ground thermal measurement, bottom temperature of winter snowcover (BTS) and the control of its dynamics by means of geomatics techniques, allow demonstrating the recent activity of this periglaciar landform. Systematic monitoring using differential GPS in fifteen fixed points distributed by the rock glacier surface, show the vertical and horizontal variations during the field survey 2008, 2009 and 2010. Dynamics recorded for the present time responds to a rock glacier model of low activity in clear thermal imbalance, with fast interannual variations. The location in marginal periglacial environments of high temperate mountain like the Pyrenees, make it a useful morphoclimatic geoindicator.
Los glaciares rocosos de Sierra Nevada y su significado paleoclimático : Una primera aproximación
Authors: Palade B. , Palacios Estremera D. , Gómez Ortiz A.
Published: May 2015

En este trabajo se han identificado y cartografíado 36 glaciares rocosos en el sector occidental de Sierra Nevada. Todos los glaciares rocosos se incluyen en la categoría de los glaciares rocosos de talud. Exceptuando el caso del glaciar rocoso del Corral del Veleta que aún preserva ciertas masas de hielo interior, el resto de los glaciares rocosos han sido clasificados como formas relictas. La información cartográfica ha sido tratada en un Sistema de Información Geográfica (GIS) y los resultados indican que los glaciares rocosos se localizan entre los 2460 m y 3360 m de altitud, tienen una pendiente media de 21º y prefieren las orientaciones con menor radiación, aunque también abundan en la cara sur de la Sierra, cuando las condiciones de acumulación de nieve así lo propician. La presente localización altitudinal de los glaciares rocosos indica que se formaron con una temperatura de 6ºC inferior a la actual. Dos de los glaciares rocosos han sido datados de forma absoluta a través del isótopo cosmogénico 36Cl, así como un umbral con pulimento glaciar donde se asienta uno de ellos. Los resultados muestran que los glaciares rocosos se formaron justo después de la retirada de los hielos glaciares (hace 14 a 15 ka) y pudieron algunos sobrevivir hasta ya avanzado el Holoceno (entre hace 8 y 7 ka). El actual glaciar rocoso del Corral del Veleta es un nuevo ejemplo de formación de glaciares rocosos, después de la deglaciación de paredes muy inestables, en este caso al final de la Pequeña Edad de Hielo.
The effect of intense rainstorm events on the suspended sediment response under various land uses : the Aísa Valley experimental station
Authors: Nadal-Romero E. , Lasanta Martínez T. , González-Hidalgo J. C. , De Luis M. , García-Ruiz J. M.
Published: May 2015

Time compression was studied at the Aísa Valley Experimental Station to assess the effect of large rainfall events on suspended sediment load. The study was focused on the response of land under traditional and current land uses/land covers in Mediterranean mountain areas, including dense shrub cover, grazing meadow, abandoned field, cereal cultivation, fallow land and both active and abandoned shifting agriculture. The results confirm the importance of the largest rainfall events in explaining the geomorphological effects that occur during a small number of such events. Three groups of land uses were distinguished: (i) dense shrub cover and grazing meadow, which showed relatively little time compression; (ii) cereal cultivation, fallow land, and both active and abandoned shifting agriculture, which were characterized by a high degree of time compression and a major impact of the largest events; and (iii) the abandoned field, which was intermediate in response between the other two groups. The greater geomorpho-logical effects of the largest events in the plots at the Aísa Valley Experimental Station relative to those reported in studies in the USA, is a consequence of the Mediterranean climate charac-teristics, and in part because of scale effects. The contribution of the three largest events to total accumulated suspended sediment load ranged from 25.4 to 71.2% whereas for the five largest events it ranged from 35.4 to 76.9%. For each of the land uses the 25 largest events represented more than 80% (in some cases more than 90%) of the total suspended sediment load recorded since 1991.
El impacto del cultivo, el abandono y la intensificación de la agricultura en la pérdida de agua y suelo : el ejemplo de la vertiente norte de la Serra Grossa en el Este Peninsular
Authors: Cerdà A. , Giménez Morera A. , Burguet M. , Arcenegui V. , González Peñaloza F. A. , García-Orenes F. , Pereira P.
Published: May 2015

Land abandonment throughout the twentieth century led to an intense landscape transformation in the mountain areas of the Iberian Peninsula. In some cases, and after 50 years of abandonment, agriculture returned with the development of commercial farms and the intensification of the agrarian activities. In the Easter Iberian Peninsula, following the abandonment of olive groves, vineyards and cereals during the 50’s, has been in the past two decades the expansion of intensive citrus production on sloping terrain. Geomorphological transects and simulated rainfall experiments have quantified the impact of traditional rainfed cultivation of the 50’s, abandonment, and the intensification of farming on the processes and landforms of erosion on the northern slopes of the Serra Grossa, south of the province of Valencia. It was found that the citrus groves have the highest number of rills and gullies. These erosive morphologies were not in the traditional crop tillage, and when they formed in the abandoned fields were soon controlled by the growth of vegetation. The abandonment of the crops reduced the soil losses, but the intensification of the agriculture with the citrus production has accelerated the soil erosion rates that exceed by several orders of magnitude (x4) the soil erosion rates measured during the abandonment and multiply by 17 the quantified traditional rainfed agriculture soil losses. Tillage of traditional rainfed orchards reduced runoff, but increased the concentration of sediments of the surface wash.
El papel del relieve en la definición de unidades de paisaje : el caso de Muntanyes d'Ordal (Barcelona)
Authors: Serrano Giné D.
Published: May 2015

This paper deals on the importance of the relief in the landscape and, particularly, in the definition of landscape units. It establishes a classification that differentiates three approaches, according to the relief methodological treatment. Finally it develops a methodology according to surveys with geomorphological basis that is applied to Muntanyes d’Ordal (Barcelona). The results are completed with detailed cartography, where 36 units are identified, and with a succinct reflection on the goodness and difficulties of the employed method.
La movilidad tectonica y los procesos geomorfologicos actuales de los subcarpatos de rumania
Authors: Badea L. , Balteanu D.
Published: May 2015

Los Subcárpatos de Rumania, formados por molasas neógenas plegadas asociadadas localmente al flysch paleógeno, están afectados por movimientos tectónicos positivos, con intensidades variables, que influyen de manera evidente en los procesos geomorfológicos actuales, ligados a un clima templado-continental. El modelado de vertientes se realiza esencialmente por movimientos en masa (deslizamientos, coladas de barro) a los que se unen intensos procesos de arroyamiento. Los acontecimientos extremos (precipitaciones torrenciales, potentes temblores de tierra) desempeñan el papel principal en el desencadenamiento lento y recrudecimiento de los movimientos en masa. A partir de las investigaciones realizadas, se aprecia que los Subcárpatos se encuentran entre las regiones de Europa más intensamente afectadas por los procesos geomorfológicos actuales.
Tipos de escorrentía y ritmo de evacuación de sedimentos en la Sierra de la Demanda : Sistema Ibérico
Authors: Arnáez Vadillo José , García-Ruiz José M.
Published: May 2015

Con el fin de relacionar las oscilaciones de caudal con la carga sólida y analizar la importancia relativa de los diferentes flujos que se establecen en la vertiente, se han medido periódicamente caudales, sedimentos en suspensión y conductividad del agua en dos cuencias de la sierra de la Demanda, una con importante cubierta forestal y otra con casi total ausencia de bosque. Carga sólida y caudal mantienen una correspondencia notable a lo largo del año, pero en muchas situaciones la cuenca cubierta de bosques tiene una mayor pérdida de sedimentos, aunque, en todo caso, las cifras son muy bajas. Una parte muy importante de la escorrentía de esa cuenca tiene lugar mediante pipes que posteriormente se mostraron como los más eficaces en el transporte de sedimentos, al menos durante la fusión de la nieve
Valoración de los diferentes métodos empleados en Galicia para la medida de la erosión de los suelos, con especial referencia a los suelos afectados por incendios forestales
Authors: Díaz-Fierros Viqueira Francisco , Pérez Moreira Rogelio
Published: May 2015

Se analizan críticamente los diferentes métodos empleados en Galicia para la medida de la erosión de los suelos: métodos teóricos de cálculo de la Erosividad Climática, métodos experimentales de medida del material en suspensión que arrastran los ríos, medida de la pérdida de suelo en minicuencas experimentales o según el recubrimiento de jalones enterrados, y medida microtopográfica del nivel del suelo. Se analiza también la erosión en Galicia durante el periodo histórico, según los diagramas polínicos de sedimentos y la documentación histórica
Evolución geomorfológica del cañón del río Guadalhorce en el Trías de Antequera (Archidona, Málaga)
Authors: Durán Valsero Juan José
Published: May 2015

La evolución geomorfológica del Río Guadalhorce y áreas adyacentes es consecuencia de la interacción de los procesos erosivos (superficiales y subterráneos) y la elevación halocinética del Trías (debido a la presencia de yeso y/o halita en profundidad), desde el Plioceno, de manera tal que el drenaje superficial, la Karstificación de los macizos yesíferos y el drenaje subterráneo están íntimamente ligados en la actualidad.
Dinámica de vertientes en Cantabria Oriental
Authors: García Codrón Juan Carlos
Published: May 2015

Se estudian los deslizamientos que se generaron en el SE de Cantabria en relación con las lluvias catastróficas de agosto de 1983. Sus características y distribución espacial no pueden entenderse sin invocar el tipo de hábitat y los usos del suelo de la región que facilitan, mucho más que los simples condicionantes físicos, el desarrollo de diversos procesos de erosión acelerada.