El papel del piping en la espeleogénesis del sistema endokárstico de Seso (Pirineo central,Huesca)

[ES] El sistema endokárstico de Seso (Boltaña, Huesca), localizado en el sector central surpirenaico, presenta una espeleogénesis singular. La excavación mecánica en condiciones vadosas de material margoso fácilmente erosionable (procesos de piping) constituye el principal mecanismo espeleogenético. La disposición espacial del sistema endokárstico respecto a las terrazas datadas del río Ara permite situar la formación de la cavidad en el Pleistoceno superior, probablemente coincidiendo con fases húmedas del MIS 4[EN] The Seso Cave system (Boltaña, Huesca province) in the Southcentral Pyrenees presents a singular speleogenesis. Vadose mechanical entrenchment of highly erosive and dispersive marls (piping processes) is the main espeleogenetic mechanism. Geometric relationship between the endokarstic system and a terrace of the Ara River chronologically controlled allows dating the cave formation in the Upper Pleistocene, probably during stages of the MIS 4 with high water availabilityEste trabajo es una contribución del Proyecto CGL2009-10455/BTE (Ministerio de Ciencia e Innovación y Fondos Europeos) y de los Grupos de Investigación Geomorfología y Cambio Global y Paleoambientes del Quaternario del Gobierno de Aragón.Agradecemos la ayuda económica del Geoparque del Sobrarbe y la colaboración de Enrique Oliver en el trabajo de laboratorio. Los autores agradecen los comentarios realizados por Juan José Durán, Jerónimo López- Martínez y un revisor anónimo.Peer reviewe

Extreme Floods in Small Mediterranean Catchments: Long-Term Response to Climate Variability and Change

Climate change implies changes in the frequency and magnitude of flood events. The influence of climate variability on flooding was evaluated by an analysis of sedimentary (palaeofloods) and documentary archives. A 500-year palaeoflood record at Montlleó River (657 km2 in catchment area), eastern Spain, revealed up to 31 palaeofloods with a range of discharges of 20–950 m3 s−1, and with at least five floods exceeding 740–950 m3 s−1. This information contrasts with the available gauged flood registers (since year 1971) with an annual maximum daily discharge of 129 m3 s−1. Our palaeoflood dataset indicates flood cluster episodes at (1) 1570–1620, (2) 1775–1795, (3) 1850–1890, and (4) 1920–1969. Flood rich periods 1 and 3 corresponded to cooler than usual (about 0.3 °C and 0.2 °C) climate oscillations, whereas 2 and 4 were characterised by higher inter-annual climatic variability (floods and droughts). This high inter-annual rainfall variability increased over the last 150 years, leading to a reduction of annual maximum flow. Flood quantiles (>50 years) calculated from palaeoflood+gauged data showed 30%–40% higher peak discharges than those using only instrumental records, whereas when increasing the catchment area (1500 km2) the discharge estimation variance decreased to ~15%. The results reflect the higher sensitivity of small catchments to changes on flood magnitude and frequency due to climate variability whereas a larger catchment buffers the response due to the limited extent of convective storms. Our findings show that extended flood records provide robust knowledge about hazardous flooding that can assist in the prioritization of low-regret actions for flood-risk adaptation to climate change

Geospatial Artificial Intelligence (GeoAI) in the Integrated Hydrological and Fluvial Systems Modeling: Review of Current Applications and Trends

This paper reviews the current GeoAI and machine learning applications in hydrological and hydraulic modeling, hydrological optimization problems, water quality modeling, and fluvial geomorphic and morphodynamic mapping. GeoAI effectively harnesses the vast amount of spatial and non-spatial data collected with the new automatic technologies. The fast development of GeoAI provides multiple methods and techniques, although it also makes comparisons between different methods challenging. Overall, selecting a particular GeoAI method depends on the application's objective, data availability, and user expertise. GeoAI has shown advantages in non-linear modeling, computational efficiency, integration of multiple data sources, high accurate prediction capability, and the unraveling of new hydrological patterns and processes. A major drawback in most GeoAI models is the adequate model setting and low physical interpretability, explainability, and model generalization. The most recent research on hydrological GeoAI has focused on integrating the physical-based models' principles with the GeoAI methods and on the progress towards autonomous prediction and forecasting systems

Role of piping processes in the speleogenesis of Seso Cave (Central Pyrenees, Huesca province)

El sistema endokárstico de Seso (Boltaña, Huesca), localizado en el sector central surpirenaico, presenta una espeleogénesis singular. La excavación mecánica en condiciones vadosas de material margoso fácilmente erosionable (procesos de piping) constituye el principal mecanismo espeleogenético. La disposición espacial del sistema endokárstico respecto a las terrazas datadas del río Ara permite situar la formación de la cavidad en el Pleistoceno superior, probablemente coincidiendo con fases húmedas del MIS 4The Seso Cave system (Boltaña, Huesca province) in the Southcentral Pyrenees presents a singular speleogenesis. Vadose mechanical entrenchment of highly erosive and dispersive marls (piping processes) is the main espeleogenetic mechanism. Geometric relationship between the endokarstic system and a terrace of the Ara River chronologically controlled allows dating the cave formation in the Upper Pleistocene, probably during stages of the MIS 4 with high water availabilit

Topographical change caused by moderate and small floods in a gravel bed ephemeral river-a depth-averaged morphodynamic simulation approach

In ephemeral rivers, channel morphology represents a snapshot at the end of a succession of geomorphic changes caused by floods. In most cases, the channel shape and bedform migration during different phases of a flood hydrograph cannot be identified from field evidence. This paper analyses the timing of riverbed erosion and deposition of a gravel bed ephemeral river channel (Rambla de la Viuda, Spain) during consecutive and moderate- (March 2013) and low-magnitude (May 2013) discharge events, by applying a morphodynamic model (Delft3D) calibrated with pre- and post-event surveys by RTK-GPS points and mobile laser scanning. The study reach is mainly depositional and all bedload sediment supplied from adjacent upstream areas is trapped in the study segment forming gravel lobes. Therefore, estimates of total bedload sediment mass balance can be obtained from pre- and post-field survey for each flood event. The spatially varying grain size data and transport equations were the most important factors for model calibration, in addition to flow discharge. The channel acted as a braided channel during the lower flows of the two discharge events, but when bars were submerged in the high discharges of May 2013, the high fluid forces followed a meandering river planform. The model results showed that erosion and deposition were in total greater during the long-lasting receding phase than during the rising phase of the flood hydrographs. In the case of the moderate-magnitude discharge event, deposition and erosion peaks were predicted to occur at the beginning of the hydrograph, whereas deposition dominated throughout the event. Conversely, the low-magnitude discharge event only experienced the peak of channel changes after the discharge peak. Thus, both type of discharge events highlight the importance of receding phase for this type of gravel bed ephemeral river channel

Dinámica morfosedimentaria de ríos efímeros afectados por extracciones de gravas: cartografía en SIG y detección de cambios morfológicos

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Geológicas, leída el 23-11-2018Mediterranean regions have a long history of human occupation and land uses, particularly centered next to fluvial courses. Environmental pressures along rivers increased as the population increased since late XIX century. In Spain, rivers are public spaces and only recently public administrations became sensible in regard of the environmental conditions of fluvial corridors. In Europe, the Water Framework Directive 2000/60/EC (WFD) was adopted in 2000 in order to implement an ambitious piece of European environmental standards for river management and water quality conservation. In the Mediterranean region most river courses cease to flow for some time of the year, and the proposed methods to control river environmental status, i.e. water quality measurements or identification of aquatic biota, have practical problems for their implementation. Thus, non-perennial rivers lack of effective environmental protection, even so, they constitute more than 50% of the total river network and sometimes reaching 90% in Mediterranean basins, e.g. Segura River basin...El entorno mediterráneo ha sido un lugar concurrido a lo largo de toda la historia y en el cual los ríos siempre han jugado un papel decisivo para las culturas que habitaron –y habitan– las tierras de alrededor del Mar Mediterráneo. Como cabría esperar, estos ríos han sido sometidos a una cierta presión, que desde entonces ha ido aumentando conforme la población se ha ido incrementando y concentrando en núcleos de población. En el año 2000, la Directiva Marco del Agua Europea (WFD) apareció para definir unos criterios mínimos y unas guías de conservación de los ríos. Sin embargo,estas directrices han sido diseñadas por y para países centro europeos donde los ríos presentan agua permanentemente (ríos perennes). Pero este no es el caso de los ríos en el entorno Mediterráneo, donde las condiciones climáticas hacen que los ríos pierdansu caudal parte del tiempo (ríos no perennes o temporales). Por tanto, ninguno de los parámetros propuestos para el control ambiental, como por ejemplo la demanda biológica de oxígeno, es aplicable a ellos. De esta manera, los ríos no permanentes se encuentran sin regulación a pesar de constituir más del 50 % de la red fluvial mundial y hasta el 90% en el entorno mediterráneo, como en el caso de la cuenca hidrográfica del Segura...Fac. de Ciencias GeológicasTRUEunpu