Articles publicats (Grup de Recerca de Dinàmica Fluvial (RIUS))
Permanent URI for this collection
- ItemOpen AccessReconstrucción post-evento del flash-flood del 1 de septiembre de 2021 en Les Cases d’Alcanar (Tarragona)(Universitat Politècnica de València, 2023) Balasch Solanes, J. Carles (Josep Carles); Calvet, Jaume; Tuset Mestre, JordiLa crecida que se produjo el 1 de septiembre de 2021 en Les Cases d’Alcanar (Tarragona), es una de las de mayor magnitud del litoral mediterráneo occidental durante la época instrumental. Se ha realizado una reconstrucción post-evento determinando el caudal punta mediante el modelo hidráulico 2D IBER y la respuesta hidrológica de la cuenca a través del software hidrológico global HEC-HMS. Tras una lluvia de 251.9 mm en unas 3 horas, se estima que el pico fue de 159 m3·s-1 a la entrada de la población y el volumen de escorrentía fue de 1.15 hm3. El coeficiente de escorrentía alcanzó un valor de 0.76. Gran parte del desbordamiento en el núcleo poblado fue debido a la oclusión de los drenajes transversales al barranco y a la falta de capacidad de drenaje del canal. Los datos reconstruidos se consideran de un gran valor para la planificación de estructuras en cuencas pequeñas que carecen de datos de aforo.
- ItemOpen AccessSensitivity analysis in mean annual sediment yield modeling with respect to rainfall probability distribution functions(MDPI, 2023-01) Rodríguez González, César Antonio; Rodríguez-Pérez, Ángel Mariano; López Alonso, Raúl; Hernández-Torres, Jose Antonio; Caparrós-Mancera, Julio JoseAn accurate estimation of the mean annual sediment yield from basins contributes to optimizing water resources planning and management. More specifically, both reservoir sedimentation and the damage caused to infrastructures fall within its field of application. Through a simple probabilistic combination function implemented in hydrometeorological models, this sediment yield can be estimated on a planning and management scale for ungauged basins. This probabilistic combination methodology requires the use of probability distribution functions to model design storms. Within these functions, SQRT-ET max and log-Pearson type III are currently highlighted in applied hydrology. Although the Gumbel distribution is also relevant, its use has progressively declined, as it has been considered to underestimate precipitation depth and flow discharge for high return periods, compared to the SQRT-ET max and log-Pearson III functions. The quantification of sediment yield through hydrometeorological models will ultimately be affected by the choice of the probability distribution function. The following four different functions were studied: Gumbel type I with a small sample size, Gumbel type I with a large sample size, log-Pearson type III and SQRT-ET max. To illustrate this, the model with these four functions has been applied in the Alto Palmones basin (South Iberian Peninsula). In this paper, it is shown that the application of Gumbel function type I with a small sample size, for the estimation of the mean annual sediment yield, provides values on the conservative side, with respect to the SQRT-ET max and log-Pearson type III functions.
- ItemOpen AccessLong-term geomorphic adjustments following the recoupling of a tributary to its main-stem river(Elsevier, 2023) Blackburn, Joel; Marteau, Baptiste; Vericat Querol, Damià; Batalla, Ramon J.; Comte, Jean-Christophe; Gibbins, ChristopherRiver restoration and rehabilitation projects are widespread, but rarely include the data needed to fully evaluate if they are successful in achieving their goals or how long the process of readjustment takes before a new ‘recovered’ regime state is reached. Here we present a seven-year post-project dataset detailing the morpho-sedimentary responses of a river to the reconnection of a formerly diverted tributary, and relate observed changes to conditions in the river prior to the reconnection. We describe changes in the tributary and main-stem channels, including changes in channel planform, morphology, and the export of coarse and fine sediment from the tributary to the main-stem river. We use the data to develop a conceptual model of the system's response to the reconnection. Marked geomorphic changes occurred within the first two years after the reconnection. Changes during this ‘shock phase’ included dramatic erosion and subsequent deepening and widening of the tributary channel, rapid development of a confluence bar and an increase in fine sediment delivered to the main-stem. After this shock phase, and despite the continued occurrence of high magnitude flow events, the rate of geomorphic change in the tributary began to decrease, and the rate of growth of the confluence bar slowed. Fine sediment volumes in the main-stem also decreased steadily. After an adjustment phase lasting a total of approximately 4.5 yr (including the initial 2-yr shock phase), the tributary to mainstem system appeared to reach a new dynamic equilibrium that we consider the adjusted regime state. This new regime state was characterised by, among other things, an increase in geomorphic heterogeneity in the tributary and main-stem channels. Changes in both fluvial processes and forms indicate that within 4.5 yr the project was successful in achieving its goal of augmenting sediment and increasing geomorphic heterogeneity. Our conceptual model of adjustment mirrors that developed by Petts and Gurnell (2005), with the river passing through a complex and dynamic adjustment phase before reaching a new regime state. However, unlike the responses to impoundment represented by Petts and Gurnell, our model of river response to rehabilitation charts increases in dynamism and heterogeneity.
- ItemOpen AccessDownstream changes of particle entrainment in a hydropeaked river(Elsevier, 2020-11-25) López Alonso, Raúl; Garcia, Celso; Vericat Querol, Damià; Batalla, Ramon J.Hydropeaking, through artificially generated flow peaks, affects hydro-sedimentary dynamics on rivers. The frequency and magnitude of such artificial flow pulses impact sedimentary process and, inevitably, affects bed-material entrainment. This study analyses the entrainment of particles in six sections of a Pyrenean river under frequent hydropeaking. Three equations of particle entrainment with contrasting behaviours, validated for particle mobility from tracer data, have been used to predict the initiation of motion in each section. Results show that the peak discharge generated by the hydropower station mostly affects the section immediately downstream from the hydropower plant, where the finer fractions of the bed are mobilised. The mobile grain sizes include fine to medium gravels (< 20 mm). Channel geometry and higher slopes also have an effect on particle entrainment. Entrainment of the finer size fractions of the bed is termed partial transport, i.e. a partially size-selective transport that occurs downstream from the hydropower station and winnows the sand and small gravel further downstream.
- ItemOpen AccessA framework for Hydrological characterisation to support Functional Flows (HyFFlow): Application to a tropical river(Elsevier, 2021) Chong, Xin Yi; Gibbins, Chris N.; Vericat Querol, Damià; Batalla, Ramon J.; Teo, Fang Yenn; Lee, Karen Suan PingStudy region: Sarawak, Malaysia. Study focus: This paper presents a framework (‘HyFFlow’) designed to provide a systematic characterisation of river flow regimes. HyFFlow consists of four packages, together yielding information on rainfall and flow patterns. They include analyses to identify and characterise different types of high flow event, based on their magnitude, shape and duration, and assessment of the timing and duration of periods of high and low flow. HyFFlow also includes assessment of temporal patterns (seasonality and long-term trends) in rainfall and flow. The characterisation provides a comprehensive baseline against which future changes can be assessed. New hydrologic insights for the region: HyFFlow analyses indicated subtle and complex changes to long-term hydro-climatological conditions in the Baleh catchment, Malaysia: (i) analyses of the hydrograph indicated that there have been reductions in flow in the wet season, but not at other times of the year, and (ii) while there is no evidence of long-term trends in precipitation across the catchment (no change in monthly rainfall values over a 51- year period), there has been an increase in the number of days each month with no rainfall in some sub-catchments. HyFFlow analyses also identified four main types of high flow event in the Baleh whose functional roles need to be assessed as part of future geomorphic and ecological studies.