http://hdl.handle.net/2117/5302 2013-05-22T09:14:09Z http://hdl.handle.net/2117/19291 Title: Desarrollo de herramientas para la evaluación preliminar de la peligrosidad de corrientes detríticas Authors: Bregoli, Francesco; Bateman Pinzón, Allen; Medina Iglesias, Vicente César de; Hurlimann Ziegler, Marcel Abstract: Con el objetivo de proporcionar recomendaciones para la alerta temprana de fenómenos potencialmente desencadenantes de corrientes detríticas (“Debris Flow”), uno de los temas principales es la identificación preliminar de zonas de riesgo. Esta identificación es sustancialmente diferente de los mapas de riesgo que se suelen realizar por las autoridades de cuenca con el fin de dar una guía para planes de gestión del territorio. En el caso de alerta temprana, una identificación más aproximativa de las zonas de riesgo es suficiente. En esta perspectiva, los dos componentes del riesgo, peligrosidad y vulnerabilidad, se pueden estimar de una manera simplificada. En este trabajo se han desarrollado unas herramientas para la evaluación rápida de peligro por corrientes detríticas. Se han adaptado metodologías existentes y modelos simplificados y se ha llevado a cabo un útil paquete común de metodologías para una rápida evaluación de la peligrosidad. Se modelan tanto la iniciación como la propagación de corrientes detríticas. Uno de los requisitos del proyecto es definir una herramienta utilizable en diferentes contextos donde el nivel de detalle en los datos de entrada puede ser muy variado. Para lograr este objetivo se define un enfoque multinivel. La metodología se aplica en tres cuencas con características diferentes. 2013-05-16T12:17:48Z http://hdl.handle.net/2117/19255 Title: High-speed debris-flows generating 2D impulse waves: Experimental analysis Authors: Bregoli, Francesco; Bateman Pinzón, Allen; Medina Iglesias, Vicente César de Abstract: When a landslide or a debris-flow falls in a water body, a big wave, known as impulse wave or landslide tsunami wave, can be generated. That phenomenon can be highly destructive and unlikely predicted, involving dams and shorelines. Disastrous past events have been extensively analyzed and experimental studies have been carried out by different authors, but do not fully account for the description of the phenomenon. In the present study we introduce a new experimental set up installed in the fluvial-morphodynamic laboratory of the GITS team in the Technical University of Catalonia. The experimental device consists of a wheeled box sliding on a steep slope flume, releasing granular material, which enters a 2D basin. Defining a set of governing parameters and after several run of experiment, a description of the behavior of the waves was attempted. First results are here presented and analyzed. 2013-05-15T14:03:26Z http://hdl.handle.net/2117/18875 Title: Overtopping formula for vertical tiers-headed breakwaters Authors: Altomare, Corrado; Damiani, Leonardo; Gironella Cobos, Xavier Abstract: The semi-empirical methods are useful tools to understand the wave overtopping phenomena, but uncertainty remains on their applicability. It’s necessary to carry out campaign surveys or laboratory tests to support them. In this paper we apply the methods proposed in the European Overtopping Manual (2007) in order to assess the flows over a vertical breakwater, marking the need to calibrate those methodologies to take into account the peculiar geometry of the structural system. This was done by introducing appropriate correction factors. The results show an improved accuracy, among numerical results and physical ones. 2013-04-18T15:12:49Z http://hdl.handle.net/2117/18855 Title: Contaminant removal and clogging development in shallow subsurface flow wetlands: effect of primary treament and operation strategy Authors: Pedescoll Albacar, Anna; Corzo Hernández, Angélica; Alvarez, Eduardo; Puigagut Juárez, Jaume; García, Joan 2013-04-17T12:48:03Z http://hdl.handle.net/2117/18854 Title: Gravel composition related to clogging development in horizontal subsurface flow constructed wetlands Authors: Pedescoll Albacar, Anna; Passos, Fabiana Lopes del Rei; Alba, Esther; García, Joan; Puigagut Juárez, Jaume 2013-04-17T12:46:03Z http://hdl.handle.net/2117/18748 Title: Incorporation of continental and urban run-off into a coastal circulation model: application to the Catalan coast Authors: Liste, Maria; Grifoll Colls, Manel; Keupers, Ingrid; Monbaliu, Jaak; Espino Infantes, Manuel Abstract: A 3D hydrodynamical model has been set up to incorporate the continental and urban run-off into the Catalan Coastal waters. Particular attention was paid to introducing correctly the freshwater plumes and attention was also paid to determinate the influence of the land discharge profile with regard to the distributed continental run-off. The model domain includes a small part of the Catalan Coast where the combination of local land topography with torrential rainfall caused considerable local runoff on a short period of time with a large impact on the receiving coastal waters. The Regional Ocean Modeling System (ROMS) simulations were used to examine the dispersal to a freshwater delivery from two relevant event; a low river discharge typical of mean conditions during April 2011 and a high discharge representative of the storm event during March 2011 are considered. We have observed the plume responses to an abrupt change in river discharge. During the mean conditions, low salinity water is concentrated around the rivers mouth while during the flood event, the plume spread offshore in the direction of river water outflow and turned downstream close to the coast. The differences between a simulation including the river outflow as a land forcing and a simulation including river and urban runoff as a land forcing suggested that the urban runoff plays an important role in the spreading and shape of the river plume. 2013-04-09T18:04:52Z http://hdl.handle.net/2117/18741 Title: Improving the reliability of closed chamber methodologies for methane emissions measurement in treatment wetlands Authors: Corbella Vidal, Clara; Puigagut Juárez, Jaume Abstract: Non-homogeneous mixing of methane (NHM) within closed chambers was studied under laboratory conditions. The experimental set up consisted of a PVC vented chamber of 5.3 litres of effective volume implemented with a power-adjustable 12V fan. NHM was addressed by injecting a known volume of methane and extracting, afterwards, gas samples from the top, middle and bottom sections of the chamber. NHM within the chamber was studied under different experimental situations such as the fan position (top vs lateral), fan airflow strength (23 vs 80 cubic feet per minute) and the mixing time before sample withdrawal (5, 10, 15 and 20 minutes). The potential bias of methane flux densities caused by NHM was addressed by monitoring the difference between linearly expected and estimated flux densities of ca. 400, ca. 800 and ca. 1600 mg CH4.m-2.d-1. Results showed that methane within the chamber was under non-homogeneous conditions. Accordingly, for mixing times before sample withdrawal ranging from 5 to 20 minutes methane concentrations at the bottom of the chamber were between 20% to 70% higher than those recorded at the middle or top sections of the chamber, regardless the fan position or fan airflow strength. Furthermore, NHM led to notable biases on flux density estimation. Accordingly, flux density estimated from top and middle sampling sections were systematically lower (ca. 50%) than those expected, regardless the flux density considered. Alternatively, flux densities estimated from bottom samples showed a lesser bias (between 10% higher to 25% lower than expected flux densities). 2013-04-09T15:08:52Z http://hdl.handle.net/2117/18740 Title: The influence of operational and design parameters on vertical redox profiles in sub-surface flow constructed wetlands: surveying the optimal scenario for microbial fuel cell implementation Authors: Garfi, Marianna; Corbella Vidal, Clara; Puigagut Juárez, Jaume Abstract: The objective of the present work was to determine the optimal redox gradient that can be obtained in sub-surface flow constructed wetlands (SSF CWs) to maximize the energy production with microbial fuel cells (MFCs). To this aim, a pilot plant based on SSF CW was evaluated for vertical redox profiles. Key operational and design parameters surveyed that influences redox conditions in SSF CW were the presence of plants (Phragmites australis) and the flow regime (continuous and discontinuous flow regime). Redox potential (EH) within the wetlands was analysed at a 5, 15 and 25 cm depth. Results obtained indicated that EH daily variation within the wetlands was small for depths of 5 cm and 25 cm, regardless operational or design conditions. On the contrary, the redox variation was of notable extent at 15 cm depth and ranging from +50 mV to – 300 mV, and especially pronounced for discontinuous flow planted wetlands. Overall, discontinuous flow and planted wetlands showed a higher redox potential at the bottom of the wetlands (between 50 and 100 mV higher) than those unplanted operated at a continuous flow. Furthermore, the maximum attainable redox gradient under the conditions here considered (redox difference between the surface of the wetland and the bottom or the middle part of the bed) is between 350 and 450 mV, being the continuous flow planted wetlands the configuration that offers the best balance between the maximum redox gradient and its stability along the day. Finally, the redox gradients obtained for planted wetlands operated under continuous flow regime would lead to a power production ranging of some 40 mW/m2 of wetland. 2013-04-09T15:03:23Z http://hdl.handle.net/2117/18467 Title: Multivariable model predictive control of water levels on a laboratory canal Authors: Horvath, Klaudia; Van Overloop, P.J.; Galvis Restrepo, Eduard; Gómez Valentín, Manuel; Rodellar Benedé, José Abstract: Automatic control of irrigation canals can reduce the loss of water in considerable amounts, therefore it is generating ecologic and economic benefits. There have been many different types of automatic controllers developed, but only few of them had the opportunity of being tested on the field due to the long delay time and the inconveniences of interrupting the operation of the irrigation. Therefore, the automatic controllers developed for large irrigation canals should be tested before by means of numerical simulations and/or laboratory experiments. The Technical University of Catalonia possesses a laboratory irrigation canal with the length of 220m, with 3 motorized gates, and 11 level sensors that are connected to a SCADA system. This facility makes it possible to test controllers of any type, since all the instrumentation and real time operation runs within a flexible working environment running in Matlab-Simulink . The canal can be configured from one pool to three pools, which allows the development of multivariable control. A numerical model of the canal has been developed using the 1D hydrodynamic model SIC. With the help of this software it is possible to simulate the hydraulics of the canal and, due to the link between SIC and Matlab, also to test any controller developed previously in the Matlab environment. In this work a centralized multivariable model predictive controller for water levels is developed and validated by means of numerical simulation. 2013-03-22T09:16:04Z http://hdl.handle.net/2117/18449 Title: Simplified modeling of a laboratory irrigation canal for control purposes Authors: Galvis Restrepo, Eduard; Horvath, Klaudia; Gómez Valentín, Manuel; Rodellar Benedé, José Abstract: http://upcommons.upc.edu/e-prints/bitstream/2117/15391/1/SAICA2011_proceedings.pdf 2013-03-21T09:38:09Z http://hdl.handle.net/2117/18379 Title: Indagine sperimentale sui processi di trasmissione di energia e massa a tergo di barriere frangiflutti a porosità controllata Authors: Marzeddu, Andrea 2013-03-18T19:39:18Z http://hdl.handle.net/2117/18111 Title: Aplicación del modelo SWMM 5.0 para la estimación del arrastre de depósitos de sedimentos y contaminantes asociados en sistemas de alcantarillado unitario Authors: Seco, Raquel Irene; Gómez Valentín, Manuel Abstract: veles de partículas sólidas y otros contaminantes se observan en los caudales vertidos desde sistemas unitarios al medio fluvial receptor durante el período inicial de una tormenta. Las investigaciones en este campo sugieren que la principal fuente de estos contaminantes está vinculada al proceso de erosión y resuspensión de sólidos depositado s en los conductos del sistema durante el periodo seco antecedente al evento de precipitación. Este trabajo aborda el desarrollo de una metodología capaz de tratar, en una primera aproximación, el transporte de sedimentos dentro de las conducciones de un sistema de alcantarillado unitario. Su implementación se basa en la aplicación modificada, de un modelo del sistema, en el software de dominio público Storm Water Management Model (SWMM 5.0). Así, esta metodología supone una ampliación en la capacidad de trabajo del mencionado programa de simulación, al contemplar el proceso de erosión y re-suspensión de sólidos preexistentes en el interior de sistemas unitarios, que hasta ahora no se considera. Los resultados obtenidos en un estudio piloto, demuestran la aplicabilidad de la metodología de aproximación para la obtención de la evolución de la carga sólida total y contaminantes asociados, durante un evento de tormenta. 2013-03-06T16:11:35Z http://hdl.handle.net/2117/18105 Title: Transporte de sedimentos depositados en tiempo seco en alcantarillado unitario : Estimación mediante SWMM 5.0 Authors: Seco, Raquel Irene; Gómez Valentín, Manuel Abstract: Los vertidos desde alcantarillado unitario durante eventos de tormenta pueden afectar significativamente los estándares de calidad de los medios naturales receptores. Estudios previos apuntan que la principal fuente de contaminantes está asociada a la erosión y resuspensión de sólidos que se depositan dentro de los conductos en el periodo seco antecedente a la precipitación. La predicción de sólidos que se movilizan desde el interior de las conducciones por el escurrimiento de aguas pluviales puede resultar en importantes beneficios tanto en la gestión de la contaminación de medios naturales como en el diseño de depósitos de retención. Los modelos de calidad desarrollados hasta ahora plantean formulaciones de compleja aplicación, o bien proponen el cálculo aproximado pero con una gran cantidad de variables. En este trabajo se presenta la implementación de una etodología conceptual basada en el modelo de calidad de SWMM5.0 que, con pocos parámetros , permita la valoración de la carga sólida movilizada desde los depósitos en el interior de las conducciones durante un evento de precipitación. Así, esta metodología supone una ampliación en la capacidad de trabajo de SWMM5.0 para la obtención de la evolución de la carga sólida total, al contemplar el proceso en el interior de las conducciones que actualmente no considera. Resultados iniciales muestran el potencial de su aplicación. 2013-03-06T14:00:54Z http://hdl.handle.net/2117/18074 Title: Setup of an experimental device for high-speed debris flows generating 2D impulse waves Authors: Bateman Pinzón, Allen; Bregoli, Francesco; Medina Iglesias, Vicente César de; Rast, Manuel; Bentz, Clara Abstract: Landslides and debris flows falling into reservoirs, natural lakes, fjords or seas can generate impulse waves, which can be assimilated to tsunami-water waves. Such wave’s behavior can be highly destructive regarding dams and other structures and infrastructures as well as people living along shorelines. Destructive observed past events, such Vajont Dam in Italy (1963) or Lituya Bay in Alaska (1958), are not enough to describe and finally properly prevent the phenomenon. Experimental studies on the topic have been carried out in one-dimensional (1D) and two-dimensional (2D) water basins with a sliding block or sliding granular material. Due to the lack of studies on the effect of granular material falling in a 2D basin and to explore new ranges of governing parameters of experiments, the present research work is being carried out. In the Fluvial-Morphodynamics Laboratory of GITS in the Technical University of Catalonia, a facility to study that phenomenon is set up. The whole project was founded through the project “Debris Flow” (CGL 2009-13039) by the Spanish Ministry of Science and Technology. The system consists of a steep slope flume releasing granular material in a two dimensional basin. The main drawback was to develop a system able to reach high speed mass movement which was achieved building a metallic wheeled box, sliding in rails with a very low roughness. The second issue was to define a system able to measure the velocity of the granular material and its depth, solved processing images of a high speed camera. Finally a grid on the water surface, done by laser sheets, was set. The water surface being filmed and the resulting images successively processed, the produced wave can be measured. All the measurement systems are designed to not distort the process. First results relative on a first set of experiments are presented and preliminary discussed. 2013-03-05T14:58:23Z http://hdl.handle.net/2117/17590 Title: Velocity and air concentration in air-water flow: application on a stepped spillway without sidewalls Authors: Estrella Toral, Soledad; Sánchez Juny, Martí; Dolz Ripollès, Josep; Ibáñez, R.; Domínguez, M.; Balairón, Luis; López, D. Abstract: Until now, hydraulic research of stepped spillways has focused on characterizing aspects as: the different types of flow that occur on the chute, the air inception processes, the potential negative effects associated to the risk of cavitation, the energy dissipation produced by the steps, or the discharge capacity of the spillway. These investigations, however, have focused on stepped spillways with sidewalls, which impose a constant width along the dam. This paper shows the first results of the Collaborative Applied Research project ALIVESCA, conducted between Dragados S.A., the FLUMEN Institute and the Centre for Hydrographic Studies of CEDEX. The project aims to analyze the hydraulic behavior of stepped spillways without sidewalls and establish new criteria for the design of these structures. On the construction viewpoint, avoiding the sidewalls will reduce costs and risks in the project execution. Specifically, the paper aims to analyze the velocity and the air concentration measurements over a spillway model. In particular, aeration is one of the most effective mechanisms to reduce the risk of cavitation damage because the air-water compressibility absorbs the impact of collapsing vaporized bubbles. Description: Until now, hydraulic research of stepped spillways has focused on characterizing aspects as: the different types of flow that occur on the chute, the air inception processes, the potential negative effects associated to the risk of cavitation, the energy dissipation produced by the steps, or the discharge capacity of the spillway. These investigations, however, have focused on stepped spillways with sidewalls, which impose a constant width along the dam. This paper shows the first results of the Collaborative Applied Research project ALIVESCA, conducted between Dragados S.A., the FLUMEN Institute and the Centre for Hydrographic Studies of CEDEX. The project aims to analyze the hydraulic behavior of stepped spillways without sidewalls and establish new criteria for the design of these structures. On the construction viewpoint, avoiding the sidewalls will reduce costs and risks in the project execution. Specifically, the paper aims to analyze the velocity and the air concentration measurements over a spillway model. In particular, aeration is one of the most effective mechanisms to reduce the risk of cavitation damage because the air-water compressibility absorbs the impact of collapsing vaporized bubbles. 2013-02-06T14:04:59Z