IberWQ: A GPU Accelerated Tool for 2D Water Quality Modeling in Rivers and Estuaries

Este artigo inclúese no número especial "Modelling Flow, Water Quality, and Sediment Transport Processes in Coastal, Estuarine, and Inland Waters"[Abstract] Numerical models are useful tools to analyze water quality by computing the concentration of physical, chemical and biological parameters. The present work introduces a two-dimensional depth-averaged model that computes the most relevant and frequent parameters used to evaluate water quality. High performance computing (HPC) techniques based on graphic processing unit (GPU) parallelization have been applied to improve the efficiency of the package, providing speed-ups of two orders of magnitude in a standard PC. Several test cases were analyzed to show the capabilities and efficiency of the model to evaluate the environmental status of rivers and non-stratified estuaries. IberWQ will be freely available through the package Iber.European Commission; INTERREG-POCTEP; 0034_RISC_ML_6_EXunta de Galicia; ED431C 2017/64-GRCXunta de Galicia; ED481A-2017/31

Historical and future naturalization of Magallana gigas in the Galician coast in a context of climate change

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGMagallana gigas is a naturalized species on the north coast of Galicia (Rías Altas, Northwest Iberian Peninsula), where it was unintentionally introduced. In recent decades, a greater abundance of M. gigas has been observed on the Galician coast, expanding towards the south, reaching the Artabro Gulf (Rías Centrales, NW Galician coast), probably due to ocean warming. Although this species has been cultivated in the Rías Baixas since the early 1990s and spawning has been reported, recruitment was never observed, which is likely due to the cold water upwelled during the spawning months. The future rise in seawater temperature may favor the naturalization of the non-indigenous species M. gigas southwards, in the Rías Baixas. Thermally, the Ría de Arousa seems to be the most favorable estuary for the future settlement of M. gigas, which may occur in the next decades. The extent of thermally favorable zones within estuaries is projected to increase rapidly by mid-century, and reaching 100 % of the estuarine area by the end of the century. As has already happened in other areas of the world, the expansion and naturalization of the Pacific oyster on the Galician coast will likely affect the native communities and economic activities, making it necessary to implement monitoring and management strategies to mitigate its effect.Xunta de Galicia | Ref. ED481B-2021-103Xunta de Galicia-FEDER | Ref. ED431C 2021/44Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/2020Fundação para a Ciência e a Tecnologia | Ref. LA/ P/0094/202

An accelerated tool for flood modelling based on Iber

Este artigo inclúese no número especial "Selected Papers from the 1st International Electronic Conference on the Hydrological Cycle (ChyCle-2017)"[Abstract:] This paper presents Iber+, a new parallel code based on the numerical model Iber for two-dimensional (2D) flood inundation modelling. The new implementation, which is coded in C++ and takes advantage of the parallelization functionalities both on CPUs (central processing units) and GPUs (graphics processing units), was validated using different benchmark cases and compared, in terms of numerical output and computational efficiency, with other well-known hydraulic software packages. Depending on the complexity of the specific test case, the new parallel implementation can achieve speedups up to two orders of magnitude when compared with the standard version. The speedup is especially remarkable for the GPU parallelization that uses Nvidia CUDA (compute unified device architecture). The efficiency is as good as the one provided by some of the most popular hydraulic models. We also present the application of Iber+ to model an extreme flash flood that took place in the Spanish Pyrenees in October 2012. The new implementation was used to simulate 24 h of real time in roughly eight minutes of computing time, while the standard version needed more than 15 h. This huge improvement in computational efficiency opens up the possibility of using the code for real-time forecasting of flood events in early-warning systems, in order to help decision making under hazardous events that need a fast intervention to deploy countermeasures.Water JPI—WaterWorks Programme, project Improving Drought and Flood Early Warning, Forecasting and Mitigation, IMDROFLOOD; PCIN-2015-243European Commission; project RISC_ML 034_RISC_ML_6_EXunta de Galicia; ED431C 2017/64-GRCXunta de Galicia; ED481A-2017/314Xunta de Galicia; ED481B-2018/020European Commission; IMDROFLOOD PCIN-2015-24

Analysis of two sources of variability of basin outflow hydrographs computed with the 2D shallow water model Iber: Digital Terrain Model and unstructured mesh size

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract:] Modelling hydrological processes with fully distributed models based on the shallow water equations implies a high computational cost, which often limits the resolution of the computational mesh. Therefore, in practice, modellers need to find a compromise between spatial resolution, numerical accuracy and computational cost. Moreover, this balance is probably related to the accuracy and resolution of the underlying Digital Terrain Model (DTM). In this work, it is studied the effect of the DTM resolution and the size of the computational mesh on the results and on the runtime of a hydrological model based on the 2D shallow water equations. Seven rainfall events in four different basins have been modelled using 3 DTMs and 3 different mesh resolutions. The results obtained highlight the relevance of the vertical accuracy versus the horizontal resolution of the DTMs. Furthermore, it has been observed that mesh resolutions greater than 25 m, together with LiDAR-based DTMs with horizontal resolution greater than 25 m, provide comparable outflow hydrographs.Xunta de Galicia; ED481B-2021-108Xunta de Galicia; ED431C 2021/44Xunta de Galicia; ED431C 2018/56Fondo Europeo de Desarrollo Regional (FEDER); 0034_RISC_ML_6_

Benchmarking of the Iber Capabilities for 2D Free Surface Flow Modelling

CONTENTS: 1. Introduction; 2. Test 1: Flooding a disconnected water body; 3. Test 2: Filling of floodplain depressions; 4. Test 3: Momentum conservation over a small obstruction; 5. Test 4: Speed of flood propagation over an extended floodplain; 6. Test 5: Valley flooding; 7. Test 6: Dambreak; 8. Test 7: Rainfall and point source surface flow in urban areas; 9. Test 8: Overland flow in a four-branch junction; 10. Test 9: Rainfall-runoff in a three-slope 1D channel; 11. Test 10: Rainfall-runoff over a simplified V-shaped valley; 12. Test 11: Rainfall-runoff over a simplified urban configuration; 13. References.[Abstract] Iber is a software for simulating turbulent free surface unsteady flow and transport processes in shallow water flows. The hydrodynamic module of Iber solves the depth averaged two-dimensional shallow water equations (2D Saint-Venant Equations). This document presents the performance of the software Iber in a series of two-dimensional modelling benchmark tests. Some of these tests were developed by the United Kingdom Joint Defra / Environment Agency under Defra’s Flood and Coastal Erosion Risk Management R&D program, and have been used to benchmark other 2D free surface flow models, as the 2D version of HEC-RAS

The CIM-UVigo plug-in hybrid propulsion vessel for coastal oceanographic research: a tool for the ecological transition

Peer Reviewe

Modeling salinity drop in estuarine areas under extreme precipitation events within a context of climate change: effect on bivalve mortality in Galician Rías Baixas

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThe mortality of infaunal bivalves (Venerupis corrugata, Cerastoderma edule, Ruditapes decussatus and Ruditapes philippinarum) due to a drop in salinity caused by extreme precipitation events in estuarine areas has been analyzed within a context of climate change. The Rías Baixas (NW Iberian Peninsula) were selected as a representative area of the estuarine environments where bivalve gathering is performed. Bivalve mortality under extreme precipitation events was analyzed both for historical (1990–2019) and future (2070–2099) periods. Precipitation data were retrieved from the Coordinated Regional Climate Downscaling Experiment (CORDEX) project under the Representative Concentration Pathway (RCP) 8.5 scenario and were converted into river discharges using the HEC-HMS hydrological model. The calculated river discharges were introduced into the Delft3D hydrodynamic model and simulations were performed in order to calculate transport conditions in the Rías Baixas. Salinity data were analyzed to estimate the mortality of the species due to salinity drops. In general, future conditions of moderate and severe mortality may be worse than historically observed, being more intense and covering larger areas. This is mainly observed under neap tides due to less dilution of freshwater plumes when compared with spring tides. Although all the Rías Baixas may be potentially affected, the impact will differ for each ria, being Arousa, where the highest discharges occur, the most affected. The differences among rias, especially those with a similar discharge pattern as Pontevedra and Vigo, suggest that bathymetric features also play a key role in the extent of the area affected by mortality.Xunta de Galicia | Ref. ED431C 2017/64Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/202

IberWQ: A GPU accelerated tool for 2D water quality modeling in rivers and estuaries

Numerical models are useful tools to analyze water quality by computing the concentration of physical, chemical and biological parameters. The present work introduces a two-dimensional depth-averaged model that computes the most relevant and frequent parameters used to evaluate water quality. High performance computing (HPC) techniques based on graphic processing unit (GPU) parallelization have been applied to improve the efficiency of the package, providing speed-ups of two orders of magnitude in a standard PC. Several test cases were analyzed to show the capabilities and efficiency of the model to evaluate the environmental status of rivers and non-stratified estuaries. IberWQ will be freely available through the package Iber.Xunta de Galicia | Ref. ED481A-2017/314Xunta de Galicia | Ref. ED431C 2017/64-GRCInterreg | Ref. 0034_RISC_ML_6_EEuropean CommissionEuropean Regional Development Fun

An accelerated tool for flood modelling based on Iber

This paper presents Iber+, a new parallel code based on the numerical model Iber for two-dimensional (2D) flood inundation modelling. The new implementation, which is coded in C++ and takes advantage of the parallelization functionalities both on CPUs (central processing units) and GPUs (graphics processing units), was validated using different benchmark cases and compared, in terms of numerical output and computational efficiency, with other well-known hydraulic software packages. Depending on the complexity of the specific test case, the new parallel implementation can achieve speedups up to two orders of magnitude when compared with the standard version. The speedup is especially remarkable for the GPU parallelization that uses Nvidia CUDA (compute unified device architecture). The efficiency is as good as the one provided by some of the most popular hydraulic models. We also present the application of Iber+ to model an extreme flash flood that took place in the Spanish Pyrenees in October 2012. The new implementation was used to simulate 24 h of real time in roughly eight minutes of computing time, while the standard version needed more than 15 h. This huge improvement in computational efficiency opens up the possibility of using the code for real-time forecasting of flood events in early-warning systems, in order to help decision making under hazardous events that need a fast intervention to deploy countermeasures.IMDROFLOOD | Ref. PCIN-2015-243INTERREG-POCTEP | Ref. 0034_RISC_ML_6_EXunta de Galicia | Ref. ED431C 2017/64-GRCXunta de Galicia | Ref. ED481A-2017/314Xunta de Galicia | Ref. ED481B-2018/02

The state of climate in NW Iberia

Since 1974, there has been a significant increasing trend in land and sea surface temperatures of 0.5 and 0.24°C decade-1, respectively, in the NW Iberian Peninsula. Over the same period, annual precipitation does not show any trend, although some tendencies have been detected at seasonal scales. A significant positive trend, on average of 2 cm decade–1, was also observed in sea level rise from 1943 onwards. Ekman transport perpendicular to the coast (upwelling index) showed a decrease from 1975 to 2008 at both annual and seasonal scales. In addition, the flow of the Miño River (the main river in the area) has also decreased at a mean rate of 18 m3 s-1 decade-1 since 1970. At a synoptic scale, winter cyclone frequency and winter and spring blocking activity have decreased since the 1950s, which may partially explain the winter precipitation decline and the winter and spring temperature increases. These changes in synoptic systems are also in agreement with reported trends in the dominant variability modes of atmospheric circulation affecting NW Iberia, particularly a pronounced positive trend in the North Atlantic Oscillation from the 1970s to the 1990s.Ministerio de Educación y Ciencia | Ref. CTM2007-62546-C03-03Ministerio de Ciencia e Innovación | Ref. CGL2009-09143Ministerio de Ciencia e Innovación | Ref. INCITE09383278P