Flood risk in urban areas: modelling, management and adaptation to climate change. A review

[Abstract:] The modelling and management of flood risk in urban areas are increasingly recognized as global challenges. The complexity of these issues is a consequence of the existence of several distinct sources of risk, including not only fluvial, tidal and coastal flooding, but also exposure to urban runoff and local drainage failure, and the various management strategies that can be proposed. The high degree of vulnerability that characterizes such areas is expected to increase in the future due to the effects of climate change, the growth of the population living in cities, and urban densification. An increasing awareness of the socio-economic losses and environmental impact of urban flooding is clearly reflected in the recent expansion of the number of studies related to the modelling and management of urban flooding, sometimes within the framework of adaptation to climate change. The goal of the current paper is to provide a general review of the recent advances in flood-risk modelling and management, while also exploring future perspectives in these fields of research

Orden social e imaginarios sociales (una propuesta de investigación)

A partir de los problemas actuales para definir las situaciones globales que condicionan los sistemas sociales, se detecta una tendencia generalizada de sustitución de los mecanismos de argumentación racional por los de seducción propios del discurso mediático. La elaboración de los nuevos discursos hegemónicos y de resistencia a la dominación exige una doble reconstrucción de la teoria y del método. En el articulo se hace una de investigación que parte de la vinculación entre las formas del orden social y los mecanismos de construcción (y desconstrucción) de los imaginarios sociales. Estos tendrían como función primaria la elaboración y distribución generalizada de instrumentos de percepción de la realidad social construida como realmente existente. Se incluyen en el texto algunos materiales de definición conceptual de los imaginarios, cuestiones de método y fuentes bibliográficas.This piece of research tries to define global situations which condition social systems. New hegemonic discourses, through mass media, and new resitance forms to domination are needed in order to construct and deconstruct social imaginaries

Editorial: flood susceptibility and risk maps as a crucial tool to face the hydrological extremes in developing countries: technical and governance aspects linked by a participatory approach

[Abstract:] In summary, this Research Topic wants to draw attention to two points of reflection: 1) The need to involve stakeholders at all levels in the planning of actions aimed at reducing the risks associated with floods is preponderant, given the considerable increase in urban settlements in high-risk areas of developing countries. 2) Likewise, we hope that new lines of research will open up to explore innovative solutions that help in risk management without having to resort to costly methods, which involve manpower or require continuous maintenance

Quantifying the role of individual flood drivers and their correlations in flooding of coastal river reaches

Afectado por periodo de embargo de la revista (12 meses)Flooding in coastal river reaches is the result of complex interactions between coastal and inland drivers. Flood hazard assessments need to consider how these drivers interact in space and time, for which a standard method is currently lacking. A complex hydrodynamic model is required to reproduce the physics of the combined forcings and, at the same time, to fully explore the combinations of drivers that can occur in order to determine extreme flood frequencies. In this work, we explore the individual role of astronomical tide, storm surge and river discharge and their correlations in the extreme flood levels of a coastal river reach. We apply a computationally efficient surrogate model of a 2D shallow water model based on least squares support vector machines (LS-SVM) regression to reconstruct 10000 years-long time series of water levels in the reach. As input to the model, we consider an ensemble of synthetic time series of the flood drivers, which differ in the number of variables considered and in their correlations. Probabilities of exceedance of water levels are then computed and compared. The proposed methodology can give a better understanding of the flooding processes in a multivariable environment, as low-lying coastal urban areas typically are, and can provide guidance on where to focus modelling efforts when developing flood hazard assessments in such areas.María Bermúdez gratefully acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement Nº 754446 and UGR Research and Knowledge Transfer Fund – Athenea3

Modelling Pluvial Flooding in Urban Areas Coupling the Models Iber and SWMM

[Abstract] Dual urban drainage models allow users to simulate pluvial urban flooding by analysing the interaction between the sewer network (minor drainage system) and the overland flow (major drainage system). This work presents a free distribution dual drainage model linking the models Iber and Storm Water Management Model (SWMM), which are a 2D overland flow model and a 1D sewer network model, respectively. The linking methodology consists in a step by step calling process from Iber to a Dynamic-link Library (DLL) that contains the functions in which the SWMM code is split. The work involves the validation of the model in a simplified urban street, in a full-scale urban drainage physical model and in a real urban settlement. The three study cases have been carefully chosen to show and validate the main capabilities of the model. Therefore, the model is developed as a tool that considers the main hydrological and hydraulic processes during a rainfall event in an urban basin, allowing the user to plan, evaluate and design new or existing urban drainage systems in a realistic way.Xunta de Galicia; EAPA_45/201

Estimation of flood-exposed population in data-scarce regions combining satellite imagery and high resolution hydrological-hydraulic modelling: A case study in the Licungo basin (Mozambique)

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract:] Study Region Licungo basin (Mozambique) Study Focus The Licungo basin (23,263 km2) suffers frequent severe flooding due to tropical storms, in a country that is among the world’s most vulnerable in terms of exposure to weather-related hazards and climate change. We propose a methodology for the estimation of the population exposed to flooding at the catchment scale in data-scarce regions, combining satellite imagery with integrated high-resolution hydrological-hydraulic modelling. All the input data needed are retrieved from freely-available global satellite products. The numerical model is also freeware. The methodology is therefore replicable worldwide. An estimate of the flood extent and exposed population during Tropical Storm Ana (January 2022) is presented as a case study. New Hydrological Insights for the Region Current freely-available satellite products in combination with high-resolution hydrological-hydraulic models can be used to estimate the population exposed to flooding in the whole catchment. This estimate is more realistic than the one obtained using satellite imagery alone, since satellite images are very rarely taken at the time of maximum flooding. Using the proposed methodology, we estimate that over 273,000 people (out of 1.5 million) were exposed to flooding in the Licungo basin during Tropical Storm Ana. This represents 18% of the basin population and is 8 times larger than the estimate obtained using only the available satellite images.European Civil Protection and Humanitarian Operations (ECHO); ECHO/-SF/BUD/2018/9100