Search Results (4)

In Riohacha the La Niña, phenomenon generates intense rains with consequent serious flooding. To address this reality, MODCEL, a conceptual cell-based model, had been applied and calibrated in a previous project. In this research, we compare MODCEL with IBER, a well-known, physically based 2D hydraulic model. The purpose is twofold: (i) to illustrate how system schematization can be carried out in the two modeling frameworks, which is not a trivial task and implies several choices and assumptions; (ii) to point out the strengths and weaknesses of these two models in a comparative fashion. Here, IBER has been calibrated and validated with the same data used for MODCEL. MODCEL performs slightly better, both in calibration and validation possibly because of the low resolution of the topographic information, an essential element for IBER. Furthermore, in IBER it is not possible to represent adequately all the different hydraulic works spread across the town. MODCEL, in turn, is not easy to apply because it requires a deep insight into the actual behavior of the physical system and time-consuming schematization attempts where a deep experience is needed; furthermore, it is by far less user-friendly than IBER. In any case, the two models capture sufficiently well the behavior of urban flooding and its changes according to hypothetical interventions. Full article

Risk can be defined as the relationship between the likelihood of a hazard causing a potential disaster and its consequences. This study aims to assess the likelihood that a new industrial region, located in the state of São Paulo (Brazil), will be flooded, causing the disruption of the mobility system and local economic activities. To fulfill this aim, a new approach is proposed by combining the vector information of the highway network that serves the region with the result of a quasi 2-D raster flood model, generating a set of interpreting rules for classifying the safety of routes. The model called MODCEL is a quasi-2D hydrodynamic model that represents the watershed using compartments called cells, and it was adapted to work using a raster file format in which each pixel is represented as a flow cell connected to its surroundings by the Saint-Venant equations without the inertia terms. Therefore, this study proposes an assessment framework that can be replicated for similar problems of flood risks to mobility. The possible effects of flood events on the accessibility to areas of interest are determined, indicating a possible disruption to economic activities and transportation and allowing for planning alternatives in advance. Full article

Urban flood modelling has been evolving in recent years, due to computational facilities as well as to the possibility of obtaining detailed terrain data. Flood control techniques have also been evolving to integrate both urban flood and urban planning issues. Land use control and flow generation concerns, as well as a set of possible distributed measures favouring storage and infiltration over the watershed, also gained importance in flood control projects, reinforcing the need to model the entire basin space. However, the use of 2D equations with highly detailed digital elevation models do not guarantee good results by their own. Urban geometry, including buildings shapes, walls, earth fills, and other structures may cause significant interference on flood paths. In this context, this paper presents an alternative urban flood model, focusing on the system behaviour and its conceptual interpretation. Urban Flood Cell Model-MODCEL is a hydrological-hydrodynamic model proposed to represent a complex flow network, with a set of relatively simple information, using average values to represent urban landscape through the flow-cell concept. In this work, to illustrate model capabilities, MODCEL is benchmarked in a test proposed by the British Environmental Agency. Then, its capability to represent storm drains is verified using measured data and a comparison with Storm Water Management Model (SWMM). Finally, it is applied in a lowland area of the Venetian continental plains, representing floods in a complex setup at the city of Noale and in its surroundings. Full article

This paper describes the emblematic situation of a Colombian coastal town seriously threatened by flooding and presents the whole process undertaken to elaborate an integrated action plan to cope with this problem, while improving the natural and built environment. Such a plan is a product of a project, winner of a National Colombian call for climate change initiatives, which included a thorough modeling process based on the MODCEL urban flood model, an articulated participatory process including a specific structured inquiry mainly aiming at providing data suited for model calibration, a creative phase to propose candidate alternative solutions and a quite integrated evaluation exercise which supported the transparent choice of the most sustainable plan alternative. The approach and the experience can be valuable for many other cases in Colombia and around the world, particularly in developing or emerging countries where data are scarce. The added value of this paper lies in showing a whole, integrated process, well articulated, where all pieces are indispensable but simple enough to be replicated in many cases. It merges the fundamental participatory component with an equally fundamental technical-scientific component of characterization, modeling and integrated evaluation. The multiple steps of the process are illustrated with sufficient detail to allow the reader to grasp what was actually done and why, providing a practical guide for other cases. Full article