[Project] Flood Modelling and Analysis for the Copiapó River Basin

Modelling and Analysis for Flooding in the Copiapó river Basin

 

Finances: Dirección General de Agua

Start date: November 2017

Extension: 12 months

/ The Atacama Regions is known for being one of the driest places on earth, however, throughout its history it has been affected by significant rainfall phenomenon (Vicuña-Mackenna, 1877; Aceituno et al., 2009). Even Charles Darwin, during a visit to Copiapó in 1835, talked about the area: “the abundant rainfall cause more damage than the droughts” (Revista Tierra Cultah, 2015).

Currently, the flooding and alluviums have brought challenges to the area. Between the 24th and 26th of March of 2015, for example, Atacama was affected by an extreme rainfall phenomenon, where accumulated rainfall exceded 60 mm (Bozkurt et al., 2016). According to the National Emergency Office of the Ministry of Interior (ONEMI) this events affected approximately 16,590 people and left 31 deceased. The main reason for this disaster was the unusual amount of rainfall that caused rapid floods and a large amount of accumulation of sediments (including mud and debris).

The Project Analysis for Flooding for the Copiapó Basin seeks to develop a tool that can be used by the relevant authorities and than can model and predict posible scenarios when faced with future challenges, and this tool can also be used to mitigate the effects of these threats, through prevention actions, early alerts, emergency attention, and planning and rebuilding processes.

More specifically, this projects seeks to:

• Collect information regarding hydrometeorological extreme events in the Copiapó basin.
• Determine the scope of the modelling following existing information.
• Develop a conceptual model around the functioning of the basin when faces with hydrometeorological extreme events.
• Develop a numeric model around the functioning of the basin when faces with hydrometeorological extreme events.
• Generate recommendations for improving the network in order to a better functioning model

This project has an extension of 12 months, and its development includes 5 main activities:

1. Collecting information and relevant data
2. Developing a conceptual and mathematical model
3. Calibrating and validating this model
4. Delivering and teaching the model
5. Conclusions and recomendations

Additionally, several workshops are considered with relevant actors throughout the project, in the city of Copiapó and in Santiago, to further understand the needs of the final users and to better calibrate the model and the interaction interface (computer program) of the tool. Also, the workshops will be used as a way to transfer knowledge and to carry out training in the use of the model.

 

SWIFT tool

In this case, SWIFT (Shallow Water Integrated Flood Tools) will be used, a tool that is a theoretical-computer framework developed by CSIRO for fast and precise prediction of floods. Although SWIFT has been applied successfully in many case studies in Australia, the context of the Copiapó river basin is very different, given the particular climate, topographic, availability and data quality, and SWIFT will be precisely modified to adapt to this context, following the collected data from relevant actors of the basin and according to CSIRO’s experience.

Once the model is built, the tool will allow an understanding the space-time flow of water (i) through the simulation of flooding scenarios under multiple different rainfall conditions, water flow and other, (ii) the generation of risk maps from simulations and (iii) the incorporation of mitigations measures and their evaluations through new risk maps.

This way, the tools will provide support for planning, early alert and decision making.

 

Image of CSIRO Data 61 using the SWIFT model

 

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