Training on Flood Risk Management, Flood Hazard and Flood Risk Maps

Oct 19, 2016 to Oct 20, 2016
Gammarth, Tunisia
The REC organised this Training on Flood Risk Management, Flood Hazard and Flood Risk Maps in the framework of the WATER SUM project under the “Capacity Building on Water Resources Management in a Changing Climate” action.

The aims of the training were: to assist water practitioners in flood risk mapping and the preparation of flood hazard and flood risk maps through the use of a hydrodynamic model; to implement area-specific approaches for the demonstration site; and to outline flood action programmes and flood risk management objectives.

Ms. Jovanka Ignjatovic, REC Senior Water Management Expert and WATER SUM Project Manager, opened the training and wished the participants a productive and valuable experience.

With lecturers providing on-the-spot assistance, training activities included lectures, input data preparation, and model setups. This hands-on approach ensured that all participants could follow the training flow and were able to request help from the trainer or trainer’s assistant at any time.

During the first day, the participants were given a theoretical background of water modelling through different approaches (i.e. 1D, 2D, 3D modelling) — with a more in-depth focus on 2D-based approaches, as they are the most widely used for flood modelling. The participants then paired up to form working teams to develop model inputs from data that had been collected previously from the records of the Ministry of Agriculture, Water Resources and Fisheries General Directorate of Water Resources and General Directorate of Dam and Large Hydraulic Structures.

The group then proceeded through: defining the task area; selecting a suitable mathematical model and geographical coordinate system; preparing a computational mesh and bathymetry, input data types and a time-series; and then evaluating all of this information. The working teams also prepared their own computational mesh files and set up task-area parameters for the flow model.

Day two of the training saw the DHI trainers prepare a flow model from the input files that had been distributed to the participants. Everybody was then able to execute and run pre-defined simulations (allowing for sufficient computation time).

With the models running in the background, the group discussed the necessity of model calibration and validation, as well as a general method of how to determine which model showed results in closest correlation with real measured water levels and discharges. Afterwards, the group discussed the given results and model outputs, and each participant attempted viewing a different result aspect.

Before concluding, the trainers presented a group exercise. The participants were separated into two groups, and each group was asked two questions concerning topics that had been addressed in the previous two days, namely:

  1. Which data (quantitative and qualitative) is needed in Tunisia to be able to produce flood maps?
  2. How can flood maps be put to further use (on the basis of flood risk management plans)?

The first group collected all of the necessary input data for flood modelling and collected their availability in Tunisia by percentage (0% meaning totally missing, 100% meaning existing data of good quantity and quality).

The second group collected examples of flood modelling benefits, such as: evacuation plans, localisation plans, and development plans to minimise flood hazard.

The training wound down with an evaluation, a wrap-up and closing remarks. The training contributed to pinpointing actions that will be useful when developing upcoming activities under the “Capacity building on Water Resources Management in a Changing Climate” action, such as:

  • communication with other institutions regarding data collection and data exchange;
  • selection of the “most important river reaches” in the Mejerda River basin — i.e. finishing preliminary flood risk assessments;
  • collecting relevant topological data (DEM and river channel topology) for selected river reaches, and updating this data regularly;
  • preparing hydrodynamic models (both 2D and 1D) for selected river reaches, and using these models for selected hydrological scenarios; and
  • preparation of flood hazard and flood risk maps in order to improve flood risk management capacity.

Photo gallery of the “Training on Flood Risk Management, Flood Hazard and Flood Risk Maps”

Tags: Training