for Your Safe

FloodS - The scientific tool
for global Adaptation


FloodS is an online tool to help government bodies plan effective strategies for mitigating flood damage. The system is able to simulate water levels and flow conditions, along with the impact of proposed countermeasures, providing quantitative data to evaluate the effectiveness of a city’s mitigation strategies in terms of potential flooded area and floodwater depth. Once a simulation has been generated, FloodS makes it easy to share the results among stakeholders.

The system is available for use right now, completely free of charge and accessible directly from web browser. Simulations are performed using preloaded topographic data on state-of-the-art, cloud-based infrastructure, making FloodS easily accessible to users without any need to prepare expensive hardware or conduct labor-intensive surveys.

Use Case



Assessing flood damage

Flood damage information will help to determine how the water has spread and how far it has reached. When this information is shared with policy makers, it can support decision-making on how to rescue and restore the area.

Consideration of

In considering restoration measures and in urban planning, it becomes possible to grasp the effects of stopping water in which areas, how much damage will be reduced, etc., leading to decision-making on countermeasure policies.
Flow rate information can be directly input so that it can be used even in areas where flood damage has not occurred in the past.


Here, users can view simulation results for several metropolitan areas around the world.
Areas for which high-resolution topographic data are currently available include:
・Hue (Vietnam)
・Chiang Mai (Thailand)
・Manila (Philippines)
・Kolkata (India)
・Kathmandu (Nepal)


In this view, users can simulate flooding patterns in a city of their choice, specifying parameters such as inundation coordinates, depth, and volume of water, to better understand where and how flooding is likely to occur. Simply run the simulation and observe. Results can be easily shared among stakeholders.

Case Studies

Estimation of Inundation Area

Some simulations of the heavy rain disaster that occurred in Fukui, Japan in 2004 was performed. The condition was set to the flood discharge obtained from the disaster survey. For the topography of the simulation, we used MERIT DEM prepared globally and data surveyed in Japan.

Simulation results using MERIT-DEM were able to capture the flood trends observed in real disasters. This suggests that FloodS simulations are sufficient for use in risk assessment.

However, in order to design concrete countermeasures, it is necessary to perform detailed simulations using the high topographic resolution data like AW3D, which is partly provided by FloodS.

Flooding Countermeasures

For the heavy rain disaster that occurred in Fukui Prefecture, Japan in 2004, we considered two flood damage mitigation measures through simulation.

The first measure would be to block the underpass and prevent flooding on the west side due to the high tracks. With this countermeasure in place, FloodS was able to accurately predict that inundation would not extend west of the tracks.

The second measure is that if the canal in the western part of Fukui City can be dammed, floods can be prevented from flowing north. FloodS was again able to accurately predict that inundation would not extend northward with that countermeasure in place.