Integrated Flood Analysis System (IFAS)

Needs Address

The need to create simple and inexpensive flood prediction models in developing countries that lack an adequate ground-based observation network.  Public Works Research Institute has designed such a runoff distribution calculation model with a user interface.  

Adaptation effects

Developing countries that do not have an adequate ground-based observation network can make flood predictions by utilizing satellite data and global data. If complemented with local data and rainfall data from ground-based observation, even more accurate flood forecasting is possible. 

Overview and Features

• The Integrated Flood Analysis System (IFAS) is a system that can easily create runoff analysis models, using data that is available for free via the Internet and includes geographic and land use data for almost the entire world. The system is able to conduct a series of operations required for runoff analysis, as shown in the figure below, including obtaining satellite-based rainfall data such as the satellite global precipitation map GSMaP, development of models, analysis of rainfall runoff, and the display of results.
  
  Figure: The runoff analysis process 
• IFAS is a type of user interface software developed by the International Centre for Water Hazard and Risk Management (ICHARM) to perform flood forecasting in developing countries using satellite-based rainfall data and other data even where ground observation networks are inadequate. Using satellite-based rainfall information, flood prediction can be performed even for river basins where no ground-based observation network exists, or one exists but is inadequate. If and when a ground-based observation network is put in place, it can be incorporated into the flood prediction system. 

Cost

Initial costs: 

• Access to a computer and Internet is required. 
• This system is available for free, but education and training to use the system involve costs. 

Energy source

Electrical power is needed for computer operation.

Technology performance

The system is designed to use not only local data and ground-based rainfall data, but also global data and satellite data from sources including JAXA and NASA. It is equipped with numerous features, including automatic creation of river channel networks in a river basin, graphic display flow rate changes over time, and automatic alerts. However, because satellite data is inferior to ground observation data in terms of mesh size and accuracy, these features can only be applied for major river basins of a certain size where ground-based observation is poor. The system performs a simulation of the rainfall-runoff phenomenon, and simulates water accumulating in rivers, and the timing of when and how much the river flow will increase. However, it does not analyze flow changes and flooding in the event water volumes increase to the point that the river breaches its banks. 

Considerations

• Accuracy using satellite data is lower than from ground-based observation data, and time intervals are not in real-time, so this system is intended for used only as supplementary information for rivers where local ground-based observation equipment is insufficient. Therefore, it is desirable to make use of ground-based data as soon as ground observation equipment has been installed in the future. Meanwhile, it is difficult to establish appropriate parameters and obtain good results without precise flow measurement in order to convert water levels to flow volumes. Thus, it is also important to conduct precise measurement of river cross-sections and observation of flow volumes in order to accurately determine flow volumes from water levels. 
• Because satellite-based rainfall data is not in real-time, this system is not well suited for small rivers where floods can arrive quickly. 

Co-benefit, suitability for developing countries

• This system is highly adaptable. ICHARM already offers training and technical guidance in developing countries such as Indonesia, the Philippines, and Vietnam, and trainees are also accepted in Japan with JICA support. 
• The system can be operated even when absolutely no ground-based observation is being conducted. 
• Because satellite-based rainfall observation information is being used, it is possible to obtain rainfall information and analyze downstream river flow data in international rivers that straddle more than one country. 

Information Resources

International Centre for Water Hazard and Risk Management(ICHARM), Public Works Research Institute(PWRI)
http://www.icharm.pwri.go.jp/index.html