5 An Overview of the Integrated Flood Analysis System (IFAS) …
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flood simulation at different river basins with different catchment characteristics in
Asian countries. Some future studies are recommended for the applications of IFAS
in forecasting the flood event.
5.2 Integrated Flood Analysis System (IFAS)
The Integrated Flood Analysis System (IFAS) is a flood forecasting system that used
to perform rainfall–runoff simulation for river basins with insufficient hydrological
data to reduce its vulnerability to flooding disasters. IFAS is developed by the International Centre for Water Hazard and Risk Management (ICHARM). The IFAS software is capable to import satellite-based rainfall data such as GSMaP and 3B42RT
for insufficient ground observation river basin and other data includes geographic
and land use data for almost the entire world (ICHARM 2011). 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. The Public Works Research Institute Distributed
Hydrological Model (PDHM) is employed in IFAS software as its runoff simulation
model. The structure of PDHM is consists of a surface tank model, subsurface tank
model, aquifer tank model, and river tank model. IFAS 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. The system is able
to conduct a series of operations required for runoff analysis.
5.2.1 Model Structures
The structures of IFAS can be classified into four main components: input rainfall,
basin model, runoff calculation engine, and results display interfaces as shown in
Fig. 5.1. The input rainfall data for IFAS can be obtained either from ground-based
rain gauges or satellite rainfall data. The global satellite rainfall datasets provided
by National Aeronautics and Space Administration (NASA) and National Oceanic
and Atmospheric Administration (NOAA), USA, and Japan Aerospace Exploration
Agency (JAXA) offer different spatial and temporal resolutions and time of delay.
The IFAS runoff basin model can be developed by utilizing global GIS data. The
GIS tool kits were used to obtain the geophysical data and construct the river basin
model. The imported global GIS data includes catchment elevation, land use/land
cover, soil type, and geology. The topography map and river channel network for
the modeled catchment can be constructed by using the digital elevation model
(DEM) data provided by the United States Geological Survey (USGS) as shown
in Fig. 5.2. The land use data can be downloaded from the Global Land Cover
Characterization (GLCC) database provided by USGS. Meanwhile, the soil type and
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flood simulation at different river basins with different catchment characteristics in
Asian countries. Some future studies are recommended for the applications of IFAS
in forecasting the flood event.
5.2 Integrated Flood Analysis System (IFAS)
The Integrated Flood Analysis System (IFAS) is a flood forecasting system that used
to perform rainfall–runoff simulation for river basins with insufficient hydrological
data to reduce its vulnerability to flooding disasters. IFAS is developed by the International Centre for Water Hazard and Risk Management (ICHARM). The IFAS software is capable to import satellite-based rainfall data such as GSMaP and 3B42RT
for insufficient ground observation river basin and other data includes geographic
and land use data for almost the entire world (ICHARM 2011). 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. The Public Works Research Institute Distributed
Hydrological Model (PDHM) is employed in IFAS software as its runoff simulation
model. The structure of PDHM is consists of a surface tank model, subsurface tank
model, aquifer tank model, and river tank model. IFAS 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. The system is able
to conduct a series of operations required for runoff analysis.
5.2.1 Model Structures
The structures of IFAS can be classified into four main components: input rainfall,
basin model, runoff calculation engine, and results display interfaces as shown in
Fig. 5.1. The input rainfall data for IFAS can be obtained either from ground-based
rain gauges or satellite rainfall data. The global satellite rainfall datasets provided
by National Aeronautics and Space Administration (NASA) and National Oceanic
and Atmospheric Administration (NOAA), USA, and Japan Aerospace Exploration
Agency (JAXA) offer different spatial and temporal resolutions and time of delay.
The IFAS runoff basin model can be developed by utilizing global GIS data. The
GIS tool kits were used to obtain the geophysical data and construct the river basin
model. The imported global GIS data includes catchment elevation, land use/land
cover, soil type, and geology. The topography map and river channel network for
the modeled catchment can be constructed by using the digital elevation model
(DEM) data provided by the United States Geological Survey (USGS) as shown
in Fig. 5.2. The land use data can be downloaded from the Global Land Cover
Characterization (GLCC) database provided by USGS. Meanwhile, the soil type and