Geoinformation for Disaster and Risk Management - ISPRS

The local capacity to use geoinformatics for LFEWS
is gradually growing but still limited to a small
number of institutions, such as universities and a
few others. Substantial training is needed to enable
more institutions to make full use of the potential of
remote sensing and GIS tools. Cost remains a factor
limiting the spreading of geoinformatics to many
offices. However, the potential of free or low cost
tools and data in flood risk management is
substantial. There are several free and open-source
(FOSS) GIS and remote sensing programs covering a
wide range of tasks. Nevertheless, for specific
processing tasks, such as for actual flood modeling
or more advanced image processing, commercial
software is still needed, and was also used in the
setting up of the Binahaan LFEWS. Use was made of
free or low-cost satellite data (e.g. Landsat, SRTM, or
GDEM). The project also used SPOT data obtained
via a Planet Action project of SPOT Imaging, which
supports projects related to adaptation to climate
change. Also the potential of 3-hourly data from the
Tropical Rainfall Measurement Mission (TRMM)
satellite to estimate real-time rainfall was assessed.
These data are available without charge via the
internet. Historical ground rainfall measurements
were compared with the respective TRMM data.
However, for the watershed size considered here, the
error of the TRMM data was too large for the data to
be used for warning purposes. Nevertheless, the data
have been used successfully elsewhere, and new
instruments and algorithms suggest that satellitebased
rainfall estimates may soon be reliable enough
for most areas. Their most significant advantage is
that for areas where no rain or river gauges exist,
early warning will still be possible. Even where
ground instruments are available, real-time satellite
estimates mean an extra time advantage
Figure 4: Land use map of Binahaan river basin based on SPOT and ASTER data.
61