4. Results and Discussion
The distribution of rainfall in 2001 is illustrated in
figure 3. It is evident that the year 2001 provided
exceptional high frequency and amount of rainfall during
September. A flood risk map of the Northeast based on
this analysis was shown in figure 4. The risk areas are
summerized in table 2. The high risk areas extend from
the river bank to some extent depending the size of the
stream. The larger extent of overflow can be found along
the main rivers. The land use in the high and moderate
risk areas are mainly restricted to paddy field, range land
and riverine forest. The study provides an overall insight
into the potential flood risk areas and the interaction of
drainage pattern, land form and amount of rainfall. The
SAR data using in combination with land form proved
ideal for regional flood risk assessment. The
combination of resolution delivered product that is
superior to anything else currently available. The cloud
penetrating capabilities of SAR is only a source of
informtion for immediate assessment of flooding and
flood risk area analysis. This paper represents that we
can view the flood from space, to detect reasonably the
extent of flood and the assessment of the flood risk areas.
With low frequency of hydrological stations, it is not
possible to determine the flood area without observation
of the flooding as it develops. The SAR data offers best
solution for forcasting the flood risk area when using in
supplement with terrain and hydrological data
and mosaicing. The images were produced and used for
visual interpretation. Land form map layer was prepared
from Landsat data, topographic map and field
experiences.