Floods over large regions are a characteristic of Ganga basin as well as flood
plain portions of middle and lower Brahmaputra valley. Other parts of the country
especially the deltaic regions of Krishna, Godavari, Mahanadi and other large
basins and some coastal areas prone to cyclonic storms also require regional flood
management. Weather data and especially rainfall data collection in real time and its
use for the simulation of the probable flood event is quite important. The data of
releases from the reservoirs lying at the head of the catchment also assumes great
importance. In case of low lying areas near the coast line require state of tides and
seal levels at the time of flood as a crucial input for handling the inundation in the
region. The data pertaining to water is of prime importance in flood management as
it provides vital clues about the temporal and aerial spread of disaster and its
relative magnitude. This input is very valuable for the disaster preparedness and
management activities.
2.3.2 Urban and Peri-Urban Flood Management
Urban flooding has come up as a special disaster which has many similarities but
crucial specialities which the conventional regional flood management does not
have. With growing urbanization, the percentage of population residing in urban
conglomerations is approaching 50%, and a very large segment of this population
resides in vulnerable areas of slums and unauthorized colonies largely located in
low lying areas and near the banks of rivers and drains.
In urban flooding scenario, the phenomena is much more of drainage congestion
rather than the extreme flooding due to intense rainfall. Drainage capacity plays an
important part in determining the flooding extents. The granularity of the rainfall
data is very important as the aerial extent is generally limited, but the affected
population is very high due to high population densities in urban areas. Many of our
large cities namely, Mumbai, Chennai, Kolkata and Surat are lying in poorly
draining coastal areas. In most of the cities, the real-time information about the
carrying capacity of the natural drainage network is required to be assessed regularly for anticipating the flooding problems. Oftentimes, the developments obstruct
the natural slopes in the catchment areas of the drains leading to flooding.
As witnessed in case of flooding episodes in Chennai and Surat, the operation of
reservoirs lying on the upstream of the cities in the basin and coordination with the
urban authorities is of great importance. Data flow mechanisms coupled with
simulation models are important. Since natural extreme events are rare, the data
collection and transmission systems are not well oiled and leave gaps in
performance.
Data Usage for Development, Management of Water Resources
139
plain portions of middle and lower Brahmaputra valley. Other parts of the country
especially the deltaic regions of Krishna, Godavari, Mahanadi and other large
basins and some coastal areas prone to cyclonic storms also require regional flood
management. Weather data and especially rainfall data collection in real time and its
use for the simulation of the probable flood event is quite important. The data of
releases from the reservoirs lying at the head of the catchment also assumes great
importance. In case of low lying areas near the coast line require state of tides and
seal levels at the time of flood as a crucial input for handling the inundation in the
region. The data pertaining to water is of prime importance in flood management as
it provides vital clues about the temporal and aerial spread of disaster and its
relative magnitude. This input is very valuable for the disaster preparedness and
management activities.
2.3.2 Urban and Peri-Urban Flood Management
Urban flooding has come up as a special disaster which has many similarities but
crucial specialities which the conventional regional flood management does not
have. With growing urbanization, the percentage of population residing in urban
conglomerations is approaching 50%, and a very large segment of this population
resides in vulnerable areas of slums and unauthorized colonies largely located in
low lying areas and near the banks of rivers and drains.
In urban flooding scenario, the phenomena is much more of drainage congestion
rather than the extreme flooding due to intense rainfall. Drainage capacity plays an
important part in determining the flooding extents. The granularity of the rainfall
data is very important as the aerial extent is generally limited, but the affected
population is very high due to high population densities in urban areas. Many of our
large cities namely, Mumbai, Chennai, Kolkata and Surat are lying in poorly
draining coastal areas. In most of the cities, the real-time information about the
carrying capacity of the natural drainage network is required to be assessed regularly for anticipating the flooding problems. Oftentimes, the developments obstruct
the natural slopes in the catchment areas of the drains leading to flooding.
As witnessed in case of flooding episodes in Chennai and Surat, the operation of
reservoirs lying on the upstream of the cities in the basin and coordination with the
urban authorities is of great importance. Data flow mechanisms coupled with
simulation models are important. Since natural extreme events are rare, the data
collection and transmission systems are not well oiled and leave gaps in
performance.
Data Usage for Development, Management of Water Resources
139