application of remote sensing and gis for flood risk analysis: a case ...

IRJC
International Journal of Social Science & Interdisciplinary Research
Vol.1 Issue 11, November 2012, ISSN 2277 3630
Although the occurrence of such disasters cannot be prevented or regulated, the proper
application of scientific knowledge based on past experience can minimize the economic and
health consequences of the population.
INTRODUCTION:
The natural hazards can be listed as avalanches and landslides in Himalayas, cyclones in coastal
areas, drought in rain-scarcity areas, earthquakes in seismic and tectonic activities affected areas
and floods in heavy rainfall area. Hence effect of these hazards causes damages at various
degrees to an extent of disaster, the phenomena of these kinds of disaster due to flood demands a
systematic study.
Disaster means a catastrophe, a calamity or mishap, a grave occurrence, which causes a serious
disruption of the functioning of a society, causing widespread human, material or environmental
losses exceeding the ability of the affected society to cope using only its resources.
A Flood is defined as the overflow of areas that are normally submerged with water or a stream
that has broken its normal confines or has accumulated due to lack of drainage. Floods are
among the most common and destructive natural hazards causing extensive damage to
infrastructure, public and private services, the Environment, the economy and devastation to
human settlements. The flood has different types, they are; River flood, Coastal flood, urban
flood, storm flood etc these may be flash flood or slow onset flood. 28
B. Normal floods are expected and generally welcomed in many parts of the world as they
provide rich soil, water and a means of transport, but flooding at an unexpected scale (damaging
flood) and with excessive frequency causes damage to life, livelihoods and the environment.
Over the past decades, the pattern of floods across all continents has been changing, becoming
more frequent, intense and unpredictable for local communities, particularly as issues of
development and poverty have led more people to live in areas vulnerable to flooding. The
Fourth Assessment Report (2007) of the Intergovernmental Panel on Climate Change (IPCC)
predicts that „heavy precipitation events, which are very likely to increase in frequency, will
augment flood risk‟. These floods will affect life and livelihoods in human settlements in all
areas, e.g., coastal zones, river deltas and mountains. Though there were continuous efforts to
mitigate flood and its effects on victims.
C. Floods by nature become a complex event and caused a range of human vulnerabilities,
inappropriate development planning and climate variability with the exception of flash floods,
whose scale and nature are often less certain. Hence it requires more comprehensive studies
about flood to formulate appropriate strategies to mitigate flood and its impacts.
NEED FOR THE STUDY
Floods are an endemic problem in India. The National Commission on Floods, more commonly
known by its Hindi name „Rashtriya Barh Aayog‟, in 1980 estimated that about 40 mha of area is
flood-prone. This was later revised to 33.5 mha. On an average, 7.5 mha Area is affected by
floods in any one year, in some or other part of the country. Large flood events capture the
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