Floods - Extreme Events: A Physical Reconstruction and Risk Assessment - page 57

Social and economic impacts of floods
Floods are responsible for up to 50 000 deaths and adversely affect some
75 million people, on average, worldwide every year (Smith, 2001). Drowning is
not the only cause of death in floods. Disease is common after floodwaters pass,
especially in less developed countries. Gastrointestinal diseases mainly break out
due to damaged sewerage systems and low sanitation standards. Malaria and
typhoid outbreaks after floods in tropical countries are also common. In many
western countries it has been observed that survivors of catastrophic flood events
suffer some form of mental illness that can be directly related to the flood event.
French andHolt(1989) concluded that flood victims can suffer psychological
problems for up to five years after the flood event. The emotional strain of the
event on financial and social costs would appear to be a catalyst for these impacts
(ARMCANZ, 2000). The Buffalo Creek, West Virginia floods of 1972, left 90% of
survivors with mental anguish 18 months after the event (Smith, 2001).
The floodplains of the Yangtze River are home to 5% of the world's population
(Chapman, 1999). Five million people lost their lives in floods in China between
1860 and 1960. The Chinese have had flood defence for cities for the last 4000
years but large losses still continue with 3000 lives lost and 15 million people left
homeless in the 1998 floods (Smith, 2001). Deaths from flooding in Bangladesh
account for nearly three-quarters of the global loss of life from floods (Smith,
2001). It has been estimated that in India and Bangladesh 300 million people live
in areas that are affected by floods. Chapman (1999)suggests that 3000 people
and 100 000 head of cattle perish in flooded river systems in these countries
every year. Indeed, in 1991, 140 000 people were killed in floods in Bangladesh.
In 1993 in the US midwest, the Mississippi and Missouri Rivers affected nine
states, with 50 000 damaged homes resulting in the evacuation of 54 000 people
from flood affected areas (Smith, 2001).
Physical damage to property is one of the major causes of tangible loss in
floods. This includes the costs of damage to goods and possessions, loss of income
or services in the flood aftermath and clean-up costs (ARMCANZ, 2000). There
are also secondary losses such as declining house values where properties are
deemed to be in a flood prone area. Some impacts of floods are intangible and
are hard to place a monetary figure on. For example, every year in Bangladesh it
has been estimated that riverbank erosion of farmland leaves one million people
landless (Smith, 2001). Intangible losses also include increased levels of physical,
emotional and psychological health problems suffered by flood-affected people
(ARMCANZ, 2000).
Floods are an expensive phenomenon, with the estimated average annual cost
of flooding in Australia alone being AUS $350 million (ARMCANZ, 2000). In 1948 a