Flood is the overflow of water that submerges land that is usually dry.

1. SOCIAL
SCIENCE
PROJECT
BY:
VANSHKA SINGH
SESSION (2021 -2022)

2. FLOOD
THE WATER DISASTER

3. INDEX
o Introduction
o Causes of Flood
o Effects of Flood
o Prevention against Floods
o Safety tips
o 2020 Assam Floods
o 2018 Kerala Floods
o Bibliography

4. INTRODUCTION
A Flood is an overflow of water that submerges land that is usually dry. Sometimes a river might receive
extra water, either from heavy rains or other natural disasters. When this happens, the water overflows
from its normal path in the river bed and onto the dry land.
Floods can occur within minutes or over a long period, and may last days, weeks, or longer. Floods are
the most common and widespread of all weather-related natural disasters. Human changes to the
environment often increase the intensity and frequency of flooding, for example land use changes such
as deforestation and removal of wetlands, changes in waterway course and larger environmental issues
such as climate change and sea level rise.
Flooding may occur as an overflow of water from water bodies, such as a river, lake, or ocean, in which
the water overtops or breaks levees, resulting in some of that water escaping its usual boundaries,[2] or
it may occur due to an accumulation of rainwater on saturated ground in an areal flood.Floods can also
occur in rivers when the flow rate exceeds the capacity of the river channel.

5. CAUSES
Flood is usually a result of natural causes. They are
part of the water cycle, and
the environment is adapted to flooding. It may also
be caused by man-made factors. It causes huge
damage to life and property. There are many
different causes leading to flooding. Some
prominent among them include:
Massive Rainfall
The amount, location, and timing of water reaching
a drainage channel from natural precipitation and
controlled or uncontrolled reservoir releases
determines the flow at downstream locations.
Drainage systems and the effective infrastructure
design aid during heavy rains. They help
the drainage of excess water into reservoirs in an
easy way. But in cases of heavy rainfall, the systems
stop working. Thus flood is caused.

6. Overflowing of the Rivers
The people living along the river always have a risk of life from the
overflowing of the Rivers.
In August 2010, Pakistan experienced some of the worst floods of
the century. The annual monsoon, on which Pakistani farmers
and consumers rely, was unusually strong. Tons of water drenched the
nation. The Indus River burst its banks. Because the river flows
almost directly through the narrow country, almost all of Pakistan was
affected by flooding. Millions of Pakistanis lost their homes, and
almost 2,000 died in the floods. The impact of the floods continued
long after the monsoon dwindled and the Indus subsided. Pakistanis
experienced food shortages, power outages, and loss of infrastructure.
Outbreaks of cholera and malaria developed near resettlement camps.

7. Several different weather conditions can cause extreme rainfall in a region. Tropical
cyclones form in some tropical and subtropical areas, usually in the summer, can
produce huge amounts of rain, causing flooding and flash flooding once the storm
reaches land.
They can also send a rush of water from the ocean onto coastlines in an event called a
storm surge, which floods low-lying areas. A storm surge is a type of coastal flood. They
can be devastating. The storm surge that accompanied the 1970 Bhola cyclone flooded
the low-lying islands of the Ganges Delta in India and Bangladesh. More than 500,000
people were killed, and twice that number were left homeless.

8. Collapsed Dams
In the event of huge rainfall, the dams built begin to collapse.
Thus, causing the flood situation to become even critical for the
people living around. Engineers may also intentionally flood
areas to prevent the possibility of worse flooding. When heavy
rains caused the Souris River to flood in 2011, for example, the
water level nearly reached the top of the Alameda Reservoir in
Oxbow, Saskatchewan, Canada. Faced with the prospect
of catastrophic flooding if the entire dam broke, engineers
chose to release huge amounts of water. The reservoir
remained intact, but the release contributed to massive floods
in both Saskatchewan and the U.S. city of Minot, North Dakota.

9. Ice and snow melts
In cold regions, heavy snow over the winter usually stays unmelted for some time. Some mountains have an
ice cap on them. Sometimes the ice suddenly melts when the temperature rises, resulting in massive
movement of water into places that are usually dry. This is usually called a snowmelt flood
Climate change
The climatic changes caused due to human practices also add to the risk of flooding. Human beings cut trees
in a large number, thus affecting the process of photosynthesis. Thus increased level of carbon-di-oxide in the
atmosphere cause changes in climate posing threats of natural disasters like floods etc.

10. EFFECTS
 Floods cause more than $40 billion in damage worldwide annually. Death tolls have increased in
recent decades to more than 100 people a year. In China's Yellow River Valley some of the world's
worst floods have killed millions of people. The primary effects of flooding include loss of life and
damage to buildings and other structures, including bridges, sewerage systems, roadways, and
canals. When floodwaters recede, affected areas are often blanketed in silt and mud. The water and
landscape can be contaminated with hazardous materials such as sharp debris, pesticides, fuel, and
untreated sewage. Potentially dangerous mold blooms can quickly overwhelm water-soaked
structures. Oftentimes, major flooding results in dislocation and dysfunction of normal life long after
flood waters recede.
 Residents of flooded areas can be left without power and clean drinking water, leading to outbreaks
of deadly waterborne diseases like typhoid, hepatitis A, and cholera.
 Flooding hinders economic growth and development because of the high cost of relief and
recovery associated with floods.

11. Flooding can also create lasting trauma for victims. The loss of loved ones or homes can
take a steep emotional toll, especially on children. Displacement from one’s home and
loss of livelihood can cause continuing stress and produce lasting psychological impacts.
What areas are at risk from flash floods?
Densely populated areas are at a high risk for flash floods. The construction of
buildings, highways, driveways, and parking lots increases runoff by reducing the
amount of rain absorbed by the ground. This runoff increases the flash flood
potential. Low spots, such as underpasses, underground parking garages,
basements, and low water crossings can become death traps. Areas near rivers are at
risk from floods.

12. PREVENTION
AGAINST
FLOODS
It’s not always possible to prevent floods, but it is often
possible to minimize flood damage. Structures around rivers,
lakes, and the sea can contain flood waters. Levees, runoff
canals, and reservoirs can stop water from overflowing.
To try to mitigate the risk, many governments mandate that
residents of flood-prone areas purchase flood insurance and
set construction requirements aimed at making buildings more
flood resistant—with varying degrees of success.
Natural and man-made reservoirs help prevent flooding.
Natural reservoirs are basins where freshwater collects. Man-
made reservoirs collect water behind a dam.
Conserving wetlands also reduces the impact of floods.
Wetlands provide a natural barrier, acting as a giant sponge
for storm surges and flood plains.

13. Flood
Safety Tips
While floods have many causes, there are proven flood safety and flood prevention tips to
help keep families, businesses, and communities safe. Here are some steps you can take
before, during, and after flooding to keep yourself and those you care about safe:
The first thing you should do before a flood is assemble an emergency kit. Your flood
emergency kit should include food, water, and medicine. You should pack a supply of these
items that will last each person three days. You should also put the following in your kit:
o Phone Charger
o Batteries
o Blankets
o Flashlights
o First Aid Kit
o Rubber Boots and Gloves
o NOAA Weather Radio
You should also have a cell phone on hand. Familiarize yourself with your local emergency
management agency and how they communicate with your community. A Flood Advisory means you
should be mindful of possible flooding because a weather event is forecast to occur that could result in
flooding. A Flood Watch means you should prepare for flooding because conditions are favorable for
a specific hazardous weather event to occur.

14. THE 2020 ASSAMFLOODS refers to the significant flood event of the Brahmaputra River in the Indian north-eastern
state of Assam and coincided with the COVID-19 pandemic. Initial flooding started in May 2020 due to heavy rainfall
affecting 30,000 and destroying crops across 5 districts. As of October 2020 the floods affected over five million
people

15. On 16 August 2018, severe floods affected the south Indian state Kerala, due to unusually high rainfall during the monsoon
season. It was theworstflood in Keralain nearlya century. Over 483 people died, and 140 are missing. About a million people
were evacuated. The Indian government had declared it a Level 3 Calamity, or "calamity of a severe nature". It is theworst
floodin Keralaafterthe greatflood of 99 thattook placein 1924.

16. BIBLIOGRAPHY
WIKIPEDIA- FLOOD, THE 2020 ASSAM FLOODS, 2018 KERALA FLOODS
https://www.nssl.noaa.gov/education/svrwx101/floods/
https://www.earthnetworks.com/flooding/ : EARTH NETWORK_WHAT IS FLOOD?
NATIONAL GEOGRAPHIC-
FLOODS: https://www.nationalgeographic.com/environment/article/floods#:~:text=Po
tentially%20dangerous%20mold%20blooms%20can,%2C%20hepatitis%20A%2C%20and
%20cholera

17. THANK YOU!