Riverine Disaster: Indigenous Coping Mechanism and Vulnerability Reduction Method of Flood & Riverbank Erosion and Difference between Flood & Riverbank Erosion.

2. PRESENTATED
BY
Presented by
H. M. Touhidul Islam
ID: 1317029
Department of Disaster Management,
Begum Rokeya University, Rangpur.

3. PRESENTATION ON
Riverine Disaster: Indigenous Coping Mechanism and Vulnerability
Reduction Method of Flood & Riverbank Erosion and Difference between
Flood & Riverbank Erosion

4. Outline
About riverine Disaster
Coping Mechanism
Vulnerability Reduction method
 Flood
River bank erosion
 Differences between Flood and River bank
erosion
Recommendations

5. Riverine
disasters
Riverine means relating to or
situated on a river or riverbank.
So that Riverine disasters Implies
that disasters relating to or
situated on a river or riverbank.

6. Flood
A flood is an overflow of water that submerges land that is
usually dry.
A flood occurs when the Geomorphic Equilibrium in the river
system is disturbed because of intrinsic or extrinsic factors or
when a system crosses the Geomorphic threshold.
a) Flooding in a river due to aggradation of river bed
(intrinsic)
b) Flooding in a river due to heavy rainfall (extrinsic)
Floods in major cities especially during rainy season are
proving to disastrous not only to environment but also have
serious implications for human life and property.

7. River Bank Erosion
Bank erosion is the wearing away of the banks of a stream or river.
Bank erosion occurs through two dominant processes:
01
Hydraulic Action
Or Fluvial Erosion
02
Mass Failure

8. Hydraulic Action
Fluvial erosion or hydraulic action is the direct removal of soil particles by
flowing water.
Hydraulic processes at or below the water surface entrain sediment and
directly contribute to erosion, particularly of non-cohesive banks, by
processes of bank undercutting, bed degradation, and basal cleanout.
Undercutting Bed Degradation Basal Clean Out

9. Mass Failure
• Mass failure occurs when the weight of a stream bank is greater than the
strength of the soil, causing the bank to collapse. This process is dependent
upon a number of factors including the internal strength of the soil (e.g.
clay vs. sand), soil-water content, and vegetation.
Cohesive Mass wasting
Mass wasting event caused by a drop-in river stage or a rise of the water

11. Indigenous
Coping
Mechanism
The application of indigenous or
local knowledge in the face of
hazards and other threats is
generally referred to as a
traditional ‘coping mechanism’
or ‘coping strategy’.

12. Coping Strategy to Flood & River Bank Erosion Applying Indigenous
Knowledge

13. Pre-Disaster Preparedness
applying Indigenous Knowledge
RAISING PLINTH OF THE HOUSE
The houses in the areas are always over
flooded by the water, so the community
people adopt ‘raising plinth’ mechanisms
for the protection of homesteads.
Protecting Homestead

14. Protecting the superior
mud in the homestead
from washing away
becomes the next
challenge, which is
commonly solved by
planting of dhol-kolmi
(local vegetation) and
banana tree.

15. MAKING SCAFFOLD IN THE HOUSE
During flood, the local people try to set up strong pillars
and scaffold for their houses. This is a common
preparation strategy of the people for upcoming flood.
The method is easy and safer for emergent period for
shelter.
Raising tube well for pure drinking water
With the protection of plinth, many cautions and
financially solvent people buy extra pipe to raise the tube-
well base above flood level to ensure fresh source of
water

16. Protecting livestock
Protection of livestock is thus a crucial preventive strategy used by the local people.
Depending on affordability they
Elevate cattle sheds
Store fodder
Vaccinate their cows in advance.

17. Protecting Harvest
Vegetable can be grown in the homestead garden

18. Seeding should be transplanted in higher quantities since they get
damages by the flood
Few farmers also preserve seeds in advance, so that even if the flood
destroys the expected production, they still get a chance for re-sowing
seeds, if time permits.
Depending on the land type, flood tolerant alternative crops can be
grown.
Submerged tolerant
rice variety by IRRI

19.  Prior to floods, and during riverbank erosion people try to store dry
food that does not need to be cooked, such as chira (flattened rice),
muri (puffed rice), gur (molasses).
 Making movable chula (alga chula)
Storing food, fuel and
preparing portable
stove

20. FUEL PRESERVATION:
preserve the fuels like jute sticks,
sticks with cow dung, dried shrubs
and whatever they use for cooking in
the time of crisis.

21. • MAKING GHUCHI
• shidol
• Dry fish
• Dry meat
• For cooking purposes, they preserve rice, peas etc. as back up.

22. For communication purposes, people also
build locally developed bridges called shako.
Those who can afford buy boats beforehand
or start repairing old ones
Few people also plant Banana trees which can prove useful during flood.
People use these trees for making rafts which serve both as transport and as
shelter during floods.
Emergency communication and
transportation

23. During flood they suffered from fever, cold, diarrhea. They stored some
medicine, saline considering the flood situation. They apply some traditional
knowledge for Health criticalities.
• For Jandis they take medicine from ‘Kabiraj’.
• Tulshi leaf is used for cold.
• They know how to make saline. In case of Diarrhea& Dysentery they take
handmade saline.
• ‘Dublar Ras’ is used for the constipation & also for injury.
• Neem leaf is also used for worm of children.
Health

24. Almost everybody knows swimming including children. When they are
6-7 years old their family guides them to gain knowledge of swimming.
Because for both the flood and riverbank erosion the people mostly
need to know swimming.
Self-Preparedness

25. During disaster
coping mechanism
Floating Bed Cultivation(Hydrophonics)
Where without soil and grass cultivate crops in water. During the
monsoon, farmers use small boats to manage the floating agricultural
land.

26. Using Boats and Banana Vella
The affected people use boats and banana vella for transportation.
They generally use banana vella for moving one place to another place
for their livelihood, to gather foods and necessary things.

27. Fish Culture in Case
The affected people sometimes take step to indigenous fish cultivation by
using case which is covered by nets. For that fishes cannot escape from it
and by this way affected people are coping with flood disasters.

28. The households experiencing riverbank erosion first send away their
women and children to safely.
Take shelter sometime in embankment
& also in relative’s house.
Social bonding among neighbor is a great capital for them. During
disaster most of the time robbers attack them. So they formed a
committee themselves to guard the char people by rotation

29. Coping mechanism in
Post Disaster period
Clean the dirt from yard
and Make the land
cultivable for next
harvesting
After flood they again rebuilt
their houses themselves
From traditional
knowledge they make a
crop plan
Lots of diseases occur in this
situation and Sometimes
they take treatment from
Kabiraj.

30. Forms of coping
Forms of coping

31. Technological
This category is quite broad; including land management
systems as well as what is more usually thought o f as
technology, such as building materials and construction
methods.
Farmers who work in the marginal lands practice mixed
cropping, intercropping techniques which reduces risk of
poor harvest. Alternative crops may be kept in reserve to
plant where others are ruined by Hoods. Pesticides made
from local plants are applied to crops.
Also, at many places, houses are constructed on raised
platform so that they remain above flood levels.

32. economic/material
One of the principal elements in this category is
economic diversification. Members of a rural
household engaged in agriculture may undertake
other work, such as making and selling handicrafts,
carpentry, building or blacksmithing.
During periods of food shortage, they will eat food
of poorer quality or eat less food, and look for ‘wild
foods', such as seeds, nuts, roots and berries.
If a crisis becomes acute, they will begin to sell
their assets, but sale of livelihood assets (e.g.
animals, tools, seeds for planting next year's crop or
even land) is seen as a last resort.

33. social/organis
ational
This heading includes indigenous
organisations that provide support in
countering disasters: kinship networks,
mutual aid and self-help groups.
People who are suffering – from
shortage of food for instance - often call
upon kin, neighbors, or patrons for help.
Labor and food sharing during crises is
standard in many societies.

34. cultural
This includes religious beliefs and
norms which helps the community in
perceiving warning systems about the
disaster and provide the medium to
pass on the knowledge and experiences
from one generation to another
generation.
This is passed on in the forms of stories,
tales as well as other practices.

35. Vulnerability
Reduction
Method
• Flood
• River Bank Erosion

36. Vulnerability Reduction
Method of Flood
Vulnerability reduction can be done into ways:
Structural ways1
Non-Structural ways2

37. • Make levees, embankment to control the water
• Drainage channel improvement regularly/ timely to keep perfect
deepness of the river and allowing it to carry more water
• Developed pumping system
• River and wetland restoration
• Floodwall
Structural ways
1

38. • Diversion of Flood Water
• Natural Detention Basins
• Flood Safe Public Utility Installations

39. • Insurance
• Afforestation
• Flood forecasting, early warning and evacuation system
• Community preparedness
• Make policy, rules to under control human beings
• Zoning and mapping of vulnerable zone
• Land use pattern management
Non-Structural ways2

41. Flood Risk Management Cycle

42. Vulnerability Reduction Method of
Riverbank Erosion
Pre-disaster vulnerability Reduction Method:
• Tree plantation
• Mattressing along the bank line
• Embankment establishment
• River
• erosion forecasting & prediction
• River erosion mapping
• Awareness generation among people of affected areas
• Training on river erosion management to representative & officials

44. During-disaster vulnerability Reduction Method:
• Emergency food & shelter assistance
• Emergency evacuation
• Using sand bags for the protection of embankments

45. Figure: Losses and Coping Mechanisms of Riverbank Erosion

46. Post-disaster vulnerability Reduction Method
• Reconstruction efforts are focused on economic reactivation, public
health, educational opportunities, housing, environmental etc.
• Physical infrastructure repairs & municipal development enhance
natural resource management
• Proper implementation of policies, technologies, standards, laws &
institutional organization.

47. Difference
between Flood
and
Riverbank
Erosion
Flood No Riverbank Erosion
It is a natural event or occurrence where
a piece of land (or area) that is usually
dry, suddenly gets submerged under
water.
1 Simply it is defined as the process of
wearing of the banks of a stream river.
Riverbank erosion is the deterioration of
the banks of a river or stream.
It is a hydrological process. 2 Riverbank erosion is a ―geo-morphological
process of alluvial floodplain rivers.
It occurs when a stream runs out of its
confines and submerges surrounding
areas.
3 It occurs when the top soil that encloses a
river or stream washes away.
It is because of inadequate sediment
accumulation, local relative sea level rise,
deforestation in the upstream region,
greenhouse effect, excessive
development, monsoon downpour etc.
4 It is because of saturation of banks from
off-stream source, redirection and
acceleration of flow within the channel,
poor soil drainage, wave action, excessive
sand/gravel extraction,
intense water from rainfall etc.

48. It is not occur for riverbank erosion. 5 It can occur due to flood.
There are different types of flood as:
Monsoon flood
River flood
Coastal flood
Flash flood etc
6 Three types of riverbank erosion occur:
•Vertical,
•Head ward and
•Lateral erosion.
Impacts of flood are physical injury, illness and loss
of life, disrupt normal drainage systems, severe
damage to properties, seriously disrupt public and
personal transport, erosion, bank erosion, land
sliding and damage to vegetation etc.
7 Impacts of riverbank erosion are loss of occupation
and loss of property, homelessness, identity crisis,
extra cost for medical treatment and education etc.
8

49. Recommendations
• Awareness on to be built among all the stakeholders.
• Programmes of rural poverty reduction and alleviation need to tackle
biases against poor farmers and women.
• Regular drazing of the river is of importance to reduce the risks of
catastrophic flood damage in the locale.
• Joblessness at times of flood is a huge problem. Both GO and NGOs
should create more job opportunities even on temporary basis for the
villagers.
• A better coordination between GO and NGOs in relation to flood
awareness programs may also be considered.

50. Recommendations
• Necessary guidelines to be prepared and circulated.
• Policy guidelines may be issued. Pilot project may be taken up.
• Establishment of more Community-based Organizations.
• Increase inter- sectoral coordination for program planning and
implementation.
• Better farm management through new information dissemination,
motivation and technological innovation;
• promotion of climate resilient crops (submergence varieties);
• short duration and early crops;

52. Thank You