2. Introduction
• Water resources are sources of water that are useful
or potentially useful.
• Uses of water include agricultural, industrial,
household, recreational and environmental activities.
• Virtually all of these human uses require fresh water.
3. A graphical distribution of the locations of
water on Earth
A graphical distribution of the locations of water on Earth.
4. Fresh Water
• Fresh water is a renewable resource, yet the world's
supply of clean, fresh water is steadily decreasing.
• Water demand already exceeds supply in many parts
of the world and as the world population continues to
rise, so too does the water demand.
5. How people use
water
resource?
Household use:
ways
Wash the garden.
Turning off the
fire.
Wash dirty
dishes
Wash the car.
Personal use:
ways
To drink water,
when you’re
driving bicycle.
Take a shower
Recreational use:
ways
Play in the beach.
Go to the pool.
Fishing
Surf
Uses of water
6. Uses of Fresh
Water
Types
Agricultural: The
69% of water is
use for
irrigation.
Irrigation in
some areas is
necessary for
crops grow.
Aquaculture: is a
small agricultural
growing.
Industrial: The 15%
of water is use for
industrial things. The
major use of
industrial is power
plants. Oil refineries
which is use with a
chemical process.
Manufacturing plants
which use water as a
solvent.
Industrial water is
lower than agricultural
water.
Household:
The 15% of
water is use
for
household.
Household
uses are:
Drinking
Bathing
Water
Cooking
Sanitation
Gardening
Recreational:
Recreational
water has a
small use.
Recreational
use is mostly
needed for
reservoirs.
This type of
use of water is
specific for
places and good
times.
Environme
ntal water
has a small
use.
Environme
ntal water
is use
mostly for:
Artificial
wetlands
Artificial
lakes
This is to
create a
wildlife
habitat.
7. Water Resources-Use and Overutilization
• The water Cycle through evaporation and precipitation, maintains
hydrological systems
• All aquatic ecosystems are used by a large number for their daily
needs such as washing irrigation, cooking etc.
• One of the greatest challenges today is the management of these
water resources.
• Due to increasing population there is an enormous supply for the
available freshwater resources.
• India is likely to face water crisis by 2025.
• With growth of human population larger amounts of water will be
required to fulfill basic needs Today in many areas this need cannot
be met.
• Overutilization of water occurs at various levels:
• Most people use more water than required to carry out basic
activities such as brushing, bathing, washing and cleaning etc.
• Farmers also sometimes use double the water required for
irrigation.
• There are many ways in which the farmer can increase the yield by
using less water for irrigation.
9. •Sources of Fresh Water
•Surface Water is water in a river, lake or fresh water wetland.
•Surface water is naturally replenished by precipitation
•naturally lost through discharge to the oceans, evaporation, and sub-surface
seepage.
10. •Sub-Surface water or groundwater
•One of our most valuable resources is the water beneath our feet.
• groundwater is fresh water located in the pore space of soil and rocks.
• It is also water that is flowing within aquifers below the water table.
•Sometimes it is useful to make a distinction between sub-surface water that is
closely associated with surface water and deep sub-surface water in an aquifer
(sometimes called "fossil water").
11.
12.
13.
14. An aquifer is an underground formation of permeable rock or loose material which can
produce useful quantities of water when tapped by a well. Aquifers come in all sizes.
They may be small, only a few hectares in area, or very large, underlying thousands of
square kilometers of the earth's surface. They may be only a few meters thick, or they
may measure hundreds of meters from top to bottom.
15.
16. How Much Do We Depend On Groundwater?
According to United States Geological Survey (USGS) figures, groundwater
provides an estimated:
22% of all freshwater withdrawals
37% of agricultural use (mostly for irrigation)
37% of the public water supply withdrawals
51% of all drinking water for the total population
99% of drinking water for the rural population
17. FLOODS
FLOODS ARE NATURAL PHENOMENA.
FLOODS ARE WATER RELATED DISASTER
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 threshold);
(b) Flooding in a river due to heavy rainfall (extrinsic
threshold)
18. TYPES OF FLOODS
Types of floods
•Flash floods
•River floods
•Coastal Floods
•Urban Flood
According to their duration flood can be
divided into different categories:
•Slow-Onset Floods: Slow Onset Floods
usually last for a relatively longer period, it
may last for one or more peeks, or even
months.
•Rapid-Onset Floods: Rapid1Onset Floods
last for a relatively shorter period, they
usually last for one or two days only.
•Flash Floods: Flash Floods may occur within
minutes or a fe1w hours after heavy
rainfall, tropical storm, failure of dams or
levees or releases of ice dams. And it causes
the greatest damages to society.
19. Contd….
Floods
Natural
Storm Surge,
Tsunami, Glacial Melt,
Landslide, Riverine,
Estuarine & Marine Flood
Eg: bursting of landslide
blockades in the catchment
areaof the Bhagirathi River in
August 1978 (Gupta and Dave,
1982).
Man made
Breach of
Dam/ Barrage/
Embankment
Release from Reservoir,
Urban Flood
Eg: In the year 2009,Almatti
and Naryanpur dams on the
Krishna River in Karnataka.
This water along with rain
water reached Andhra Pradesh
near the Srisailam dam. It
causes a hevy floods in
andhrapradesh
7/4/2015 19Floods- Disaster Managment
21. FACTORS
VEGETATION COVER
This varies seasonally. The type and
amount will affect interception and
stemflow/throughfall. Overland flow is
reduced. Lag time will be increased.
ROCK TYPE
Impermeable rocks prevent groundwater
flow and encourage through flow and
overland flow. These rocks will decrease
lag time. Permeable rock will have the
opposite effect.
LAKES & RESERVOIRS
These will store floodwater and
thus reduce lag time and control
river response to heavy rainfall.
SOIL TYPE & DEPTH
Deep soils store more
water, pipes in the soil
encourage through flow.
Soils with small pore
spaces will reduce
infiltration and increase
overland flow.
LAND USE
Impermeable surfaces
created by urbanisation will
reduce infiltration and
encourage overland flow.
Different types of crops
affect interception rates e.g.
cereals 7-15%.
RAINFALL INTENSITY & DURATION
Intense rain will increase overland
flow and reduce lag times. Gentle
rain over a longer time will allow
more infiltration.
SLOPES
Steep slopes will encourage
overland flow and gentle
slope will slow run off down.
CLIMATE
The distribution of rainfall over the
year and the temperatures will
affect the lag times.
22. FLOODS IMPACTS
• Human Loss
• Property Loss
• Affects the Major Roads
• Disruption of Air / Train / Bus services
• Spread of Water-borne Communicable Diseases
• Communication Breakdown
• Electricity Supply Cut off
• Economic and Social Disruption
• Increase in Air / Water Pollution
7/4/2015 Floods- Disaster Managment 22
24. Drought
• Rains are very unpredictable. This leads to periods
where there is serious scarcity of water.
• Drought prone areas are faced with irregular periods
of famine as farmers have no income.
• Drought prone areas Development Programs:
• Under this scheme, people are given wages in bad
years for activities like building roads, minor
irrigation works and plantation programs.
• It is a major problem in arid and semi arid regions.
• Drought affects home, agriculture, industry, leads to
malnutrition problems in children due to food
shortages
25. • Major factor responsible for drought is
deforestation.
• Due to denuded forest cover the rainwater rushes
down the river and is lost.
• Forest cover permits the water to remain in the
same area and gradually seep into the ground.
• This charges the underground stores of water in
natural aquifers. Which later can be use during the
period of no monsoons.
26. Causes of drought
Natural / Physical causes:
- Weather: increased amount of
anticyclone weather (hot + dry)
means air holds less moisture so
you get less rain
- Global warming: weather
patterns change (e.g. Sahel is
becoming hotter + drier)
- Hotter weather = more
evaporation than precipitation
- El Nino: random weather event
that reverses normal weather
patterns (e.g. Australia has years
of drought + then years of flood)
Human causes:
- Overpopulation: too many people
living in an area using too much
water
- Overcultivation: planting too
many crops which use up too
much water
- Overextraction: removing too
much water from wells so they
dry up
- Deforestation: cutting down trees
which otherwise store water +
hold soil together
- Politics: fighting over water, or
companies being greedy + taking
too much water to then sell on
27. Conflicts over Water
Scarcity of water has increased conflicts over water
among various states and countries. Some water
conflicts are:
1. Indus water dispute.
2. Ganga water dispute.
3. Cavery water dispute.
4. Yamuna water dispute.
28. Conflicts over water
• Multiple conflicts between countries.
• Around 20 major cities in India face chronic or interrupted
water shortages.
• Around 100 countries all around the world share the waters of
13 large rivers and lakes.
• The upstream countries could stare the downstream countries
leading to political instability. Eg. Ethiopia (Upstream) and
Egypt (Downstream) are highly dependent on the river Nile
for their water supply.
• International accords that look at fair distribution of water will
become critical to the world peace
• India and Bangladesh already have a pact for fair usage of
water of Ganges River.
29. DAMS – Introduction
• There are more than 45000 dams all around the
world, which play an important role in in
communities and economies that harness these
water resources for economic development.
• 30-40% of the irrigated land worldwide relies on
dams.
32. Dams Problems
• Fragmentation and physical transformation of rivers
• Impacts on riverine ecosystems
• Social consequences of large dams due to
displacement of people.
• Water logging and salinization of surrounding land.
• Dislodging animal population.
• Disruption of fishing and waterway traffic.
33. EFFECT ON ENVIRONMENT
• Greenhouse gas emissions
The reservoirs of power plants in tropical regions may produce
substantial amounts of methane, carbon di oxide. This is due to plant
material in flooded areas decaying in an anaerobic environment, and
forming methane, a very potent greenhouse gas.
• Soil Erosion
One of the first problems with dams is the erosion of land. Dams hold
back the sediment load normally found in a river flow, depriving the
downstream of this. In order to make up for the sediments, the
downstream water erodes its channels and banks. This lowering of the
riverbed threatens vegetation and river wildlife. One of the reasons
dams are built is to prevent flooding. However, most ecosystems which
experience flooding are adapted to this and many animal species
depend on the floods for various lifecycle stages, such as reproduction
and hatching. Annual floods also deposit nutrients and replenish
wetlands.
34. Contd-
Species Extinction
As fisheries become an increasingly important source of food supply, more
attention is being paid to the harmful effects of dams on many fish and
marine mammal populations. The vast majority of large dams do not
include proper bypass systems for these animals, interfering with their
lifecycles and sometimes even forcing species to extinction.
Changes to Earth's Rotation
NASA geophysicist Dr. Benjamin Fong Chao have found evidence that large
dams cause changes to the earth's rotation, because of the shift of water
weight from oceans to reservoirs. Because of the number of dams which
have been built, the Earth's daily rotation has apparently sped up by eight-
millionths of a second since the 1950s. Chao said it is the first time human
activity has been shown to have a measurable effect on the Earth's
rotation.
