1. BKT 2063
Chapter 6
By
Dr. Shafiqur Rahman
Faculty of Agro Industry and Natural Resources
UMK
2. Water is an integral part of life on
this planet. It is an odorless,
tasteless, substance that covers
more than three-fourths of the
Earth's surface.
3. Most of the water on Earth, 97% to
be exact, is salt water found in the
oceans. We can not drink salt water
or use it for crops because of the
salt content
4. The fresh water in ice caps is not
available for use by people or plants.
That leaves about 1% of all the Earth's
water in a form useable to humans and
land animals. This fresh water is found
in lakes, rivers, streams, ponds, and in
the ground.
5. Only about 3% of Earth's water is
fresh. Two percent of the Earth's
water (about 66% of all fresh water)
is in solid form, found in ice caps
and glaciers.
6. The water cycle, also known as the
hydrologic cycle or H2O cycle,
describes the continuous movement
of water on, above and below the
surface of the Earth. Water can change
states among liquid, vapor, and solid
at various places in the water cycle.
7.
8.
9. The water moves from one reservoir to
another, such as from river to ocean, or
from the ocean to the atmosphere, by the
physical processes of evaporation,
condensation, precipitation, infiltration,
runoff, and subsurface flow. In so doing,
the water goes through different phases:
liquid, solid, and gas.
10. The sun, which drives the water cycle, heats
water in oceans and seas. Water evaporates as
water vapor into the air. Ice and snow can
sublimate directly into water vapor. Evapo-
transpiration is water transpired from plants
and evaporated from the soil. Rising air
currents take the vapor up into the atmosphere
where cooler temperatures cause it to
condense into clouds
11. The water cycle figures significantly in the
maintenance of life and ecosystems on Earth
By transferring water from one reservoir to
another, the water cycle purifies water,
replenishes the land with freshwater, and
transports minerals to different parts of the
globe.
12. The hydrosphere is the sum total of
water on Earth, except for that portion
in the atmosphere. This combines all
water underground as well as all
freshwater in streams, rivers, and lakes;
saltwater in seas and oceans; and
frozen water in icebergs, glaciers, and
other forms of ice.
13. 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.
15. Water is continually moving around,
through, and above the Earth. It moves
as water vapor, liquid water, and ice. It
is constantly changing its form. Water
on Earth is known by different terms,
depending on where it is and where it
came from.
16. Meteoric water - is water in circulation
Connate water - "fossil" water, often
saline.
Surface water - water in rivers, lakes,
oceans and so on.
Subsurface water - Groundwater
Groundwater - exists in the zone of
saturation, and may be fresh or saline.
17.
18. During the 20th century, more than half
the world’s wetlands have been lost
along with their valuable environmental
services. Biodiversity-rich freshwater
ecosystems are currently declining
faster than marine or land ecosystems.
22. Surface water
Surface water is water in a river, lake or
fresh water wetland. Surface water is
naturally replenished by precipitation
and naturally lost through discharge
to the oceans, evaporation,
evapotranspiration and sub-surface
seepage.
23. In order to understand drinking water
contamination, it is necessary to first
understand from where our drinking
water comes. For most urban
residents, relying upon municipal
water systems, drinking water comes
from two major sources: groundwater
and surface water.
25. Groundwater refers to any subsurface water that
occurs beneath the water table in soil and
other geologic forms (Rail, 2000). Scientists
estimate that groundwater makes up 95% of all
freshwater available for drinking. Groundwater
is a significant source of water for many
municipal water systems in many countries of
the world. Rural residents, withdrawing their
water from wells, also rely upon groundwater.
26. Groundwater is generally stored in
aqueducts, underground layers of
porous rocks that are saturated with
water. These aqueducts receive water
as soil becomes saturated with
precipitation or through stream and
river runoff.
27. Each source of water has a unique set
of contaminants; groundwater stores
pesticide chemicals and nitrate while
surface water contains most bacteria
and other microorganisms. Because of
the interconnectedness of this two
water sources
30. The degradation of the quality of water
that make it unsafe or harmful to human
beings, animals and aquatic life.
Disturbs the normal use of water for
irrigation, agriculture, industries and
human consumption.
Can be caused by natural or
anthropogenic process.
31. Biological agents - Include bacteria,
parasitic fungi and protozoa
Main source include human sewage,
animal and plant wastes, decaying
organic matter, industrial wastes etc.
Chemical agents- The inorganic
chemical agents like acids, salts,
metals (lead and mercury)
32. The radioactive substances- released
from nuclear wastes, nuclear plants and
uraniumetc.
The organic chemicals includes
agrochemicals (pesticides, herbicides),
detergents and chlorine containing
compounds, oils, grease and plastic.
33. Water pollution categories depending on
the source and storage of water
Ground water pollution
Surface water pollution
Sea water pollution
34. Point source water pollution refers to
contaminants that enter a waterway
from a single, identifiable source, such
as a pipe or ditch. Examples of sources
in this category include discharges
from a sewage treatment plant, a
factory, or a city storm drain
36. Non–point source pollution refers to
diffuse contamination that does not
originate from a single discrete source.
NPS pollution is often the cumulative
effect of small amounts of
contaminants gathered from a large
area. A common example is the
leaching out of nitrogen compounds
from fertilized agricultural lands
38. Water pollution is caused by point and
non-point sources. Point sources
include sewage treatment plants,
manufacturing and agro-based
industries and animal farms. Non-point
sources are defined as diffused sources
such as agricultural activities and
surface runoffs.
39. In 2006, the Department of Environment
(DOE) registered 18,956 water pollution
point sources comprising mainly
sewage treatment plants (9,060 : 47.79%
inclusive of 601 Network Pump
Stations), manufacturing industries
(8,543 : 45.07%), animal farms (869 :
4.58%) and agro-based industries (484 :
2.55%)
40. Reservoirs are man-made lakes created
by the damming of rivers to serve one
or more purposes, such as hydropower
production, water supply for drinking,
irrigation and flood protection.
41. Valley dammed reservoir
A dam constructed in a valley relies on
the natural topography to provide most
of the basin of the reservoir. Dams are
typically located at a narrow part of a
valley downstream of a natural basin
42. An irrigation system in northern Mexico. Water
for agricultural use is most efficient
43.
44. Dam
A physical barrier constructed across a
river or waterway to control the flow of
raise the level of water. Purpose of
construction may be for flood control,
irrigation need, hydro-electric power
production and or recreational usage.
47. The World Summit on Sustainable Development
(WSSD)
in 2002 confirmed the importance of water and its
critical
relationship to other development issues that
underlie
efforts to achieve the Millennium Development
Goals. A
key target agreed at the Conference was for
countries to
prepare:
National integrated water resources management
and water efficiency plans by 2005.
