The document discusses water resources and related topics. It begins by introducing the student project and listing the contents to be covered, which include the hydrosphere, features of water, types of water resources, uses of water, the water cycle, water as a precious resource, freshwater resources, water pollution, water-related diseases, floods, droughts, and dams. It then provides details on these topics, describing things like the water cycle, groundwater resources, surface water resources, uses of water in agriculture, industry, domestic applications, and hydropower generation. It also discusses issues like water pollution, diseases related to water, and environmental problems caused by dams.
2. CONTENTS
1) HYDROSPHERE
2) FEATURES OF WATER
3) TYPES OF WATER RESOURCES
4) USE OF WATER RESOURCES
5) WATER CYCLE
6) WATER:- A PRECIOUS NATURAL RESOURCE
7) FRESHWATER RESOURCE
8) WATER POLLUTION
9) WATER RELATED DISEASES
10) FLOOD
11) DROUGHT
12) DAM
3. HYDROSPHERE
A hydrosphere is the total amount of water on a planet. The
hydrosphere includes water that is on the surface of the planet,
underground, and in the air. A planet's hydrosphere can
be liquid, vapor, or ice.
On Earth, liquid water exists on the surface in the form
of oceans, lakes and rivers. It also exists below ground—
as groundwater, in wells and aquifers. Water vapor is most visible
as clouds and fog.
The frozen part of Earth's hydrosphere is made of ice: glaciers, ice
caps and icebergs. The frozen part of the hydrosphere has its own
name, the cryosphere.
About 97% of the earth’s surface is covered by water and most of the
animals and plants have 60-65% water in the body.
4.
5. FEATURES OF WATER
(i) It exists as a liquid over a wide range of
temperature i.e. from 0° to100°C.
(ii) It has the highest specific heat, due to which it
warms up and cools down very slowly without causing
shocks of temperature jerks to the aquatic life.
(iii) It has a high latent heat of vaporization Hence, it
takes a huge amount of energy for getting vaporized.
That’s why it produces a cooling effect as it
evaporates.
(iv) It is an excellent solvent for several nutrients.
Thus, it can serve as a very good carrier of nutrients,
including oxygen, which are essential for life. But, it
6. TYPES OF WATER
RESOURCES
Saltwater Resources
Saltwater is abundant in the surface of the planet.
However, saltwater is currently not particularly useful when
it comes to potable water supplies. Desalination plants,
while they do exist, are scarce because the energy required
for desalination makes the process extremely expensive.
That said, there are saltwater resources from which
humans benefit, aside from beautiful ocean views.
Saltwater fish are a staple in much of the world's diet .
Furthermore, tidal waters are being used as a source of
hydroelectric energy. So, while saltwater is not helpful in
dealing with scarce water supplies, it does provide
resources that humans rely on.
7. Groundwater Resources
Groundwater is the most plentiful of all freshwater resources. As
water percolates into the ground through layers of soil, clay, and
rock, some of it adheres to the topmost layers to provide water to
plants. This water is in what is called the unsaturated, or vadose,
zone. Most of the pores in the vadose zone are filled with air, rather
than water.
Gravity continues to move the water down through the ground.
Eventually, the water reaches the saturated zone, where all the pores
are filled with water. The separation between the saturated and
unsaturated zone is called the water table.
Aquifers are areas of permeable rock that hold water. Typically,
aquifers are made of bedrock that has many fractures and connected
pores, such as limestone, sandstone and gravel. Shale and clay layers
are impermeable, and therefore make poor aquifers. An aquifer is
"recharged" through precipitation from above percolating through the
layers of soil and rock. Therefore, there is significant interaction
between surface water and ground water.
8. Most often, groundwater is accessed by humans via wells. To
build a well, one must drill down past the water table. In most
cases, a pump is placed in the bottom of the well, and it is
pumped into homes, businesses and water treatment plants,
where it is then dispersed. As water is pumped from the
ground, a cone of depression forms around the well. The
groundwater from the surrounding area moves towards the
well. Wells can run dry during times of drought, or if
surrounding wells are pumping too much water, causing the
cone of depression to be large.
Water pumped from wells is generally very clean. The layers of
soil, clay and rock acts as a natural filter. However,
contaminants from nearby contaminated soils, leaky
underground tanks, and septic systems can pollute a well,
rendering it unusable. Furthermore, salt water intrusion can
occur when the rate of pumping near a shoreline exceeds the
rate of recharge. Saltwater gets pulled from the ocean into the
cone of depression, and enters the well.
Subsidence, the gradual settling of the land due to continuous
pumping and development, has also become an issue as
groundwater is mined. This occurs when groundwater is
9. Surface Water Resources
Surface water is the water that exists in streams and lakes. This water is
primarily used for potable water supply, recreation, irrigation, industry,
livestock, transportation and hydroelectric energy. Over 63 percent of the
public water supply is withdrawn from surface water. Irrigation gets 58
percent of its water supply from surface water. Industry gets almost 98
percent of its water from surface water systems. Therefore, surface water
conservation and quality is of the utmost importance.
Watershed organizations continuously measure the stream flow and quality
of surface water. Stream flow is monitored to warn of flooding and drought
conditions. Water quality is very important, as the majority of the water used
in the United States comes from surface water. It is the measure of how
suitable the water is from a biological, chemical and physical perspective.
Water quality can be impacted negatively by both natural and human causes:
electrical conductivity, pH, temperature, phosphorus levels, dissolved
oxygen levels, nitrogen levels and bacteria are tested as a measure of water
quality.
Water that runs off into the stream can naturally carry sediment, debris and
pathogens. Turbidity, the measure of suspended sediment in a stream, is
also a measure of water quality. The more turbid the water, the lower the
water quality.
Manmade contaminants such as gasoline, solvents, pesticides, and nitrogen
from livestock can wash over the land and can leach in to waterways,
10. USE OF WATER RESOURCES
Water resources are used for agricultural, industrial, domestic,
recreational, and environmental activities. Majority of the uses require
fresh water.
However, about 97 percent of water found on the earth is salt water
and only three percent is fresh water. A little over two-thirds of the
available fresh water is frozen in glaciers and polar ice caps. The
remaining freshwater is found mainly as groundwater and a negligible
portion of it is present on the ground or in the air.
Following is a brief account of how water is used in different sectors:-
Agricultural Use
Agriculture accounts for 69 percent of all water consumption
basically in agricultural economies like India. Agriculture, therefore, is
the largest consumer of the Earth’s available freshwater.
By 2050, the global water demand of agriculture is estimated to
increase by a further 19% due to irrigational needs. Expanding
irrigation needs are likely to put undue pressure on water storage. It
11. Industrial Use
Water is the lifeblood of the industry. It is used as a raw material coolant, a
solvent, a transport agent, and as a source of energy. Manufacturing
industries account for a considerable share in the total industrial water
consumption. Besides, paper and allied products, chemicals and primary
metals are major industrial users of water.
Worldwide, the industry accounts for 19 percent of total consumption. In
industrialized countries, however, industries use more than half of the water
available for human use.
Domestic Use
It includes drinking, cleaning, personal hygiene, garden care, cooking,
washing of clothes, dishes, vehicles, etc. Since the end of World War II there
has been a trend of people moving out of the countryside to the ever-
expanding cities. This trend has important implications on our water
resources.
Government and communities have had to start building large water-supply
systems to deliver water to new populations and industries. Of all water
consumption in the world, domestic use accounts for about 12 percent.
Use for Hydropower Generation
Electricity produced from water is hydropower. Hydropower is the leading
renewable source of electricity in the world. It accounts for about 16 percent
of total electricity generation globally. There are many opportunities for
hydropower development throughout the world.
12. WATER CYCLE
The water cycle is often taught as a simple circular cycle of
evaporation, condensation, and precipitation. Although this can
be a useful model, the reality is much more complicated. The
paths and influences of water through Earth’s ecosystems are
extremely complex and not completely understood.
The water cycle shows the continuous movement of water
within the Earth and atmosphere. It is a complex system that
includes many different processes. Liquid water evaporates into
water vapor, condenses to form clouds, and precipitates back to
earth in the form of rain and snow. Water in different phases
moves through the atmosphere (transportation). Liquid water
flows across land (runoff), into the ground (infiltration and
percolation), and through the ground (groundwater).
Groundwater moves into plants (plant uptake) and evaporates
from plants into the atmosphere (transpiration). Solid ice and
13.
14. WATER: A PRECIOUS
NATURAL RESOURCE
Although water is very abundant on this earth, yet it is very
precious. Out of the total water reserves of the world,
about 97% is salty water(marine) and only 3% is fresh
water. Even this small fraction of fresh water is not
available to us as most of it is locked up in polar ice caps
and just 0.003% is readily available to us in the form of
groundwater and surface water.
Overuse of groundwater for drinking, irrigation and
domestic purposes has resulted in rapid depletion of
groundwater in various regions leading to lowering of
water table and drying of wells. Pollution of many of the
groundwater aquifers has made many of these wells unfit
for consumption.
Rivers and streams have long been used for discharging
the wastes. Most of the civilizations have grown and
flourished on the banks of rivers, but unfortunately,
15. FRESHWATER RESOURCE
Freshwater accounts for only some 6 percent of the
world's water supply, but is essential for human uses
such as drinking, agriculture, manufacturing, and
sanitation. As discussed above, two-thirds of global
freshwater is found underground. If you dig deeply
enough anywhere on Earth, you will hit water. Some
people picture groundwater as an underground river or
lake, but in reality it is rarely a distinct water body .
Rather, groundwater typically fills very small spaces
(pores) within rocks and between sediment grains. The
water table is the top of the saturated zone . It may lie
hundreds of meters deep in deserts or near the surface
in moist ecosystems. Water tables typically shift from
season to season as precipitation and transpiration
levels change, moving up during rainy periods or
16.
17. WATER POLLUTION
Many different types of contaminants can pollute water
and render it unusable. Pollutants regulated in the
United States under national primary drinking water
standards include:
• Microorganisms such as cryptosporidium, giardia, and
fecal coliform bacteria
• Disinfectants and water disinfection byproducts
including chlorine, bromate, and chlorite
• Inorganic chemicals such as arsenic, cadmium, lead,
and mercury
• Organic chemicals such as benzene, dioxin, and vinyl
chloride
• Radionuclides including uranium and radium
18. Water pollution is the contamination of water bodies, usually as
a result of human activities. Water bodies include for example
lakes, rivers, oceans, aquifers and groundwater. Water pollution
results when contaminants are introduced into the natural
environment. For example, releasing inadequately treated
wastewater into natural water bodies can lead to degradation of
aquatic ecosystems. In turn, this can lead to public health
problems for people living downstream. They may use the same
polluted river water for drinking or bathing or irrigation. Water
pollution is the leading worldwide cause of death and disease,
e.g. due to water-borne diseases.
Control of water pollution requires appropriate infrastructure
and management plans. The infrastructure may include
wastewater treatment plants. Sewage treatment plants and
industrial wastewater treatment plants are usually required to
protect water bodies from untreated wastewater. Agricultural
wastewater treatment for farms, and erosion control from
construction sites can also help prevent water pollution.
Nature-based solutions are another approach to prevent water
19. WATER-RELATED DISEASES
Water-related illnesses fall into four major categories:
• Waterborne diseases, including cholera, typhoid,
and dysentery, are caused by drinking water
containing infectious viruses or bacteria, which often
come from human or animal waste.
• Water-washed diseases, such as skin and eye
infections, are caused by lack of clean water for
washing.
• Water-based diseases, such as schistosomiasis,
are spread by organisms that develop in water and
then become human parasites. They are spread by
contaminated water and by eating insufficiently
cooked fish.
• Water-related insect vectors, such as
20. FLOOD
A flood is an overflow of water that submerges land that is
usually dry. In the sense of "flowing water", the word may
also be applied to the inflow of the tide. Floods are an area of
study of the discipline hydrology and are of significant
concern in agriculture, civil engineering and public health.
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, 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, particularly at bends or
meanders in the waterway. Floods often cause damage to
homes and businesses if they are in the natural flood plains
of rivers. While riverine flood damage can be eliminated by
21. In some countries like India and Bangladesh rainfall does not occur
throughout the year, rather, 90% of it is concentrated into a few
months (June-September). Heavy rainfall often causes floods in the
low-lying coastal areas. Prolonged downpour can also cause the
over-flowing of lakes and rivers resulting into floods. Deforestation,
overgrazing, mining, rapid industrialization, global warming etc. have
also contributed largely to a sharp rise in the incidence of floods,
which otherwise is a natural disaster. Floods have been regular
features of some parts of India and Bangladesh causing huge
economic loss as well as loss of life.
22. DROUGHT
A drought or drouth is an event of prolonged shortages in the water
supply, whether atmospheric (below-average precipitation), surface
water or ground water. A drought can last for months or years, or
may be declared after as few as 15 days. It can have a substantial
impact on the ecosystem and agriculture of the affected region and
harm to the local economy. Annual dry seasons in the tropics
significantly increase the chances of a drought developing and
subsequent bush fires. Periods of heat can significantly worsen
drought conditions by hastening evaporation of water vapour.
Drought is a recurring feature of the climate in most parts of the
world.
Drought affect food production and human society, so they are
considered a disaster, of natural, supernatural or human cause.
There are about 80 countries in the world, lying in the arid and
semiarid regions that experience frequent spells of droughts, very
often extending up to year long duration. When annual rainfall is
below normal and less than evaporation, drought conditions are
23.
24. DAMS
A dam is a barrier that stops or restricts the flow of water or
underground streams. Reservoirs created by dams not only suppress
floods but also provide water for activities such as irrigation, human
consumption, industrial use, aquaculture, and navigability.
Hydropower is often used in conjunction with dams to generate
electricity. A dam can also be used to collect water or for storage of
water which can be evenly distributed between locations. Dams
generally serve the primary purpose of retaining water, while other
structures such as floodgates or levees (also known as dikes) are
used to manage or prevent water flow into specific land regions.
Benefits
River valley projects with big dams have usually been considered to
play a key role in the development process due to their multiple uses.
India has the distinction of having the largest number of river-valley
projects. These dams are often regarded as a symbol of national
development. The tribals living in the area pin big hopes on these
projects as they aim at providing employment and raising the
standard and quality of life. The dams have tremendous potential for
economic upliftment and growth. They can help in checking floods
25. Environmental Problems
The environmental impacts of big-dams are also too many due to
which very often the big dams become a subject of controversy. The
impacts can be at the upstream as well as downstream levels.
(A) The upstream problems include the following:
(i) Displacement of tribal people
(ii) Loss of forests, flora and fauna
(iii) Changes in fisheries and the spawning grounds
(iv) Siltation and sedimentation of reservoirs
(v) Loss of non-forest land
(vi) Stagnation and waterlogging near reservoir
(vii) Breeding of vectors and spread of vector-borne diseases
(viii) Reservoir induced seismicity (RIS) causing earthquakes
(ix) Growth of aquatic weeds.
(x) Microclimatic changes.
26. (B) The downstream impacts include the following:
(i) Water logging and salinity due to over irrigation
(ii) Micro-climatic changes
(iii) Reduced water flow and silt deposition in river
(iv) Flash floods
(v) Salt water intrusion at river mouth
(vi) Loss of land fertility along the river since the sediments carrying
nutrients get deposited in the reservoir
(vii) Outbreak of vector-borne diseases like malaria
Thus, although dams are built to serve the society with multiple
uses, but it has several serious side-effects.
