This document provides information about water resources and the hydrologic cycle. It discusses what water is, where it can be found on Earth, and how much of the planet is covered in water. It then describes the hydrologic cycle, including the processes of evaporation, transpiration, sublimation, condensation, precipitation, and infiltration. It discusses different water reservoirs like oceans, glaciers, groundwater, and surface water. It provides details on the water cycle and movement of water between these various reservoirs.

1. “Water Resources”
CHAPTER : IV
by: Apango, John Howard
& Dela Cruz, Carl

2. 2
What is Water ?
- A colorless,
transparent,
odorless liquid that
forms the seas,
lakes, rivers, and
rain and is the
basis of the fluids
of living organisms.

3. 3
Where can you
find Water ?
- Water exists in the air as
water vapor, in rivers and
lakes, in icecaps and
glaciers, in the ground as
soil moisture and in
aquifers, and even in you
and your dog.
- Water exist in different
subsystems on Earth
including: Hydrosphere,
Geosphere, Biosphere.

4. 4
How big is Water ?
- The Earth is
covered with 71%
of water, that
makes up the
bodies of water
including oceans,
seas, lakes and
others.

5. “The Hydrologic Cycle”
LESSON: 4.1

6. 6
“The Hydrologic Cycle”
The Hydrologic Cycle, also know as water cycle, is
the movement of water around Earth’s surface and its
subsystems. The cycle consists of interconnected
pathways and reservoirs. Reservoirs are the places
where water resides for varying amount of time, while
pathways are the process that allow water to move
between reservoirs and subsystems.

7. 7
“Process of Hydrologic Cycle”
- Evaporation
- Transpiration
- Sublimation
- Condensation
- Precipitation
- Infiltration

8. 8
Evaporation
The process in which
liquid water changes
into vapor. It occurs in
the ocean, surface
water bodies,
vegetation, andsoil. About 80% of water vapor in the atmosphere
evaporates from the ocean.

9. 9
Transpiration
The evaporation of
water from the
leaves and stems of
plants, which
contributes to about
10% of the water vapor in the atmosphere.

10. 10
Sublimation
In high altitudes,
ice can directly
transform into water
vapor in a process
called Sublimation.

11. 11
Condensation
The change of the
physical state of matter
from the gas phase into
the liquid phase, and is
the reverse of
vaporization.

12. 12
Precipitation
Transfers water
from the atmosphere
to Earth’s surface in
liquid or solid form as
rain, snow, or hail.

13. 13
Infiltration
Rain that falls into
the land surface and
penetrates the soil.

14. “Earth’s Water”
LESSON: 4.2

15. 15
“Earth's Water Budget”
The Earth’s Water Budget, is the total amount of
water in the planet, which remains constant through
time. Water moves and changes in form, but is neither
created nor destroyed. Only a very small percentage is
added to the hydrologic system by volcanic eruptions
and meteors from space. Most of the water on Earth
today have been cycling through the hydrologic system
for billions of years.

16. 16
“Earth's Water Budget”
The United Nations World Water Development 2005 Report
characterized the amount of water in the different reservoirs.
Ocean - The largest reservoir that contains about 97.5% of Earth's total
water, which is mostly saline water (mixture of sodium chloride in water).
Freshwater - Which is only 2.5% of Earth's total water, and is found in
Glaciers (68.7%), Groundwater (30.1%), permafrost (0.8%), surface water,
and atmospheric water.
The surface water in rivers, lakes, swamps, soil moisture, living things,
atmospheric water vapor, ground ice, and permafrost, constitute only about
0.4% of total freshwater supply or less than 0.02% of the total water on Earth.

17. 17
“Earth's Water Budget”
The residence time is the average length of time
spent by water molecule in a reservoir. In large
reservoir, the residence time of water is longer
The total amount of water in the planet remains
contant, the volume of water present in each reservoir
varies and their volumes affect other reservoirs.

18. 18
There were different Reservoirs:
i. Saltwater Reservoir
ii. Freshwater Reservoirs
- Glaciers and Ice Sheets
- Permafrost
iii. Surface Water Reservoirs
- Stream
- Lakes
- Wetlands
a. Marsh
b. Swamp
c. Estuary
- Floods
- Groundwater
Saltwater Reservoir
Freshwater
Reservoir
Freshwater
Reservoir

19. 19
“Saltwater Reservoir”
There is only one global or world ocean
and it covers 71% of Earth. It is
geographically divided into five distinct
regions and into numerous seas, gulfs,
bays, and straights. The total volume of
water in the world's ocean is about 1340
million km³.

20. 20
The Five Big Oceans from Largest to Smallest:
- Pacific Ocean - Atlantic Ocean
- Indian Ocean - Southern Ocean
- Arctic Ocean

21. 21
“Saltwater Reservoir”
Ocean is vast body of saline water, the
saltiness of saltwater is called Salinity. The
major elements present in seawater are
sodium and chlorine ions. Other natural
elements are also present in seawater in
very low concentrations. The salinity of
seawater varies from 33 to 37 parts per
thousands.

22. 22
“Saltwater Reservoir”
The salinity of seawater is maintained within a
narrow range by the processes in the Hydrologic cycle.
- Evaporation removes water, making the remaining
solution saltier.
- Precipitation adds water, causing dilution.
Inflow from river and groundwater also makes the
sea less salty. As sea water freezes, salt is excluded
because of its structure, making the unfrozen seawater
saltier.

23. 23
Three Major Zones in the Ocean
- Surface Layer (Epipelagic)
- Thermocline (Mesopelagic)
- Deepzone (Bathypelagic)

24. 24
Three Major Zones in the Ocean
Surface Layer - consist of relatively warm, low-density water,
extends from the ocean surface to a depth of 100m. This layer is
only about 2% of the water in the ocean but it is the home of
most marine plants and animals.
Thermocline - the temperature of water decreases rapidly with
depth. At high altitudes, the thermocline reaches the surface
and extends up to 1500m.
Deep Zone - the temperature here is uniformly low. Eighty
percent of the water in the ocean is in the deep zone.

25. 25
Thermohaline Circulation
The surface ocean
currents flow clockwise in the
northern hemisphere and
counterclockwise in the
southern hemisphere. In the
deep zone, there is a
thermohaline circulation
driven by density differences, which is controlled by
temperature(thermo) and salinity(haline). This circulation is
propelled by the sinking of cold, salty, and dense water in
the Polar Regions, and rising of the warm, less salty water
of the Tropics.

26. 26
“Freshwater Reservoir”
Most of the freshwater on Earth is stored
in glaciers situated in inaccessible areas
such as the Polar Regions and high
mountains. The readily available
freshwater sources are the surface water
reservoir and groundwater reservoir.

27. 27
Glacier and Ice Sheets
A Glacier is a permanent body of ice, which consists largely
of recrystallized snow. In Polar Regions and high-altitude
regions, not all of the snow that fall melts because of very cold
temperature even during summer.
An Ice Sheet is a mass of glacial land ice extending more
than 50,000 km². There are currently ice sheets covering most
of Greenland and Antarctica.
On Earth, about 70% of freshwater is locked up in glaciers
and ice sheets.

28. 28
Permafrost
A soil, rock, or sediment that is frozen for more than
two consecutive years is called permafrost. Most of the
permafrost is found in Polar Regions, although they
may exist in high-altitude regions. The total water
stored as underground ice in a permafrost is estimated
to be 300,000 km³. It comprises about 0.8% of the total
freshwater resource.

29. 29
“Surface Water Reservoirs”
Surface waters include the streams, lakes,
and wetlands where water from rainfall, melting
snow and ice, and groundwater flows. They
represent 0.3% of Earth's total water resource.
This resource is harnessed for irrigation,
recreation, transport, fishing, drinking, and
hydropower.

30. 30
Stream
A moving body of surface water that
flows downslope toward sea level
because of gravity. It has clearly-defined
passageways called channels where
particles and dissolved substances are
transported. A river is a stream with a
considerable volume and a well-defined
channel. Rivers constitute about 1.6% if
the total surface and atmospheric water.

31. 31
Lakes
Lakes are large inland bodies of
fresh or saline water. Its upper surface
is exposed to the atmosphere and is
essentially flat. It forms in places where
water collects in a low area(depression)
and behind natural or human made
dams. Lakes store 67% of the total
surface and atmospheric

32. 32
Wetlands
Land areas where
water covers the surface
for significant periods is
referred to as wetlands.
They vary in size--from
relatively large in flat
areas to small in steep
areas. A fragile
ecosystem that is sensitive to the amount and quality of water.
Wetlands constitute about 8.5% of the total land surface and
atmospheric water. There were types of wetlands include
marshes, swamps, and estuaries.

33. 33
Types of Wetlands:
1. Marsh - is a shallow wetland around lakes, streams, and
oceans where grasses and reeds are the dominant
vegetation.
2. Swamp - is a wetland with lush trees and vegetation
found in low-lying areas beside slow moving rivers.
3. Estuary - is a partly enclosed coastal body of water
where freshwater from stream meets the saltwater from the
sea.

34. 34
Floods
It is a natural event
wherein an area that
is usually dry is
submerged under
water. It usually
happens when the
rate of precipitation
is higher than the rate in which it could be absorbed
by the ground or carried by streams.

35. 35
Groundwater
It is freshwater found
in the rock and soil layers
beneath the surface. The
groundwater is the
largest reservoir of liquid
fresh water on Earth. It
constitutes about 30.1%
of the total freshwater on
the planet.

36. 36
“Groundwater Profile”
When a well is
excavated in the ground,
the first layer
encountered is the moist
soil layer on the surface.
Beneath this is a zone in
which the spaces
between the particles are
filled mainly with air.
This is called the zone of aeration or unsaturated zone. The layer
beneath the zone of aeration is the zone of saturation. In this later, the
spaces between the particles are filled with water.

37. “Water as a Resource”
LESSON: 4.3

38. 38
“Water as a Resource”
Most of the early human civilizations were
developed along the world's greatest rivers--the Tigris
and Euphrates of Mesopotamia, the Nile River of the
Egyptians, and the Yellow River of the Huang-He
civilization. Their vast floodplains supported
agriculture, and their large channels allowed
commerce to flourish. Today, billions of people are still
dependent on water channels for food, water,
transportation, and recreational, and religious
activities.

39. 39
“Activities Affecting the Quality of Water”
Throughout the world, there is an increasing
pressure in Earth's water resources. This is
mainly due to how human activities have sped
up and caused climate change and variations in
natural conditions.

40. 40
The human activities affecting water
resources include the following:
1. Population growth, particularly in water-short regions
2. Movement of large number of people from the
countryside to towns and cities
3. Demands for greater food security and higher living
standards
4. Increased competition between different uses of water
resources
5. Pollution from factories, cities, and farmlands

41. 41
Water Resource Management and Conservation
The ever-increasing pressure in water resources calls for an
effective water resources management. It involves planning,
developing, distributing, and managing the optimum use of
water resources. Successful management requires accurate
knowledge of the available resources and demandsm and
mechanisms necessary to translate policies into actions.
One of the solutions is by desalination, it involves the
reduction of the mineral content by taking the salt out of
seawater and brackish water to produce freshwater. Middle East
is one of the regions who practiced desalination.

42. 42
In the Philippines, several laws and regulations have been
enacted for the protection, conservation, and management of
freshwater resources.
1.) Presidential Decree(PD)No.424 of 1974 created the National Water Resources
Council(NWRC) to coordinate and integrate water resources development.
2.) PD No. 1067 (1976) instituted the Water Code which consolidated the laws
governing the ownership, appropriation, utilization, exploitation, development,
conservation, and protection of the water resources to regulation by the NWRC.
3.) Executive Order(EO) No. 222 of 1995 established the Presidential Committee on
Water Conservation and Demand Management which was tasked to prepare a
nationwide Water Conservation Plan
4.) Republic Act(RA) No. 8041 or the National Water Crisis Act of 1995 addressed the
country's water problems through an integrated water management program and
development of new water resources and conservation of identified watersheds,
among other provisions.
5.) The Philippine Clean Water Act of 2004 also provided a comprehensive water
quality management.