2. Climate and Weather
Climate: Weather is generalization of the
day to day weather conditions over a long
period of time usually thirty years.
Weather: Weather refers to the
atmospheric conditions of any place for a
short period of time (temporary changes in
3. Difference between weather and
WEATHER: Weather is
what conditions of the
atmosphere are over a
short period of time.
CLIMATE: Climate is
how the atmosphere
"behaves" over relatively
long periods of time.
4. Seasons of Pakistan
Pakistan has four seasons
Winter (mid December to March)
Early summer (April to June)
Late summer (July to September)
Post monsoon (October to Mid December)
The quantity of water, expressed in inches, precipitated as rain,
snow, hail, or sleet in a specified area and time interval.
Only in a few northern areas humid conditions are found. The
rainfall in Pakistan is highest in northern areas decreases towards
Sources of rainfall in Pakistan:
The Western Depression
6. Monsoon winds:
Monsoon winds are seasonal winds which blow during
summer and winter. The summer winds are called
South-west monsoons and the winter winds are called
South-west monsoon are giant sea breezes which bring
rainfall. the rains began when the ocean are less heated
and land is more heated. The air from the land rises
developing a low pressure and it attracts the cool air
causing heavy rainfall.
North-east monsoons blow from the land towards the
7. Western depression
Western Depression are the cyclones
which originate in Mediterranean Sea,
they travel across Afghanistan and Iran
and then reach the western part of
Pakistan. The moisture in the air is
evaporated causing rainfall.
8. Convectional currents
Hot air rises during summer and when it reaches the
high layer of atmosphere, condensation takes place
causing rainfall. Strong winds accompanying the storms
may pick up dust with them
Only northern and north western areas of Pakistan
receive rainfall from Convectional currents. Southern
Pakistan despite being more hot then the northern areas
experience less rainfall because of temperature
9. Relief rainfall:
Relief rainfall is related to the height of
land. It occurs where moist unstable air
moves up a mountain edge and it is
chilled, heavy condensation takes place
and rainfall occurs.
10. Tropical cyclones:
Tropical cyclones bring heavy rainfall for
few hours and can cause a lot of
destruction. They originate in Arabian Sea
quite often but rarely reach the coast of
Pakistan. Therefore, this source of rainfall
is totally unreliable.
11. Climatic zones of Pakistan
Region: Northern, north western and western highlands.
Areas: Chitral, Murree, Muzzafarabad, Drosh, Quetta,
Kalat, Parachinar, Waziristan
Climate: the winters are long, cold and snowy and
summers remain short and mild
Rainfall is normally associated with altitude. Rainfall in
Northern Mountain is highest in the highland zone.
Rainfall in the western mountain is less
The temperature conditions also vary from north to west
depending on the altitude.
North: Summers are short and mild because of
transfer of heat from central Pakistan and high
angle of sun.
Winters are very cold because of high altitude
and low angle of sun.
West: summers are dry and warm in Western
mountain because of continental effect, aridity
and high angle of sun
Winters are mild warm because of low angle of
sun, altitude and Western Depressions.
The growth of tress is retarded because of severe cold
winters. At some places rivers and torrents also freeze
and during winter farming is not practiced and people are
involved in indoor activities.
Transhumance is also practiced
People live their as nomadic herdsman
Many northern areas are not accessible due to
landslides and heavy snowfall
Lack of water supple discourages human settlements
14. Sources of rainfall:
15. Arid zone
Regions: south-eastern desert, and south-western Balochistan
Areas: Kharran Desert south-western Balochistan, south-eastern
It is markedly dry and hot. Hot dusty winds prevail continuously from
mid –May to mid-September, rainfall takes place during winter
season in south-western Balochistan, in south eastern desert
monsoons bring little rainfall. Extreme heat, dust storms are the
main features of this arid climate.
Winters are cool-mild because of low angle of sun, summers are hot
because of high angle of sun. Summers are very hot during the day.
16. Life and Economic activities
The region is deficient of moisture.
the temperature is so extreme that it isn’t suitable for habitation or
The majority of people are nomadic, they move from one place to another
with their animals.
Because rainfall is very low that’s why unique system of karez is
Through perennial canals many areas are irrigated.
People there wear thick and rough clothes in order to protect them
from extreme heat.
They move from one place to another in search of water.
Source of rainfall
Little rainfall from Western Depression and monsoon winds.
17. Lowland Zone – Semi arid to arid
Region: Indus plain except the Coastal areas.
Areas: Islamabad, Sialkot, Sarghoda, Multan, Jacobabad, and
It has arid and extreme climate with hot summers, cool winters and
summer monsoon rainfall.
Thunderstorms are also common in north and north-west of the
Indus plain. The upper Indus plain and Lower Indus plain there’s
less rainfall and spells of very high temperature.
Winters are cool-mild because of low angle of sun and continental
effect and summers are hot due to high angle of sun and continental
18. Life and Economic activities:
The plain is drained through four
tributaries of Indus River, economically; it
is the most productive region of Pakistan.
There is a well developed canal system
and many crops are grown there such as
millet, wheat, cotton and sugarcane
Population is high and there’s moderate
rainfall and tolerable temperature.
19. Sources of rainfall:
Convectional rainfall in northern Punjab
Western depression in northern Punjab
20. Coastal zone
Region: Indus Delta, Karachi and Makran coast
Areas: Karachi, Jiwani, Pasni, Ormara and Gwadar
The climate is dominated by sea breezes throughout the year; the maritime
influence keeps the daily temperature low. The temperature on land and sea
is different; land and water absorb the sun’s heat and water and also radiate
it. In summer the land heats up, while ocean remains cool. In winter the land
loses heat quickly and becomes cold while ocean remains hot.
The humidity level is usually high, more than 50% from April to September.
Means monthly temperature is 32۫ and May, June and October are the
During October the climate is dominated by dry winds from south-eastern
desert. Rainfall is scanty; the rainfall is experienced during monsoon
21. Life and economic activities:
The rainfall takes place during monsoon season, many tourist visit Karachi
in November and February and most of the social events are held in these
months. The extent of precipitation affects the supply of drinking water in
Gwadar. The development of Gwadar port had made is a major district of
Pakistan and had contributed in the economic development of Balochistan.
Economic activities could be carried out throughout the year because of
moderate climate. Farming is possible, the sea ports are operational
throughout the year in order to carry international trade, roads and rail
transport links are never closed in the year for the businesses, air flights are
rarely cancelled, all types of industries are present there.
However, during summer months, tropical cyclones sometimes cause
coastal flooding in low-lying areas causing damage to infrastructure. Fishing
is nearly impossible when the sea is wild and fishing communities face
22. Sources of rainfall:
23. Factors affecting temperature of
The areas that lie near the equator encounter more amounts of sun rays than the areas that don’t
lie near the equator. Southern Pakistan receives more amounts of sun rays as compared to
The areas that are away from the sea are unaffected by maritime influence, consequently; they
are more hot as compared to areas near sea. Winters are extreme and summer temperatures are
Altitude and temperature
Cloud cover and temperature
In daytime cloud cover reduces the amount of heat by reflecting the heat back to the space but in
night time it traps the out going heat and because of this the cloudy nights are warm.
Latitude and angle of sun
The sun rays don’t fall at the same angle everywhere.
During summer, the northern hemisphere is tilted towards the sun and the northern areas of
Pakistan absorb more heat because of high angle of sun, during winter the northern hemisphere
is tilted away from the sun and the northern areas experience sun for shorter duration.
24. River flood
Overflow of large amount of water beyond its
normal limit, especially over what is normally dry
Rivers are considered by many people around
the country as the best place for economic
development. Water is tentatively an imperative
resource for human beings but its excess may
lead to disaster. Excessive water in rivers bring
25. Reasons of floods
The current flooding in Pakistan is mainly due to climate change. It is the
unusual climate-change-led seasonal cycle of land temperature in Pakistan
that has exacerbated the monsoon rainfall and produced the hugest volume
of water in the northern mountainous region of the country ever recorded in
the history, causing floods in the Indus river basin.
The wood is in demand and because of this there’s excessive cutting of
tress which increases surface run off, the trees mangroves act as a barrier
and they can protect the settlements from floods but because of increasing
industrialization and urbanization the water pollution is increasing
The embankments around the river are not heightened, water easily
reaches the settlements.
The dams don’t have much capacity to store water and because of this extra
water is not store causing flood.
26. Ways to reduce the risk of floods
Planting more trees in order to keep check of the flow of water
Build levees in order to prevent the spread of floodwater
Stop building on floodplains
Build flood controlling Dams.
Building Canals (Drains of Extra Water).
Using less greenhouse gases and reducing pollution in order to stop
global warming which is one of the major causes of floods
Prevent Soil Erosion.
Do not build on high flood risk area.
Flood warning should be given through media
Floodwater must be drained out and facilities to the refugees must
27. Effects of flood
The farmers aren’t able to use the land until the water
drains; they face destruction of crops and loss of food
supplies. The load of river improve the fertility of land
the houses will cut off from the shops and services, mud
houses are damaged and water-borne diseases are
The transport system is severely affected, roads and
railway tracks are damaged and old routes are arduous
to follow because they are drained with water.
During monsoon season they must move to
somewhere else in order to protect their
Local residents should change their place and
arrangements should be made in order to fulfill
the basic necessities of life.
The transport authorities should prepare a
precaution plan and should tell the transporters
about the alternative ways. Roads and railway
tracks must be repaired on an emergency basis.
29. Benefits of floods
Floods return nutrients to the land and contribute
to the health of wetlands
Floods distribute rich sediments and refresh
stream. A flooded field could be used to cultivate
Allowing rivers and streams to overflow can
prevent more serious flooding
The high level of fish production because of
Floods recharge the ground water supplies.
A storm is any disturbed state of an astronomical
body's atmosphere especially affecting its surface, and strongly
implying severe. It may be marked by
strong wind, hail, thunder and/or lightning (a thunderstorm),
heavy precipitation (snowstorm, rainstorm), heavy freezing rain (ice
storm), strong winds (tropical cyclone, windstorm), or wind
transporting some substance through the atmosphere
Drought is an extended period when a region notes a deficiency in its water supply.
A drought can last for months or years, or may be declared after as few as 15 days.
Generally, this occurs when a region receives consistently below average
There are four ways of categorizing drought
Exist where crop cultivation isn’t possible
Occurs in areas with well-defined rainy and dry season
It is the result of a water deficiency that reduces crop yields
It is the result of abnormally low rainfall
32. Causes of drought
Unreliability of monsoon winds may lead to seasonal drought
The dry and hot winds can reduce the moisture contents of sandy
Global climate is constantly changing leading to changes in
Deforestation on foothills increase soil erosion and reduces rainfall
Mismanagement of water resources
The disputed and unfair distribution of water
Over grazing of land
33. Effects of drought
The effects of drought on physical environment are sever, the land
is turned into a desert and because of this the soil is exposed
leading to soil erosion, many species are extinct because of lack of
food. There’s rise in temperature and loss of vegetation, because of
low precipitation there’s extension of desert areas.
Drought not only effect physical environment but also human
environment, drought affect
Loss of life because of widespread famines, malnutrition, health
problems and starvation
Nomadic lifestyle because people migrate from the areas that are
affected by drought and because of this urbanization is increased
causing an increase in domestic waste leading to water pollution.
34. Drought management
Water storage schemes: reservoirs and dams should be
built in order to store water and some traditional methods
should also be utilized in oreder to store water. The
areas that receive heavy rainfall can utilize the water
through perennial canal system. More projects are
required in order to mett the needs of people.
New methods should be used, desalination process
should be used, conversion of waste water in to clean
water through chemical treatment
Drought resistant seeds should be used
High priority should be given to the allocation of water to
industrial areas and to meet the basic needs of people.