Climatic Regions of Pakistan
The atmospheric conditions at any conditions at any place are known as weather.Climate is a generalization of the day to day weather conditions during the course of a year.It means average weather,including its variation from season to season.Temperature ,pressure,wind rainfall etc.are the composite parts or elements of climate.The climate of a particular place is controlled by several geographical ractors like:
(a) Distance from the equator
(b) Distance from the Sea
(c) Altitude or height above sea level etc.
Climate of Pakistan
The whole of Pakistan lies in the warm temperate zone.It lies roughly between 24 degree N and 37degree N latitude.Pakistan is noted for hot summer and cold winters with semi-arid to arid conditions prevailing in most parts,sub-humid conditions in a small area in the north.The topographic diversity and location of large areas a long distance from the sea have all the more intensified the climate contrasts.The rainfall is generally low .The monsoons bring such marked characteristics that a seasons in Pakistan.
1.Winter season (from November to February)
2.Summer season (from March to June)
3.Monsoon or Rainy season (from July to October)
Climatic Regions Of Pakistan
Keeping in view the various climatic factors,Pakistan can be divided into the following climatic regions:
1.Sub-Tropical Continental Highland Type
This region includes the mountains in the North and West of the Indus plain.In this region winters are cold and lengthy and often the temperatures goes below the freezing point; and the higher peaks remain snow -covered throughout the year.But here summer remains short cool and temperature .The North Western mountain areas have less amount of rainfall as compared to North Eastern mountains,e.g.from South of Kohat and Waziristan rainfall decreases,so Quetta division in Baluchistan has a dry climate and there the mean annual rainfall is not more than 50 to 100 millimeters.It mostly comes during winter and spring .The North Western mountainous areas are less fertile and have barren rocks without any natural vegetation.Due to some rain in winter and spring,some grass and shrubs appear,which promotes the rearing of sheep and goats.
2.Sub-Tropical Continental Plateau Type
This region includes the north western part of Baluchistan Province.Here winters are cold ,and in summer temperature goes higher enough and often dust storms prevail .Although it has higher altitude ,but due to poor rainfall,these have turned into arid desert.In these areas there is scarcity of rain water and it is less than 10 inches or 25 cm.annually ,but some of the places of these areas have the lowest rainfall e.g.Nokundi has only 1.95 inches or 5 cm.of rainfall annually,and rain often comes during the months of January and February.
3.Sub-Tropical Continental Low Lands Type
This region includes the interior areas of Punjab and Sindh provinces.It has generally arid and extreme climate.Here summer remains long and hot,but winters are cool and short.It has the hotest places of the country such as Jaccobabad and Sibbi.
The rainy season begins in the middle of the summer months.The places which are situated near pledmont areas have enough rainfall e.g. Sialkot has about 30 inches or 88.3 cm. of annual rainfall.But the western part of this plain is drier than the eastern due to very poor rainfall e.g. Thal and Cholistan desert in Punjab and Nara and Tharparker desert in Sindh.
4.Sub-Tropical Coastal Areas Type
This region includes the coastal strip around Karachi and Makran coast in Baluchistan.Here due to the influence of the sea,the temperature remains moderate ;the rainfall is about 7 inches or 18 cm.annually,but due to proximity of the sea ,a large amount of humidity remains in the atmosphere.The influence of sea breeze during day time is felt throughout the summer.
Need And Importance Of Irrigation
1.Most of the plain areas of Pakistan have been built by alluvial soil brought by the River Indus and its tributaries.But due to deficient rainfall ,agricultural activities cannot be performed without adopting some artificial means of irrigation.So the areas lying between the rivers have provided irrigation facilities through canals and various types of crops are grown in these areas.
2.The Rivers of our country used to take millions of gallons of water into the Arabian Sea.That water is being used for canal irrigation and a number of dry desert areas have become fertile and productive regions of our country.
3.The supply of water in our rivers remains irregular during the year.To regulate the water supply throughout the year the year the water is stored by constructing barrages,dams and weirs etc.
4.The slope of our country lies from north east towards south.This helps in the construction of canals and water can easily be distributed through canals from higher regions to lower areas.
5.All the rivers of our country come from snow-covered mountainous areas,having abundance of rainfall in summer ,in those rivers a huge amount of water comes due to heavy rainfall and the melting of snow during summer.Thus we store this surplus water in huge dams which is used for irrigation purposes in dry season.
6.The upper and lower areas of Indus plain have soft soil,where digging of canals is easier,and cheap labour is available in abundance.That reduces the cost of construction.That is why canal irrigation is preferred in our country.
7.Canal water adds to the fertility of the soil by bringing a number of organic and in-organic matters with it,while the water of tube -wells lacks all these matters,so people prefer canal irrigation.
8.Canal irrigation is the cheapest and easiest means by which vast areas can be commanded and made productive.