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World Geography / Climatology

Climatic Zones of the World

    Natural regions or climatic zones of the world can be divided on the basis of latitudes. Depending on the latitudes there are 5 climate regions, namely (i) Equatorial Region, (ii) Tropical and Subtropical Regions, (iii) Mid-Latitude Regions, (iv) High Latitude Regions and (v) Polar and Subpolar Regions. There is gradual decrease in temperature from Equatorial regions to Polar regions. That means, the regions near the Equator are generally hotter when compared to the regions near the Poles.

    Equatorial Region ( 100 N - 50 S )

    • The areas of Equatorial region include Amazon basin in South America, Indonesia, Malaysia, Congo basin in Africa, etc. Here we find Amazon type of natural vegetation.
    • Here the climate is humid and has very high temperature ( hot climate ). There will be rainfall every month and summer will be there throughout the year. Here mean monthly temperature is more than 210C. The rainfall is convectional type and the average rainfall here is more than 200 cm.
    • Dense evergreen forests, also known as Selva forests, are developed here and it is a 3-tier vegetative system. The trees here will have Umbrella shaped canopy. Sun rays cannot reach the ground here. The forest is pitch-dark at the floor, which is marshy in nature.
    • The prominent trees that grow here are Mahogany, Ebony, Rosewood, Brazilwood, Tamarind, etc. They are the only surviving virgin forests. They are regarded as global sinks of Carbon Dioxide. Here the biodiversity is maximum. The prominent fauna here are primates, monkeys, langurs, snakes, lizards, crocodiles, vipers, etc. Poisonous insects live in these forests.

    Tropical and Subtropical Regions ( 100 - 300 )

      Eastern Margins of Continents

      • Here, the climate is known as Monsoonal variety or Caribbean variety. The areas include Central America, East coast of Brazil, Caribbean Islands, East coast of Africa, South Asia, Southeast Asia, Philippines, Small parts of North Australia, etc.
      • Here summers are hot and winters are warm or cool. Rainfall here is high having an annual average of more than 100 cm. The rainfall is received during 3-4 months of summer ( rainy season ).
      • Here forests are generally dense but they are deciduous forests as there are long dry seasons. These deciduous forests are called Monsoon forests and are found in North East, Central and East India, Myanmar, Cambodia, etc. They have wide biodiversity. Here forests are degraded but yield timber from Teak, Sal, Mahua, Bamboo, etc. They support wildlife animals like Elephants, Lions, Tigers, Rhinoceros, etc.

      Western margins of Continents ( Sahara Natural Region )

      • The areas include Mojave or Mexican desert, Atacama desert, Kalahari desert, Sahara desert, Thar desert, West Australian desert, etc.
      • Here summers are hot or very hot and winters are cool. Here days are hot and nights are cool ( higher diurnal thermal range ). Highest recorded temperature of 580C was registered at Azizia in Libya. The annual average rainfall is less than 15 cm.
      • Trees are scattered in this region. Palm or Date palm trees, bushes or scrubs ( in order to reduce the transpiration ), Megatherms ( can withstand high temperature) and Xerophytes varieties are found here. Scrubs are of Cactus variety ( thorn bearing ). The fauna found here are burrowing animals, rabbits, rodents, rats, etc.

      Interiors of the Continents ( Sudan Type of Natural Region or Savanna variety )

      • They are typically developed in Sudan. The areas include Sudan, Nigeria, Kenya, Malawi, Uganda, Tanzania, Brazilian Plateau region, Australia, South Africa, etc.
      • Here the summers are hot and winters are warm or cool. The rainfall is moderate ranging from 50–70 cm and is received throughout summer. There is lot uncertainty of rainfall and hence these areas are drought prone and they cannot support forests. Here the vegetation includes small patches of woody jungles and in between there exists vast extent of grassland ( tall and coarse variety of grass having a height in the range of 5–7 m ).
      • In Africa, these grasslands are called Savanna or Elephanta. In Brazil, they are called Campos. In Australia, they are called Parklands. In South Africa, they are called Tropical Veld or Lowveld.
      • They are known for rich wildlife like Lions, Zebras, Rhinos, etc. Here Prey Predator relationship is well established. This region is called Big Game country region or Hunter's paradise.

    Mid-Latitude Regions ( 300 - 600 )

      Western Margins of Continents ( Mediterranean type of Climate )

      • They are found around Mediterranean sea area, which include Spain, France, Italy, Portugal, Greece, Adriatic Coast, Black Sea, Coast of Turkey, Morocco, Algeria, Tunisia and also found in Californian coast of US, Cape Province of South Africa, Central Chile, Victoria province of Australia, etc.
      • It is the most pleasant climate for human living. Here summers are warm to hot and winters are cool or occasionally cold. Here, rainfall is received in winter. Here, winters are humid and summers are dry.
      • The temperate forests that are present here are known as Sclerophyll forests. Trees like Olive, Fig, Cork are found only in this region. The forest are being replaced by orchards and particularly citrus fruits ( grapes, sweet lemon, lemon, pomegranate, etc. ) are cultivated. The region is known for manufacturing of wines, jams, jellies, etc.

      Eastern Margins of Continents ( China type of Climate ) ( 400 – 600 )

      • The areas include East and Southeast China, Southeast US, Natal Province of South Africa, etc.
      • Here summers are hot and winters are cool. Rainfall here is high ranging around annual average of 100 cm. Rainfall is normally concentrated in summer but even winters also have some rainfall. Here the forests are temperate forests.

      Interior Mid-Latitudes

        Here the Lowlands are of Turanian variety and Highlands are of Iranian variety.

      • Turanian Variety
        • Turan is a Province in Russia. The areas of Turanian variety include Russia, Ukraine, Belarus, Chechnya, Uzbekistan, Kazakhstan, Turkmenistan, Poland, Czech Republic, Slovakia, Hungary, Goergia, etc. They support short, soft and juicy grasses ( temperate grasses ).
        • They are called by different names in different areas. They are called Steppes in Russia, Europe and Asia, Prairies in US and Canada, High Velds in South Africa and Downs in Australia.
        • All these grasslands are lost and now there is commercial ( capital intensive, highly mechanized, modern ) agriculture happening in these areas. Wheat, Maize and Cotton are exported on large scale from these areas. These areas are called Bread Baskets of the World. These are covered by Chernozem variety of soil or black soil.

      • Iranian Variety
        • These are found in Western China, Tibetan Plateau, Iranian Plateau, Large parts of Afghanistan, Patagonia region, etc.
        • They are covered by high plateaus and mountains. Here winters are harsh and rainfall is low. These are cool or temperate deserts. These are barren rocky terrains.

    High Latitude Regions ( 600 - 800 )

      Western Margins of Continents ( British type or West European type of Climate )

      • The areas include Britain, Belgium, Netherlands, Luxembourg, Austria, Switzerland, Denmark, Latvia, Lithuania, Germany, Estonia, North-West US, South-West Canada, Tasmania, New Zealand, etc.
      • Here summers are warm to cool and winters are cold but not always frozen ( cool to cold ). Rainfall is fairly high and evenly distributed throughout the year. It is a typical example of maritime climate ( under the influence of ocean or sea, neither summers are hot nor winters are harsh ).
      • Here we can find temperate, broad leaved evergreen forests. Most forests have been cleared. In higher reaches, the hilltops are covered with pastures. The cool and humid climate promotes milk production. It is a zone of commercial dairy farming ( capital intensive dairy farming ). Here we can find good quality cattle breeds like Jersey, Hartford, Swiss Brown, etc.
      • Here countries export dairy products on large scale. Denmark is Butter base of Europe and UK is Cheese base. Switzerland is rich in milk products, chocolates and ice creams. These areas are known for floriculture, e.g. in Holland, Jasmine, Rose, Lily, Tulips are cultivated on commercial lines.
      • These areas are also known for market gardening practice or truck farming ( cultivation of fruits and vegetables on commercial lines and supplying to the markets ). Tasmania is known as Garden state of Australia.

      Interiors of the Continents ( Siberian variety of climate or Taiga variety )

      • The areas include Norway, Sweden, Finland, Siberian area of Russia, US, Canada, etc.
      • Here summers are cool and winters are harshly cold, chill and frozen. Mean monthly temperature here is 8-100C. Maximum summer temperature will be 150C and minimum temperature is -500C. Maximum annual thermal range is found in this region. This highest thermal range is due to continentality, that is being away from the oceans ( there won't be any moderation by the sea ).
      • The vegetation here includes coniferous forests, where the trees are thin and tall ( 20-30 m) and are having conical shaped canopy. We do not find trees having broad leaves here but the leaves will be like needles ( hence are called needle leaved forests ). There will be heavy rainfall in winter but snow will not accumulate on trees.
      • Pine, Fir, Spruce, Cedar are the species of trees found here which yield softwood, which is useful for manufacturing of newsprint variety of paper. These forests are evergreen type of forests.

    Polar and Subpolar Regions ( Tundra Vegetation )

    • The areas include Alaska, North Canada, Finland, Russia, Norway, etc. Here summers are cool to cold and the temperature range is 6-80C. Summer occurs for brief period ( 2-3 months ). Winters are frozen and temperature is in the range of -200C to -300C. Winters are long ( 9-10 months ).
    • There will be snow melting in summer which makes it marshy. During winter, there will not be any vegetation. During summer, some plants which are ephemeral ( which are having short life cycle ), inferior variety plants, microtherm or hekistotherm ( which survive in very low temperature ) grow here.
    • Cryptogams ( non-flower bearing plants ) like Algae, Lichens, Ferns and Phanerogams like Rhododendrons grow here. Sometimes, pastures may appear here. Fur bearing animals like polar bears, reindeer, seals, penguins ( all are hibernating varieties ), etc. live here. Greenland, Iceland and Antarctica are Permafrost plains.