IAS Prelims (GS) preparation 2018
Day # 18 (April 10, 2017)
Topics of the day: Geography 8th NCERT Chapter – 1& 2 key points
- Resources are generally classified into natural, human made and human.
- Resources that are drawn from Nature and used without much modification are called natural resources. The air we breathe, the water in our rivers and lakes, the soils, minerals are all natural resources.
- On the basis of their development and use resources can be classified into two groups, actual resources and potential resources.
- Actual resources are those resources whose quantity is known. These resources are being used in the present. The rich deposits of coal in Ruhr region of Germany and petroleum in the West Asia, the dark soils of the Deccan plateau in Maharashtra are all actual resources.
- Potential resources are those whose entire quantity may not be known and these are not being used at present. These resources could be used in the future. The level of technology we have at present may not be advanced enough to easily utilise these resources. The uranium found in Ladakh is an example of potential resource that could be used in the future.
- Based on their origin, resources can be abiotic or biotic.
- Abiotic resources are non-living while biotic resources are living. Soils, rocks and minerals are abiotic but plants and animals are biotic resources
- Natural resources can be broadly categorized into renewable and non-renewable resources.
- Renewable resources are those which get renewed or replenished quickly. Some of these are unlimited and are not affected by human activities, such as solar and wind energy.
- Non-renewable resources are those which have a limited stock. Once the stocks are exhausted it may take thousands of years to be renewed or replenished.
- Coal, petroleum and natural gas are some examples.
- On the basis of their distribution resources can be ubiquitous or localised.
Resources that are found everywhere like the air we breathe, are ubiquitous. But those which are found only in certain places are localised, like copper and iron ore
- People use natural resources to make buildings, bridges, roads, machinery and vehicles, which are known as human made resources.
- People are human resources
- Improving the quality of people’s skills so that they are able to create more resources is known as human resource development.
- Balancing the need to use resources and also conserve them for the future is called sustainable development.
Chapter 2
- Land degradation, landslides, soil erosion, desertification are the major threats to the environment because of the expansion of agriculture and constructional activities.
- Afforestation, land reclamation, regulated use of chemical pesticide and fertilisers and checks on overgrazing are some of the common methods used to conserve land.
- Landslides are simply defined as the mass movement of rock, debris or earth down a slope.
- The thin layer of grainy substance covering the surface of the earth is called soil.
- Soil is made up of organic matter, minerals and weathered rocks found on the earth. This happens through the process of weathering. The right mix of minerals and organic matter make the soil fertile.
- Weathering: The breaking up and decay of exposed rocks, by temperature changes, frost action, plants, animals and man.
- Factors which lead to soil degradation are deforestation, overgrazing, overuse of chemical feritilisers or pesticides, rain wash, landslides and floods.
- Some methods of soil conservation are
a.Mulching: The bare ground between plants is covered with a layer of organic matter like straw. It helps to retain soil moisture.
b.Contour barriers: Stones, grass, soil are used to build barriers along contours.
Trenches are made in front of the barriers to collect water.
c.Rock dam: Rocks are piled up to slow down the flow of water. This prevents gullies and further soil loss.
d.Terrace farming: These are made on the steep slopes so that flat surfaces are available to grow crops. They can reduce surface run-off and soil erosion.
e.Intercropping: Different crops are grown in alternate rows and are sown at different times to protect the soil from rain wash.
f.Contour ploughing: Ploughing parallel to the contours of a hill slope to form a natural barrier for water to flow down the slope g.Shelter belts: In the coastal and dry regions, rows of trees are planted to check the wind movement to protect soil cover .
- Rain water harvesting is the process of collecting rain water from roof tops and directing it to an appropriate\ location and storing if for future use.
- Vultures in the Indian subcontinent were dying of kidney failure shortly after scavenging livestock treated with diclofenac, a painkiller that is similar to aspirin or ibuprofen.
- Forests are broadly classified as evergreen and deciduous depending on when they shed their leaves.
- Evergreen forests do not shed their leaves simultaneously in any season of the year. Deciduous forests shed their leaves in a particular season to conserve loss of moisture through transpiration. These forests are further classified as tropical or
temperate based on their location in different latitude
- National Park: A natural area designated to protect the ecological integrity of one or more ecosystems for present and future generations.
- An international convention CITES has been established that lists several species of animals and birds in which trade is prohibited.
- Biosphere reserves Series of protected areas linked through a global network, intended to demonstrate the relationship between conservation and development.
- CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) is an international agreement between governments. It aims to ensure that international trade in specimens of wild animals and plants does not threaten their survival.