IAS Mains Geography Optional 2017 – Paper 1 Section a YouTube Lecture Handouts

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IAS Mains Geography Optional 2017 Solutions: Paper 1 Section A

1 a. Write a Note on Pseudo Volcanic Features

  • Pseudo volcanic Features – These are non-volcanic and resemble volcanic features
  • Meteorite Craters – Lonar Lake, Maharashtra
  • Salt Plugs – high pressure salt acts as intrusion & forms plug domes
  • Mud Volcano – hydrocarbons from the petroleum-bearing beds beneath cause mud-eruptions

1 B. Distinguish between Low Energy Coasts and Coral Coasts

  • Low Energy Coast
  • Coasts sheltered from storms and swells by adjacent topographical features (barrier island, reef, embayment, shoal, headland) , by their position with respect to prevailing wind direction, by their position in a climatic belt, by gentle offshore topography, or by a combination of these factors.
  • Deposition > Erosion
  • Landforms include spits and beaches
  • Coral Coast - Upper limit of coral reef growth along the coast is limited by the level of low tide and tidal conditions influence the height of coral reefs. Includes reefs and calcareous deposits along the shore

1 C. Discuss the Impacts of Ocean Currents on Air Mass Behaviour

  • Oceans – cover 71% area, absorb twice the radiation
  • Have immense heat capacity
  • Thermohaline circulations
  • Ocean Currents - difference in salinity, the waves breaking, temperature, the wind or even the Coriolis effect
  • Currents – conveyor belt – global climate change – cold and warm current
  • Influence of the flow of currents depends on saltiness of water, earth՚s rotation, land topography & orientation of the wind – Brings cold water to earth՚s surface from the depths & forces away the original surface water. As a result, ocean is often cooler to the eastern coastal side than the western coastal side.
  • Warming temperatures transported by ocean currents can promote atmospheric instability & potential for precipitation and storms - case for air masses over western boundary currents of the North Pacific (Kuroshio current) and North Atlantic gyres (Gulf Stream) .

1 D. Describe the Characteristics of Biological Deserts

  • Biological desert – is area without life
  • Very deep ocean waters
  • 30 Oct Report – Many seamounts in Pacific Ocean are Biological Deserts
  • Due to Pollution
  • Due to Trawlers and Nets
  • Due to silting, sediment, and frequent flooding

1 E. Explain the Concept of Micro Carbon Sink and Its Relevance

  • Small natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period.
  • Carbon sequestration - process by which carbon sinks remove carbon dioxide (CO2) from the atmosphere
  • Gained momentum after Kyoto Protocol, which promotes their use as a form of carbon offset
  • Removes CO2 from atmosphere
  • Regenerate agriculture
  • Ocean is largest sink of CO2 but acidification taking place – alternatives

2 a. Discuss the Forces Which Govern the Air Movement on the Earth՚s Surface

  • Explain Pressure Gradient Force (HP to LP)
  • Coriolis force
  • Friction
  • Gravitation
  • Heat (Convectional)

2 B. “The Knowledge of Slope Analysis Has Limited Field Application in the Slope Management.” Explain

Illustration: 2 B. “The Knowledge of Slope Analysis Has Limited Field Application in the Slope Management.” Explain
  • Slope analysis – Davis, Penck, King (talked about origin and development) – mainly natural causes
  • Management focuses on anthropogenic causes & the present state – not related to evolution process
  • Using terraces, benches, reduce slope angles, drainage, cover cropping
  • Slope erodes due to surface runoff, wind & detachment of top soil

2 C. Describe the Configuration of the Pacific Ocean Floor

  • Largest – 35% of ocean area
  • Numerous islands – including coral islands
    Illustration: 2 C. Describe the Configuration of the Pacific Ocean Floor
    Illustration: 2 C. Describe the Configuration of the Pacific Ocean Floor
  • Trenches and plateaus
  • Mariana, Mindando & Philippine trench
  • South- Pacific Antarctic Submarine Ridge

3 a. “Climate Change is a Reality.” Explain with Suitable Examples

  • Carbon pollution – warming the earth – extreme weather conditions
  • Temperature is rising – glacier melting
  • Proceeding at a rate unprecedented in last 1300 years
  • Swallow entire islands and creep closer to populated areas of great coastal cities like New York, Melbourne, Venice, Dakar, Guayaquil, and Chittagong
  • Parali Island – vanished (Lakshdweep)
  • Mumbai & Mangalore – coastal flooding
  • Glacial melting
  • Extreme weather events like torrential rain, floods, heat waves, and drought are becoming more frequent and intense

3 B. Distinguish between the Characteristics of Chernozem and Sierozem Soils

Chernozem Soils

  • Black colored
  • High humus
  • Very fertile
  • High phosphoric acid, phosphorous and ammonia
  • High agricultural yields
  • European Steppes

Sierozem Soils

  • Grey soil (at surface & light below)
  • Cool temperate semi-arid areas
  • Shrub and grasses
  • Carbonate layer or hardpan

Include Map

Zonal Classification of Soil by USDA - 12 Soils Categorized

3 C. Give a Classification of Plants Based on the Amount of Water Requirement

  • Hygrophytes: Water-loving plants in humid areas - water hyacinth, mangroves, rice, and banana (plentiful rain in all seasons)
  • Mesophytes: moist and not wet conditions
  • Tropophytes: grow in regions with alternate wet and dry seasons
  • Nerophytes: drought regions for example, cacti and euphorbias
  • Phreatophytes: arid conditions by growing long roots which obtain water from underground reserves.
  • Xerophytes – dry loving plants
  • In The Plants (1963) - pygmy cedar (Peucepyllum) has unique ability to live without soil water. It replenishes its water supply from the water vapor in the air at night time

A. Discuss the Concept of Periglacial Cycle as Propounded by Peltier

  • Peltier (1950) gave “cycle of periglacial erosion” – followed ideas of Troll gave process based classification for morphogenetic classification based on climatic controls
  • Proposed how relative importance of different weathering and erosional processes would vary with annual temperature & precipitation within the normal cycle area
  • Landform equation LF = f [m (geological material) , dm⟋dt (rate of change) , de⟋dt (rate of erosion) , du⟋dt (rate of uplift) , t (total duration) ]
  • Periglacial - climatic and geomorphic conditions found in the edges of Pleistocene ice sheets and glaciated areas, later explained intense frost action
  • Peltier (1950) - periglacial climate - mean annual air temperatures of between -150 C and -10 C, precipitation between 120 and 1400 mm per annum - ‘intense frost action, strong mass movement, and the weak importance of running water’ .

B. “Climate, Slope Gradient and Rock Structure Influence the Avulsion of Channels” . Explain

  • Explain drainage formation – antecedent and superimposed
  • Avulsion - rapid abandonment of a river channel and the formation of a new river channel
  • Slope Gradient – centripetral & centrifugal
  • Rock structure – trellis drainage
  • Climate change – floods and droughts and change of river course
  • Changes in course of Sarasvati River

Antecedent and Superimposed (Discordant) and 8 Accordant Drainage Patterns

C. Discuss the Perception, Attitude, Value and Emotion (PAVE) Theory of Environmental Management

  • BKW (Burton, Kates & White) school – Behavioural geographic approach
  • MOSS (Mitchell, O՚Riordan, Saarinen & Sewell) school of PAVE – Natural resource management
  • They emphasized perceptions and attitude in resource decision making, behavioural and institutional analysis & resource management model.

Manishika