Geography Answer Writing Practice 2019 brings you the synopsis for the Day-11 questions. The GeoVillae is the Geography Optional online learning platform. The objective of this program is to enable aspirants to score more than 300 plus in Geography Optional in CSE Mains 2019.
Q.1) On the outline map of India, mark the location of all the following. Write the significance of these locations, whether physical/commercial/economic/ecological/ environmental/cultural, in not more than 30 words for each entry.: (2 x 5 =10 marks)
Answer
i) Aizwal
Aizawl is the capital of the state of Mizoram in India. The population of Aizawl strongly reflects the different communities of the ethnic Mizo people.
Aizawl has a mild, sub-tropical climate due to its location and elevation. Under the Köppen climate classification, Aizawl features a humid subtropical climate (Cwa) but very rainy.
ii)Kota
Kota formerly known as Kotah, is a city located in the southeast of northern Indian state of Rajasthan. It is located on the banks of Chambal River.
The city of Kota was once the part of the erstwhile Rajput kingdom of Bundi.
Kota has a semi-arid climate (Köppen climate classification BSh) with high temperatures throughout the year. Summers are long, hot and dry, starting in late March and lasting till the end of June.
iii) Nagpur
Nagpur is the winter capital and the third largest city of the Indian state of Maharashtra after Mumbai and Pune.
The city has the Zero Mile Stone locating the geographical centre of India, which was used by the British to measure all distances within the Indian subcontinent.
Nagpur has tropical savannah climate (Aw in Köppen climate classification) with dry conditions prevailing for most of the year.
iv) Nagapattinam
Nagapattinam is a town in the Indian state of Tamil Nadu and the administrative headquarters of Nagapattinam District. The town came to prominence during the period of Medieval Cholas (9th–12th century CE) and served as their important port for commerce and east-bound naval expeditions.
The Chudamani Vihara in Nagapattinam constructed by the Srivijayan king Sri Mara Vijayattungavarman of the Sailendra dynasty with the help of Rajaraja Chola I was an important Buddhist structure in those times.
Nagore Durgha, a 16th-century minaret located in Nagore, is one of the important pilgrimages centres of the town. Kanduri festival is a 14-day event celebrated for the annual urs(anniversary) of the saint Hajrath Shahul Hamid (1490–1579 CE), in honor of whom the minaret was built.
v) Narora
Narora is a town located on the banks of river Ganges, in district Bulandshahar, Uttar Pradesh. It has Narora Atomic Power Station. The plant houses two reactors, each a pressurized heavy-water reactor (PHWR) capable of producing 220 MW of electricity. This provides energy security for the surrounding region.
Q.2) Explain the following terminologies in about 50 words each: (5 x 5 =25 marks)
i) Hydrological cycle
The water cycle, also known as the hydrological cycle or the hydrologic cycle, describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time but the partitioning of the water into the major reservoirs of ice, fresh water, saline water and atmospheric water is variable depending on a wide range of climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor.
The water cycle involves the exchange of energy, which leads to temperature changes. When water evaporates, it takes up energy from its surroundings and cools the environment. When it condenses, it releases energy and warms the environment. These heat exchanges influence climate.
ii) Global warming
Global warming, the phenomenon of increasing average air temperatures near the surface of Earth over the past one to two centuries. Climate scientists have since the mid-20th century gathered detailed observations of various weather phenomena (such as temperatures, precipitation, and storms) and of related influences on climate (such as ocean currents and the atmosphere’s chemical composition). These data indicate that Earth’s climate has changed over almost every conceivable timescale since the beginning of geologic time and that the influence of human activities since at least the beginning of the Industrial Revolution has been deeply woven into the very fabric of climate change.
iii) Urban heat island
An urban heat island (UHI) is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. The temperature difference usually is larger at night than during the day and is most apparent when winds are weak. UHI is most noticeable during the summer and winter. The main cause of the urban heat island effect is from the modification of land surfaces. Waste heat generated by energy usage is a secondary contributor. As a population center grows, it tends to expand its area and increase its average temperature. The less-used term heat island refers to any area, populated or not, which is consistently hotter than the surrounding area.
iv) Anthropogenic climate change
Anthropogenic climate change refers to the production of greenhouse gases emitted by human activity. By examining the polar ice cores, scientists are convinced that human activity has increased the proportion of greenhouse gases in the atmosphere, which has skyrocketed over the past few hundred years.
The IPCC, Fourth Report released in 2007 stated that, multiple lines of evidence confirms that the post-industrial rise in greenhouse gases does not stem from natural mechanisms. In other words, this is anthropogenic climate change, and the significant increases in the atmosphere of these potent greenhouse gases are a result of human activity.
v) Aerosols
An aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog, dust, forest exudates and geyser steam. Examples of anthropogenic aerosols are haze, particulate air pollutants and smoke. The liquid or solid particles have diameters typically <1 μm;
Several types of atmospheric aerosol have a significant effect on Earth’s climate: volcanic, desert dust, sea-salt, that originating from biogenic sources and human-made. Volcanic aerosol forms in the stratosphere after an eruption as droplets of sulfuric acid that can prevail for up to two years, and reflect sunlight, lowering temperature. Desert dust, mineral particles blown to high altitudes, absorb heat and may be responsible for inhibiting storm cloud formation. Human-made sulfate aerosols, primarily from burning oil and coal, affect the behavior of clouds.
Q.3) Explain the role of evaporation in Hydrological cycle. (2018) (20 marks) (the question had been asked for 10 marks in the exam. Here it has been asked for 20 marks)
Approach
- Define hydrological cycle in the introduction.
- Mention the role of evaporation role in hydrological cycle.
Answer
The water cycle, also known as the hydrological cycle or the hydrologic cycle, describes the continuous movement of water on, above and below the surface of the Earth.
Evaporation is the process by which water changes from a liquid to a gas or vapor. Evaporation is the primary pathway that water moves from the liquid state back into the water cycle as atmospheric water vapor.
Studies have shown that the oceans, seas, lakes, and rivers provide nearly 90 percent of the moisture in the atmosphere via evaporation, with the remaining 10 percent being contributed by plant transpiration.
Evaporation from the oceans is the primary mechanism supporting the surface-to-atmosphere portion of the water cycle. After all, the large surface area of the oceans (over 70 percent of the Earth’s surface is covered by the oceans) provides the opportunity for large-scale evaporation to occur.
On a global scale, the amount of water evaporating is about the same as the amount of water delivered to the Earth as precipitation. This does vary geographically, though. Evaporation is more prevalent over the oceans than precipitation, while over the land, precipitation routinely exceeds evaporation.
Most of the water that evaporates from the oceans falls back into the oceans as precipitation. Only about 10 percent of the water evaporated from the oceans is transported over land and falls as precipitation. Once evaporated, a water molecule spends about 10 days in the air.
The process of evaporation is so great that without precipitation runoff, and groundwater discharge from aquifers, oceans would become nearly empty.
Uses of evaporation
One way to produce table salt is to evaporate saline water in evaporation ponds, a technique used by people for thousands of years.
Evaporation helps in the transfer of energy and heat from surplus latitude to deficient latitudes.
Evaporation determines the micro-climate of a region. Example- regions with more lakes have equable climate than those do not have on the same latitudinal zone.
Evaporation determines the aridity of a place.
Water evaporated from the water bodies stay in atmosphere and affects the humidity and helps in cloud formation.
Evaporation is a purifying process. One of the ways you can purify sea water is to heat it so it evaporates and then collect the steam. The steam is pure water and getting it back to a liquid requires our next phase of the water cycle.
Q.4) “Contemporary global climate change is an anthropogenic phenomenon”. Discuss (2011) (15 marks)
Approach
- Define anthropogenic climate change in introduction.
- Various man-made factors of climate change.
- Suggest some measures in conclusion.
Answer
Climate change may refer to a change in average weather conditions, or in the time variation of weather within the context of longer-term average conditions, defined by the World Meteorological Organization as a 30 years or longer term. Climate change is caused by factors such as biotic processes, variations in solar radiation received by Earth, plate tectonics, and volcanic eruptions.
The present climate change is largely influenced by human activities. Anthropogenic climate change is defined by the human impact on Earth’s climate while natural climate change are the natural climate cycles that have been and continue to occur throughout Earth’s history.
Human induced climate change is directly linked to the amount of fossil fuels burned, aerosol releases and land alteration from agriculture and deforestation.
In 2013, the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report concluded, “It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century”.
The largest human influence has been the emission of greenhouse gases such as carbon dioxide, methane, and nitrous oxide. In view of the dominant role of human activity in causing it, the phenomenon is sometimes called “anthropogenic global warming” or “anthropogenic climate change.”
The beginning of the Industrial Revolution shows a major spike in temperature levels and climate influences. The product of fossil fuel burning is the emission of a greenhouse gas: carbon dioxide which traps heat.
Climate change is generally associated with global warming; however, some small areas like the tropical Pacific show that the release of aerosols into the atmosphere the area has actually cooled (or at least warmed much slower than the rest of the world).
Important man-made causes
Carbon dioxide levels are substantially higher now than at any time in the last 750 000 years. Beginning with the industrial revolution in the 18th century, the combustion of fossil fuels has elevated CO2 levels from a concentration of approximately 280 parts per million (ppm) in the atmosphere in pre-industrial times to around 387 ppm today.
Land use change (mainly deforestation in the tropics) accounts for up to one third of total anthropogenic CO2 emissions.
Agricultural activities such as livestock digestion, manure use, paddy rice farming, land use and wetland changes, pipeline losses, and vented subsurface landfill emissions all lead to higher methane atmospheric concentrations.
The use of fertilizers can also lead to higher nitrous oxide (N2O) concentrations.
Prior to widespread fossil fuel use, man’s largest effect on local climate was to change land use by activities such as irrigation, deforestation, and agriculture.
Land use may alter the local albedo (reflectivity of the Earth’s surface) by reducing vegetation ground cover, altering the way sunlight is absorbed or reflected.
According to the United Nations, livestock is responsible for 18 per cent of the world’s greenhouse gas emissions. This percentage includes the effect of deforestation in order to create grazing land, as well as livestock natural methane gas emissions. These include nitrous oxide (which has 296 times the global warming potential of CO2) and methane (which has 23 times the global warming potential of CO2).
In the Amazon rainforest, 70 per cent of deforestation is specifically carried out to create grazing land.
Cement manufacture contributes CO2 to the atmosphere when calcium carbonate is heated, producing lime and carbon dioxide. CO2 is also produced by burning the fossil fuels that provide the heat for the cement manufacture process.
It is estimated that the cement industry produces around 5 per cent of global man-made CO2 emissions, of which 50 per cent is produced from the chemical process itself, and 40 per cent from burning fuel to power that process.
The amount of CO2 emitted by the cement industry is more than 900 kg of CO2 for every 1000 kg of cement produced.
Aerosols (particles suspended in the atmosphere), particularly sulphate aerosols from fossil fuel combustion, exert a cooling influence by reducing sunlight.
The use of Chlorofluorocarbons (CFCs) has increased in refrigeration systems and use of CFCs and halons in fire suppression systems and manufacturing processes.
Impacts
Future climate change and associated impacts will differ from region to region. Ongoing and anticipated effects include rising sea levels, changing precipitation, and expansion of deserts in the subtropics.
Future warming is expected to be greater over land than over the oceans and greatest in the Arctic, with the continuing retreat of glaciers, permafrost, and sea ice.
Other likely changes include more frequent extreme weather events such as heat waves, droughts, wildfires, heavy rainfall with floods, and heavy snowfall; ocean acidification; and massive extinctions of species due to shifting temperature regimes.
Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels.
Because the climate system has a large “inertia” and greenhouse gases will remain in the atmosphere for a long time, many of these effects will persist for not only decades or centuries, but tens of thousands of years.
Measures to contain climate change
- Adapting renewable energy and reducing the use of fossil fuels.
- Promoting Green transportation and Public transportation.
- Afforestation and ceasing the process of deforestation.
- Cropping pattern should be based on climate and not based on commercial needs.
- Use of energy efficient machines, gadgets, equipment etc.
- Carbon tax to discourage use of fossil fuels.
- Containing population rise.
Q.5) Explain how new science and technology can enable India to overcome the challenges posed by climate change and ensure the increase in food production to meet its demands. (15 marks)
Answer
India has rightly recognized the importance of tackling climate change and reducing carbon emissions for sustaining its economic growth and climate resilience. India’s Intended Nationally Determined Contributions (INDCs) under the Paris agreement aim to reduce its GDP emission intensity by 33 per cent to 35 per cent from the 2005 level by 2030.
The climate change has adverse effects on food production viz.
The changing climate would affect the length and quality of the growing season and farmers could experience increasing damage to their crops, caused by a rising intensity of droughts, flooding or fires.
A looming vulnerability is the world’s fisheries, which provide an important source of protein for at least half the world’s population. Fisheries are already stressed by overexploitation and pollution.
Warming surface waters in the oceans, rivers and lakes, as well as sea level rise and melting ice, will adversely affect many fish species.
Role of new science and technology
Genetic modification of plant varieties can be used for nutrient fortification, tolerance to drought, herbicides, diseases or pests, and for higher yields.
Transgenic modification confers a number of benefits, including tolerance to biotic stresses (insects and disease), abiotic stresses (drought), improved nutrition, taste and appearance, herbicide tolerance and reduced use of synthetic fertilizers.
New methods of nitrogen fixation and other fertilizer components that avoid the current capital- and energy-intensive methods could make nutrient supplementation more environmentally sustainable.
New technologies to make biological fertilizers (composting, manure or dung) more viable and effective could also increasingly replace the use of synthetic fertilizers.
Precision agriculture can help facilitate the precise application of inputs to crop type and soil conditions in ways that increase yields while minimizing potential environmental impacts.
Low-cost and affordable drills, renewable energy-powered pumps and technologies for desalination and improved water efficiency can potentially make water more available for food production.
Water desalination technologies such as off-grid solar-powered electrodialysis reversal systems can remove salts and minerals from such brackish water.
Biofortification – or the breeding of critical micronutrients and vitamins into staple crops – has emerged as an effective approach to combat malnutrition, especially in developing countries.
Big data and the Internet of things can be harnessed for a number of agricultural applications, including farmer decision support, precision farming and insurance.
Accurate and reliable weather forecasts enable farmers, especially those near the equator, to capitalize on rainfall for crop production in regions of extreme weather variability.
There is an urgent need to increase investment in high-quality research that is coherent with production models adapted to the needs of smallholder farmers. The constantly changing ecological, environmental and biodiversity contexts require continuous research and development to produce inputs and disseminate knowledge that maximizes agricultural yields while safeguarding the environment.