BBA Environmental Studies Question Unit 5
BBA Environmental Studies Question Unit 5 :- In this unit, you will read and learn Environmental pollution : Definition, causes, effects and control measures of : (a) air pollution, (b) water pollution, (c) soil pollution, (d) marine pollution, (e) noise pollution, (f) thermal pollution, (g) nuclear hazards.
solid waste management : Causes, effects and control measure of urban and industerial waste management of urban and industrial wastes, role of an individual in prevention of pollution, pollution case studies. Disaster management : floods, eathquake, cyclone and land slides.
Q.1. Define pollution and describe air pollution in delan. (2012)
Ans. Pollution : Pollution may be defined as undesirable change in the physical, chemical or biological aspects of environment makes it harmful for human beings, living organisms (plants, animal and microbes) and for cultural aspects. Any excessive addition undesirable materials to the physical environment (air, land and water) making it unfit for living beings is pollution.
Man-made pollution is called as anthropogenic pollution. This is mainly caused by over use, misuse or mismanagement of natural resources by men, e.g. agricultural pollution, industrial pollution etc.
Natural pollution may result from volcanic eruption, UV radiation, soil erosion, forest fire, decomposition of dead organic matter etc.
Air Pollution : It refers to the release into the atmosphere of materials in concentrations that are harmful to human beings, plants, animals and buildings or other objects.
Air pollution is caused either due to natural causes or anthropogenic (man-made) causes.
Natural Causes : The natural causes of pollution are as follows :
- Forest fire.
- Marsh gases.
- Cosmic dust
- Pollens, spores etc
- Extra terrestrial substances
- Volcanic eruption-releasing CO, H2S, SO2 etc
- Decay products of natural organic or inorganic substances.
Anthropogenic Causes : The anthropogenic causes of pollution are as follows :
- Domestic emission
- Industrial emission
- Vehicular emissions
- War (chemical and/biological weapons)
Q.2. Describe noise pollution. Give its effects. How can be controlled?
Ans. Noise Pollution : It is an undesirable sound. High pitch sounds are produced by power plants, automobiles, jets, aeroplane, trains, rockets. DI., TV, bomb explosions, rockets, public broadcasting systems, crackers, generators etc. The loudness of noise is measured in decibel (dB).
1 dB = 20 log 10 (P/Pref)
P= Measured sound pressure in dynes/cm
Pref = Reference sound pressure which is equal to barely audible sound taken 0.002 dynes/cm.
According to WHO, 45 dB is considered safe noise level for city.
Noise level 80 dB or above causes noise pollution. 100 dB noise is uncomfortable and 120 dB is painful.
Effects of Noise Pollution
- Sudden loud noise may cause constriction of blood vessels, skin becomes pale, pupil dilates, eyes close, muscle tense, B.P. increases
- Also affect on secretions of ductless glands.
- Temporary loss of hearing. Explosions may cause deafness. Continuous exposure to high noise may cause permanent damage of the ear.
- Disturb sleep and proper rest of animals/human beings.
- Sudden noise may cause accidents.
- Irritation in behaviours of human/animals.
- Stomach disorder.
- Damage to heart, brain and liver has been reported in animals due to prolonged noise pollution.
- interferes in conversation, concentration and upsets mood.
- Noise producing industries, railway stations and aerodromes should be located at proper distance from human settlements.
- A green vegetation belt of medium height around the airport is a good idea to reduce noise
- Main roads should be away from city
- Noisy machines should be settled in sound proof chambers.
- Use of sound proof chambers for generators.
- Use of insulating material to check noise production.
- Ear malts and cotton plugs should be used by workers in noisy places.
- Noise on roads may be reduced by planting many rows of trees on both sides of roads.
- Silence zones are essential near colleges, schools, hospitals and residential areas.
Q.3. Describe soil pollution. Give its effects. How can it be controlled? (2012)
Explain the causes responsible for the degradation of soil resources in modern are. (2013)
Ans. Soil is a very important resource. Nowadays pollution of soil in rural, urban and industrial areas has become a serious problem.
In crop lands, weeds grow and compete with crop land for water and mineral. Some liner Sodium Chlorate, with other compounds are spread to kill these weeds. These chemicals cause soil pollution and are harmful to microbes. Many herbicides, fungicides are used which cause soil pollution. Compounds like DNOC (Dinitro compounds), weed killers like MCPA, Simazine, 24-D Moneron, organic herbicide, Dalapon, paraquat have long lasting effect on soil and remain for a very long time. These also show advance effect on soil microbes and create problems for human beings and animals. Fungicids are poisoned and get incorporated into soil. Some of them are washed in with rain, later on enters food chain and create serious problems to fish, birds, mammals. Insecticides like Bttc DDT, Aldrin pollute soil through rain. These chemicals slow biomagnification and also affect activities of bacteria, earth worms adversely, Some chemicals influence the reproduction in earth worms. Compounds like Benoyl, Carboyl, Forrnofos, Carbonates are toxic to earth worms, Nematodes etc. Sodium methyl bromide, oxamyl are also toxic to earth worms. Pesticides also effect soil decomposition, enzyme activity of CO2 evolution.
Industries, pollute soil through their effluents which have metals, plastics, chemicals. Threat of Soil pollution also comes from human wastes, animal excretes, hospital waste etc.
Soil acquires radio-active pollution from nuclear explosions. Major pollutants of soil are industrial exhausts, urban wastes and agricultural activities.
Effects of Soil Pollution
- Pollutants alter natural composition of soil.
- Pollutants may kill soil microbes which contributes to fertility of soil.
- Chemicals, pesticides, insecticides, weedcides, herbicides etc. make soil toxic for planting
- Use of chemical fertilizers may spoil the quality of soil in long run.
- Human wastes, animal wastes, hospital wastes, industrial wastes pollute soil and cause on vield, which subsequently affect the human and animal health adversely.
- Recycling of wastes
- Burning of wastes without oxygen.
- Use of cattle dung in productin of cooking gas.
- Use of domestic wastes, sludge for composting.
- Use of biofertilizers
- Proper treatment of industrial wastes, agricultural wastes, hospital wastes at source before final disposal.
Q.4. What is nuclear hazards? What are its causes?
Ans. Nuclear Hazards : Nuclear pollution may be defined as ‘the physical pollution of air, water and soil caused by radioactive materials’. The radioactive wastes are mainly released from the thermo-nuclear explosions in which disintegration of atomic nuclei of certain elements emit electromagnetic waves of very short wavelength. The radioactive elements are uranium, thorium, radium etc. The nuclear pollution poses a serious threat to all living organisms.
The electromagnetic waves are a-rays, B-rays and y-rays. Thea-rays are normally a health hazard in the form of internal radiation through ingestion, inhalation or open wounds. These do not cause external hazard since they cannot penetrate other layers of skin. B-rays can be a health hazard either as internal or external radiation due to ionization in the tissues. X-rays and Y-rays are very penetrating compared to a and B-rays. They constitute the chief health hazard of external radiation although y-rays can be a hazard also as internal radiation.
Causes of Nuclear hazards
Main sources of radioactive pollution are both : Natural and Man-made. Their details are as follows:
Natural Sources: These are as follows:
- Cosmic rays which are fast moving highly energetic radiations. They reach the earth from outer space. The intensity of cosmic rays in the biosphere is low, therefore they are not a health hazard. But they are a major hazard in space.
- The terrestrial radiation from nuclides of radioactive elements are present in the rocks, soil and water. These elements could be uranium 235, uranium 238, radon 222, radium 224, thorium 232 and carbon 4 etc.
Man-made Sources: These are as follows:
- Testing of nuclear weapons such as :
(a) The use of uranium 235 and plutonium 239 for fission.
(b) Hydrogen of helium as fusion material.
Atomic explosions are uncontrolled chain reactions. They give rise to a very large neutron-flux conditions that cause other materials in the surrounding to become radioactive.
Huge clouds of fine radioactive particles and gases are thrown up in the environment and are carried away to distant areas by the winds. Gradually, they settle down on earth as fall out or are brought down by rain. Strontium-90, iodine-131, cesium-137, unused explosives and activation products are the radioactive substances present in the fallout. When raindrops containing these radioactive particles fall on earth, radioactivity is transferred to soil particles causing soil pollution. From the soil, these radioactive materials are washed into different water sources where the aquatic organism absorb and accumulate them through the food chains and many pass them to human beings.
2. Atomic reactors and nuclear fuel :
(a) In a nuclear power plant, processed nuclear fuel is inevitable.
(b) Both the fuel elements and coolants are sources of radiation pollution.
(c) Besides these, the disposal or radioactive wastes from atomic reactors is a grave problem because the fission and activation products contained in them are hazardous to living organisms. Even if these are dumped in underground tanks for natural decay, they may become free and escape into the surroundings. Inert gases and halogens escape as vapours and pollute the environment as they settle on land or are washed into surface water with rain. BBA Environmental Studies Question Unit 5
3. Radioactive Isotopes :
(a) A large number of radioactive isotopes such as 1251, 14C, 32P and their compounds find wide usage in scientinc research. The waste water from these research institutions contain various amounts of radioactive materials. When this waste water reaches different water sources such as rivers, streams, lakes etc. through the sewers, they cause water pollution.
(b) Radioactive iodine and phosphorus also enter the food chain through water and may finally reach man through fish etc.
4. Other Sources:
Varying concentration of radiations enter the human body during different medical treatments. For instance, X-rays are common for detecting skeletal disorders, therapy for cancer patients often includes radium and other isotope radiations
Q.5. What is an earthquake? What are its causes and effects?
Ans. Earthquake: An earthquake is a major demonstration of power of tectonic forces caused by endogenetic thermal conditions of the interior of the earth. It is a motion at the ground surface, ranging from a faint tremor to a wild motion capable of shaking buildings, apartments and causing gaping fissures to open in the ground. The earthquake is a form of energy of wave motion transmitted through the surface layer of the earth in widening circles from a point of sudden energy release. The magnitude or intensity of energy released by an earthquake is measured by the RICHTER SCALE devised by Charles F. Richter in 1935. The number indicating intensity on Richter scale ranges between 0 to 9 but in fact the scale has no upper limit of number because it is a logarithmic scale. It is estimated that the total annual energy released by all earthquakes is about 104 ergs and most of this is from a small number of earthquakes of magnitude over 7. The following description of Richter scale may help in assessing the devastation caused by the energy release during earthquakes of varying magnitudes. The world’s largest and most intensive record earthquake was of the magnitude of 9 and the number of recorded earthquake increases 10 times as magnitude decreases by one. BBA Environmental Studies Question Unit 5
Q.6. Write an essay on flood disaster management.
Ans. Flood Disaster Management
Flood disaster management may be categorized with two groups:
- Structural Management
The general approach is aimed at preventing flood water from reaching the potential damage centres, which results in a large number of embankments along the various flood prone rivers. Structural measures may be grouped into the following:
(i) Dams and reservoirs. (ii) Embankment, flood wall, sea wall. (iii) Drainage improvement (iv) Channel improvement.
- Non-structural Management
Non-structural management is aided at modifying the susceptibility to flood damage as well as modifying the loss burden. The various non-structural measures are as follows:
- Modifying the susceptibility to flood damages through:
- Flood plain management.
- Flood forecasting and warning.
- Flood proofing inducing distiller preparedness and response planning
- Modified the flood loss burden, through:
- Disaster relief.
- Flood fighting including public health measures.
- Setting up of flood forecasting and warning services.
Q.7. Write a short note on different types of floods.
Generally there are three types of floods given as follows:
- Storm Surge : Floods in coastal areas and in river estuaries are due to storm surges, which results from the sea being driven on to the land by meteorological forces.
The physical forces act together. Storm with intense low pressure causes the level of sea size because of barometric effects. Strong winds associated with this storm when directed to share, drive the sea on the land. Storm surges are associated with tropical cyclones. The storm then produces the surges also give rise to heavy rainfall.
- Snow Melt Foods : When the snow melts, it infiltrates into soil. Water from the melting snow release catastrophically causing large runoff very rapidly. The warm rainwater on large cold spell may cause the snow pack to melt while the underlying ground is still frozen, which prevent any infiltration. Snow melt floods can be very large.
- Flash Floods : Flash floods are floods of short duration into a relatively high peak discharge. They arise from local precipitation of extremely high intensity, typical of thunderstorms. High concentration of rainfall on a small area can have devastating effects as the river flow can rise to several hundred times the normal flow in the space of a few hours. Such floods are common in arid and semi arid areas. Mountainous areas are prone to thunderstorms and the steep terrain and thin soils in the mountains assume high runoff with a short delay time.
Q.8. What is a fault and what are its different types?
Fault is a fracture or zone of fractures between two blocks of rocks. It allows the block to move relative to each other. This movement may occur rapidly, in the form of an earthquake or may occur slowly, in the form of a creep. Fault may range in length from a few millimeter and thousand of kilometers. The fault surface can be horizontal or vertical or may have an angle. BBA Environmental Studies Question Unit 5
Earth scientists use the angle of fault with respect to the surface (dip) and the direction of slip along the fault to classify the faults. The faults are of following types :
1 Normal Fault : Din slip fault in which the block above the fault has moved downward relative to the block below.
- Thrust Fault: A dip slip fault in which upper block, above the fault plane, moves up and ove the lower block
- Strike-slip Fault: The two blocks slide past one another, e.g. San andreas fault.
- Left Lateral Strike-slip Fault: Displacement of the far block is to the left when viewed either side.
- Right Lateral Strike-slip Fault: The displacement of the far block is to the right when viewed from either side.
Q.9.Describe radioactive pollution.
What is meant by Radio Active Pollution? Suggest measures to check it. (2013)
Ans. Radioactive Pollution
It is a physical pollution of soil, air or water with radioactive materials.
Natural Sources or Radio Active Pollution
- Cosmic rays that reach the earth from outer space.
- Emissions from isotopes of uranium (238U and 235U ) and thorium (232Th ) etc.
- Nuclides of elements depicting radioactivity, e.g. 40K, 14C etc.
- Radiation originating from our body form radioactive nucleides like potassium.
Anthropogenic Sources of Radioactive Pollution
- X-rays used in radiotherapy and diagnostic purpose. Treatment of cancer by gamma radiations.
- Use of radioactive materials in the field of research, medicine, industry etc.
- Operation of nuclear reactions and disposal or nuclear wastes may cause pollution of land.
- Nuclear power plants.
- Use of nuclear installation for research etc. may cause wide range effects on flora/fauna. This causes imbalance in nature.
- Atomic explosions performed by various countries produce effect on local area as well as on board geographical region.
- Various electrical implements, generate electric fields causing radiation hazards.
Effects: It depends on:
(i) Strength of radiation, (ii) rate of diffusion, (iii) duration of exposure, (iv) half life of pollutants, (v) environmental factors like rainfall, wind, temperature etc.
- Non-ionising radiation (e.g. UV) have low penetrability and cause sunburn, blindness, adverse effect on metabolism and DNA, RNA.
- Ionising radiations (X-Rays) have very high penetrability and cause damage of cells by breaking macro-biomolecules. It may cause mutations, cancer, tumour, formation of burns, loss of hair, bleeding, change metabolism.
- Dividing cells show more prominent effect e.g., skin cells, bone marrow cells, gamete forming cells, embryo cells.
- Radiation also show wide range of effect on plants as well as animals life. Dairy milk and products may get slighty contaminated.
- Control of occupational radiation exposure.
- Nuclear detoxification.
- Minimise risks of nuclear power.
- Minimise X-ray hazards.
- Disposal of radioactive wastes alongwith inert material after dilution.
- Radioactive wastes should be concentrated at some appropriate ratio and locked up in a crystalline rock line structure synthesised for this purpose.
- Radioactive wastes should be changed into harmless form.
- Minimise atomic explosion and use of atomic weapons.
Q.10. Describe marine pollution.
Ans. Marine Pollution : Sea is the sewer of the world nowadays. Water pollutants (e.g. pesticides, fertilizers, detergents, toxic metals, infection agents, radioactive wastes etc.), reach directly from coastal cities and indirectly from distant places through rivers. Discharges of oil, detergents, sewage, grease, garbage from ships also play an important role in polluting sea water. Oil spilled in tanker accidents is a serious threat to ocean life. Oil in sea water affects adversly the flora and fauna of sea water, especially phytoplanktons, zooplanktons, algae, coral reefs, birds, fishes, mammals, invertebrates etc. In 1989, linkage from oil tanker near Alaska resulted in damage to sea water biota especially coral reefs and death of about 3900 aquatic birds. In 1991, during Gulf War about 200 million gallons of oil spread in Persian Gulf causing serious damage to marine ecosystem. BBA Environmental Studies Question Unit 5
Oceans have limited to dispersal capacity through turbulance and lack decomposing capacity. Therefore, wastes discharged into sea cause localised pollution. People using sea food often suffer from infectious diseases such as cholera, hapatitis, G.I. disorders etc.
Various remedies and control measures that can arrest marine pollution are as follows:
- Direct discharge into sea from coastal areas should be discouraged.
- Minimize development activities near coastal areas.
- Use biotechnological methods to remove oil spills.
- Hot spots should be protected.
- Strict rules must be made to avoid misuse of sea by anyone. People should not throw any waste and rubbish into it.
- International fraternity should, by and large, agree to a norm in which the seas are not made dumping godown of wastes.
Q.11. What is Tsunami tragedy? Explain disaster management in India.
Ans. Tsunami Tragedy : Tsunami is Japanese word related to large seismically generated sea wave capable of considerable destruction in certain coastal areas especially where underwater earthquake occurs.
It was December 26, 2004 and time was at 6.29 a.m. in the morning an undesired earthquake erupted in Sumatra, triggering off tidal wave called Tsunami after this at 7.49 a.m., Tsunami hit Car Nicobar, the island was mostly wiped out. Then tidal waves reached for south coast of India at 8.48 a.m., Tamil Nadu was hit. The worst affected areas by this Tsumani were Andaman and Nicobar Islands and their inhabitants.
Disaster is not predictable, they follow no standard operating procedure. Disaster management is preparedness about unknown tragedy which will come suddenly:
Q.12. Define the word natural disasters. How do you prevent losses of natural disasters?
Ans. Natural Disasters: Geological processes like earthquakes, volcanoes, floods and landslides are normal natural events which have resulted in the formation of the earth that we have today. They are, however disastrous in their impacts when they affect human settlement.
Measurements to Prevent Loss of Lives
From Earthquakes : Damage to property and life can be prevented by constructing earthquake-resistant buildings in the earthquake prone zones or seismic areas. For this, the structures are heavily reinforced, weak spots are strategically placed in the buildings that can absorb vibrations from the rest of the buildings, pads or floats are placed beneath the building on which it can shift harmlessly during ground motion. Wooden houses are preferred in earthquake prone areas as in Japan. BBA Environmental Studies Question Unit 5
From Floods : These are as follows:
- Flood plains the low lying areas which get inundated during floods help to reduce floods.
- Building up of flood control structures like flood walls or deepening of river channels have only transferred the problems downstream. Building walls prevents spilling out the flood water over flood plains, but it increases the velocity of water to affect the areas downstream with greater force.
- River net working in the country is also being proposed to deal with the flood problem
Q.13. What is marine pollution? What are its effects? (2012)
Ans. Marine Pollution : Marine pollution is a global problem. It affects the health of the oceans near both developed and developing countries. Some marine pollution problems are local, but many have international implications. It is a complex problem.
This form of marine pollution is quantitatively greater than oil discharges on the sea. Consequently, it appears to be more harmful because ocean dumping takes places in and around a region which is vital for the marine ecosystem. Plankton, the microscopic plant which forms of animal and plant life, which is the basic food for other organisms, thrives in this very region. Thus, damage done to the marine ecosystem by the wastes disposed retards the sustenance of such marine creatures.
Effects of Marine Pollution : Main effects of marine pollution are the following:
- It destroys the marine life and disturbs the marine ecosystem.
- It harms the coastal amenities enjoyed by locals and tourists.
- It endangers the exploration of off-shore minerals.
- It endangers the rare species of the oceans.
- It destroys the estuaries ecosystems.
- Sea fishes, animals, birds and other living organisms are killed by oil seepage etc.
- It poses threat to flora and fauna.
- It destroys the oceans’s food sources.
- Shell fishes are subjected to polio, virus, hepatities, and other pathogens.
Q.14. What is earthquake and how it happens?
Ans. Earthquake is caused by a sudden slip or a fault. Stresses in the earth’s outer layer push the sides of the fault together, stress builds up and the rocks slips suddenly, releasing energy in waves that travel through the earth’s crust and cause the shaking that we feel during an earthquake. Earthquake occurs when plates grind a scrape against each other. In California there are two plates, the Pacific plate and the north American plate. BBA Environmental Studies Question Unit 5
Q.15. What is the difference between foreshocks and aftershocks in relation to earthquakes?
Ans. Foreshocks: which precedes larger earthquakes in the same location. Aftershocks. Smaller earthquakes occurring in the same general area dumm following a larger event or main shock.
Generally aftershock represents minor readjustments along the portion of a fault that slipped at the time of the main shock The frequency of these aftershocks decreases with time. nis e earthquakes (730 kms.) are much less likely to be followed by aftershocks than shallow earn quane.
Q.16. Define the following terms:
Ans.(a) Xerosere: In xerosere the seral stages from the pioneer to the climax community begins at terrestrial oil (a bare rock or sand).
(b) Hydrosere: If serial stages from pioneer community to climax community begins from open water, it is called hydrosere.
(C) Lithosere : In this pioneer community starts from bare rock. (d) Psammosere: In this type of succession the pioneer community begins on sand.
Q.17. Write short note on ‘automobiles and air pollution’. (2012)
Ans. Automobiles and Air Pollution : The number of auto vehicles on roads has immensely increased. They have become a major source of pollution, particularly air pollution. The detail are as under:
A filthy grey haze of inter mist, auto exhausts and the chemicals hang lower and longer than ever before in world’s most polluted cities. The smoke makes the eyes water, coats the lungs with layer of microscopic, noxious soot; and covers us with black grime. The situation of air pollution has reached to such a grim state which presents a fierce scene given as follows:
- In metropolitan cities, the air we breathe, is so harmful that it is equivalent to smoking of 10 to 20 cigarettes a day
- In India, more than 40,000 premature deaths occur due to air pollution every year as reported by World Bank.
- Air pollutants viz. sulphur dioxide (SO2), oxides of nitrogen as NO,, suspended particulate matter (SPM) and respirable suspended particulate matter (RSPM) have been great cause of air pollution.
- Recent studies reveal that the number of patients with respiratory diseases and allergies have roughly doubled since 1990.
In major cities, fast growing traffic and congestion of traffic routes are the major culprits among others
Q.18.Give an account of thermal pollution. (2012)
Ans. Thermal pollution is the rise in temperature of air and natural water bodies due to addition of heated effluent to it. It causes undesirable changes in nature and environment. BBA Environmental Studies Question Unit 5
Sources of Thermal Pollution
The sources of thermal pollution are as follows:
- Effluents from the Thermal Nuclear Power Plant: Temperature usually 10°C higher than the coolant receiving water, the aquatic life (fauna and flora) is severely affected.
- Effluents from Thermal Power Plant: the discharged water from thermal plants has 15°C higher temperature and it decreases DO (Dissolved Oxygen) content causing death of fishes and other aquatic organisms.
- Hydroelectric Power Effluent : This process results in negative thermal loading of water system.
- Industrial Effluent : Many industries like textiles paper, pulp, sugar etc. produce heated effluents and may raise the temperature of water body.
- Domestic Sewage : The untreated sewage is usually discharged in canals/lakes/ rivers/streams. It can cause rise in temperature and may have deleterious effects on aquatic life. Dissolve oxygen is also reduced causing anaerobic condition for fishes.
Physical Conditions of Aquatic Habitat
- Increase in vapour pressure and temperature.
- Increase in silting rate of suspended particles.
- Decrease in density and viscosity.
- Decrease in solubility of CO2 and 02.
- Increase in COD (chemical oxygen demand) and BOD (biological oxygen demand).
- Increase in toxicity.
- Change in physiological activities and metabolic rate.
- May cause problems with reproduction
- May cause variations in distribution pattern of organisms.
- Development of water-blooms of blue green algae.
Following methods are used to control the thermal pollution :
- Cooling Ponds: Water from condensers is stored where natural evaporation causes cooling. This water is recirculated or discharged in nearest water body.
- Spray Towers : Water from condensers is received in spray ponds and after that, water is sprayed through hozzles in the form of fine jets house flies the drops dissipate their heat to surrounding atmosphere and cooled water is discharged in nearest aquatic body or recirculated.
- Cooling Towers: These are is of two types :
(a) Wet Cooling Tower: The hot water is sprayed over baffles. The cool air entering from sides may take away the heat. This results in cooling of water. This water can be recycled or discharged in Waterbody in this process, in the vicinity of cooling tower and large amount of water is lost in evaporation.
(b) Dry Cooling Tower: In this process hot water moves through a system of pipes. Cool air is passed over these hot pipes with the help of fans. In this way, warm air goes out through the tower and water is cooled. This is a better process in comparision of wet colling tower. Here, no loss of water occurs. BBA Environmental Studies Question Unit 5
Q.19. What is soil erosion? How it can be checked?
What is soil erosion? Explain the measures of soil erosion. (2011)
Ans. Soil Erosion
Soil erosion is a natural process. It occurs when there is a loss or removal of layer of soil due to rain, wind, deforestation or any other human activity. The extent of soil erosion is determined by several factors given below :
- Type of Soil : Small grained and open structure soil erodes more than the larger gain and closed structure soil. The loam type soil erodes less, as it swells up by wetting.
- Ground Slope : The ground having steeper slope erodes more than the ground having mild slope. It is because the infiltration on steeper ground is slow but the run-off is very fast
- Intensity and Amount of Rainfall : If the intensity of rainfall is more, the soil erosion is more. This situation arises when the absorption capacity of soil is lesser as compared to heavy rainfall.
- Landscape and Distribution of Rainwater : If the landscape of the ground surface is such that the rainfall distributes evenly and there is not a plenty of run-off; the erosion will be less. Hence, the layer of soil is not washed away when the water moves along gradually.
- Mismanaged Soil Resources : The soil erosion is aggravated by following reasons also:
- Improper surface drainage
- Removal of forest litter.
- Overgrazing by cattle.
Desertification : Causes and Effect
Desertification is a gradual process of land degradation which ultimately leads to ‘desert formation’. This is like an imperfection on the earth surface in which, different pieces of degraded alnd lying here and there, assimilate together. In this way the vast areas of productive lands degrade and join together to form a desert.
Causes of desertification: Desertification is caused due to the following reasons:
- Natural reasons such as climatic change.
- Manmade reasons such as excessive use of land in:
(i)Deforestation (ii) over cultivation (iii) overgrazing (iv) industrialization (v) urbanization (vi) irrigation projects (vii) mining (viii) dam construction etc.
The population explosion has also contributed a lot towards desertification, by putting a great pressure on land.
Q.20. Write a short note on modern agriculture.
Ans. Modern Agriculture : Agriculture is the oldest and largest sector amongst, various production sectors in the world. Over the years, there has been considerable change in the methodologies of farming. Due to advancement in technologies the early days ‘manual farming has been replaced by ‘mechanized farming’. The bullock carts have been replaced by tractors, conventiona wooden ploughs are replaced by metallic multi-point ploughs etc. BBA Environmental Studies Question Unit 5
Modern agriculture methodologies have substantially changed the farming, crops production, harvesting and the related environmental scenario. The changes are both ways i.e. favourable and unfavourable also. Major contributions to modern agriculture practices have been brought by following machines, equipments and chemicals:
- Mechanical factors : These are as follows:
(c) Agricultural equipments
2. Chemical factors: These are as follows:
Amongst these the contribution of mechanical factors are favourable, but those of chemicals is under question. They have shown both the positive and the negative effects. Whereas the chemical factors have brought a revolution in agricultural production in short duration; their long-term effects tend to be detrimental.
Q.21. Write a very short note on water conservation. (2012)
Ans. Water Conservation : Water conservation can be defined as the means used to save or preserve water, i.e. any beneficial deduction in water loss, use, or waste. A reduction in water use accomplished by implementation of water conservation or water efficiency measures. BBA Environmental Studies Question Unit 5
Q.22. Discuss importance of pollution on public health. (2012)
Ans. If the environment is polluted the health of mankind/living organism will deteriorate and they may be affected by critical diseases as given below :
- Air-borne Disease: These are as follows:
- Asthma, cough, bronchitis due to S02.
- Guiddiness, defects of nervous system, gametotoxicity due to Pb.
Q.23. What are the aims of health education? (2012)
Ans. The following are the main aims and objectives of health education :
- To Provide Information about Health and Hygiene: It aims at acquainting the pupils and the teachers with the functioning of the body, the rules of health and hygiene and the precautionary measures for warding off disease. It is to be notice of the pupils how bad habits, unhygienic ways of living, addiction to smoking and liquor and such unhealthy práctices, result in evil consequences.
- To Maintain Norms of Good Health : It helps the school authorities to keep certain norms of health in school. A number of programmes of good health develops among the pupil sufficient habits of hygienic living, hygienic surroundings such as cleanliness etc.
- To Take Precautionary and Preventive Measures : Its aim is to take adequate precautions against contamination and spread of diseases. So good sanitary arrangements are made urinals and toilets are kept clean. Sweeping should be done daily, and the rooms and the furniture are to be kept near and tidy. The eatables in the tuck-shop are saved from flies.
- To Take Curative Measures : Remedials action against disease is also taken. A physicomedical check-up is made to check deformities. Disabilities and disease detected, and remedial measures suggested. A good number of pupils suffer from myopea. An eye-examination reveals the extent of short-sightedness. If glasses are not used in time, myopea will increase rapidly. Some pupils have bad teeth. If the suffer from pyorrhea, immediate medical treatment is needed.
- To Develop and Promote Mental and Emotional Health : Mental and emotional health are also equally necessary in the school health programmes. While physical health makes a physically fit, mental and emotional health enables him to maintain an even temper and happy deposition.
- To Develop a Sense of Divic Responsibility among Pupils : This is little sense of civic responsibility in our students. They generally fail in their duty to help their fellow students in particular and other persons in general. They do not come to the aid of others in time of need and alleviate their sufferings. So, one of the objective of health education is to cultivate a sense of civic responsibility. Through health education, pupils to be made conscious of social crimes, like spitting anywhere, sneezing and coughing on the faces of others.
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