Synonyms
More meanings
Tip: select a single word for meaning & synonyms.
Select multiple words normally to copy text.
Human Activities and Degrading Environment: NBSE Class 11
Get notes, summary, questions and answers, MCQs, extras, and PDFs of Chapter 5 “Human Activities and Degrading Environment” which is part of NBSE Class 11 Environment Education. However, the notes should only be treated as references and changes should be made according to the needs of the students.
If you notice any errors in the notes, please mention them in the comments
Summary
The chapter discusses the impact of human activities on the environment, focusing on how these activities have led to the degradation of natural resources. It begins by explaining how early humans lived in harmony with nature, but as populations grew and technology advanced, humans started to significantly alter the environment. The Industrial Revolution marked a major turning point, leading to widespread exploitation of fossil fuels and natural resources.
The chapter highlights the depletion of essential natural resources like soil, water, and air. Soil erosion, caused by deforestation and poor agricultural practices, has led to the degradation of a significant portion of the world’s cropland. The increasing demand for water, driven by agriculture and industry, is depleting underground water sources, leading to problems such as saltwater intrusion in coastal areas and subsidence in inland regions. Air quality has seen some improvements in industrialized nations, but issues like acid rain persist due to emissions of sulfur dioxide and nitrogen oxides.
The chapter also addresses the effects of urbanization, which has led to various environmental challenges. These include vehicular emissions that contribute to air pollution, land use changes that encroach on natural environments, and the stress on civic amenities like water supply, electricity, and waste disposal. Urban areas face additional problems such as inadequate housing, particularly in slums, and health issues related to pollution and poor sanitation.
In rural areas, the use of synthetic pesticides and inorganic fertilizers has led to soil and water pollution, as well as health risks for both humans and animals. Desertification, caused by overgrazing and overcultivation, is another significant problem in rural regions.
Textbook solutions
Multiple-Choice Questions
1. In which continent is soil erosion least?
A. Australia
B. Europe
C. Antarctica
D. North America
Answer: C. Antarctica
2. Which of the following is not responsible for ozone layer depletion?
A. Ultraviolet rays
B. Aerosol spray
C. Refrigeration
D. Cleaning solvents
Answer: A. Ultraviolet rays
3. Which of the following is not an effect of acid rain?
A. Corrosion of metal
B. Volcanic eruptions
C. Weathering of monuments
D. Acidification of lakes and soils
Answer: B. Volcanic eruptions
4. Why do people migrate from one place to another?
A. To get a better job
B. To improve their access to social amenities
C. For better education
D. All of these
Answer: D. All of these
5. Methaemoglobinemia occurs due to the presence of which of the following in drinking water?
A. Chlorates
B. Sulphates
C. Nitrates
D. Oxalates
Answer: C. Nitrates
Short Answer Questions
1. How have human activities caused soil erosion?
Answer: Human activities have caused soil erosion by degrading one-fifth to one-third of the cropland of the world, posing a significant threat to food supply. In the developing countries, the increasing need for food and firewood has resulted in deforestation and cultivation of steep slopes, causing severe erosion. Adding to the problem is the loss of prime cropland to industry, dams, urban sprawl, and highways. The amount of topsoil lost each year is at least 7.6 million tonnes, which is enough, in principle, to grow 9 million tonnes of wheat. Soil erosion and the loss of cropland and forests also reduce the moisture-holding capacity of soils and add sediments to streams, lakes, and reservoirs.
2. What has caused contamination of water?
Answer: Contamination of water has been caused by a steady decline in the availability and quality of water. Human beings already use 55% of available freshwater runoff. This level of consumption will be an increasing problem as the population rises. About 75% of the world’s rural population and 20% of its urban population have no ready access to uncontaminated water. In many regions, water supplies are contaminated with toxic chemicals and nitrates.
3. What constitutes farm waste?
Answer: Farm waste constitutes animal wastes, which are regarded as an important source of soil fertility but also give rise to serious problems of odour and water pollution. Animal wastes enter water supplies when the runoff carries the wastes into water courses. Such wastes containing pathogenic organisms are ultimately transmitted to humans. Moreover, animal wastes cannot simply be treated as municipal sewage.
4. Define (i) overgrazing (ii) overcultivation (iii) desertification.
Answer:
(i) Overgrazing: Overgrazing refers to the excessive grazing of pasture in a given area by a great number of livestock.
(ii) Overcultivation: Overcultivation means continuous cultivation without allowing the land to remain free from cultivation for a certain period of time.
(iii) Desertification: Desertification is a process where the productive potential of a land decreases rapidly.
5. What is the difference between urban environment and natural environment?
Answer: The difference between urban environment and natural environment lies in the physical environment in urban areas, with its complex mix of built (Artificial) and natural elements. The urban environment might be considered the opposite of the natural environment since it concentrates so many people, buildings, and economic activities and their supporting infrastructure such as roads, water pipes, drains, and electricity and telephone systems. Larger cities, central business districts, downtown areas, and industrial estates may have little visible that can be associated with the natural environment. Human activities have radically shaped their environment, and they seem far removed from natural processes and resources. The other parts of the cities, however, seem less removed – for instance parks, greenbelts, rivers, coastlines, or residential areas with large gardens and plenty of open spaces. However, all urban centres remain dependent on natural resources and on natural processes for disposing of their wastes.
6. What are the effects of acid rain?
Answer:
(i) Acid rain corrodes metals.
(ii) Acid rain weathers stone buildings and monuments.
(iii) Acid rain injures and kills vegetation.
(iv) Acid rain acidifies lakes, streams, and soils.
7. Differentiate between migrant and floating population.
Answer:
Migrant population: Migration is the permanent or semi-permanent change in the residence of an individual person or group of people.
Floating population: Floating population refers to people who migrate to urban areas with the intention of eventually returning to their former home.
8. How do pesticides enter a food chain?
Answer: Pesticides enter a food chain by being taken in by plant eaters or absorbed directly through the skin by aquatic organisms such as fish and various invertebrates. The pesticide is further concentrated as it passes from herbivores (plant-eaters) to carnivores (meat-eaters). It becomes highly concentrated in the tissues of animals at the end of the food chain, such as peregrine falcon, bald eagle, and osprey. Chlorinated hydrocarbons interfere in the calcium metabolism of birds, causing thinning of eggshells and subsequent reproductive failure. As a result, some large predatory and fish-eating birds are almost on the verge of extinction.
Long Answer Questions
1. Discuss the stress on waste disposal methods due to increased human activities.
Answer: The stress on waste disposal methods due to increased human activities arises because human activities have increased and, in the course of meeting their own needs, they have been producing more and more waste. As a result, the usual methods of waste disposal like landfill, incineration, composting, resource recovery, and recycling are proving not very viable in light of the increased stress on waste disposal. Slums represent one of the worst types of environmental degradation, which have become concomitant to urbanisation and industrialisation. About 17% of India’s urban population lives in slums. National Building Organisation estimates reveal that in small and medium towns, slumdwellers comprise about 10%, while the figure is 20% for cities with populations between a lakh and a million, and about 31% for the largest cities. Delhi records the highest of 47.50% of slumdwellers. Amongst the states, Bihar has 37.50% of its urban population as slumdwellers, followed by Maharashtra with 32.63% and West Bengal with 31.53%. Kerala with 8.81% and Karnataka with 14.43% are the two states with the lowest percentage of urban population in slums. The slumdwellers live in environments with inadequate living space, water supply, and sewage facilities, causing steady deterioration of surrounding regions as well as human health.
2. How do chemical pollutants and physical hazards affect the health services?
Answer: Chemical pollutants and physical hazards affect health services by presenting environmental problems best identified in terms of the nature of the hazard. For instance, biological pathogens, chemical pollutants, and physical hazards challenge the health departments of various countries, especially with growing populations and new health problems arising from hitherto unknown pollutants. The most serious urban environmental problems worldwide in regard to health are biological pathogens (disease-causing agents) in urban water, food, air, and soil. Tens of millions of urban dwellers suffer each year from malaria or other diseases spread by insects, including hundreds of children under five who die due to these diseases. People of all ages suffer from intestinal parasitic infestations caused by pathogens in the soil, water, or food and from respiratory and other diseases caused or exacerbated by pathogens in the air, both indoors and outdoors. There is a large and growing list of chemical pollutants that are known to cause or contribute to ill health or premature death. Air pollution is sufficiently serious in many cities to have demonstrable health impacts. There is also a growing list of chemicals in the urban environment about which there is concern, even if the precise health impact is not known. Physical hazards are a major source of injury and premature death in most urban areas. Domestic accidents are often the most serious, especially if a high proportion of the population live in overcrowded dwellings made of flammable materials, as is common in many urban shanty towns. Road accidents are often among the most serious causes of injury and premature death.
3. How is stress on transport and air pollution connected?
Answer: Stress on transport and air pollution are connected because as most cities grow and more people settle in the suburbs, the use of both private and public transport has increased. More people needing transport to travel to and from their workplaces has led to the building of flyovers, highways, and train tunnels that have claimed land. Many times, these constructions have also encroached on the so-called ‘green belt’ areas in cities and towns. More vehicles have obviously led to more exhaust fume emissions that have polluted the air and caused health problems for many people. Providing transport facilities to a growing populace also results in stress on authorities to provide cheaper and more frequent transport services.
4. How has demand for housing increased in urban areas?
Answer: The demand for housing in urban areas has increased significantly over centuries. This demand was often met by unplanned additions and subdivisions of existing structures. Where climate permitted, squatting (occupying without title or payment of rent) became commonplace, but provided only temporary shelter. By the 19th century, with the Industrial Revolution, people were moving to cities in unprecedented numbers. Workers made their homes in sheds, railway yards, and factory cellars, typically without sanitation facilities or water supply. In the post-industrial society of the 20th century, housing in developing nations and poor parts of developed countries continues to be of insufficient quality and does not meet the demand of some parts of the population. Vacant, abandoned inner-city housing exists alongside structures that are usable but overcrowded, and buildings that are structurally reclaimable but functionally obsolete.
5. Why does urban population show fluctuation?
Answer: Urban population shows fluctuation due to migration and floating populations. Migration is the permanent or semi-permanent change in the residence of an individual person or group of people. It represents a spatial redistribution of people and can have important consequences for the use and development of land and other resources, living conditions, availability of jobs, and possibly political, social, and economic stability. In places like Nagaland, where people depend on agriculture for their livelihood and face unemployment due to a lack of industries, people migrate to different cities for better employment opportunities. People also send their children to big cities for higher education and training, becoming more aware of the benefits of a better life. In metropolitan cities of India and the world, migrants come in an effort to improve their lives, such as by securing better or more secure jobs or by improving their access to social amenities like schools or hospitals. They gradually settle down permanently in the cities. The floating population in urban areas includes people who migrate with the intention of eventually returning to their former home. Time scales can vary from years to even shorter periods. Such migrants include examples of labourers from Uttar Pradesh and Bihar who reach Punjab to earn a living during the farming season and later return to their home towns or villages.
6. How does use of inorganic fertilisers cause environmental problems in rural areas?
Answer: The use of inorganic fertilisers causes environmental problems in rural areas by transforming rural environments, especially in the 21st century, as governments have encouraged the adoption of modern varieties of crops and livestock together with the associated packages of external inputs (such as fertilisers, pesticides, antibiotics, credit, machinery) necessary to make these productive. Inorganic fertilisers, including nitrogen, phosphate, and potash, are now used on a large scale. When phosphates and nitrates are used carelessly, they may reach estuaries and lakes through runoffs, leading to algal blooms that choke whole stretches of water. This leads to the rotting of plants, depletion of oxygen, and death of fish. Even herbicides and insecticides used on farmland have been known to contaminate both surface and groundwater. Some of these pollutants are carried to distant places by wind, rain, and rivers, and have been found even in high mountains and seaside swamps. Fertilisers can be transmitted to groundwater by leaching and to surface waters by natural drainage and storm runoff. Nitrates are of prime concern since their presence in drinking water may cause methaemoglobinemia in infants, commonly known as ‘blue babies’. The same process occurs in the stomachs of ruminants, affecting livestock through nitrate poisoning. Plant nutrients also lead to eutrophication. The enrichment of water with nutrients is referred to as ‘eutrophication’. Plant nutrients, nitrogen, and phosphorus stimulate the growth of algae and other aquatic plants. Excessive growth of these plants and their subsequent decay produces bad odours and depletes the oxygen content of water.
7. What are the effects of use of synthetic pesticides?
Answer: The effects of the use of synthetic pesticides include disastrous environmental side-effects. Extensive use of synthetic pesticides derived from chlorinated hydrocarbons in pest control has led to persistent and resistant environmental degradation. These organochlorine pesticides are highly persistent and tend to resist biological degradation. Relatively insoluble in water, they cling to plant tissues and accumulate in the soil, at the bottom of streams and ponds, and in the atmosphere. Once volatilised, the pesticides are distributed worldwide, contaminating wilderness areas far removed from agricultural regions, even reaching the Antarctic and Arctic Zones. Although these synthetic chemicals are not found in nature, they nevertheless enter the food chain. The pesticides are either taken in by plant eaters or absorbed directly through the skin by aquatic organisms such as fish and various invertebrates. The pesticide becomes further concentrated as it passes from herbivores (plant-eaters) to carnivores (meat-eaters). It becomes highly concentrated in the tissues of animals at the end of the food chain, such as peregrine falcons, bald eagles, and ospreys. Chlorinated hydrocarbons interfere with the calcium metabolism of birds, causing thinning of eggshells and subsequent reproductive failure. As a result, some large predatory and fish-eating birds are almost on the verge of extinction. Because of the dangers of pesticides to wildlife and human beings, and because insects have acquired resistance to them, the use of halogenated hydrocarbons such as DDT is declining in the Western world, although large quantities are still used in developing countries.
8. What do you know about the degrading effect of pollution on the ozone layer?
Answer: The degrading effect of pollution on the ozone layer was discovered during the 1980s when scientists found that human activity was having a detrimental effect on the global ozone layer, a region of the atmosphere that shields the Earth from the sun’s harmful ultraviolet rays. Without this gaseous layer, no life is possible on Earth. Studies showed that the ozone layer is being damaged by the increasing use of industrial chemicals called chlorofluorocarbons (CFCs) that are extensively used in refrigeration, air-conditioning, cleaning solvents, packing materials, and aerosol sprays. Initially, it was believed that the ozone layer was being reduced gradually all over the globe. However, in 1985, further research revealed a growing ozone hole concentrated above Antarctica. Because of the growing threat of these dangerous environmental problems, many nations began working towards eliminating the manufacture and use of CFCs by the 2000s. However, CFCs remain in the atmosphere for more than 100 years, so ozone destruction will continue to pose a threat for decades to come.
Think and Answer
Has urbanisation proved to be a boon or a bane? Discuss in light of the effects on the environment.
Answer: Urbanisation has had both positive and negative effects on the environment, making it a subject of debate whether it is a boon or a bane. On one hand, urbanisation has led to economic growth, improved infrastructure, and better access to services such as healthcare and education. It has facilitated technological advancements and created numerous opportunities for employment and innovation. Urban areas often provide better living standards and have the potential to efficiently manage resources due to concentrated populations.
On the other hand, urbanisation has also caused significant environmental degradation. The expansion of urban areas has led to deforestation, loss of biodiversity, and the destruction of natural habitats. The increase in industrial activities and vehicular emissions has contributed to air and water pollution, making cities the epicentres of environmental hazards. The stress on waste disposal systems, inadequate housing, and the overuse of natural resources like water and land have resulted in severe environmental issues. Urban sprawl has also led to the encroachment on agricultural land, reducing the space available for food production and leading to problems like food insecurity.
Moreover, the concentration of populations in urban areas has led to the formation of slums, where people live in overcrowded and unsanitary conditions, further exacerbating environmental problems. The demand for housing, transportation, and energy in urban areas has increased the pressure on natural resources, leading to unsustainable consumption patterns. The environmental impact of urbanisation is further amplified by the generation of large amounts of waste and the challenges associated with its disposal.
Extras MCQs
1. Where did Homo sapiens first appear?
A. Asia
B. Europe
C. Africa
D. South America
Answer: C. Africa
Q. What revolution allowed early humans to begin altering the environment?
A. Industrial Revolution
B. Agricultural Revolution
C. Technological Revolution
D. Information Revolution
Answer: B. Agricultural Revolution
Q. What is the main cause of soil erosion in developing countries?
A. Urbanisation
B. Deforestation
C. Mining
D. Industrialisation
Answer: B. Deforestation
Q. What was a major outcome of the Industrial Revolution on the environment?
A. Decreased air pollution
B. Preservation of natural resources
C. Extensive exploitation of fossil fuels
D. Reduction in water pollution
Answer: C. Extensive exploitation of fossil fuels
Q. Which of the following is a significant consequence of soil erosion?
A. Increase in forest cover
B. Enhanced water quality
C. Loss of cropland
D. Decreased food production
Answer: C. Loss of cropland
Q. What environmental problem is caused by the depletion of underground aquifers?
A. Soil erosion
B. Water pollution
C. Surface subsidence
D. Deforestation
Answer: C. Surface subsidence
Q. Which chemical is primarily responsible for the depletion of the ozone layer?
A. Nitrogen oxides
B. Sulphur dioxide
C. Chlorofluorocarbons (CFCs)
D. Carbon dioxide
Answer: C. Chlorofluorocarbons (CFCs)
Q. What term describes the enrichment of water with nutrients, leading to excessive growth of aquatic plants?
A. Desertification
B. Eutrophication
C. Overgrazing
D. Salinisation
Answer: B. Eutrophication
Q. What is a primary concern related to the use of nitrates in agriculture?
A. Air pollution
B. Water pollution
C. Soil degradation
D. Loss of biodiversity
Answer: B. Water pollution
Q. What environmental issue is closely associated with overgrazing?
A. Acid rain
B. Soil erosion
C. Air pollution
D. Forest depletion
Answer: B. Soil erosion
Q. Which process leads to the rapid decrease in the productive potential of land?
A. Eutrophication
B. Desertification
C. Overgrazing
D. Urbanisation
Answer: B. Desertification
Q. What is the primary source of energy that has been extensively exploited since the Industrial Revolution?
A. Wind energy
B. Solar energy
C. Fossil fuels
D. Hydroelectric power
Answer: C. Fossil fuels
Q. What problem is caused by the extensive use of synthetic pesticides?
A. Increase in soil fertility
B. Contamination of water bodies
C. Reduction in crop yield
D. Improvement in air quality
Answer: B. Contamination of water bodies
Q. Which substance is associated with causing methaemoglobinemia (‘blue babies’) when found in drinking water?
A. Phosphates
B. Nitrates
C. Chlorofluorocarbons
D. Sulphates
Answer: B. Nitrates
Q. What environmental impact is caused by overcultivation?
A. Water contamination
B. Increase in biodiversity
C. Soil degradation
D. Forest regeneration
Answer: C. Soil degradation
Q. What is the primary pollutant that causes acid rain?
A. Carbon dioxide
B. Nitrous oxides
C. Methane
D. Ozone
Answer: B. Nitrous oxides
Q. What does urbanisation mean?
A. Development of rural areas
B. Redistribution of populations to rural settlements
C. Removal of the rural character of a town or area
D. Increase in rural population
Answer: C. Removal of the rural character of a town or area
Q. Which discipline focuses on environmental justice in urban areas?
A. Political science
B. Environmental health
C. Economics
D. Urban planning
Answer: A. Political science
Q. What is a significant contributor to air pollution in urban areas?
A. Increased agricultural activity
B. High population density
C. Vehicular emissions
D. Industrial decline
Answer: C. Vehicular emissions
Q. What causes acid deposition?
A. Emissions of carbon monoxide
B. Emissions of sulphur dioxide and nitrous oxides
C. Overgrazing in rural areas
D. Deforestation
Answer: B. Emissions of sulphur dioxide and nitrous oxides
Q. What type of land use is commonly associated with the highest rents in urban areas?
A. Residential
B. Recreational
C. Central business district
D. Non-developed
Answer: C. Central business district
Q. What percentage of India’s urban population lives in slums?
A. 10%
B. 31%
C. 17%
D. 47.50%
Answer: C. 17%
Q. What is a major impact of increased population on electricity?
A. Decreased use of renewable energy
B. Increased energy crisis
C. Overproduction of electricity
D. Decreased electricity consumption
Answer: B. Increased energy crisis
Q. What is the most serious urban environmental problem worldwide related to health?
A. Noise pollution
B. Lack of green spaces
C. Biological pathogens
D. Increased transportation
Answer: C. Biological pathogens
Q. Which state in India has the lowest percentage of urban population living in slums?
A. Maharashtra
B. Bihar
C. Kerala
D. Karnataka
Answer: C. Kerala
Q. Which mode of transportation is most relied upon in Nagaland?
A. Railways
B. Roads
C. Air transport
D. Waterways
Answer: B. Roads
Q. What is the primary source of acid rain?
A. Emissions from vehicles
B. Agricultural activities
C. Industrial waste
D. Natural disasters
Answer: A. Emissions from vehicles
Q. What is the main concern for sustainable development in urban areas?
A. Unlimited use of natural resources
B. High levels of industrialisation
C. Meeting human needs without threatening the environment
D. Expanding urban population
Answer: C. Meeting human needs without threatening the environment
Q. What is a common characteristic of slums in urban areas?
A. Abundant green spaces
B. High-quality housing
C. Inadequate living space and sanitation
D. Low population density
Answer: C. Inadequate living space and sanitation
Q. What is a primary reason for migration to metropolitan cities?
A. Better access to education
B. Climate conditions
C. Agricultural opportunities
D. Political stability
Answer: A. Better access to education
31. What type of waste is classified as solid waste?
A. Liquids
B. Gases
C. Semi-solid materials
D. Energy
Answer: C. Semi-solid materials
Extra Questions and Answers
1. Where did human beings apparently first appear?
Answer: Human beings apparently first appeared in Africa.
Q. What were the main environmental modifications made by early human beings?
Answer: Early human beings modified the environment through activities such as controlling and using fire to eliminate natural vegetation, domesticating plants and animals, which led to overgrazing, soil erosion, and widespread destruction of natural vegetation for crops. They also denuded mountains, depleted forests for wood fuel, and slaughtered wild animals for food.
Q. What happened as human populations increased and technology expanded?
Answer: As human populations increased and technology expanded, more significant and widespread environmental problems arose, culminating in the Industrial Revolution, which involved the discovery, use, and exploitation of fossil fuels and extensive exploitation of Earth’s mineral resources.
Q. How much topsoil is lost each year?
Answer: At least 7.6 million tonnes of topsoil are lost each year.
Q. What is causing the growing world water problem?
Answer: The growing world water problem is aggravated by the depletion of underground aquifers, saltwater intrusion along coastal areas, and the compaction of porous rocks and sediments in inland areas due to the expanding human population’s need for irrigation and industrial water use.
Q. What percentage of the world’s rural and urban populations lacks access to uncontaminated water?
Answer: About 75% of the world’s rural population and 20% of its urban population lack access to uncontaminated water.
Q. What are fossil fuels? Why is their conservation important?
Answer: Fossil fuels are important sources of energy that are present in limited quantities. Conservation is important because excessive use causes pollution and global warming.
Q. What are the effects of human activities on the ozone layer?
Answer: Human activities, particularly the use of industrial chemicals like chlorofluorocarbons (CFCs), have damaged the global ozone layer, creating a growing ozone hole above Antarctica. This damage continues to pose a threat due to the long-lasting presence of CFCs in the atmosphere.
Q. What are the environmental side effects of using synthetic pesticides derived from chlorinated hydrocarbons?
Answer: Synthetic pesticides derived from chlorinated hydrocarbons are highly persistent, resist biological degradation, and tend to accumulate in soils and aquatic environments, leading to contamination far removed from agricultural regions and even affecting wilderness areas such as the Antarctic and Arctic Zones.
Q. How do inorganic fertilisers and farm wastes affect the environment?
Answer: Inorganic fertilisers, when used carelessly, can lead to the eutrophication of water bodies, while farm wastes, particularly animal manure, can cause pollution when washed into streams and rivers, leading to odour and water pollution.
Q. What is desertification, and what causes it?
Answer: Desertification is the process where the productive potential of land decreases rapidly. It is caused by overgrazing, which is the excessive grazing of pasture, and overcultivation, which means continuous cultivation without allowing the land to remain free from cultivation for a period.
Q. What are some sources of water pollution in rural areas?
Answer: In rural areas, rivers are often treated like rubbish grounds, with garbage smothering fish and plankton, and villagers pollute the water by bathing cattle and washing clothes in streams and rivers, endangering the health of all living beings.
Q. What does urbanisation mean and how does it affect the environment?
Answer: Urbanisation means the removal of the rural character of a town or area, leading to increased mobility, impersonality, and large agglomerations of crowds and dwellings, often resulting in significant environmental challenges.
Q. What constitutes the urban environment?
Answer: The urban environment is a complex mix of built (artificial) and natural elements. It includes people, buildings, economic activities, and infrastructure such as roads, water pipes, drains, electricity, and telephone systems.
Q. How does the urban environment differ from the natural environment?
Answer: The urban environment differs from the natural environment because it concentrates many people, buildings, and economic activities, creating a setting that often appears far removed from natural processes and resources.
Q. What are some health issues related to urban environments in Nagaland?
Answer: Nagaland faces a significant burden of infectious diseases related to inadequate sanitation and water facilities, prompting the state government to implement total sanitation campaigns to improve conditions, especially for children in schools.
Q. What impact does vehicular emissions have on urban environments?
Answer: Vehicular emissions release harmful chemicals, including carbon monoxide, sulphur dioxide, nitrogen oxides, and hydrocarbons, which contribute to air pollution, smog formation, and adverse effects on human health, particularly brain development in children.
Q. What causes acid deposition? What are its effects?
Answer: Acid deposition is caused by the burning of fossil fuels and the emission of sulphur dioxide and nitrous oxides from power plants and vehicles. Its effects include the corrosion of metals, weathering of stone buildings, injury to vegetation, and the acidification of lakes, streams, and soils.
Q. How is land use classified in urban areas?
Answer: Land use in urban areas is classified into categories such as residential, industrial, and communication purposes. These patterns reflect responses to urban growth and decline, with central business districts being highly competitive areas for land use.
Q. What are ‘zones of transition’ in urban areas?
Answer: Zones of transition, also known as ‘inner city’ areas, are typically on the decline and characterized by high-density, poor housing, and urban social problems. They are located on the fringe of central business districts and often experience high land value.
Q. What is the significance of migration and floating population in urban areas?
Answer: Migration and floating populations represent a spatial redistribution of people, influencing land use, resource development, living conditions, job availability, and socio-economic stability. Migrants often seek better opportunities and social amenities in urban areas.
Q. What challenges does urban housing face, particularly in developing countries?
Answer: Urban housing in developing countries is often insufficient in quality and quantity, leading to the rise of shanty towns with inadequate infrastructure. These areas lack basic human needs like water, sanitation, electricity, and roads, resulting in poor living conditions.
Q. How does urbanisation impact water supply and electricity?
Answer: Urbanisation increases demand for water and electricity, leading to water shortages, depletion of underground water, and energy crises. Renewable energy resources are often insufficient, and non-renewable resources are becoming increasingly scarce, posing challenges for sustainable development.
Q. What percentage of India’s urban population lives in slums?
Answer: About 17% of India’s urban population lives in slums, with higher percentages in larger cities. Delhi has the highest slum population at 47.50%, followed by Bihar with 37.50%, Maharashtra with 32.63%, and West Bengal with 31.53%.
Q. What environmental and health issues are prevalent in urban slums?
Answer: Urban slums often suffer from inadequate living space, water supply, and sewage facilities, leading to environmental degradation and health problems such as respiratory diseases, infections, and other issues related to poor sanitation.
Q. What are the main environmental health concerns in urban areas?
Answer: The main environmental health concerns in urban areas include biological pathogens in water, food, air, and soil, chemical pollutants, and physical hazards. These issues contribute to diseases, injuries, and premature deaths, particularly in overcrowded and polluted environments.
Q. How does transportation contribute to environmental degradation in urban areas?
Answer: Transportation contributes to environmental degradation by increasing vehicle emissions, leading to air pollution, health problems, and the loss of green belt areas due to the construction of roads, highways, and other transport infrastructure.
Q. What are the transportation challenges in Nagaland?
Answer: Nagaland primarily relies on roads for transportation, with limited rail connections. The National Highway links major cities, but the state faces challenges in providing adequate and sustainable transport services, especially with a growing population and reliance on road transport.
Q. What are the causes and consequences of soil erosion?
Answer: Soil erosion is rampant everywhere except in Antarctica and is degrading one-fifth to one-third of the world’s cropland, posing a significant threat to food supply. In developing countries, the increasing need for food and firewood has led to deforestation and the cultivation of steep slopes, causing severe erosion. Additionally, the loss of prime cropland to industry, dams, urban sprawl, and highways exacerbates the problem. The amount of topsoil lost each year is at least 7.6 million tonnes, which could, in principle, grow 9 million tonnes of wheat. Soil erosion and the loss of cropland and forests also reduce the moisture-holding capacity of soils and add sediments to streams, lakes, and reservoirs.
Q. How have forests and wildlife been affected by human activities?
Answer: Forests have been significantly affected by the expanding human population and industrialization. The clearing of forests has destroyed the habitats of many plant and animal species. Forest resources, which provide food, timber, medicines, fibres, oils, and many other useful products, must be used in a judicious and sustainable manner that is both environmentally and developmentally sound to prevent further damage.
Q. What were the findings regarding the ozone layer in the 1980s? What actions were taken?
Answer: During the 1980s, scientists discovered that human activity was having a detrimental effect on the global ozone layer, a region of the atmosphere that shields the Earth from the sun’s harmful ultraviolet rays. Studies showed that the ozone layer was being damaged by the increasing use of industrial chemicals called chlorofluorocarbons (CFCs). In 1985, further research revealed a growing ozone hole concentrated above Antarctica. As a result, many nations began working towards eliminating the manufacture and use of CFCs by the 2000s. However, because CFCs remain in the atmosphere for more than 100 years, ozone destruction will continue to pose a threat for decades to come.
Q. What are the environmental side effects of using synthetic pesticides?
Answer: The extensive use of synthetic pesticides derived from chlorinated hydrocarbons in pest control has disastrous environmental side effects. These organochlorine pesticides are highly persistent and tend to resist biological degradation. They cling to plant tissues, accumulate in the soil, and contaminate the atmosphere, even reaching wilderness areas far removed from agricultural regions, such as the Antarctic and Arctic Zones. Once volatilized, these pesticides enter the food chain, becoming highly concentrated in the tissues of animals at the end of the food chain, such as peregrine falcons, bald eagles, and ospreys. Chlorinated hydrocarbons interfere with the calcium metabolism of birds, causing thinning of eggshells and subsequent reproductive failure.
Q. How does the use of inorganic fertilizers impact the environment?
Answer: The use of inorganic fertilizers, including nitrogen, phosphate, and potash, has increased significantly with the modernization of agriculture. However, when phosphates and nitrates are used carelessly, they may reach estuaries and lakes through runoff, leading to algal blooms that choke entire stretches of water. This causes the rotting of plants, depletion of oxygen, and death of fish. Herbicides and insecticides used in farmland can also contaminate both surface and groundwater. Some of these pollutants are carried to distant places by wind, rain, and rivers, and have been found even in high mountains and seaside swamps.
Q. What are the environmental problems caused by farm animal wastes?
Answer: Farm animal wastes are regarded as an important source of soil fertility, but they also give rise to serious problems of odor and water pollution. Animal wastes enter water supplies when runoff carries them into watercourses, transmitting pathogenic organisms to humans. Additionally, animal wastes cannot simply be treated as municipal sewage. The large quantity of organic material produced by cattle and pigs, primarily composed of phosphates, contributes to water pollution when washed into drains and streams. Excess amounts of nitrates in combination with phosphates can cause issues like eutrophication, leading to further environmental degradation.
Q. How does urbanisation affect the environment and human society?
Answer: Urbanisation, which refers to the removal of the rural character of a town or area, is associated with the development of civilization. It involves the redistribution of populations from rural to urban settlements. As a result, human beings, who originally lived in small, scattered communities, now face increased mobility, impersonality, and the massive agglomeration of crowds and dwellings. This shift has led to the concentration of people, buildings, and economic activities in urban areas, often resulting in significant environmental challenges, including the disruption of natural ecosystems, the creation of waste, and the depletion of natural resources needed to support urban life.
Q. What are the environmental health concerns in urban areas?
Answer: Environmental health concerns in urban areas primarily center on the control of infectious and parasitic diseases, whose incidence and transmission are often increased by overcrowding, poor-quality housing, and inadequate provision for water supply, sanitation, and drainage. These conditions, prevalent in many urban areas in Africa, Asia, and Latin America, pose significant risks to public health and contribute to the spread of diseases. Addressing these issues requires a multidisciplinary approach, with each professional discipline bringing its own concerns to the table in addressing environmental problems in urban areas.
Q. What chemicals are released from vehicle exhausts?
Answer: Vehicle exhausts release a mixture of chemicals including carbon monoxide, sulphur dioxide, nitrogen oxides, and hydrocarbons. Some gasoline also contains lead which appears in the exhaust fumes. This can have adverse effects on brain development in children.
Q. What causes acid deposition?
Answer: Acid deposition is caused by burning fossil fuels and by the emission of sulphur dioxide and nitrous oxides into the air from power plants and motor vehicles. These chemicals interact with sunlight, moisture, and oxidants to produce sulphuric and nitric acids, which are carried with the atmospheric circulation and fall back to Earth in the form of rainfall and snowfall, commonly referred to as acid rain with dry deposits in the form of dry particles and atmospheric gases.
Q. What are the effects of acid rain?
Answer: (i) Acid rain corrodes metals. (ii) Acid rain weathers stone buildings and monuments. (iii) Acid rain injures and kills vegetation. (iv) Acid rain acidifies lakes, streams, and soils.
Q. What is the central business district (CBD) in urban areas?
Answer: The central business district is usually located in the centre of the town, and this district is the area of most intense competition for land, with the highest rents. In larger cities, it is often associated with the traditional area of financial services, such as Wall Street in New York.
Q. Why do people in Nagaland migrate to different cities?
Answer: The people in Nagaland depend on agriculture for their livelihood. There are a few industries in the state, so people are facing unemployment. To get better employment, they migrate to different cities. Nowadays, people send their children to big cities for higher education and training. They have become more aware of a better life.
Q. What is a floating population in urban areas?
Answer: Floating population in urban areas includes people who migrate with the intention of eventually returning to their former home. Time-scales can vary from years to even shorter periods. Such migrants include examples of labourers from Uttar Pradesh and Bihar who reach Punjab to earn a living during the farming season and return to their hometowns or villages later on.
Q. How has urban housing demand been fulfilled historically?
Answer: Demand for urban housing has been on the increase for centuries now. This demand was filled by unplanned additions and subdivisions of existing structures. Where climate permitted, squatting became commonplace, but it provided only temporary shelter. By the 19th century, with the Industrial Revolution, people were moving to cities in unprecedented numbers, often living in poor conditions.
Q. What are the conditions in shanty towns in developing countries?
Answer: In developing countries, in the urban areas, housing demands are still largely unmet, resulting in people being forced to live in shanty towns, settlements in which the houses are very poorly equipped to deal with basic human needs. Shanty towns have very little in the way of infrastructure. They are usually without water, sanitation, electricity, or roads.
Q. What is the impact of urbanisation and industrialisation on water availability?
Answer: Due to urbanisation and industrialisation, more and more water is required for running industries and irrigation systems. As a result, there is a depletion in the underground availability of water and its quality, due to its contamination with toxic chemicals, nitrates, phosphates, and sulphates.
Q. What is the stress on electricity supply due to population growth?
Answer: An increased population needs more electricity for consumption, resulting in an energy crisis. Electricity generated from renewable resources like water is not sufficient to meet the needs of the growing population, and there is uncertainty about how long electricity from non-renewable energy resources such as coal, petroleum, and natural gas will last.
Q. What is solid waste disposal?
Answer: Solid waste disposal is the disposal of normally solid or semi-solid materials resulting from human and animal activities that are useless, unwanted, or hazardous. Solid wastes can be classified as garbage, rubbish, ashes, large wastes, dead animals, sewage treatment solids, industrial wastes, mining wastes, and agricultural wastes.
Q. Write a note on transportation in Nagaland?
Answer: Nagaland depends mostly on roads for transportation. The National Highway (NH) runs from Dimapur to Kohima and reaches Imphal in Manipur. A main road links Mokokchung with Amguri in Assam. A short distance of Northeast Frontier Railway passing through Dimapur from Assam is the only rail link with the rest of India. Initially, NST (Nagaland State Transport) buses were the only means of passenger transport in the state, but private operators are now also providing services.
49. How has the Industrial Revolution affected the environment?
Answer: The Industrial Revolution, which began in the mid-18th century, had profound effects on the environment. It marked a period of rapid technological advancement, leading to the discovery, use, and exploitation of fossil fuels and the extensive extraction of mineral resources. These activities significantly altered the Earth’s landscape, atmosphere, and water systems. The widespread use of fossil fuels, such as coal and oil, contributed to the release of large amounts of greenhouse gases and pollutants into the atmosphere, leading to global warming and air quality deterioration. The extraction of minerals disrupted natural ecosystems and depleted resources that had accumulated over millions of years. The Industrial Revolution set the stage for the modern era’s environmental challenges, including climate change, pollution, and resource depletion, which continue to impact the planet today.
