Unit I. Part -b. Environmental Issues

7/31/2019 Unit I. Part -b. Environmental Issues

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b. Environmental issues:

Concept of environmental technology,Impact of technology and growing population on environment,disasters management,acid rainozone depletion.

Applications of Remote Sensing and Geographic Information System (GIS). 02 Hrs

b.1 Concept of environmental technology,the term environmental technologies can be and is being used in various ways. The concept mayrefer solely to end-of-pipe technologies and the remediation of already polluted/damaged areas.However, it can also cover integrated clean technologies and, in an even wider sense, issues likemonitoring, measuring, product change or environmental management systems. In the ETAP(Environmental Technologies ActionPlan for the European Union) and in this report, the concept isused in its wide sense, as encompassing all technologies whose use is less environmentally harmfulthan relevant alternatives.

b.2 Impact of technology and growing population onenvironment,Impact of Technology on EnvironmentWe have been inventing & innovating different activities, products & services for thebenefit & the development of our society. Unfortunately we have been using thistechnology in an uncontrolled & unplanned way and this has created number ofenvironmental issues. Such facets of technology & their environmental issues are

Industrialization

Urbanization,

Transportation,

Modern Agriculture Mining, etc. (write few impacts of each on the environment)

To control or to minimize such impact on the environment, it is necessary to adoptenvironmental technology to every branch of technology. Through, such sustainabilityapproach we can minimize or even can eliminate the impacts of technology on ourenvironment.

Impact Population on EnvironmentIn the last five decades a phenomenal rise in the world population has taken placewith technology revolution & is expected to grow further.World population trend at different times based on UN demographic studies is

Years Population (billions)

1950 2.51998 5.92001 6.22050 8.9 (forecast)

Total Land area of the world 130 million km2

This growing population coupled with economic (technology) revolution is having a

great impact on our environment as well as on our social well being. They are listed

as


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1. Food: Sufficient food cannot be produced for the large masses, and this resultin hunger & malnutrition. Under- nourished people, particularly children,cannot build a healthy nation.

2. Shelter: Housing is one of the biggest problems posed by the abnormalincrease in population. It is not possible for all the people on earth to have aroof over their heads.

3. Water: demand for water increases. Coupled with this is the global shortage offresh water due to global warming. Availability of water is decreasing at analarming rate in some parts of the world. Water famine is setting in posing aserious threat to food production. Tensions are building up over the sharing ofwater. Shortage of water creates unsanitary conditions and health problems.

The cost of drinking and domestic uses also increases.4. Resources: At such a rate of population increase, natural resources such as

minerals and fossil fuels will soon be depleted and non-renewable resourceswill not be available to future generations. Competition for resources will leadto tensions.

5. Health care: It is quite natural for disease to spread in populous areas. Healthcare facilities become inadequate.

6. Education: Education becomes difficult. Illiteracy can not be contained.7. Energy: Energy is the key for all activities. Energy availability is very less in

over-populous countries.8. Jobs: Unemployment, particularly among youth, is an out fall of overpopulation.9. Transportation problems: More vehicles will ply, resulting in huge consumption

of huge consumption of fossil fuels & emission of air pollution along withcongestion.

10. Shortage of land: Food production will be affected & land hunger has alreadyset in.

11.Environmental problems:a. Problems related to waste disposal.b. Water pollution

c. Land pollutiond. Spread of diseasese. Deforestation.

12.Shortage of infrastructural facilities,13.Comforts & creational facilities dwindle.14.Rescue & rehabilitation during emergencies such as floods, cyclones,

earthquake, and other calamities become difficult.15.As the population is not evenly distributed all over the world, inequalities

among the countries lead to competition for food, water, fuel, jobs, & otherproblems. Tensions build up & wars are breaking out over sharing of resources.

This will be further aggravated by uncontrolled population growth.16.Economy and purchasing power: for an over population country, it takes

extremely hard to become economically strong. Its purchasing power will notbe enough to provide good living conditions for its citizens.

17.Impact on HABITATSa. Habitat alteration: Habitat alteration are changes made to the

environment that adversely affect ecosystem function, although notperhaps completely or permanently. One example is livestock grazing,Livestock, such as cattle can effectively trample aquatic vegetation and


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cause accelerated bank erosion (especially in streams) and this canresult in unsuitable habitat for dependent insects & other organisms

b. Habitat destruction: Habitat destruction is defined as the completeelimination of a localized or regional ecosystem leading to the total lossof its former biological function (Dodd and Smith 2003). For example,mining, housing developments or agricultural developments etc.

c. Habitat fragmentation: Habitat fragmentation is a process ofemergence of discontinuities (fragmentation) in an organism's preferredenvironment (habitat). Habitat fragmentation is a secondary Habitatfragmentation is a secondary affect of habitat destruction. Habitatfragmentation is frequently caused by humans when nativevegetationis cleared for human activities such as agriculture, rural development orurbanization. Habitats which were once continuous become divided intoseparate fragments. After intensive clearing, the separate fragmentstend to be very small islands isolated from each other by crop land,pasture, pavement, or even barren land. This Habitat fragmentationresults in

i. reduction in the total area of the habitat

ii. increase in the amount ofedgeiii. decrease in the amount of interior habitativ. isolation of one habitat fragment from other areas of habitatv. breaking up of one patch of habitat into several smaller patchesvi. decrease in the average size of each patch of habitat

Reasons for Population GrowthNo single reason can be pinpointed for the increase in population. Some of theidentifiable causes are

Ignorance about the importance of optimum population, small family size &comforts, and future availability of resources.

Illiteracy, particularly among women.

Belief that social security comes with more human beings at a place or in aregion.

Lack of facilities like infrastructure to propagate the benefits of small families &family planning.

Socio-economic & religious issues.

Unethical national policies toward technological innovations.

Control of Population growth

Education: Literacy plays a major role in checking population growth.

Technology: stress should be given to resource conservation & alternativeenvironment friendly technology (sustainable development) through research

& development. Improving economic condition: the economy of a country & its population are

closely related as in the case of western countries where the economicallysound societies are found lesser populated with good facilities.

Publicity: the importance of birth control, the significance of family size &related information should be effectively published through various media,school books & other sources. People in the remotest of the villages shouldalso be made aware of the comforts that can be derived from small family size.
http://en.wikipedia.org/wiki/Habitat_(ecology)http://en.wiktionary.org/wiki/nativehttp://en.wikipedia.org/wiki/Vegetationhttp://en.wikipedia.org/wiki/Agriculturehttp://en.wikipedia.org/wiki/Subdivision_(land)http://en.wikipedia.org/wiki/Urbanizationhttp://en.wikipedia.org/wiki/Continuum_(mathematics)http://en.wikipedia.org/wiki/Edge_effecthttp://en.wikipedia.org/wiki/Habitat_(ecology)http://en.wiktionary.org/wiki/nativehttp://en.wikipedia.org/wiki/Vegetationhttp://en.wikipedia.org/wiki/Agriculturehttp://en.wikipedia.org/wiki/Subdivision_(land)http://en.wikipedia.org/wiki/Urbanizationhttp://en.wikipedia.org/wiki/Continuum_(mathematics)http://en.wikipedia.org/wiki/Edge_effect


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Incentives such as scholarships to children, subsidies, and exemption from taxto smaller families could be offered.

Participation of NGOs: NGOs can contribute in popularizing population controlprograms.

Model Question:

What are the social initiatives that could be taken to control the impacts ofpopulation & technology?

What are the causes of population growth?

What is habitat fragmentation & habitat alteration? What are their impacts?

What are the impacts of population growth?

What is the role of communication & education in controlling the populationgrowth? (ESSAY)

b.3 disasters management,

The term disaster owes its origin to the French word Desastre which is a combination of two words

des meaning bad and aster meaning star. Thus the term refers to Bad or Evil star. A disaster can be

defined as A serious disruption in the functioning of the community or a society causing wide spread

material, economic, social or environmental losses which exceed the ability of the affected society to copeusing its own resources.

A disaster is a result from the combination of hazard, vulnerability and insufficient capacity or measures

to reduce the potential chances of risk.

A disaster happens when a hazard impacts on the vulnerable population and causes damage, casualties

and disruption. Any hazard flood, earthquake or cyclone which is a triggering event along with greatervulnerability (inadequate access to resources, sick and old people, lack of awareness etc) would lead to

disaster causing greater loss to life and property. For example; an earthquake in an uninhabited desert

cannot be considered a disaster, no matter how strong the intensities produced.

An earthquake is disastrous only when it affects people, their properties and activities. Thus, disasteroccurs only when hazards and vulnerability meet. But it is also to be noted that with greater capacity ofthe individual/community and environment to face these disasters, the impact of a hazard reduces.Therefore, we need to understand the three major components namely hazard, vulnerability andcapacity with suitable examples to have a basic understanding of disaster management.

What is a Hazard

Hazard may be defined as a dangerous condition or event, that threat or have the potential for causinginjury to life or damage to property or the environment. The word hazard owes its origin to the wordhasard in old French and az-zahr in Arabic meaning chance or luck. Hazards can be grouped intotwo broad categories namely natural and manmade.

1. Natural hazards are hazards which are caused because of natural phenomena (hazards withmeteorological, geological or even biological origin). Examples of natural hazards are cyclones, tsunamis,earthquake and volcanic eruption which are exclusively of natural origin. Landslides, floods, drought,


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fires are socio-natural hazards since their causes are both natural and man made. For example floodingmay be caused because of heavy rains, landslide or blocking of drains with human waste.2. Manmade hazards are hazards which are due to human negligence. Manmade hazards are associatedwith industries or energy generation facilities and include explosions, leakage of toxic waste, pollution,dam failure, wars or civil strife etc. The list of hazards is very long. Many occur frequently while otherstake place occasionally. However, on the basis of their genesis, they can be categorized as follows:

Table: Various types of hazardsTypes Hazards

Geological Hazards1. Earthquake2. Tsunami3. Volcanic eruption4. Landslide5. Dam burst

Water & Climatic Hazards1. Tropical Cyclone2. Tornado and Hurricane

3. Floods4. Drought5. Hailstorm6. Cloudburst7. Landslide8. Heat & Cold wave9. Snow Avalanche10.Sea erosion

Environmental Hazards1. Environmental pollutions2. Deforestation

3. Desertification4. Pest Infection

Biological1. Human / Animal Epidemics2. Pest attacks3. Food poisoning4. Weapons of MassDestruction

vulnerability

Vulnerability may be defined as The extent to which a community, structure, services or geographic areais likely to be damaged or disrupted by the impact of particular hazard, on account of their nature,

construction and proximity to hazardous terrains or a disaster prone area. Vulnerabilities can becategorized into physical and socio-economic vulnerability.Physical Vulnerability: It includes notions of who and what may be damaged or destroyed by naturalhazard such as earthquakes or floods. It is based on the physical condition of people and elements at risk,such as buildings, infrastructure etc; and their proximity, location and nature of the hazard. It also relatesto the technical capability of building and structures to resist the forces acting upon them during a hazardevent. In case of an earthquake or landslide the ground may fail and the houses on the top may topple orslide and affect the settlements at the lower level even if they are designed well for earthquake forces.


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Socio-economic Vulnerability: The degree to which a population is affected by a hazard will not merelylie in the physical components of vulnerability but also on the socioeconomic conditions. The socio-economic condition of the people also determines the intensity of the impact. For example, people whoare poor and living in the sea coast dont have the money to construct strong concrete houses. They aregenerally at risk and loose their shelters when ever there is strong wind or cyclone. Because of theirpoverty they too are not able to rebuild their houses.

capacityCapacity can be defined as resources, means and strengths which exist in households and communitiesand which enable them to cope with, withstand, prepare for, prevent, mitigate or quickly recover from adisaster. Peoples capacity can also be taken into account. Capacities could be:Physical Capacity: People whose houses have been destroyed by the cyclone or crops have beendestroyed by the flood can salvage things from their homes and from their farms. Some family membershave skills, which enable them to find employment if they migrate, either temporarily or permanently.Socio-economic Capacity: In most of the disasters, people suffer their greatest losses in the physical andmaterial realm. Rich people have the capacity to recover soon because of their wealth. In fact, they areseldom hit by disasters because they live in safe areas and their houses are built with stronger materials.However, even when everything is destroyed they have the capacity to cope up with it. Hazards arealways prevalent, but the hazard becomes a disaster only when there is greater vulnerability and less of

capacity to cope with it. In other words the frequency or likelihood of a hazard and the vulnerability of thecommunity increases the risk of being severely affected.risk

Risk is a measure of the expected losses due to a hazard event occurring in a given area over a specifictime period. Risk is a function of the probability of particular hazardous event and the losses each wouldcause. The level of risk depends upon:

Nature of the hazard Vulnerability of the elements which are affected Economic value of those elements

A community/locality is said to be at risk when it is exposed to hazards and is likely to be adverselyaffected by its impact. Whenever we discuss disaster management it is basically disaster riskmanagement. Disaster risk management includes all measures which reduce disaster related losses of

life, property or assets by either reducing the hazard or vulnerability of the elements at risk.

Disaster Management:Local, regional, national and (where necessary) international organisations are allinvolved in mounting a humanitarian response to disasters. Each will have a prepareddisaster management plan. These plans cover prevention, preparedness, relief andrecovery (see below).

Disaster prevention

These are activities designed to provide permanent protection from disasters. Not all disasters,particularly natural disasters, can be prevented, but the risk of loss of life and injury can bemitigated with good evacuation plans, environmental planning and design standards. In January

2005, 168 Governments adopted a 10-year global plan for natural disaster risk reduction called theHyogo Framework. It offers guiding principles, priorities for action, and practical means forachieving disaster resilience for vulnerable communities.Disaster preparedness

These activities are designed to minimise loss of life and damage for example by removingpeople and property from a threatened location and by facilitating timely and effective rescue,relief and rehabilitation. Preparedness is the main way of reducing the impact of disasters.
http://www.preventionweb.net/english/professional/publications/v.php?id=1037&pid:3&pif:3http://www.preventionweb.net/english/professional/publications/v.php?id=1037&pid:3&pif:3http://www.preventionweb.net/english/professional/publications/v.php?id=1037&pid:3&pif:3http://www.preventionweb.net/english/professional/publications/v.php?id=1037&pid:3&pif:3


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Community-based preparedness and management should be a high priority in physical therapypractice management.Disaster relief

This is a coordinated multi-agency response to reduce the impact of a disaster and its long-termresults. Relief activities include rescue, relocation, providing food and water, preventing disease

and disability, repairing vital services such as telecommunications and transport, providingtemporary shelter and emergency health care.Disaster recovery

Once emergency needs have been met and the initial crisis is over, the people affected and thecommunities that support them are still vulnerable. Recovery activities include rebuildinginfrastructure, health care and rehabilitation. These should blend with development activities, suchas building human resources for health and developing policies and practices to avoid similarsituations in future.Disaster management is linked with sustainable development, particularly in relation to vulnerablepeople such as those with disabilities, elderly people, children and other marginalised groups.

Earthquake

Earthquakes are destructive forms of natural hazards. Earthquakes are caused by

movement of massive land areas, called plates on the earths crust. These plates are

in a constant state of motion. As the plates move relative to one another, stresses

from and accumulate until a fracture or abrupt slippage occurs. This sudden release

of stress is called an earthquake.

The magnitude of an earthquake, as expressed by Richter scale, is a measure

of the amplitude of seismic waves.

Effects of earthquake: The initial effect of an earthquake is the violent ground

motion. Additionally the ground often fissures or cracks and there can be largepermanent displacements horizontally sometimes as much as 10-15 meters. Often as

destructive as the earthquake itself are the resulting secondary effects such as

landslides, fires, tsunamis and floods. The risk of fire immediately after an

earthquake is often high because of broken electrical lines and gas mains.

As the vibrations and waves continue to move through the earth building on the

earths surface are set in motion.

Earthquake management:

1. Determine the optimum structures of existing buildings.2. Building of earthquake proof structures.3. Shutdown certain dangerous industries like nuclear reactors, electrical power

stations, oil and gas pipelines.4. Implement procedures for evacuating buildings and dangerous areas.5. Training teams for search and rescue operations, disaster assessment.6. Training adequate personal trauma care.7. Preparing plans and necessary equipment for alternative water supply.


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8. Reviewing the essential facilities like hospitals, fire stations and communicationinstallations.

Cyclones

The violent storms bring widespread devastation to coastlines and islands lying intheir erratic pathos. A windstorms destructive work is done by the high wind, flood

producing rains and associated storm surges. Tropical cyclones are known around the

workd by various names hurricanes in the Atlantic and Caribbean, typhoons in the

West Pacific, baguios in the Philippines.

Effects of cyclones:

1. Loss of human lives.2. Damage to houses and other physical structures.3. Destroy supply lines, crops and food stocks.

4. Destruct agriculture and destroy crops.5. disrupt economy

Cyclone disaster mitigation (management)

1. Regulatory control and their relative effectiveness in coastal areas zoningordinance would regulate minimum building height, type of land use.

2. Building regulations establish minimum standards of design, construction andmaterials in order to avoid structural collapse.

3. Measures to reduce economic losses include agriculture losses, safeguard ofpower grids etc.

4. developing an effective forecasting system5. Developing warning and evacuation procedures for people threatened by

floods6. Maintaining stocks of necessary medical stuff.7. Establishing emergency communication system.

Floods

A flood occur when a stream or river overflows its banks, shortly after periods of

excessinve rainfall or snowmelt. Flash floods are local floods of great volume and

short duration. Riverine floods are caused by precipitation over large areas or by

melting of the winters occumulation of snow or by both. Flood water is mostly acombination of numerous and widespread rainfall events, possibly with considerable

snowmelt contribution. In coastal areas, it could be combination of astronomical tides,

stors surges or tsunamis.

Impacts of floods

1. damage of houses, floatation of houses, undercutting of house and by debris.


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2. health related effects, in which it may promote secondary threat of water-borne and vector-borne diseases.

3. Impact on agriculture, in which huge losses to agricultural crops due tosubmersion of crops and crop storage facilities.

Flood control measures (management)

1. Channelization construction of open channels is a common method ofreducing the size of floodway.

2. Detention facilities detention facilities such as dams store flood water andrelease them at lower rates.

3. Flood proofing retrofit flood proofing of existing buildings.4. Flood detection and warning system flood detection system can range from

inexpensive networks of volunteer rainfall and stream stage observers liketelemetered gauges and computer models.

5. Public awareness programs

b.4 ACID RAIN

Acid rain is rain or any other form ofprecipitation that is unusually excessive

acidic. Acid rain is infact a cocktail of mainly sulfuric acid (60 to 70 %) & nitric acid

(30 to 40 %) with a little hydrochloric acid. This acidification of rain is a natural

phenomenon, where the atmospheric carbon dioxide reacts with water to form

carbonic acids to make this natural rain water slightly acidic (pH- 5.6).

However, during recent years, due to increased anthropogenic activities, like

industrialization, transportation, urbanization, use of fossil fuels, etc. the atmospheric

concentration of sulphur dioxide, oxides of nitrogen, chlorides, etc. has increased

enormously. These constituents react with water to form their respective acids. These

acids reduces the pH of the rain water, some time to as low as that of lemon juice

(pH- 2.2).

Effects:

1. Acid rain causes acidification of lakes and streams and contributes2. It damages the vegetation by wearing away the waxy protective coating of

leaves, damaging them and preventing them from being able tophotosynthesize properly

3. Dissolve and wash away the nutrients and minerals in the soil & making itunfertile
http://en.wikipedia.org/wiki/Rainhttp://en.wikipedia.org/wiki/Precipitation_(meteorology)http://en.wikipedia.org/wiki/Acidhttp://en.wikipedia.org/wiki/Rainhttp://en.wikipedia.org/wiki/Precipitation_(meteorology)http://en.wikipedia.org/wiki/Acid


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4. In addition, acid rain accelerates the decay of building materials and paints,including irreplaceable buildings, statues, and sculptures (corrosion) that arepart of our nation's cultural heritage.

5. Prior to falling to the earth, sulfur dioxide (SO2) and nitrogen oxide (NOx) gasesand their particulate matter derivativessulfates and nitratescontribute tovisibility degradation and harm public health.

Control:

1. Reduce emissions2. Find alternative sources of energy3. Restoring the Damage done by Acid Rain

http://www.epa.gov/acidrain/effects/index.htmlEnvironmental chemistry: BK Sharma & H KAUR

b.5 ozone depletion.Ozone is an unstable blue gas having pungent odour. Chemically, it is an allotrope of Oxygen which is anelement in the gaseous form. It has three oxygen atoms in its single molecule and in the language ofChemistry; its molecular formula is 03. It is used as a powerful oxidant, bleach, and water purifier. It isalso used to treat industrial wastes.

Where is ozone found?If found in the troposphere; ozone acts as a powerful pollutant. But, when found in the stratosphere, it actslike a friend of the earth because it shields most of the ultra violet radiations and does not allow them topass on towards the same. In stratosphere, it is found in the form of a dense layer called as the OzoneLayer or the Ozone Belt. Thus, the Ozone Belt in the stratosphere acts like a Protective Umbrella of theearth. Let us see, how this gas is formed in the atmosphere.

How is ozone formed?Ozone is formed in the stratosphere when oxygen molecules Photo dissociate after absorbing an UVPhoton of shorter wavelength(less than 240 nm) to produce two oxygen atoms. Ozone is mainly producedfrom oxygen containing molecules such as Sulphur dioxide, Nitrogen Oxides, etc. also when thesemolecules are exposed to ultraviolet radiations. In Chemistry, a molecule is the particle of any substancethat can remain in a free state. But, what is an atom? Well, an atom is the smallest particle of a substancethat can not usually remain in a free condition. Two or more atoms combine to form a molecule. Throughthe foregoing lines, we came across another term, allotrope. One of the two or more different forms ofmolecules of an element is called as an allotrope.A large number of ozone molecules assemble around the earth to form the Ozone Layer which extendsfrom 13 to 48 km above the earth surface. On an average, it is about 230 Dobson units (DU) in thickness.DU is the unit which measures thickness of the ozone layer. It equals to 0.01 mm.

Ozone depleting substancesChlorofluorocarbons (CFCs or Freons), Methane, Nitrous Oxides (N2O), Carbon Tetrachloride (CCl4),Methyl Bromide (a soil fumigant and insecticide), aircraft emissions, n- propyl bromide and Halon- 1202are major agents that cause depletion of ozone layer. Hence, these are called as Ozone DepletingSubstances (ODS).How is the Ozone Layer Depleted?
http://www.epa.gov/acidrain/effects/index.htmlhttp://www.epa.gov/acidrain/effects/index.html


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Chlorofluorocarbons or Freons get accumulated in greater amounts at high altitudes and gradually reachto the stratosphere. Under the influence of intense short wave ultraviolet radiations they release chlorineatoms. A single chlorine atom can react with more than, 100,000 molecules of ozone and can convertthem into oxygen. Other ozone depleting substances like methane, nitrous oxide, methyl bromide etc. too,pass through a series of reactions under the influence of UV-radiations of sunlight and catalysts found inthe air and help in the depletion of ozone layer.

Ozone molecule absorbs UV light between 310 and 200 nm. The ozone molecule absorbs oxygen atomto form two molecules of Oxygen, and the Ozone cycle continues. Ozone is destroyed by a number of free radicals catalysts like Hydroxyl radical, Nitric oxide radical,and Bromine through natural and anthropogenic sources.

Effects of the Depletion of Ozone Layer

I. General Effects

Ozone absorbs ultraviolet radiations so that much of it is never allowed to reach to the earth surface. Theprotective umbrella of ozone layer in the stratosphere protects the earth from harmful ultravioletradiations. Ozone plays an important role in the biology and climatology on the earths environment. Itfilters out all the radiations that remain below 3000. Radiations below this wavelength are biologically

harmful. Hence any depletion of ozone layer is sure to exert catastrophic impacts on life in the biosphere.The Ultraviolet radiation is one of the most harmful radiations contained in the sunlight. Ozone layer inthe stratosphere absorbs these radiations and does not allow it to reach to the earth.

The depletion of Ozone layer may lead to UV exposures that may cause a number of biologicalconsequences like Skin Cancer, damages to vegetation, and even the reduction of the population ofplanktons (in the oceanic Photic zone).

Some of the remarkable effects of the UV radiations or the effects of depletion of the Ozone Layer arementioned below.

(1) UV radiation causes sun- eye- diseases (cataract), skin diseases, skin cancer and damage to immune

system in our body.(2) It damages plants and causes reduction in crop productivity.(3) It damages embryos of fish, shrimps, crabs and amphibians. The population of salamanders isreducing due to UV-radiations reaching to the earth.(4) UV- radiations damage fabrics, pipes, paints, and other non-living materials on this earth.(5) It contributes in the Global Warming. If the ozone depletion continues, the temperature around theworld may rise even up to 5.5 Celsius degrees.

II.Specific Effects

The specific effects of depletion of Ozone Layer have been observed on Human Society, Agriculture,Plants and Animals etc. These effects have been summarized as below-

A. Effects of Ozone Depletion on Human Society

(i).The flux of ultra violet radiation in the biosphere is increased due to ozone depletion. It has seriouslyharmful effects on human societies like formation of patches on skin and weakening of the humanimmune system.(ii). It may cause three types of skin cancer like basal cell carcinoma, squamous cell carcinoma andmelanoma. A 10 per cent decrease in stratospheric ozone has been reported to cause 20 to 30 per cent


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increase in cancer in human society. Each year, about 7000 people die of such diseases each year in USA.About 10 percent increase in skin cancer has been reported in Australia and New Zealand.(iii).Exposure to UV radiations damages skin of the sun-bathing people by damaging melanocyte-cells orby causing sun-burns due to faster flow of blood in the capillaries of exposed areas.(iv).Exposure to UV radiations due to ozone depletion may cause leukemia and breast cancer.(iv).Exposure of UV radiation to human eye damages cornea and lens leading to Photo keratitis, cataract

and even blindness.(v).The Ambient Ozone Exposure may cause Emphysema, bronchitis, asthma and even obstruction oflungs in human beings.(vi).Exposure to radiations due to ozone depletion has been reported to cause DNA breakage, inhibitionand alteration of DNA replication and premature ageing in human beings.

B. Effect of Ozone Depletion on Agriculture

(i). Radiations reaching to the earth due to ozone depletion cause severe damage to plants including crops.As per reports, ultra violet radiations reaching to the earth cause losses up to 50 per cent in Europeancountries.(ii).The radiation reaching to the earth due to the depletion of the ozone layer cause visible damages inplants. They adversely affect the rate of photosynthesis that finally results into decrease in the agricultural

production.(iv).The UV radiation enhances the rate of evaporation through stomata and decreases the moisturecontent of the soil. This condition adversely affects the growth and development of crop plants andreduces the crop yield.(v). The ozone reduction adversely affects the weather pattern which in turn affects the crop productionby encouraging plant injuries and disease development.(vi). The UV radiation reaching to the earth surface alters the global balance between radiation andenergy. This condition of imbalance causes seasonal variations that further reduce the crop production.(vii). A number of economically important plant species such as rice, depend on cyanobacteria residing intheir roots for the retention of nitrogen. These bacteria are sensitive to UV light and they are hence, arekilled instantly.

C. Effects of Ozone Depletion on other Plants and Animals(i).The ozone layer depletion causes climatic alterations that cause physiological changes in plants andanimals. The change in the energy balance and radiation may affect the survival and stability of livingorganisms.(ii).The depletion of ozone layer may cause changes in thermal conditions of the biosphere. It may affecttype, density and stability of vegetation which in turn may affect different bio-geo-chemical cyclesoperating in nature. Interruption in these cycles damages important process of ecosystem leading todangerous conditions for plants and animals.(iii).The depletion of ozone layer causes death of plankton- populations in fresh as well as marinewaters .This condition seriously affects the transfer of materials in ecosystems. The recent researchesgave analyzed a widespread extinction of planktons 2 million years ago that coincided with the nearbysupernova. Planktons are particularly susceptible to effects of UV light and are vitally important to the

marine food webs.

The Ozone Hole

The hole in the context of ozone depletion relates to thinning of the ozone layer in a certain area. Here,the word hole is considered as a hole in the ground which in the context of ozone layer is thinning ofozone in a certain area up to certain depth as measured by scientists. In fact, ozone hole is an area wherethe ozone concentration drops to an average of about 100 Dobson Units. The word Dobson has beentaken from the name of the famous scientist and climatologist G. M. B. Dobson, who observed the ozonehole for the first time in 1956, over Halley Bay.


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The satellite measurements done in September 2000 revealed that the thinning of ozone layer in Antarctichad reached a record 28.3 million sq km which was about one million sq km greater than the record of1998. Thinning of ozone in such a big area is rightly termed as ozone hole. The ozone hole in theNorthern Latitudes has also been recorded. The ozone hole over Antarctica may expose not only theAntarctica but also a large area of the pacific and Atlantic oceans and South America as well.

The ozone hole over Antarctica was first discovered by Farman, Gardiner and Shanklin in 1985. Theyjointly declared their findings through a paper published in the May issue of Nature (an importantInternational Journal) in 1985. The entire scientific community was shocked to know their findings.

On the basis of observations made through a network of ground based Dobson Spectrophotometer, anInternational Panel of scientists confirmed that the Ozone Layer was being depleted at all latitudes outside the tropics. Out of a big group of scientists across the world, Crutzen, Molina, and Rowland wereawarded the Nobel Prize in Chemistry for their work on Stratospheric Ozone, in 1995.The scientificassessment of ozone depletion is going on across the world since 1981, under the sponsorship of theUnited Nations Environment Programme (UNEP), and the most recent measurement was done during theyear 2006. Here are the comparative pictures showing the Ozone Holes over Antarctica during the spring

seasons of two different years.

Why is the Ozone Hole over Antarctica, usually formed during spring months?A circulation pattern of gases traps the ozone over the South Pole for several months but not duringwinter. This circulation pattern is called as Antarctic Polar Vortex. Within this vortex, the substantialozone loss was detected for the first time during 1980. During extreme cold conditions, the polar wintersare dark and continue up to three months without solar radiations. This leads to the decrease intemperature. The polar vortex traps air and contributes in further falling temperature which goes down upto -80 0c. The low temperature forms cloud particles that contain nitric acid and ice. These clouds providesurfaces for chemical reactions that lead to ozone depletion. During the Antarctic winters and springs,reactions that take place on the surface of the Polar Stratospheric Clouds (PSCs) convert pollutants intofree radicals such as Cl and ClO.

These clouds can also remove NO2 from the atmosphere by converting it to nitric acid. It prevents thenewly formed ClO from being converted back into ClONO2. The role of sunlight is the fundamentalreason why the Antarctic ozone depletion is greatest during spring. The Antarctic ozone depletion iscaused during September to early December. Over 50 per cent of the lower stratospheric ozone isdestroyed during the period of the Antarctic Spring.

Prevention and Control of Depletion of the Ozone LayerBanning the production and use of ozone depleting substances is one important way of preventing furtherdepletion of the ozone layer in the stratosphere. On the other hand, alternatives to these chemicalcompounds should also be searched out so as to replace these chemicals. Scientists of the University ofCalifornia, U.S.A. devised a possible way of plugging the ozone hole by injecting alkanes or propanes

into the atmosphere of Antarctica. The alkanes have the affinity of reacting with ozone destroyingchlorine atoms. According to the scientists, about 50,000 tones of alkane or propane would have to beblown to check the ozone loss. These chemicals could be released from an altitude of about 15 km by agroup of hundreds of large aircrafts.

Global Efforts for Controlling the Depletion of the Ozone Layer


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Since ozone depletion is a Global Environmental Problem, it requires strong global efforts and co-operations for its solution. The International Community is taking up strong efforts as a result of whichglobal consumption of ozone depleting substances has decreased markedly.Following the UNEPs Governing Councils meeting to co- ordinate activities on protecting ozone layerin 1975, United States, Canada, Norway and Sweden banned the use of CFCs. The production capacity ofthe European Union (E U) was frozen allowing limited uses of aerosols. In March 1985, 28 countries of

the world agreed on Vienna Convention for the protection of the ozone layer. In September 1987,different countries of the world adopted Montreal Protocol on substances that deplete ozone layer. TheGeneral Assembly of the United Nations voted to designate September 16 as the World Ozone Day,

to mark the signing of the Montreal Protocol, the 16th September, 1987. By December 2001, 182countries ratified the Vienna Convention and 181 the Montreal Protocol. By 2000, 96 chemicals weresubject to control under the Montreal Protocol.

b.6 Applications of Remote Sensing and Geographic Information

System (GIS).Remote sensing can be defined as the collection of data about an object from a distance.

Humans and many other types of animals accomplish this task with aid of eyes or bythe sense of smell or hearing. Geographers use the technique of remote sensing tomonitor or measure phenomena found in the Earth's lithosphere, biosphere, hydrosphere,and atmosphere.Remote sensing of the environment by geographers is usually done with the help ofmechanical devices known as remote sensors. These gadgets have a greatly improvedability to receive and record information about an object without any physicalcontact. Often, these sensors are positioned away from the object of interest by usinghelicopters, planes, and satellites. Most sensing devices record information about anobject by measuring an object's transmission ofelectromagnetic energyfrom reflecting andradiating surfaces.GIS is the development of innovative software applications for the storage, analysis,

and display of geographic data. Thus, the activities normally carried out on a GISinclude:

The measurement of natural and human made phenomena and processes from a spatialperspective. These measurements emphasize three types of properties commonly associated withthese types ofsystems: elements,attributes, andrelationships.

The storage of measurements in digital form in a computer database. These measurements areoften linked to features on a digital map. The features can be of three types: points, lines, or areas(polygons).

The analysis of collected measurements to produce more data and to discover new relationshipsby numerically manipulating and modeling different pieces of data.

The depiction of the measured or analyzed data in some type of display - maps, graphs, lists, or

summary statistics.

Remote sensing imagery has many applications in mapping land-use and cover, agriculture, soils

mapping, forestry, city planning, archaeological investigations, military observation, and

geomorphological surveying, among other uses. For example, foresters use aerial photographs for

preparing forest cover maps, locating possible access roads, and measuring quantities of trees harvested.

Specialized photography using color infrared film has also been used to detect disease and insect damagein forest trees.
http://www.physicalgeography.net/physgeoglos/r.html#remote_sensinghttp://www.physicalgeography.net/physgeoglos/l.html#lithospherehttp://www.physicalgeography.net/physgeoglos/b.html#biospherehttp://www.physicalgeography.net/physgeoglos/h.html#hydrospherehttp://www.physicalgeography.net/physgeoglos/a.html#atmospherehttp://www.physicalgeography.net/physgeoglos/r.html#remote_sensorhttp://www.physicalgeography.net/physgeoglos/e.html#electromagnetic_energyhttp://www.physicalgeography.net/physgeoglos/r.html#reflectionhttp://www.physicalgeography.net/physgeoglos/r.html#radiationhttp://www.physicalgeography.net/physgeoglos/s.html#systemhttp://www.physicalgeography.net/physgeoglos/s.html#system_elementhttp://www.physicalgeography.net/physgeoglos/s.html#system_attributehttp://www.physicalgeography.net/physgeoglos/s.html#system_attributehttp://www.physicalgeography.net/physgeoglos/s.html#system_attributehttp://www.physicalgeography.net/physgeoglos/s.html#system_relationshiphttp://www.physicalgeography.net/physgeoglos/s.html#system_relationshiphttp://www.physicalgeography.net/physgeoglos/r.html#remote_sensinghttp://www.physicalgeography.net/physgeoglos/l.html#lithospherehttp://www.physicalgeography.net/physgeoglos/b.html#biospherehttp://www.physicalgeography.net/physgeoglos/h.html#hydrospherehttp://www.physicalgeography.net/physgeoglos/a.html#atmospherehttp://www.physicalgeography.net/physgeoglos/r.html#remote_sensorhttp://www.physicalgeography.net/physgeoglos/e.html#electromagnetic_energyhttp://www.physicalgeography.net/physgeoglos/r.html#reflectionhttp://www.physicalgeography.net/physgeoglos/r.html#radiationhttp://www.physicalgeography.net/physgeoglos/s.html#systemhttp://www.physicalgeography.net/physgeoglos/s.html#system_elementhttp://www.physicalgeography.net/physgeoglos/s.html#system_attributehttp://www.physicalgeography.net/physgeoglos/s.html#system_relationship

Unit I. Part -b. Environmental Issues

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