DMC-104: Geography and Environment

DMC-104: Geography and EnvironmentCourse Teacher: Dr. Syed Hafizur Rahman (SHR)

M. Sc. (JU), Ph. D. (Birmingham University, United Kingdom)

Permanent PositionProfessorDepartment of Environmental SciencesJahangirnagar University, Dhaka-1342

E-mail: [email protected]

Class Hour: 03:00 to 05:00 (Wed & Thu)

Course ContentPart 2: Environmental Studies• Multidisciplinary nature of environmental Studies: Definition,

scope and importance, Institutions in Environment, People in Environment.

• Natural Resources: Renewable and non-renewable resources, Natural resources and associated problems, Role of an individual in conservation of natural resources, Equitable use of resources for sustainable lifestyles.

• Ecosystems: Concept of an ecosystem, Structure and function of an ecosystem, Producers, consumers and decomposers, Energy flow in the ecosystem, Ecological succession, Food chains, food webs and ecological pyramids, Introduction, types, characteristic features, structure and function of the following ecosystems (Forest ecosystems, Grassland ecosystems, Desert ecosystems, Aquatic ecosystems).

Course Content• Biodiversity and its conservation: Introduction,

Definition (genetic, species and ecosystem diversity), Biogeographical classification of Bangladesh, Value of biodiversity, Biodiversity at global, national and local levels, Conservation of biodiversity: In-situ and Ex-situ conservation of biodiversity.

• Environmental Pollution: Definition, causes, effects and control measures of Air Pollution, Water pollution, Soil pollution, Marine pollution, Noise pollution, Thermal pollution and Nuclear hazards; Solid waste (Causes, effects and control measures of urban and industrial wastes), Role of an individual in prevention of pollution, Concept of Disaster (Floods, earthquakes, cyclones and landslides).

Course Content• Social Issues and the Environment: From

unsustainable to sustainable development, Urban problems related to energy, Water conservation, rainwater harvesting, water shed management, Resettlement and rehabilitation of people, its problems, Environmental Ethics, the ethical basis of environment education and awareness.

• Environmental Issues: Green house gases and their impact, trends and projection of future emissions, global warming, acid rain, ozone layer depletion, climate change and sustainable development.

Course Content• Human population and the Environment:

Global population growth, Methods of sterilization, Urbanization.

• Environment and human health: Environmental health, Climate and health, Infectious diseases Water-related diseases, Risks due to chemicals in food, Cancer and environment, Human rights and valued education.

Importance of Environment Study• Environment is not a single subject. It is an integration of several

subjects that include both Science and Social Studies. • To understand all the different aspects of our environment we

need to understand biology, chemistry, physics, geography, resource management, economics and population issues.

• Thus the scope of environmental studies is extremely wide and covers some aspects of nearly every major discipline.

• We live in a world in which natural resources are limited. Water, air, soil, minerals, oil, the products we get from forests, grasslands, oceans and from agriculture and livestock, are all a part of our life support systems.

• Without them, life itself would be impossible. As we keep increasing in numbers and the quantity of resources each of us uses also increases, the earth’s resource base must inevitably shrink.

Importance of Environment Study• The earth cannot be expected to sustain this expanding

level of utilization of resources. Added to this is misuse of resources. We waste or pollute large amounts of nature’s clean water; we create more and more material like plastic that we discard after a single use; and we waste colossal amounts of food, which is discarded as garbage.

• Manufacturing processes create solid waste byproducts that are discarded, as well as chemicals that flow out as liquid waste and pollute water, and gases that pollute the air.

• Increasing amounts of waste cannot be managed by natural processes. These accumulate in our environment, leading to a variety of diseases and other adverse environmental impacts now seriously affecting all our lives.

Importance of Environment Study• Air pollution leads to respiratory diseases, water pollution

to gastrointestinal diseases, and many pollutants are known to cause cancer.

• Improving this situation will only happen if each of us begins to take actions in our daily lives that will help preserve our environmental resources.

• We cannot expect Governments alone to manage the safeguarding of the environment, nor can we expect other people to prevent environmental damage.

• We need to do it ourselves. It is a responsibility that each of us must take on as ones own.

Ecosystem: Concept• An ‘Ecosystem’ is a region with a specific and recognizable

landscape form such as forest, grassland, desert, wetland or coastal area.

• The nature of the ecosystem is based on its geographical features such as hills, mountains, plains, rivers, lakes, coastal areas or islands. It is also controlled by climatic conditions such as the amount of sunlight, the temperature and the rainfall in the region.

• The geographical, climatic and soil characteristics form its non-living (abiotic) component. These features create conditions that support a community of plants and animals that evolution has produced to live in these specific conditions.

Ecosystem: Concept• The living part of the ecosystem is referred to as its biotic

component.• Ecosystems are divided into terrestrial or land based

ecosystems, and aquatic ecosystems in water. • These form the two major habitat conditions for the Earth’s

living organisms.• Definition: The living community of plants and animals

in any area together with the non-living components of the environment such as soil, air and water, constitute the ecosystem.

Producers, consumers, Decomposers

• Every living organism is in some way dependent on other organisms. Plants are food for herbivorous animals which are in turn food for carnivorous animals.

• Thus there are different tropic levels in the ecosystem. Some organisms such as fungi live only on dead material and inorganic matter.

• Plants are the ‘producers’ in the ecosystem as they manufacture their food by using energy from the sun. In the sea these include tiny algal forms to large seaweed.

• The herbivorous animals are primary consumers as they live on the producers. In a forest, these are the insects, amphibia, reptiles, birds and mammals.


• The herbivorous animals include for example hare, deer and elephants that live on plant life. They graze on grass or feed on the foliage from trees. In the sea, there are small fish that live on algae and other plants.

• At a higher tropic level, there are carnivorous animals, or secondary consumers, which live on herbivorous animals. In our forests, the carnivorous animals are tigers, leopards, jackals, foxes and small wild cats. In the sea, carnivorous fish live on other fish and marine animals. Animals that live in the sea range in size from microscopic forms to giant mammals such as the whale.


• Decomposers or detrivores are a group of organisms consisting of small animals like worms, insects, bacteria and fungi, which break down dead organic material into smaller particles and finally into simpler substances that are used by plants as nutrition.

• Decomposition thus is a vital function in nature, as without this, all the nutrients would be tied up in dead matter and no new life could be produced.

Structural and Functional aspects of Ecosystem

• Structural aspectsComponents that make up the structural aspects of an

ecosystem include:– 1) Inorganic aspects – C, N, CO2, H2O.– 2) Organic compounds – Protein, Carbohydrates, Lipids –

link abiotic to biotic aspects.– 3) Climatic regimes – Temperature, Moisture, Light &

Topography.– 4) Producers – Plants.– 5) Macro consumers – Phagotrophs – Large animals.– 6) Micro consumers – Saprotrophs, absorbers – fungi.

Structural and Functional aspects of Ecosystem

• Functional aspects– 1) Energy cycles.– 2) Food chains.– 3) Diversity-interlinkages between organisms.– 4) Nutrient cycles-biogeochemical cycles.– 5) Evolution.

What is biodiversity?

• ‘Biological diversity’ or biodiversity is that part of nature which includes the differences in genes among the individuals of a species, the variety and richness of all the plant and animal species at different scales in space, locally, in a region, in the country and the world, and various types of ecosystems, both terrestrial and aquatic, within a defined area.

• Biological diversity deals with the degree of nature’s variety in the biosphere. This variety can be observed at three levels; the genetic variability within a species, the variety of species within a community, and the organisation of species in an area into distinctive plant and animal communities constitutes ecosystem diversity.

Pollution

• Pollution is the effect of undesirable changes in our surroundings that have harmful effects on plants, animals and human beings.

• This occurs when only short-term economic gains are made at the cost of the long-term ecological benefits for humanity.

• No natural phenomenon has led to greater ecological changes than have been made by mankind.

• During the last few decades we have contaminated our air, water and land on which life itself depends with a variety of waste products.

• Pollutants include solid, liquid or gaseous substances present in greater than natural abundance produced due to human activity, which have a detrimental effect on our environment.

• The nature and concentration of a pollutant determines the severity of detrimental effects on human health. An average human requires about 12 kg of air each day, which is nearly 12 to15 times greater than the amount of food we eat. Thus even a small concentration of pollutants in the air becomes more significant in comparison to the similar levels present in food.

• Pollutants that enter water have the ability to spread to distant places especially in the marine ecosystem.

Pollution

Types of pollution

• Air Pollution• Water Pollution• Soil Pollution• Marine Pollution• Noise Pollution• Thermal Pollution• Nuclear hazards

Water Pollution

• When the quality or composition of water changes directly or indirectly as a result of man’s activities such that it becomes unfit for any purpose it is said to be polluted.

• When a source of pollution can be readily identified because it has a definite source and place where it enters the water it is said to come from a point source. Eg. Municipal and Industrial Discharge Pipes.

• When a source of pollution cannot be readily identified, such as agricultural runoff, acid rain, etc, they are said to be non-point sources of pollution.

Causes of Water Pollution• The major causes of pollution and degradation of river

water quality are related to land based activities, when adequate regulatory measures are not incorporated and the stakeholders do not show proper concern.

• In Bangladesh, the underlying driving forces for this are poverty, an unhealthy national economy, lack of institutional strength, and lack of awareness and education (UNEP, 2001).

• Pathogens, oxygen depleting wastes, inorganic plant nutrients, water soluble inorganic chemicals, organic chemicals, sediment of suspended matter, water soluble radioactive isotopes and hot water released from power plants are the major sources of river pollution.

Causes of Water Pollution• Decreased in water flow, siltation in and mouth of river,

river erosion, submerged sand bars and decreased river depth are major physical degradation and erosion due to anthropogenic activities, unplanned sand mining and unethical encroachments in around river are major anthropogenic degradation in river ecology all over Bangladesh.

• Sea water intrusion and runoff from agricultural wastes are major sources of pollution in coastal areas of Bangladesh.

Noise Pollution

• Noise may not seem as harmful as the contamination of air or water but it is a pollution problem that affects human health and can contribute to a general deterioration of environmental quality.

• Noise is undesirable and unwanted sound. Not all sound is noise. What may be considered as music to one person may be noise to another. It is not a substance that can accumulate in the environment like most other pollutants.

• The most direct harmful effect of excessive noise is physical damage to the ear and the temporary or permanent hearing loss often called a temporary threshold shift (TTS).

Role of an Individual in Prevention of Pollution

• There are a host of environmental problems caused by human actions on the environment. If we are to respond to these problems we have to recognize that each of us is individually responsible for the quality of the environment we live in.

• Our personal actions can either worsen or improve our environmental quality. Several people may feel that environmental problems can be solved with quick technological fixes.

• While a majority of individuals would want a cleaner environment, not many of them want to make major changes in their lifestyle that could contribute to a cleaner environment.


• Decisions and actions taken by individuals to a very large extent determine the quality of life for everyone.

• This necessitates that individuals should not only be aware of various environmental issues and the consequences of their actions on the environment but should also make a firm resolve to develop environmentally ethical lifestyles.

• With the help of solar energy, natural processes developed over billions of years can indefinitely renew the topsoil, water, air, forests, grasslands and wildlife on which all forms of life depend, but only as long as we do not use these potentially renewable resources faster than they are replenished.


• Some of our wastes can be diluted, decomposed and recycled by natural processes indefinitely as long as these processes are not overloaded.

• Natural processes also provide services of flood prevention, erosion control at no costs at all. We must therefore learn to value these resources and use them sustainably.

Concepts that help individuals contribute towardsa better quality of our environment and

human life:

• Develop respect or reverence for all forms of life.• Each individual must try to answer four basic questions:

– Where do the things that I consume come from?– What do I know about the place where I live?– How am I connected to the earth and other living things?– What is my purpose and responsibility as a human being?

• Try to plant trees wherever you can and more importantly take care of them. They reduce air pollution.

• Reduce the use of wood and paper products wherever possible. Manufacturing paper leads to pollution and loss of forests which releases oxygen and takes up carbon dioxide. Try to recycle paper products and use recycled paper wherever possible.


human life:

• From the mail you receive reuse as many envelopes that you can.• Do not buy furniture, doors, window frames made from tropical

hardwoods such as teak and mahogany. These are forest based.• Help in restoring a degraded area near your home or join in an

afforestation program.• Use pesticides in your home only when absolutely necessary and

use them in as small amounts as necessary. Some insect species help to keep a check on the populations of pest species.

• Advocate organic farming by asking your grocery store to stock vegetables and fruits grown by an organic method. This will automatically help to reduce the use of pesticides.


human life:

• Reduce the use of fossil fuels by either walking up a short distance using a car pool, sharing a bike or using public transport. This reduces air pollution.

• Shut off the lights and fans when not needed.• Don’t use aerosol spray products and commercial room air

fresheners. They damage the ozone layer.• Do not pour pesticides, paints, solvents, oil or other products

containing harmful chemicals down the drain or on the ground.• Buy consumer goods that last, keep them as long as possible and

have them repaired as far as possible instead of disposing them off. Such products end up in landfills that could pollute ground water.


human life:• Buy consumer goods ages in refillable glass containers instead of

cans or throwaway bottles.• Use rechargeable batteries.• Try to avoid asking for plastic carry bags when you buy groceries

or vegetables or any other items. Use your own cloth bag instead.

• Use sponges and washable cloth napkins, dish towels and handkerchiefs instead of paper ones.

• Don’t use throwaway paper and plastic plates and cups when reusable versions are available.

• Recycle all newspaper, glass, aluminum and other items accepted for recycling in your area. You might have to take a little trouble to locate such dealers.


human life:

• Set up a compost bin in your garden or terrace and use it to produce manure for your plants to reduce use of fertilizers.

• Try to lobby and push for setting up garbage separation and recycling programs in your localities.

• Choose items that have the least packaging or no packaging.• Start individual or community composting or vemicomposting

plants in your neighborhood and motivate people to join in.• Do not litter the roads and surroundings just because the

sweeper from the Municipal Corporation will clean it up. Take care to put trash into dustbins or bring it back home with you where it can be appropriately disposed.


human life:

• You must realize that you cannot do everything and have solutions for every problem in the world. You can however concentrate on issues that you feel strongly about and can do something about. Focusing your energy on a particular issue will help you get better results.

• You could join any of the several NGOs that exist in our country or become volunteers. Organize small local community meetings to discuss positive approaches of pollution prevention.

• Learn about the biodiversity of your own area. Understand the natural and cultural assets. This would help you to develop a sense of pride in your city/town/village and will also help you understand the problems facing their survival.


human life:

• You cannot improve your world by not voting. You have the option to make a choice rather than complain later on.

• It is important that you do not get discouraged at the first sign of trouble. Do not stay on the negative aspects. But take positive actions wherever you can to make the world a better place to live in.

• When talking to elected officials always be courteous and reasonable. You may disagree with a particular position but be respectful in doing so as you will gain little by being hostile and brash.

• Take care to put into practice what you preach. Remember environment protection begins with YOU.

DMC-104: Geography and Environment

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