Forest Resources
*It is biotic community, predominantly of trees, shrubs or any other woody vegetation.
Importance of forest:
Provides shelter to animals, human beings.
Provides wood/timber.
Raw material like paper, plywood, timber, toys, boxes etc.
Bamboos are used for roofing, walling etc.
Minor forest products like gums, resins, dyes, fibres, medicines, insecticides, fruits etc.
Ecological benefits like – clean air and water
Reduce stress, absorb noise
Having healing qualities
Prevent soil erosion
Improve soil quality
Responsible for continuous supply of water in springs & wells.
Reducing environmental pollution by absorbing CO2 & gases.
Deforestation:
Land degradation in arid, semi-arid & sub-humid areas resulting from various factors including climatic variations & human activities.
Causes:
1.
Shifting (Jhum) Cultivation: It involves slash and burn agriculture practices by landless indigenous people who clear trees to grow crops.
2. Commercial logging: It involves cutting trees for sale as timber or pulp.
Commercial logging employs heavy machinery to remove cut trees & build roads.
3. Mining & dams: Industrial development causes land occupation & displacement of forest people.
4. Expansion of agri-buisness: for ornamental plants, rubber, fruit trees etc.
Effects:
1. Soil erosion by rain water.
2. Strong winds causes denuded land mass into sand deserts.
3. Rainfall declines and ultimately climate change.
4. Loss of flora & fauna.
5. Loss of biodiversity leading to disturbance in ecological balance.
6. Increase in CO2 concentration results in global warming.
Measures:
1. Use of firewood should be discouraged and other energy resources such as biogas, solar energy etc. have to be provided.
2. Understanding in between the persons who manage & those utilize.
3. Community forests should be developed.
4. Protection of standing trees.
Timber Extraction
1. Wood used for engineering purposes like building, houses, making furniture etc. is called timber.
2. Timber extraction resulted in fragmentation of the remaining forest as well as decrease in biodiversity.
Kind of timber extraction:
1. Clear filling system: due to harvesting of commercial trees.
2.Selective logging: large individuals of a few commercially marketable species are harvested while other trees left standing.
3. Mechanized logging: method uses heavy machinery for pulling, lifting & transporting logs.
4. Hand Logging
Effects:
1. Degraded forest
2. Flood may be intensified
3. Loss of biodiversity
4. Climatic changes
5. Soil erosion
Forest conservation 1. Conservation of reserve forests:
These are the forests where water bodies are located.
No commercial exploitation is allowed.
Chipko movement is the case study:
In 1970, Gopeswar & other villagers of Tehri-Garhwal, in Alkananda river flood came due to harvesting of forests. Later Sunderlal Bahuguna said to protect 5F’s i.e. Food, Fodder, Fiber, Fuel, Fertilizer.
2.Limited Production forests:
Less fertile areas
Annual growth may be harvested in a very careful and controlled manner to avoid soil & tree damage.
3.Production forests:
Lies in flat lands and manage high degree production.
4. Conservation of commercial or exploitative forestry:
These supply goods & services to meet the needs of local people for 5F’s, medicines etc.
This can be achieved by:
Intensive Implantation: Forestry includes planting all the available land from villagers field to commercial land.
It can be done by two types:
Social Forestry: uses community lands, individual holdings for producing needs of community.
Capative/Production/Agroforestry: developed to fulfil the needs of various forest based industries.
Mining
Its the act of extracting ores, coal etc. from the earth.
Mining on industrial scale can produce environmental damages from exploitation and development, even after mine closed.
Effects:
1. It produce enormous quantities of waste. Water dissolves these to produce contaminated fluid, pollutes soil, river, groundwater.
2. Causes air pollution due to removal of toxic gases, CH4 etc.
3. Deforestation including loss of flora & fauna.
4. Noise pollution
5. Migration of tribal people
6. Lowering of ground water table.
Dams
Potential use could be for irrigation, hydroelectricity and water transport to deficit areas.
Benefits:
1. Helps to river floods.
2. Hydroelectricity generation
3. Year around water supply
4. Helped to improve ecosystems by creating new wetlands, fishing etc.
Problems:
1. Loss of species & ecosystems.
2. Loss of water through evaporation & seepage into porous rock beds.
3. Due to evaporation water becomes saline so unusable.
4. Enormous weight of water might crack the dams.
5. Rehabilitation & resettlement of displaced people.
6. Water related diseases have been linked with the creation of reservoirs.
Case Studies:
1.Narmada Dam Project: Narmada Bachao Andolan 2.Tehri Dam: on Bhagirathi
Water Resources Overutilization
• 1% water is fresh water which comes from rivers, streams, lakes and groundwater sources.
• Degradation of these sources by disposal of sewage and industrial effluents without treatment.
Problems:
• Heavily pumped well can lower local water level.
• Excessive pumping of groundwater causes porous formations of collapse, resulting in setting of the above surface.
• Overuse of freshwater reservoir along coastlines often allows salt water to intrude
into aquifers used for domestic as well as industrial purposes.
Overcome problem:
Reclamation of sewage and waste water.
Development of groundwater, surface water sources.
Artificial rain making
Transfer of surplus water
Desalination of sea water
Floods
When water from heavy rainfall, melting ice or snow or a combination of these, exceeds the carrying capacity of the receiving river system.
Effects:
Plains have become sitted with mud and sand. Thus affecting cultivable land areas.
Extinction of civilization
Economic damage
River carries fertile sediments and deposits it on the level land along its lower course, such areas are called flood plains which are very fertile.
Measures:
By building dam upstream.
Management of rainfall and resultant run off is very important. Such management is based on watershed which means an area bounded by the divide line of water flow. Thus it may be drainage stream. Himalayas are most critical watershed.
Networking of rivers proposed at national level.
Draught
An extended period a season, year, several years of deficient rainfall relative to the statically multi year average of the region.
It destroy an area slowly and have devasting effects on agriculture and water supplies.
Types:
1. Meterological Darught: Described in terms of comparison to some normal or average amount of previous pattern of precipitation.
2.Agriculture Draught: Agriculture impacts, focusing on precipitation shortages, differences between actual and potential evapotranspiration, soil water deficit, reduced groundwater etc.
3. Hydrological Draught: Deficiencies in surface and subsurface water supplies.
4. Socio-economic Draught: Physical water shortages start to affect the health, wellbeing & quality of life of the people.
Effects:
Population growth & their shifts.
Economic damage
Vegetation loss
Fragmentation of biodiversity
Measures:
Urbanization & demographic characteristics.
Social behavior and environmental awareness.
Reduce the risk by mitigation & preparedness.
Conflicts over water
Conflicts over sharing of river waters in the country as rivers flow through more than one state.
Major river conflicts are in India as follows:
1. Sharing of Cauvery water by Karnataka & Tamil Nadu
2. Krishna water by Karnataka & Andhra Pradesh
3. Bhavani water by Tamilnadu & Kerala
4. Satlej-Yamuna water by Punjab & Haryana.
For resolving dispute tribunals have been appointed.
Case study:
Cauvery River dispute
Mineral Resources
Defined as elements, chemical compounds, minerals, rocks that are concentrated in a form, that can be extracted to obtain a usable commodity.
Classification:
1.Metallic Minerals:
Get metals for Ex Fe, Cu, Au etc.
Exist as ores 2. Non-metallic:
For Ex: Nitrate, Sulphur, Potash, Salt, Coal, Petroleum, Mineral Fuel
Conversion to product Surface
mining
Metal ore Separation of ore from gangue
Smelting Melting
metal Discarding
of product Recycling
Life Cycle of a Metal Resource
Smelting – heating to release metals but creating air polluting by-products
Effects of using & extracting:
1. Degradation of land.
2. Pollution of surface and groundwater resources due to release of harmful trace elements Ex Cd, Co, Cu, Pd etc.
3. Effect on growth of vegetation.
4. Deforestation including loss of flora & fauna.
5. Physical changes in the land, soil, water and air associated with mining directly & indirectly affect the biological environment.
6. Accidental discharge of pollutants.
7. Air pollution
Mineral exploration and environment issues:
1. Exploration: causes habitat disruption, noise pollution, acid mine drainage.
2. Mining & milling: causes wildlife loss, sedimentation, vegetation failure.
3. Smelting & Refining: SO2 emission contribute to acid rain, toxic chemical
4. Mine closure: seepage of toxic solution into ground water & surface water.
Types of mining
Open-pit Mining Area Strip Mining
Mountaintop Removal
Figure 15-14
Acid Mine Drainage
Food resources
Food is most important material for our body needs for its proper functioning and well being.
1. Agriculture crops constitutes an important food resource. About 300 crops are grown for food
& commercial products.
2. Domestic animals is also an important food source. For ex: milk by sheep, goat, camel etc.
3. Aquaculture: production of food by aquatic habitats for ex: fish & seafood.
Two kind of food problems:
1. Undernourishment: is lack of sufficient calories in available food, so that one has little or no ability to move or work.
Due to this:
1. Lack of energy & nutrition.
2. Susceptible to infectious diseases.
3. Permanently stunted growth, mental retardation.
2. Malnourishment: lack of specific components of food, such as proteins, vitamins or essential chemical elements.
Due to this:
1. Anemia: Inability to absorb iron.
2. Goiter: Deficiency of iodine.
3. Marasmus, Kwashiorkar: Lack of protein
Causes of food grain problems:
1.Long Term Causes:
Population Growth
Decrease in agriculture output
Decrease in productivity
Extension of commercial agriculture
Natural calamities
Change in the habit of consumption
2. Mid term Causes:
War
Defective food distribution
3. Short Term Causes:
Increase in consumption level
Deficit in production
Anti-social activities
Transport
Prevention of food crisis:
1. Increased production:
Extend the crop area
Use agriculture inventions & apply them to fields.
Increase agriculture facility for irrigation.
Plan the crops (nutritious crop).
Intensive agriculture.
2. Improvement in the process of distribution:
Government should take the wholesale trade of gain in its own hands.
Distribution of foodgrains should be done through fair price shops & consumer co-operative societies.
Construct the reserved stores.
3. Appropriate changes in the habit of consumers increased use of vegetables, fish, pulses.
4.Rural industries should be developed.
Effects of modern agriculture:
[1] Tradition Agriculture
(i) Traditional Subsistence: enough crops or live stock for farmer family survival in good years.
(ii) Traditional Intensive: increase inputs of human, draft labour, fertilizer to get higher yield.
[2] Modern Agriculture:
Uses modernized inputs like high yielding varieties, fertilizers, intense irrigation & pesticide application to boost agriculture productivity.
It increased productivity but there are some effects on environment:
i. Reduced soil fertility
ii. Increased soil salinity
iii. Water logging
iv. Effect of fertilizers & pesticides on water & soil.
v. Imbalance in ecosystem.
Water logging
It is the phenomenon of groundwater table rising too close to the ground level to sustain useful plant life.
In India water logged areas are: Deltas of Gangas
Areas of Kerala, Andaman & Nicobar islands.
Causes:
1. Over irrigation of land
2. Seepage losses from canals
3. Surface spreading of waste waters.
4. Excessive rainfall
5. Poor land drainage
Effects:
1. Can not sustain useful plant life.
2. Soil becomes saline due to evaporation.
3. Organic matter in soil undergoes an anaerobic decomposition.
Measures:
1. Excessive watering of crops should be avoided.
2. Evapotranspiration should be increases with suitable implantation.
Soil Salinity
Accumulation of excessive salts in soil is known as salinization.
Causes:
1. Continuous evaporation from water logged areas leaving the dissolved salt behind, causes accumulation of excessive salts.
2. Use of chemical fertilizer also increase salinity.
Impact:
1. When salinity increase, the land is unfit for crop.
2. Different plants have different tolerances.
3. Soil bacterial systems are upset.
Remedies:
1. Water logging should be avoided.
2. Excessive application of fertilizers should be avoided.
3. Waste water discharges should be controlled.
Overgrazing
Presence of too many animals on the land as for too long or at appropriate seasons, such the land become degraded is called overgrazing.
Effect:
1. Plants weakened.
2. Soil erosion
3. Reduce soil depth, soil organic matter
4. Soil fertility decreases.
5. Reduction in vegetation, biodiversity.
Fertilizers & Pesticides problem
To increase crop yields some important elements such as N, P & K alongwith Ca, Mg & S added to the fertilizer.
Effects:
1.
Excessive level of nitrates (NO
3), phosphates causes eutrophication.
2.
Increased salinity increases water demand of the crop.
3.
Surplus water having fertilizers get into natural water bodies &
groundwater which causes plant blooms.
4.
Crop will have inferior food value due to deficiencies of micronutrients as only few nutrients are given by fertilizers.
5.
Fertility problem.
Eutrophication
Biomagnification
Control:
1. Natural manure like composted organic wastes.
2. Chemical fertilizers should be fortified.
3. Agricultural pest control, prevention of food wastage.
4. Interplanting or rotating some leguminous crop.
Pesticides Uses:
1. Maximize crop or livestock yields.
2. For disease control
3. Preservation of building, furniture, clothing etc.
4. Control weeds.
Effect:
1.
On human health: cancer, birth defects etc.
2.
Toxicity
3.
Tendency to be concentrated by food web
4.
Soil fertility.
Measures:
1.
Banning dangerous compounds
2.
Alternative methods
3.
Controlling pesticide usages.
4.
Developing less dangerous pesticides
5.
Rotation of crop
Land resource
Land provide essential medium for development of agriculture, forestry, vegetation etc.
Agriculture land = 11%
Pastures = 22%
Forest land = 30%
Urban & agriculture land = 37%.
Land degradation
Land degradation refers to the loss of fertility or productive capacity of the soil.
Various factor are:
1. Soil erosion
2. Water logging & salination
3. Desertification
4. Shifting cultivation
5. Soil pollution
6. Urbanization
Soil erosion
Its physical detaching soil particles from original place and transporting them to some other place.
Types:
Water erosion: water cut or removes soil.
Sheet erosion: soil removed in small but uniform amount all over.
Rill erosion: run off water moves rapidly & cuts small stream like structures.
Gully erosion: several rills joined together to form broad channels called gullies.
Riparian erosion or Stream bank erosion: during floods river splash their water against the banks & thus cut through them.
Rill Erosion Gully Erosion
Stream Bank Erosion
Sheet Erosion
Desertification: lead to desert formation, either due to a natural phenomenon linked to climatic change or abusive land use.
Various factors responsible are:
1. Water erosion
2. Wind erosion
3. Depletion of soil fertility
4. Livestock grazing pressure
5. Loss of biodiversity
6. Water logging & salinity
7. Draught & flooding
8. Socio-economic constraints.
Land slides
Rapid downward movement of a mass of rock, earth or artificial fill on a slope.
Causes:
1. External causes:
Geometrical change
Unloading
Loading
Shock & vibrations
2. Internal causes:
Progressive failures such as expansion, fissuring
Physical to chemical properties change.
Seepage involves removal of cements.
Water regime change includes saturation rise in water table, excess pressure.
Energy Resource
Energy resource are exhaustible or non-renewable e.g. coal, mineral oil etc.
Some renewable energy resources e.g. biogas, wind, geothermal energy etc. which are used
Classification:
[I] classification:1. Commercial fuels: coal, petroleum products 2. non-commercial fuels: fuel wood, cow dung
[II] classification: 1. Primary energy resource: fossil fuels, nuclear, solar energy resource 2.Secondary energy resource: petrol, diesel fuel, electrical energy
[III] Classification: 1. Conventional: fossil fuels, water, nuclear energy 2.Non-conventional: Solar, wind, geothermal
[IV] classification: 1. Renewable: Solar, wind, water, geothermal 2.Non-renwable: fossil fuels, nuclear power.
Growing energy needs:
The standard of living of a given country can be directly related to per capita energy consumption.
Reasons for energy crisis:
1. The population of the world has increased rapidly.
2. Standard of living of human beings has increased.
3. 80% of the worlds energy is produced by fossil fuels.
S.No. Source Annual Contribut ion(10
8J)
1. Solar (i) electricity
(ii)Heating & cooling
3.2-9.5 16-23
2. Wind 6.6
3 Geothermal (i) Electricity
(ii)Heat
10.0 6.6
4. Ocean (i) Tidal
(ii) Wave
0.3 0.3
5. Fusion 1.6
Total 98
Alternate energy sources:
Conventional energy sources are depleting and may get exhausted in near future.
Non-renewable resources are thus utilized in future.
Need of alternate energy resources:
1. To reduce time for action.
2. Satisfy increased demand of energy.
3. New policies of energy conservation should continue.
4. Renewable sources of energy for ex: solar, wind etc. are likely to contribute during the century at global level.
Wind Energy
1. Wind mills used to grind grain & pump water.
2. Generates electricity.
3. Energy of winds over the earth’s surface is 1.6 X 107 M.W.
4. This energy can be utilized for performing mechanical & electrical works.
5. In India high speed winds are obtainable in coastal areas of Saurashtra, Western Rajasthan.
6. Variety of wind mills are there in India. They have different shape, design & direction.
7. Main problem related to it is that winds are highly variable.
Advantages:
1. Eco-friendly, Renewable.
2. Free of cost
3. Generation period is low.
4. Power generation is cheaper.
5. Large scale production of electrical energy as well as smaller sized applications.
Limitations:
1. Low energy density.
2. Variable, irregular, favourable in specific geographic locations, dangerous.
3. Favourable locations are generally away from cities.
4. Its noise can be irritating.
Hydel Energy
It is cheapest, neat & clean source of energy exploit by human civilizations in the form of water wheels.
20% of electricity generated in the world by hydropower.
In India 1st hydropower unit is established in1897 in Darjeeling.
Advantages:
1. Stations have longer life & minimum operating staff.
2. Started quickly & stopped.
3. Renewable, non-polluting & environmental benign.
4. Cost is lesser.
Limitations:
1. Land Acquisition: is a problem because proposal gone through many authorities like district authorities, state revenue development defense & forest agencies.
2. Environment aspects: soil erosion, vegetation degradation.
3. Construct Machinery: sophisticated equipment's
4. Construction problems: labour problems.
Biomass energy
Living matter or its residue, is renewable source of energy.
Biomass: Algae, plant growth, forest residues, wastes, biodegradable organic effluents from industries like sugar, distilleries etc.
Biomass allow to dry in sun and burn them to get energy.
Another method is anaerobic digestion to yield ‘biogas’.
Biogas contains methane 60%, CO2 40%, N2 & H2S in traces. Calorific value is 5000 K.cal/m3
Production: all wet slurry (organic matter) digested at pH 7.0-7.4 & temperature is maintain at 340C.
Advantages:
1. Continuous supply of energy.
2. Cost is less, pollution less.
3. Consumes CO2 & release O2.
4. Tremendous potential for rural areas as they utilize it for cooking, lighting, mechanical power &
generation of small electricity.
Tidal Energy
1. Periodic rise and fall of waters of the ocean is tide.
2. Tidal wave result by gravitational pull on ocean by moon & sun.
3. Tides contain large amount of energy. Such tide rise & fall and water can be stored during rise period and can be discharged during fall. Due to presence of water turbine rotate & generate power.
4. Firstly introduced by French in 1966.
5. Prospective sites are Gulf of Kutch, Cambay & Sunderbans, Lakshdeep island, Andaman & Nicobar Islands.
Solar Energy
Originates with the thermonuclear fusion reactions occurring in the sun.
Represents the entire electromagnetic
radiation (visible light, infrared, ultraviolet, x-rays, and radio waves).
Advantages and Disadvantages
Advantages
All chemical and radioactive polluting byproducts of the thermonuclear reactions remain behind on the sun, while only pure radiant energy reaches the Earth.
Energy reaching the earth is incredible. By one calculation, 30 days of sunshine striking the Earth have the energy equivalent of the total of all the planet’s fossil fuels, both used and unused!
Disadvantages
Sun does not shine consistently.
Solar energy is a diffuse source. To harness it, we must concentrate it into an amount and form that we can use, such as heat and electricity.
Addressed by approaching the problem through:
1) collection, 2) conversion, 3) storage.
How much solar energy?
The surface receives about 47% of the total solar
energy that reaches the Earth. Only this amount
is usable.
Applications
1. Heating and cooling of residential buildings.
2. Solar water heating.
3. Solar drying of agricultural & animal products.
4. Solar distillation
5. Salt production by evaporation of water.
6. Solar cookers.
7. Solar engines for water pumping
8. Solar furnaces
9. Solar photovoltaic cells.
10. Solar electric power.
Technology for harvesting solar energy It can be of two types:
[1] Thermal Conversion: direct heating.
[2] Photoconversion: includes photosynthesis, photochemistry, photoelectrochemistry, photogalvanisation & photovoltics.
Putting Solar Energy to Use: Heating Water
Two methods of heating water: passive (no moving parts) and active (pumps).
In both, a flat-plate collector is used to absorb the sun’s energy to heat the water.
The water circulates throughout the closed
system due to convection currents.
Tanks of hot water are used
as storage.
Heating Water: Active System
Active System uses antifreeze so that the liquid does not
freeze if outside temp. drops below freezing.
Heating Living Spaces
Best design of a building is for it to act as a solar collector and storage unit. This is achieved through three
elements: insulation, collection, and storage.
Efficient heating starts with proper insulation on external walls, roof, and the floors. The doors, windows, and vents must be designed to minimize heat loss.
Collection: south-facing windows and appropriate landscaping.
Storage: Thermal mass—holds heat.
Water= 62 BTU per cubic foot per degree F.
Iron=54, Wood (oak) =29, Brick=25, concrete=22,
and loose stone=20
Heating Living Spaces
Passive Solar
Trombe Wall Passively heated home
in Colorado
Heating Living Spaces
A passively heated home uses about 60-75% of the solar energy that hits its walls and windows.
The Center for Renewable Resources estimates that in almost any climate, a well-designed passive solar home can reduce energy bills by 75% with an added construction cost of only 5-10%.
About 25% of energy is used for water and space heating.
Major factor discouraging solar heating is low energy prices.
Mechanical wind mills
Heat
Solar & Thermal i.e.
heating & cooling
Electricity Photovoltics
Chemical fuels Biochemical
conversion
Sun
Solar Radiation
Applications
[1] Thermal conversion of solar energy:
Solar energy used to heat a fluid, which generates electricity through a conventional method.
[2] Electricity from solar energy:
Solar photovoltaic system (SPV) or solar cells are devices which directly convert incident solar radiation to electrical current.
It works on photoelectric effect.
Direct Conversion into Electricity
Photovoltaic cells are capable of directly converting sunlight into electricity.
A simple wafer of silicon with wires attached to the layers.
Current is produced based on types of silicon (n- and p-types) used for the layers. Each
cell=0.5 volts.
Battery needed as storage
No moving partsdo no wear out, but because they are
exposed to the weather, their lifespan is about 20 years.
Merits of SPV
1. Easy installation & maintenance.
2. Absence of noise & other form of pollution.
3. Long life of SPV make them favourable for use in remote & isolated areas.
Geothermal Energy
Geo (Greek for earth) Thermal (heat)
Temp. of Shallow Crust (upper 10 ft.) Constant 55-75°F (13-24°C)
Up to 14,400°F (8,000°C) at
Molten Core (approx. 4,000 mi. to center of core)
Firstly developed in Italy in 1904.
Based on geological criteria, it is classified as :
[1] Hydrothermal convention system:
Circulation of steam &/or hot water transfers heat at depth to the surface. E.g.
Geysers, 145 kms north of San Francisco.
[2] Hot igneous system:
Hot, dry rocks with or without the presence of magma.
[3] Geopressured system:
The normal heat flow from the earth is trapped in impermeable clay layers.
Two ways of electricity production:
[1] heat energy is transferred to a working fluid which operates the power cycles.
[2] Hot geothermal water and /or steam is used to operate the turbines directly.
At present this method is in use.
India has vast potential for geothermal energy which more than 340 water springs with temperature 80-1000C.
Advantages:
1. Most versatile & least polluting energy.
2. Inexpensive
3. Power generation level is high.
4. Directly use.
Limitations:
1. Away from the area needing energy.
2. Energy can not be efficiently transfer.
3. In steam polluting gases like H2S, NH3, CO2 present
4. Hot brine discharged into surface water bodies may be ecological hazardous.
5. Drilling operations cause noise pollution.
