Unit 2a Natural Res

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NATURAL RESOURCES

A natural resource is a renewable resource if it is

replaced by natural processes at a rate comparableor faster than its rate of consumption by humans.Solar radiation, tides, winds and hydroelectricity areperpetual resourcesthat are in no danger of a lack

of long-term availability.

Production of wind energy
http://en.wikipedia.org/wiki/File:Windpark_Galicia.jpghttp://en.wikipedia.org/wiki/File:Windpark_Galicia.jpghttp://en.wikipedia.org/wiki/File:Windpark_Galicia.jpghttp://en.wikipedia.org/wiki/File:Windpark_Galicia.jpg


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A non-renewable resource is a natural resource whichcannot be produced, re-grown, regenerated, or reused ona scale which can sustain its consumption rate. These

resources often exist in a fixed amount, or are consumedmuch faster than nature can recreate them. Fossil fuel(such as coal, petroleum and natural gas) and nuclearpower are examples. In contrast, resources such as timber(when harvested sustainably) or metals (which can berecycled) are considered renewable resources

A scene from a coal mine
http://en.wikipedia.org/wiki/File:Coal_mine_Wyoming.jpg


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Forest resources


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Forest Resources: It is a dense growth of trees,together with other plants, covering a large area of

land. Forests are one of the most natural resourceson this earth. Covering the earth like a green blanketthese forests not only produce innumerable materialgoods, but also provide several environmental

services which are essential for life.


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As per the latest state of forestsreport of the Forest Survey ofIndia the actual forest cover of

India is 19.27% of the geographicarea, corresponding to 63.3million hectors.

Use and Over Exploitation:

The direct benefits from forests are:

1. Fuel Wood2. Timber3. Bamboos4. Food5. Shelter6. Paper7. Rayon

8. Forest Products


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The ecological services provided by our forests maybe summed up as follows:

1. Production of oxygen: The trees produceoxygen by photosynthesis which is so vital for life onthis earth. They are rightly called as earths lungs.

2. Reducing global warming: The maingreenhouse gas carbon dioxide (CO2) is absorbedby the forests as a raw material for photosynthesis.Thus forest canopy acts as a sink for CO2 thereby

reducing the problem of global warming caused bygreenhouse gas i.e. CO2.3. Wild life habitat: Forests are the homes ofmillions of wild animals and plants. About 7 million

species are found in the tropical forests alone.


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4. Regulation of hydrological cycle: Forestedwatersheds act like giant sponges, absorbing therainfall, slowing down the runoff and slowly

releasing the water for recharge of springs. About50-80% of the moisture in the air above tropicalforests comes from their transpiration which helps inbringing rains.5. Soil Conservation: Forests bind the soil particlestightly in their roots and prevent soil erosion. Theyalso act as windbreaks.

6. Pollution moderators: Forests can absorb manytoxic gases and can help in keeping the air pure andclean. They have also been reported to absorbnoise and thus help in preventing air and noise

pollution.


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OVER EXPLOITATION OF FORESTS:

Since time immemorial, humans have dependedheavily on forests for food, medicine, shelter, woodand fuel. With growing civilization the demands forraw material like timber, pulp, minerals, fuel woodetc. shooted up resulting in large scale logging,

mining, road-building and clearing of forests. Ourforests contribute substantially to the nationaleconomy. The international timber trade alone isworth over US $ 40 billion per year.

Excessive use of fuel wood and charcoal, expansionof urban, agricultural and industrial areas andovergrazing have together led to over exploitation of

our forests leading to their rapid degradation.


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Deforestation

Deforestation is the permanent destruction ofindigenous forests and woodlands. The term doesnot include the removal of industrial forests suchas plantations of gums or pines.

The total forest area of the world in 1990 wasestimated to be 7000 million hectares which wasreduced to 2890 million hectares in 1995 and fell

down to just 2300 million hectares by 2000.


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Major causes of Deforestation:

1.Shifting cultivation: There are an estimated 300

million people living as shifting cultivators who practiceslash and burn agriculture and are supported so clearmore than 5 lakh hct. of forests for shifting cultivationannually. In India, we have this practice of North-East

and to some extent in Andhra Pradesh, Bihar and M.P.which contribute to nearly half of the forest clearingannually.

2. Fuel requirements: Increasing demands for fuelwood by the growing population in India alone hasshooted up to 300-500 million tons in 2001 ascompared to just 65 million tons during independence,

thereby increasing the pressure on forests.


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3. Raw materials for industrial use: Wood formaking boxes, furniture, railway-sleepers, plywood,

match boxes, pulp for paper industry etc. haveexerted tremendous pressure on forests. Plywood isin great demand for packing tea for Tea industry ofAssam while fir tree wood is exploited greatly for

packing apples in J & K.

4. Development projects: Massive destruction offorests occur for various development projects like

hydroelectric projects, big dams, road construction,mining etc.


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5. Growing food needs: In developing countriesthis is the main reason for deforestation. To meet

the demands of rapidly growing population,agricultural lands and settlements are createdpermanently by clearing forests.

6. Overgrazing: The poor in the tropics mainly relyon wood as a source of fuel leading to loss of treecover and the cleared lands are turned into thegrazing lands. Overgrazing by the cattle leads tofurther degradation of these lands.


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Effect of DeforestationForests are closely related with climatic change,

biological diversity, wild animals, crops, medicinalplants etc.

1.Habitat destruction of wild animals (tree-usinganimals are deprived of food and shelter.)

2.Increased soil erosion due to reduction ofvegetation cover.3.Reduction in the oxygen liberated by plants

through photosynthesis.

4. Increase in pollution.5.Decrease in availability of forest products.6.Loss of cultural diversity7.Loss of Biodiversity


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8.Scarcity of fuel wood and deterioration in economyand quality of life of people residing near forests.

9.Lowering of the water table due to more run-offand thereby increased use of the undergroundwater increases the frequency of droughts.

10.Rise in Carbon dioxide level has resulted in

increased thermal level of earth which in turnresults in melting of ice caps and glaciers andconsequent flooding of coastal areas.
http://en.wikipedia.org/wiki/File:Timber_DonnellyMills2005_SeanMcClean.jp


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http://en.wikipedia.org/wiki/File:Timber_DonnellyMills2005_SeanMcClean.jphttp://en.wikipedia.org/wiki/File:Wood_from_victoria_mountain_ash.jpg


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Timber ExtractionOne of the forestproducts most important

to human economieshas always been wood-lignified plant material.Lumber or timber iswood that is used in anyof its stages from fellingthrough readiness for

use as structuralmaterial forconstruction, or woodpulp for paper

production.
http://en.wikipedia.org/wiki/File:Wood_from_victoria_mountain_ash.jpg


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Impact of Timber ExtractionLoss of Cultural Diversity:The worlds forests, particularly the tropical

rainforests, are home to over 10 million membersof the last surviving intimately resource-basedcultures. Forest dwellers around the world havelived with this resource for millennia, yet today it isoften literally stolen from them by governments andindustries intent on turning natural capital into hardcurrency.

Loss of BiodiversityBiodiversity is the level of difference among living

things. It is important to the biological health of theplanet and therefore, to the human race because

diversity contributes to resiliency.
http://en.wikipedia.org/wiki/File:Alaskan_Trommel.jp


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http://en.wikipedia.org/wiki/File:Alaskan_Trommel.jp


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Mining is defined in the Macquarie Dictionary as theaction, process, or industry of extracting ores, etc.,from mines.

Mining is the extraction of valuable minerals or othergeological materials from the earth, usually from an

ore body, vein or (coal) seam. Materials recovered bymining include base metals, precious metals, iron,uranium, coal, diamonds, limestone, oil shale, rocksalt and potash. Any material that cannot be grown

through agricultural processes, or created artificiallyin a laboratory or factory, is usually mined.


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Impact of Mining on Environment:

It destroys forest and wetlands.It may mean that you have to cut down lots of trees

just to get to the spot that has all the gold or iron ore.Many mine require tailings dams to prevent waste beingwashed into the rivers. Unethical miners can dispensewith the dams, to save costs, resulting in massivepollution downstream. In other cases, the tailings damcan overflow, and even breach, during periods of heavy

rain.
http://en.wikipedia.org/wiki/File:Iron_hydroxide_precipitate_in_stream.jpg


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Underground coal mining can require the

removal of almost an entire layer of materialdeep under the surface. When the timbersupports collapse, this can lead to subsidence.The subsidence can mean economic loss topeople above or damage to natural areas. It caneven cause cracks in river beds, leading to lossof river flow.

Some mining involves the inadvertent dispersalof heavy metals, such as lead, into theatmosphere. This can have serious healtheffects, including mental retardation in children.

Asbestos mining causes the dispersal ofasbestos into the environment. This will causedeaths among local residents and workers, oftenseveral decades later. Fortunately, the miningand use of asbestos are banned in most parts of

the world.


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Mining should be ban!

There is no reason for a blanket ban onmining. However, the environmentalimpact of each proposed mine should be

analysed before permission to proceed isgranted. Mining operators must be awareof the potential impacts of their operations

and ensure minimum risk to theenvironment.
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A barrier or structure across astream, river, or waterway forthe purpose of confining and

controlling the flow of water.A dam is a barrier thatimpounds water orunderground streams. Dams

generally serve the primarypurpose of retaining water,while other structures suchas floodgates or levees (alsoknown as dikes) are used tomanage or prevent waterflow into specific land

regions.
http://en.wikipedia.org/wiki/File:Takato_Dam_discharge.jp


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Dams look beautiful if correctly built but they can messup the environmentRise in sea level (could flood lower elevation areas)

Shift of climatic zones to the polesUnmanaged ecosystems may face new climate basedstressesEffect on water resources as precipitation and

evaporation may change

In far too many cases, dam-building has resulted inwidespread human rights violations. As most of us

would, local peoples have persistently resisted thedestruction of their homelands and their forcedresettlement. As a result, they have had to face

different types of repression, ranging from physical and

legal threats to mass murders.


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Dams- Benefits and Problems:

Dams provide a range of economic, environmental,and social benefits, including recreation, floodcontrol, water supply, hydroelectric power, wastemanagement, river navigation, and wildlife habitat.

RecreationDams provide prime recreational facilitiesthroughout the United States. Boating, skiing,

camping, picnic areas, and boat launch facilities areall supported by dams.


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Flood ControlIn addition to helping farmers, dams help prevent

the loss of life and property caused by flooding.Flood control dams impound floodwaters and theneither release them under control to the river belowthe dam or store or divert the water for other uses.

For centuries, people have built dams to helpcontrol devastating floods.

Water Storage

Dams create reservoirs throughout the UnitedStates that supply water for many uses, includingindustrial, municipal, and agricultural.


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IrrigationTen percent of American cropland is irrigated using

water stored behind dams. Thousands of jobs aretied to producing crops grown with irrigated water.Mine TailingsThere are more than 1,300 mine tailings

impoundments in the United States that allow themining and processing of coal and other vitalminerals while protecting the environment.


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Electrical GenerationThe United States is one of the largest producers of

hydropower in the world, second only to Canada.Dams produce over 103,800 megawatts ofrenewable electricity and meet 8 to 12 percent of theNation's power needs. Hydropower is considered

clean because it does not contribute to globalwarming, air pollution, acid rain, or ozone depletion.Debris ControlIn some instances, dams provide enhanced

environmental protection, such as the retention ofhazardous materials and detrimental sedimentation.


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NavigationDams and locks provide for a stable system of

inland river transportation throughout the heartlandof the Nation.


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DisadvantagesDams are extremely expensive to build and must be

built to a very high standard.The high cost of dam construction means that theymust operate for many decades to becomeprofitable.

The flooding of large areas of land means that thenatural environment is destroyed.People living in villages and towns that are in the

valley to be flooded, must move out. This means thatthey lose their farms and businesses. In somecountries, people are forcibly removed so that hydro-power schemes can go ahead.


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The building of large dams can cause seriousgeological damage. For example, the building of the

Hoover Dam in the USA triggered a number of earthquakes and has depressed the earth's surface at itslocation.

Although modern planning and design of dams isgood, in the past old dams have been known to bebreached (the dam gives under the weight of waterin the lake). This has led to deaths and flooding.


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Dams built blocking the progress of a river in onecountry usually means that the water supply from

the same river in the following country is out of theircontrol. This can lead to serious problems betweenneighboring countries.

Building a large dam alters the natural water tablelevel. For example, the building of the Aswan Damin Egypt has altered the level of the water table. Thisis slowly leading to damage of many of its ancient

monuments as salts and destructive minerals aredeposited in the stone work from 'rising damp'caused by the changing water table level.


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Hydro power dams can damage the surroundingenvironment and alter the quality of the water bycreating low dissolved oxygen levels, which impacts

fish and the surrounding ecosystems. They also takeup a great deal of space and can impose on animal,plant, and even human environments.


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By 2020, it is projected that the percentage of powerobtained from hydro power dams will decrease to

around four percent because no new plants are inthe works, and because more money is beinginvested in other alternative energy sources such assolar power and wind power.


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The Silent valley hydroelectric project was one ofthe first such projects situated in the tropical rain

forest area of Western Ghats which attracted muchconcern of the people.

The crusade against the ecological damage and

deforestation caused due to Tehri dam was led byShri.Sunder lal Bahaguna, the leader of ChipkoMovement.

The cause of Sardar Sarovar Dam related issueshave been taken up by the environmental activitistMedha Patkar, joined by Arundhati Ray and BabaAmte.


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Water Resources
http://en.wikipedia.org/wiki/File:Poland_Solina_dam.jpghttp://en.wikipedia.org/wiki/File:Sinclair_Wetlands.jpg


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Water resources are sources of water that areuseful or potentially useful to humans. Uses of water

include agricultural, industrial, household,recreational and environmental activities. Virtually allof these human uses require fresh water.

At global scale, about 71% of earth surface iscovered with water. 97% of water on the Earth issalt water, leaving only 3% as fresh water of whichslightly over two thirds is frozen in glaciers and polar

ice caps. The remaining unfrozen freshwater ismainly found as groundwater, with only a smallfraction present above ground or in the air (1%)


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Use of Water resources:

AgriculturalIt is estimated that 69% of worldwide water use is forirrigation, with 15-35% of irrigation withdrawals beingunsustainable.

IndustrialIt is estimated that 15% of worldwide water use isindustrial. Major industrial users include power plants,

which use water for cooling or as a power source (i.e.hydroelectric plants), ore and oil refineries, which usewater in chemical processes, and manufacturingplants, which use water as a solvent.


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The portion of industrial water usage that isconsumptive varies widely, but as a whole is lowerthan agricultural use.

HouseholdIt is estimated that 15% of worldwide water use is for

household purposes. These include drinking water,bathing, cooking, sanitation, and gardening.

Recreation
http://en.wikipedia.org/wiki/Drinking_waterhttp://en.wikipedia.org/wiki/Bathinghttp://en.wikipedia.org/wiki/Cookinghttp://en.wikipedia.org/wiki/Gardeninghttp://en.wikipedia.org/wiki/Gardeninghttp://en.wikipedia.org/wiki/Cookinghttp://en.wikipedia.org/wiki/Bathinghttp://en.wikipedia.org/wiki/Drinking_water


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RecreationRecreational water use is usually a very small butgrowing percentage of total water use. Recreational

water use is mostly tied to reservoirs. If a reservoir iskept fuller than it would otherwise be for recreation,then the water retained could be categorized asrecreational usage. Release of water from a few

reservoirs is also timed to enhance whitewaterboating, which also could be considered arecreational usage. Other examples are anglers,water skiers, nature enthusiasts and swimmers.
http://en.wikipedia.org/wiki/Recreationhttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/Recreation


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Types of Water Sources:Saltwater ResourcesSaltwater is abundant in the world. However,saltwater is not useful when it comes to potablewater supplies. Desalination plants, while they doexist, are scarce because the energy required for

desalination makes the process extremelyexpensive. However, there are saltwater resourcesfrom which we benefit. Saltwater fish are a staple inmuch of the world's diet, but overfishing has put

much of the fishing population at risk. Furthermore,tidal waters are being used as a source ofhydroelectric energy. So, while saltwater is nothelpful in dealing with scarce water supplies, it's

inherent resources are being used.
http://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpg


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Groundwater ResourcesGroundwater is the most plentiful of all freshwaterresources. As water soaks into the ground, some of itadheres to clay and soil to provide water to theplants. This water is in the unsaturated. Most of thepores in the unsaturated zone are filled with air, rather

than water. Gravity continues to move the water downthrough the ground. Eventually, the water reaches thesaturated zone, where all the pores are filled withwater.
http://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://en.wikipedia.org/wiki/File:Whitewater.jpghttp://www.ehow.com/soil/http://www.ehow.com/soil/


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Surface WaterSurface water is the water that exists in streams and

lakes. This water is used for potable water supply,recreation, irrigation, industry , livestock,transportation and hydroelectric energy. Over 63percent of the public water supply is withdrawn from

surface water. Irrigation gets 58% of its water supplyfrom surface water. Industry gets almost 98 percentof its water from surface water systems. Therefore,surface water conservation and quality is of utmost

importance.
http://www.ehow.com/transportation/http://www.ehow.com/transportation/


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Drought

A drought is an extended period of months or yearswhen a region notes a deficiency in its water supply.
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Types of droughtMeteorological drought is brought about when there

is a prolonged period with less than averageprecipitation. Meteorological drought usuallyprecedes the other kinds of drought.

Agricultural droughts are droughts that affect cropproduction or the ecology of the range. This conditioncan also arise independently from any change inprecipitation levels when soil conditions and erosion

triggered by poorly planned agricultural endeavorscause a shortfall in water available to the crops.However, in a traditional drought, it is caused by anextended period of below average precipitation.
http://en.wikipedia.org/wiki/File:Drought.jpghttp://en.wikipedia.org/wiki/Meteorologyhttp://en.wikipedia.org/wiki/Agriculturehttp://en.wikipedia.org/wiki/Agriculturehttp://en.wikipedia.org/wiki/Meteorology


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Causes of drought:

Generally, rainfall is related to the amount of watervapor in the atmosphere, combined with the upwardforcing of the air mass containing that water vapor. Ifeither of these are reduced, the result is a drought.

This can be triggered by an above averageprevalence of high pressure systems, winds carryingcontinental, rather than oceanic air masses (ie.reduced water content), and ridges of high pressure

areas form with behaviors which prevent or restrictthe developing of thunderstorm activity or rainfallover one certain region.
http://en.wikipedia.org/wiki/Pressure_systemhttp://en.wikipedia.org/wiki/Windhttp://en.wikipedia.org/wiki/High_pressure_areahttp://en.wikipedia.org/wiki/High_pressure_areahttp://en.wikipedia.org/wiki/High_pressure_areahttp://en.wikipedia.org/wiki/High_pressure_areahttp://en.wikipedia.org/wiki/Windhttp://en.wikipedia.org/wiki/Pressure_system

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Unit 2a Natural Res