Geography

 

The environment refers to the total surrounding not an organism in an area including the physical surrounding, factors of climate.It also means the surroundings or conditions where a person, animal or plant lives.

                                  TYPES OF ENVIRONMENT

The environment is classified into three: physical, social & cultural environment.

i) Physical environment is the biotic & abiotic surroundings of an organism(both plants & animals).That is,it is made up of things in the surrounding which can be seen,felt or touched.Example plants,animals,climatic factors like temperature,wind, sunlight,soil,rock.Others are mountains,rivers,land ,air,etc

(ii)Social environment:This is the immediate physical & social surroundings that people livening.It is made up of people in an area,how they live & relate with one another.It includes schools,houses,roads, airports, seaports, markets,banks,farms, playgrounds, shops.social environment is a non- physical environment  created by human activities in changing the phase of landforms.

(iii) Cultural environment: This is the cultural & social aspect of a given society.That is,it is the way of life in an area.It includes language,mode of dressing, ceremonies like marriage, burial, initiation in age grade,etc perculiar to a particular place.Others are religious activities in churches,  mosques, hairstyles & ways of feeding, acceptable norms & beliefs.

                         COMPONENTS OF ENVIRONMENT

These are Biotic (living) &  Abiotic (non- living) components

(i) Biotic component:This comprises the living things ( plants & animals) which are grouped into producers, consumers,& decomposers

(a) producers are knowns as autotrophs( green plants & some micro organisms) which manufacture their own food from simple inorganic materials during the process of photosynthesis & chemosynthesis.

(b) Consumers: These are animals & some plants which cannot manufacture their own food but rely directly or indirectly on plant for their food.Consumers are also known as heterotrophs & they can be primary, secondary or tertiary consumers.

(c) Decomposers: These are bacteria & some fungi which breakdown dead plants & animals in order to feed on them.Hence nutrients ar released to the soil for use by the producers in this process.

(ii) Abiotic components: These are the non- living things. They include:

a) climatic factors e.g temperature, humidity, rainfall, wind & sunlight.

b) inorganic materials & nutrients e.g.carbon( iv)oxide, calcium,oxygen, nitrogen & phosphorus.

c)edaphic factors e.g.soils,rocks & topography

d) other factors like dust,fire,water & storm.

 

 

3RD WEEK

 

DOMAINS OF THE ENVIRONMENT.

The domains of the environment are grouped into four namely: Lithosphere, atmosphere, biosphere, and hydrosphere.

            CHARACTRISTICS OF LITHOSPHERE

a) it is the outermost layer of the earth crust.

b) it comprises of rocks and mineral materials.

 c) It represent 30% of the earth's surface.

d) it forms the land mass of about 10 to 50 km thick.

e) it is the solid part of the Earth example soil and rocks.

f)the outermost layer of the land mass is made up of loose rock materials such as gravel sand and soil.

               CHARACTERISTICS OF ATMOSPHERE

The atmosphere :This is the layer of gases that envelopes the earth

a) it is the gaseous portion of the Earth.

b) it contains water in form of vapour in lower layers.

c) weather phenomenon like cloud, rain and snow are largely confined in it.

d) over 99% lies within 30 km of the earth's surface.

e) its density decreases progressively with elevation.

f) it contains 78% nitrogen, 21% oxygen, 0.03% carbon dioxide and 0.97% of rare gases.

          CHARACTERISTICS OF BIOSPHERE

Biosphere: this is made up of living things such as man plants and animals.

a) the biosphere is a layer of life which exist on earth surface and the lithosphere.

b) it is the zone of the earth occupied by living organisms.

c)it includes organisms such as plants animals and microorganisms.

d) it has a maximum thickness of only a few kilometres.

e) it is a narrow zone where complex biological and chemical activities occur.

              CHARACTERISTICS OF HYDROSPHERE

Hydrosphere:this is the liquid part of the Earth such as rivers, lakes, seas and oceans.

a) the hydrosphere is the liquid portion of the earth.

b) it holds water in solid form e.g ice, liquid form e.g water and gaseous form e.g water vapour.

c) it covers about 70% of the earth crust.

d) it includes all forms of fresh water like lakes, rivers and streams etc, and the salty water like ocean water.

e) ocean water accounts for about 97% of the hydrosphere.

                 IMPORTANCE OF THE ENVIRONMENT

The importance of the environment are discussed under the domains of the environment.

              IMPORTANCE OF LITHOSPHERE

a)All mineral resources are derived from lithosphere.

b)all farming activities are carried out on lithosphere.

c) it forms the basis of all human settlement.

d) it helps in transportation through construction of roads, railways and airports.

e) most human activities are carried out on lithosphere e.g trading and mining.

               IMPORTANCE OF ATMOSPHERE

a) the atmosphere provides oxygen for combustion.

b) it is the habitat of some living organisms.

c) it provides oxygen for animals and plants for respiration.

d) it provides carbon dioxide for photosynthesis by plants.

e) it is a medium of communication example air routes.

f)it provides nitrogen for plants and acts as greenhouse.

g)it contains ozone layer which acts as protective cover for living organisms against the burning effect of ultraviolet rays of the sun.

                   IMPORTANCE OF BIOSPHERE

a) plants in the biosphere provide food for a man.

b) plants provide a source of energy like firewood to man.

c)they also provide clothing material from an e.g. wool and Cotton.

d)it provides raw materials for industries e.g. hides and skin, cotton, timber.

e) it provides shelter in form of timber for a man.

f)it aids the balancing and purification of atmospheric gases e.g. carbon dioxide during respiration and oxygen during photosynthesis.

g) it provides employment for man.

             IMPORTANCE OF HYDROSPHERE

a) hydrosphere is used in agriculture in form of irrigation.

b) it is a medium for sporting activities example swimming and diving.

c) it provides water for industrial and domestic uses.

d) it provides a medium of transportation.

e) it provides food for man example fish, prawns, crabs, etc.

f) it can be used to generate electricity e.g H.E.P.

g) it provides employment  for people e.g. canoe builders, fishermen,etc

h) it serves as tourist centres e.g. beaches.

            PROBLEMS FACING THE ENVIRONMENT

a) Deforestation:this is the indiscriminate destruction of forest or felling of trees without replacement. This prevents human beings from getting food and other resources from the forest.

b) Desert encroachment:This is the spread of deserts to areas which were originally not deserts before.This can cause loss of farmland, vegetation and shortage of water for human and animal consumption

c) soil erosion: This is the gradual removal of the top soil through the action of wind and water.This can lead to the damage of roads, decline in agricultural productions, removal of fertile nutrients from the soil etc.

d) Environmental pollution:when there is release of harmful substances into the environment by natural or man-made forces, it can cause biological damage to man and his resources.

e) Population explosion: The rapid increase in population as a result of high birth rate tends to lead to lead to a reduction in social amenities or over stretching of the available resources for man.

f) Global warming: The emission of dangerous gases into the atmosphere through the activities of man is fast causing changes in the climatic conditions of the environment. This has affected human beings on the earth negatively.

g) climatic change: The negative activities of Man also affect the environment thereby causing climatic changes on the environment. These changes also affect human beings negatively on the earth surface.