Thursday, March 17, 2022

Geography introduction and concepts

Geography introduction and concepts

perspectives in human geography: Areal differentiation; regional synthesis; Dichotomy and dualism; Environmentalism; Quantitative revolution and locational analysis; radical, behavioural, human and welfare approaches; Languages, religions and secularisation; Cultural regions of the world; Human development index.
osmanian 2011-01-02T21:22:27.324-08:00 environmental geography 5. Environmental Geography: Principle of ecology; Human ecological adaptations; Influence of man on ecology and environment; Global and regional ecological changes and imbalances; Ecosystem their management and conservation; Environmental degradation, management and conservation; Biodiversity and sustainable development; Environmental policy; Environmental hazards and remedial measures; Environmental education and legislation.

Human ecological adaptations

1. Introduction and Meaning

2. Types and levels of adaptations

3. Biological adaptations

4. Cultural adaptations

1. Introduction and Meaning: Human being like any other species on the earth are exposed to changes in environmental conditions, many of which are natural and other are man made like other animals survival and success depends upon the ability of humans to tolerate and tide over new conditions and changes. Such ability of the human to tolerate and tide over new conditions and to adjust to the shifting conditions in their environment is called adaptation. Human beings are different from all other species by the fact that they are spread over most part of the land surface i.e. from the equatorial to the polar regions and they have also learnt to tolerate ? conditions such as the high pressure of the deep sea and the zone gravity of the space. Surprisingly humans are not the ideal species to study in order to understand the range of biological adaptations despite their ? success as dominant species of the earth. This is attributed to their higher intellectual capacity which enables them to adjust their behavior over the environmental conditions. Thus they tend to exhibit more cultural adjustments than biological adaptations. Nevertheless there are instance of physical and biological variations in human population exposed to different climatic conditions in various geographic locations.

All organisms encounter new environment which provide newer challenges. Survival of populations may depend upon their ability to occupy new environment and humans have proved to be very successful in it. Any new environment brings in a number of new stresses related to environment to which the organism is exposed. For instance, lack of oxygen in an environmental stress at high attitudes while a desert may produce water and heat stress. Each of these environmental stress in turn will produce physiological heat stress. Each of these environmental stresses will produce physiological chain in the organism. For example the environmental ? high attitude will produce strain in the respiratory circulate system of the organism. Every strain prompts tho body to adopt in multiple ways. Thus, adaptations are brought about by strains on the organism which in turn are called by the environmental stress.

A few organisms including humans uses a strategy which minimizes the need for adaptation. The alternative for adaptation is the creation of a micro environment in which the environmental stress itself is minimized on eliminated. Here the organism creates around itself a layer of protective micro environment. These micro environment may be communal like the Beavers Log house or it can be individual like the Eskimos suite creating a micro environment is usually achieved by changing the natural behavior of the organism and is also referred to as cultural adaptations.

2. Levels of adaptations: Adaptation appears at various levels ranging from genetic to cultural levels.

i. Genetic level: Adaptation at this level involves the process of natural selection. No two organisms of the same species are alike since almost every characteristics like size, colour, personality show some variation. These variations may help some of the individuals to adapt better to suit the environment.

ii. Physiological level: Changes occurring at this level are either short or long term modifications resulting in what are called as upclimatasation responses of the body such as sweating to effect cooling. However, many of the physiological responses are long term responses such as an increase in RBC and hemoglobin at high attitude and the development of improved heat tolerance under desert conditions.

iii. Growth and development level: These changes are referred to as ontogenetic modification as they take place during the physical growth and development of the organism. Example of ontogenetic modification is the increase in body size and changing cranial morphology of migrants to North America.

iv. Cultural Level: This includes changes in the process of cultural behavior of the individual or ? and in the case of human includes the pattern of clothing, housing, food habits and technology. Example – behavioral adjustment to cold may include change in the use of shelter, dress, fire etc.

3. Biological Adaptations: Human exhibit a variety of ? adaptations to the quest for survival in a new environment biological adaptations are often irreversible since they have a genetic have and are inherited from one generation to the other. These, ? adaptations have played a crucial ride in the indutionary history and is visible from the anthropological account. Notwithstanding the evolutionary incidence of biological adaptation it is evident that cultural modifications are more dominant than biological adaptations. There are many regions where biological adaptations are less human.

a. Human are rather homogeneous species i.e. they are too generated. This feature is due to the fact that they have greater mobility and tend to spread very fast. Intermixing of population due to mobility eliminates the chances of isolation and encourages more homogeneity.

b. Humans are not restricted to any particular environment unlike many other species. This may be partly due to the fact that humans are warm blooded and can withstand fluctuations in the environmental temperature while maintaining a constant body temperature.

4. Biogeography: Genesis of soils; Classification and distribution of soils; Soil profile; Soil erosion, Degradation and conservation; Factors influencing world distribution of plants and animals; Problems of deforestation and conservation measures; Social forestry; agro-forestry; Wild life; Major gene pool centres.

Genesis of Soils

Soil is the upper thin layer of loose material on the earth’s crust. It has which is rich in nutrients and support life. Below it is the sub soil which contains weathered materials of parent rocks. Soil is the heart of the life layer i.e. biosphere it provides the nutrients to the plant life which in turn sustain animal. It is a great biological factory because it acts as a medium for various biological cycles, produces and transforms various compounds, provides nutrients and home for various plants and micro organisms.

- It is a dynamic medium where various physical, chemical and biological activities continuously takes place

- The soil in a given region is the result of

- Soil forming processes

- Factors influencing the process

Soil forming Process:

The processes – physical, chemical or biological through which soil is formed is known as pedogenesis.

It is an open system phenomenon involving gains and losses, movement of material from one part of profile to another, and various transformations within. Based on specific conditions and activities, various processes of soil genesis may be identified

1. Transolation: It involves various kinds of movement material, predominatly in downward direction due to mainly the agent of water

a. Leaching: It is the downward movement of material in solution or colloidal form. It is move dominant in humid areas than dry areas

b. Evaluation: the downward washing of clay and fine particles leaving behind deprived layer (out washing)

c. Illuviation: Reverse of eluviations. It is the deposition of material from upper layers due to illuviation leading to an enriched lower layer (inwashing).

d. Classification: Conc of calcium in layers. This occurs in dry areas, where potential evapo transpiration exceeds precipitation. The movement of soil solution is upward due to capillary action. The ineffectiveness of leaching and other solutes remain in soil. Further in grasslands the grasses use calcium drawing from lower layers and leave behind in soil after they die.

e. Salinisation / Alkanisation: it is the accumulation of calcium / sodium salts in the form of a thin whitish crust at soil surface, which is harmful to plant growth. It happens when there is excess of water and intense evaporation. The capillary rise of water from high water table and consequent evaporation leaves behind salts. It is observed in well irrigated but poor drainages areas. Ex: Punjab

2. Organic Changes: Organic material accumulates at ground surface due to decay of plant material. Degradation – Humification – Mineralization (human releases compounds) The dead plant material is degraded by microorganisms. The matter is further decomposed or humified into a dark amorphous mass. Conditions of extreme wetness may lead to formation of peaty soils. Over a long period, the humus is decomposed into nitrogenous compounds through the process of mineralization.

3. Podzolisation (cheluviation): Process through which upper horizons become rich in silica, while lower horizons are rich in iron, often forming an iron pan (this but tough horizon of iron oxides). This is due to the different solubility’s of minerals. The translocation is caused by leaching action of certain organic compounds called ? agents. These agents are rich in soils where acids are formed due to decomposition of say, health plants and conifer needless. But not in gross or deciduous areas where in soil is rich in bases.

Ex: Coniferous forests – health vegetation

4. Claying: It occurs in water logged conditions where a special type of bacteria flourishes due to an aerobic conditions, which uses up organic matter. They reduce ferric iron to a soluble ferrous state resulting in the creation of a gley horizon. Some times soil may dry up in certain patches leading to formation of ferric iron, giving a patchy red colour. Claying takes place in soil areas of permanent ground water saturation.

5. Desilication: Latersation in hot wet climate. It is opposite of podsolisution where iron / Al oxides are mobile. Here, silica is more mobile and is removed from top soil. Desilication leads to surface with oxides of Fe / Ai – called feral sols. Organic content is also low due to rapid decomposition by micro organ. The ground water movement will lead to conc. Of oxides near surface – forming hard laterilic horizons. Normally, infertile

Factors influencing soil formation:

Soil can be the product of interaction of combination of various factors, though locally one factor might have dominant influence.

1. Parent Material: It influences texture and fertility

Ex: Sandstone gives coarser soil

Shale gives finer soil

Parent material gives various initial nutrients, though they may be redistributed by soil processes.

Ex: Calcareous rocks give base rich soil. Non calcareous soils are liable to podzolisation leading to acid rich soil.

3. Oceanography: Bottom topography of the Atlantic, Indian and Pacific Oceans; Temperature and salinity of the oceans; Heat and salt budgets, Ocean deposits; Waves, currents and tides; Marine resources: biotic, mineral and energy resources; Coral reefs, coral bleaching; sea-level changes; law of the sea and marine pollution.


§ 11/3rd of earth area Asia – w. of America

Bering st – Cape Adare (Antarctica)

§ Average depth 500m (a major part)

Descent from coast to sea plains is steeper

Oceanic surface is fairly uniform

§ Most unique - Broad triangular shape

Folded mountains are found parallel to it

Completely blocked in the North – except for a narrow passage

A variety of islands

Many marginal seas are found

§ Johnstone - Divides into 4 parts

i. Northern Pacific : Deepest part, most deeps are found along island


ii. Central Pacific : Islands – Coral and Volcanic including Hawaiian


iii. SU Pacific : Variety of islands, marginal seas, continental shelf,

submarine trenches

iv. SE Pacific : Broad submarine ridge and plateau conspicuous

absence of marginal seas

1. Continental Shelf: Broad along – E. Australia, E. Indies, Asia. Various islands and marginal seas are situated here.

On W. Coast of Americas it is narrow – 50 miles

Varies according to nature of coast.

4. Deeps: 32 deeps. Mostly in the form of trenches parallel to island – arc or the mountain chain, mostly in western part

i. Aleutian trench : Arc like along Aleutian islands

ii. Kurile trench and Japan trench : Parallel to Japanese is vityez deep. Ramapo


iii. Philippines trench : E Coast of Philippines

iv. Nero deep : Arc along Mariana Is. Also called Mariana


v. Tonga Kermadic trench : Trough like depression along. Tonga and

Kermadec Is

vi. Peru Chile trench : In the form of broken trenches

5. Marginal Seas: Mostly on western part narrow, longitudinal

a) Bering sea

b) Aleutian sea

c) Okhotsk sea

d) Sea of Japan

e) Yellow sea

f) China sea ( E & S)

g) Celebes sea

h) Banda sea

On East – only GO California

Only Yellow sea is shallow

Other seas around Australia - GO Carpentaria

Arafura Sea

Bass Strait

6. Islands: 20,000 variety continental islands (belonging structurally to main land formed by submergence) – Aleutian, Chilean

Island Arcs (part of folded ranges with volcanic peaks) – Kurile, Japan, Philippines, Indonesia

Smaller scattered islands (two sub types) based on racial grouping

Melanesia – Solomon’s, Fiji

Micronesia – Marshal, Caroline’s, Gilbert

Polynesia – Cook, Tuamotu

Based on Formation

Volcanic islands - Hawaii

Coral islands – Fiji etc

Eastern Part – Galapagos, Easter Island, Juan Fernandez

2. Climatology: Temperature and pressure belts of the world; Heat budget of the earth; Atmospheric circulation; atmospheric stability and instability. Planetary and local winds; Monsoons and jet streams; Air masses and fronto genesis, Temperate and tropical cyclones; Types and distribution of precipitation; Weather and Climate; Koppen’s, Thornthwaite’s and Trewartha’s classification of world climates; Hydrological cycle; Global climatic change and role and response of man in climatic changes, Applied climatology and Urban climate. osmanian 2010-12-31T06:46:23.039-08:00 geomorphology  

1. Geomorphology: Factors controlling landform development; endogenetic and exogenetic forces; Origin and evolution of the earth’s crust; Fundamentals of geomagnetism; Physical conditions of the earth’s interior; Geosynclines; Continental drift; Isostasy; Plate tectonics; Recent views on mountain building; Vulcanicity; Earthquakes and Tsunamis; Concepts of geomorphic cycles and Landscape development ; Denudation chronology; Channel morphology; Erosion surfaces; Slope development ; Applied Geomorphology : Geohydrology, economic geology and environment.

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