Monday, November 4, 2013

Ecosystem : Meaning and Definition



        The term ecosystem was first used by A. G. Tansley in 1935 who defined ecosystem as 'a particular category of physical systems, consisting of organisms and inorganic components in a relatively stable equilibrium, open and of various sizes and kinds'.
       An Ecosystem is a community of living organisms (plants, animals and microbes) in conjunction with the nonliving components of their environment (things like air, water, mineral soil), interacting as a system. These biotic and abiotic components are regarded as linked together through nutrient cycles and energy flows. As ecosystems are defined by the network of interactions among organisms and between organisms and their environment, they can be of any size but usually encompass specific limited spaces (although some scientists say that the entire planet is an ecosystem)-From

        According to Tansley the ecosystem is comprised of two major parts viz. biome and habitat and thus 'all parts of such an ecosystem-organic and inorganic, biome and habitat may be regarded as interacting factors which, in a mature ecosystem, are in approximate equilibrium, it is through their interactions that the whole system is maintained'-                                                                                                                 (A. G. Tansley, 1935)
        F. R. Fosberg (1963) has defined ecosystem as 'a functioning, interacting system composed of one or more living organisms and their effective environment, both physical and biological'.
        According to R. L. Lindeman (1942) the term ecosystem applies to 'any system composed of physical-chemical-biological processes, within a space-time unit of any magnitude'.
        According to A. N. Strahler and A. H. Strahler (1976), 'the total assemblage of components interacting with group of organisms is known as ecological system or more simply, an ecosystem. Ecosystems have inputs of matter and energy, used to build biological structure, to produce and to maintain necessary internal energy levels. matter and energy are also exported from an ecosystem. an ecosystem tends to achieve a balance of the various processes and activities within it'.

Based on the contents of above definitions of ecosystem provided by various scientists it may be pointed out that ' ecosystems are therefore unities of organisms connected to one another and to their environment'.

Sunday, November 3, 2013

Ecology : Meaning and Definitions

ecology definition

Ecology meaning
Ecology in a very simple term. The word ‘ecology’ (‘oecology’ or ‘oekology’) derived from two greek words, ‘oikos’ meaning house or dwelling as habitat and ‘logos’ meaning the study of.

Ecology definitions
The term ‘ecology’ was first coined and used by the German biologist, Ernst Haeckel in 1869, a few conceptual terms were already proposed to reveal relationships between organisms and their environment. ecology is a science that studies the interdependent, mutually reactive and interconnected relationships between the organisms and their physical environment on the one hand and among the organisms on the other hands.
For Example, French zoologist, Isodore geoffroy St. Hilaire used the term ecology in 1859, for the study of the relations of the organisms within the family and society in the aggregate and in the community.

It may be summarized that : ecology is a science that studies interrelationships between biotic and abiotic components  of a natural ecosystem of one hand and among organisms on the other hand.

  • S. Singh, Environmental Geography

Saturday, November 2, 2013

Dulhazra Safari Park( Bangabandhu Sheikh Mujib Safari Park) - Bangladesh

Dulahazra Safari Park

Figure : Map of Dulahazra Safari Park
Location: Chakaria, Dulahazra Union,Cox’s Bazar

Climate:   The climate is subtropical in nature. The average annual rainfall is 3599 mm, hottest month is October, coldest month is January, driest month is December, wettest month is July, average maximum temperature is 34.20C and average minimum temperature is 15.60C .

How to get there
It takes 2.5 hours from Chittagong.
From Cox’s Bazar you can reach Chakaria by Bus/ Microbus or Chander Gari ( One kind of Jeep).

Where to stay
After visiting this park you have to come back to Cox’s Bazar.There are many hotels and restaurant you can find in Cox’s Bazar to stay and fooding.

Entry Permits/Fees
Adults:                                                             BDT 20
Students(Below 15 years):                                   BDT 10
Student group( 30 to 100 persons):                BDT 200
Student group( More than 100 persons):       BDT 400
Foreigner :                                                      BDT 350/ USD 5    
Visit by safari bus :                                         BDT 20

Parking fee:
Bus:                                                                    BDT 100
Car/Microbus:                                                     BDT 50

Opening time
9.00 AM

Closing time
5.00 PM

safari park
Figure 2 :We are in safari park (GES 1st year field work team)
Bangladesh is a diverse country that attracts thousands of visitors each year. Tourists flock to the country to experience its unique culture, meet its friendly locals and enjoy the magnificence of the country’s wildlife. Many reserves and conservation projects have been established in Bangladesh to protect its rare wildlife and bird populations, and one such breathtaking eco-tourism initiative is the Dulahazra Safari Park.
Dulahazara Safari Park was established in 1996.This is the only  safari park in Bangladesh, situated 107 km south of Chittagong City under Chakaria Upazila of Cox’sBazar District. Dulahazra Safari Park was developed on an undulating landscape of around 2,224 acres of area at Chakaria Upazila in Cox's Bazar District, Bangladesh, some 50 km away from the cox'sbazar, with an objective to create facilities for Eco-tourism, research work and entertainment aside from conserving wild animals in a natural environment. Dulahazra Park is home to at least 4,000 animals of 165 species. There are several attractions inside the park. After entering the park, you'll find the orchid collections at right, and a museum at the left side, both are equally attractive. You can travel inside the park by transport system of the park or by feet. Attractive animals include Lions, Bengal Tigers, Crocodiles, Bears, Chitals and lots of different types of birds and monkeys. There has a watch tower from top of which you’ll enjoy the vast ocean of green plants.
Many individuals also 'donated' some of the animals to the park . The seized and donated animals recently sent to the park include 90 spotted deer (chital), 42 barking deer (maya, a species of muntjac deer), three sambar deer, one freshwater crocodile, one saltwater crocodile, nine black bear, four pythons, 17 peacocks, 19 Turkish pheasants and two emus. Other source of animal includes the Dhaka Zoo. While the animal population in Dhaka zoo has increased over the years due to their breeding, the Dhaka zoo donates a number of lions and tigers to the Dulhazra Safari Park. Visitor Attractions: The park itself protects a large number of wild elephants which are native to the area. In the safari park there are domesticated elephants which are available for a ride. Other animal attractions include lions, Bengal tigers, Crocodiles, Bears, Chitals and lots of different types of birds and monkeys. Since the park was made open to the public, it has been drawing a huge crowd all year round — 6,000 visitors daily during peak season.

monkey in safari park
Figure 3: monkeys in safari park

Dulahazra Safari Park is absolutely located for visitors to take pleasure in day trips out to this amazing conservation area. The park has got concentration as a recreation spot for universal mass of the people and for the biologists. It is one of the learning spots as well. The place has now become a Safari Park and a Zoo. Now a days, if any wild animal is unlawfully or unintentionally caught anywhere of the country, is being transported and placed in this area. Large number of people visits Safari Park because of its magnificent natural scenic beauty and attractive undulated landscape with green coverage. Hills and water bodies are interwoven with each other. It is also recognized for its ecological importance, and scientific, aesthetic and recreational values. The forest of Dulahazara range sustains subtropical evergreen and semi evergreen trees and wildlife. This area is important feeding ground of wild elephants because the herd of wild elephants often visits this area and damages public property.
Dulahazra Safari Park project got underway Between the years 1998 and 1999, occupying only a little piece of land, which has now mature to over two thousand acres of sheltered land. The government began to play an dynamic role in the improvement of the park in 2007, ensuring that unlawfully owned animals was held and taken to the park, with many of the animals also being donated by their owners. This has allowed the park’s population to grow to nearly four thousand animals, providing visitors with 165 species to marvel at. The variety of animals that have been seized and donated is astounding, with the park taking in saltwater crocodiles, black bears, barking deer, spotted deer, pythons, emus, freshwater crocodiles, peacocks and pheasants. All the animals have been given huge areas to roam freely, with lush forests and brush for their habitats. Some animals are kept at a distance from visitors for safety reasons. The Dhaka Zoo has also assisted in growing the number of animals in Dulahazra Safari Park through their reproduction program, enabling visitors to view other wildlife such as monkeys, lions, parrots, horses, giraffes, tigers, elephants, lizards, zebras and frogs. Some of the elephants at the park are domesticated, and visitors are able to interact with them.

Visitors can be driven through the Dulahazra Safari Park by jeep to explore the extraordinary wildlife, and there is a specially constructed tower for tourists where they are able to look out over the park and view numerous animals. It is really the ideal attraction for a family outing, as it is also a research centre that focuses on conserving the environment as well as educating the public.

With the major goal of serving the national need of biodiversity conservation education, research, recreation and in-situ  and  ex-situ  conservation of the  threatened, extinct and endangered animals. The park was established in 1998 with following objectives :-
Conservation and breeding of the extinct and endangered wild animal species. in the park as ex-situ condition.
To provide assistance for in-situ conservation of critically endangered wildlife through out the country.
Development of rescue center and veterinary hospital to provide assistance to injured wildlife in the country.
Development of the Nature Interpretation Center with light and sound model for creation of conservation awareness among the public.
To bring large water body for migratory birds under scientific management.
Establishment of aviary for extinct, rare endangered species of bird.
Establishment of a Natural History Museum for plants and animals endemic to the area.

Friday, November 1, 2013

Weathering ?

weathering definition

what is Weathering ?

Weathering is a static process. The process of disintegration and decomposition of rocks in situ is generally called weathering.

weathering definition

Weathering refers to the breakdown or disintegration and decomposition of rocks in situ through mechanical and chemical changes in the rocks  and their minerals effected by water, temperature, wind, different atmospheric gases and organisms provided that there is no large-scale transport of weathered products by denudational processes except massmovement of rockwastes down the slope under the impact of gravity.

According to C.D. Ollier (1969), “weathering is the breakdown and alteration of minerals near the earth’s surface to products that are more in equilibrium with newly imposed physico-chemical conditions”
According to P. Reiche (1950), “weathering is the response of minerals which were in equilibrium within the lithosphere to conditions at or near its contact with the atmosphere, the hydrosphere, and perhaps still more importantly ,the biosphere.”
B. B. Polynov(1937), has very precisely defined weathering as ‘the change of rocks from the massive to the clastic state.’
According to B. W. Sparks, “weathering may be defined as the mechanical fracturing or chemical decomposition of rocks by natural agents at the surface of the earth”

Arthur Holmes has presented more elaborate definition of weathering which also includes the processes of weathering.According to him “ weathering is the total effect of all the various subaerial processes that cooperate in bringing about the decay and disintegration of rocks, provided that no large-scale transport of the loosened products is involved. the work of rainwash and  wind, which is essentially erosional, is thus excluded”
-A. Homes (1952)

It appears from the above definitions that weathering is essentially the breakdown of rocks due to chemical and mechanical processes at their places.

Tuesday, October 29, 2013

What is environment ?


Meaning Of Environment

The word environment’ has been derived from the French word ‘environer’ meaning to encircle or to surround. The Dictionary meaning of the word ‘environment’ is a ‘surrounding’ ; external conditions influencing development or growth of people, animals or plants; living or working conditions etc.


Environment may refer to the physical and biological factors along with their chemical interactions that affect an organism.
Primarily,the concern of all geographers is with the environment of man. But man cannot exist or be understood in isolation from the other forms of life and from plant life’
-(A.N. Strahler and A.H. Strahler,1976, p.4)
Environment refers to the sum total of conditions which surround man at a given point in space and time’
-(C.c. Park,1980, p.28)
Environment is defined more comprehensively by others “as a holistic view of the world as it functions at any point of time, with a multitude of spatial elemental and socio-economic systems distinguished by quality and attributes of space and mode of behaviour of abiotic and biotic forms’ -(K. R. Dikhshit, 1984)

Thus environment is defined as ‘(1)The circumstances and conditions (physical conditions) that surround (and affect) an organism or group of organisms , or  (2) the social and cultural conditions that affect an individual or community.Since human inhabit the natural world as well as the ‘built’ or technological, social and cultural world, all constitute parts of our environment’
-(W. P. cunnigham and M.A. Cunnigham, 2004)

What is Computer ?



A device that computes, especially a programmable electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information.
A computer is a general purpose device that can be programmed to carry out a set of arithmetic or logical operations. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem.
Conventionally, a computer consists of at least one processing element, typically a central processing unit (CPU) and some form of memory. The processing element carries out arithmetic and logic operations, and a sequencing and control unit that can change the order of operations based on stored information. Peripheral devices allow information to be retrieved from an external source, and the result of operations saved and retrieved.
The first electronic digital computers were developed between 1940 and 1945. Originally they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs). In this era mechanical analog computers were used for military applications.

Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space. Simple computers are small enough to fit into mobile devices, and mobile computers can be powered by small batteries. Personal computers in their various forms are icons of the Information Age and are what most people think of as “computers.” However, the embedded computers found in many devices from MP3 players to fighter aircraft and from toys to industrial robots are the most numerous.

Monday, October 28, 2013

what is environmental geography

Meaning of Environmental Geography

‘Environmental geography is basically the study of Environment’. If this is so, why it should not be termed as geography of environment” ? The answer is easy, the term of Environmental geography lays more emphasis on man-environment relationships.Probably K. Hewitt and F. K. Hare first used the term of  ‘environmental geography’ in Man and Environment.

Environmental Geography definition -: Define Environmental Geography

Environmental geography is the study of systematic description of different components of environment and interactions of man with these components.
Thus the definition of Environmental geography may be further broadened as follows:

“Environmental geography is the study of characteristic features of various components of the Environment, the interactions between and among the components in a geoecosystem in terms of ecosystem of varying spatial and temporal scales.”

Savindra Singh  defined Environmental Geography in 1989 as follows :

“Thus broadly speaking, environmental geography may be defined as the study of spatial attributes of interrelationships between living organisms and natural environment in general and between technologically advanced ‘economic man’ and his natural environment in particular in temporal and spatial framework.”

The final definition of environmental geography may be formulated as follows :
“environmental geography may be defined as that branch of geography  which studies the characteristics, compositions and functions of different components of the natural environmental system, mutual interdependence  of different components, various processes that link the components, the interactions of different components with each other and among themselves and consequent responses (environmental problems) in spatial and temporal context in terms of ‘geoecosystem.’ as well as interactions of technologically advanced ‘economic man’ with different components of natural ‘geoecosystem’ and resultant modifications and changes in the natural geoecosystem leading to environmental degradation and pollution, the techniques and strategies of pollution control measures and management of ecological resources” .
-(Savindra Singh,1989)


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