Sunday, December 4, 2016

Fluvial Morphology



Fluvial Morphology: Definition, concept, scope and importance

Introduction:
The history of mankind is always connected with history of river as well as fluvial geomorphology. Fluvial geomorphology is strictly the geomorphology of rivers. As rivers have always held a prominent role in the study of landforms, it is not surprising that debates about fluvialism, as to whether rivers could produce their valleys, continued to rage early in the nineteenth century until uniformitarianism prevailed, whence temperate areas were seen as the result of rain and rivers.

Geomorphology:
Geomorphology is the scientific study of landforms and the processes that shape them. Geomorphologists  seek to understand why landscapes look the way they do, to understand landform history and dynamics, and to predict future changes through a combination of field observations, physical experiments, and numerical modeling.  

Fluvial:
Fluvial refers to the processes associated with rivers and streams. Fluvial and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluvioglacial is used.

Fluvial geomorphology
Fluvial geomorphology is the study of the form and function of streams and the interaction between streams and the landscape around them.
In addition, Fluvial Morphology is the study of landforms and the fluvial processes that shape them. Fluvial processes which are associated with flowing including sediment erosion, transport, and deposition.
“Fluvial geomorphology has as its object of study not only individual channels but also the entire drainage system.”
Kruska and Lamarra (1973) cited by Schumm (1977)

 “A primary objective of fluvial geomorphology must be to contribute to an explanation of relationships among the physical properties of flow in mobile-bed channels, the mechanics of sediment transport driven by the flow, and the alluvial channel forms created by spatially differentiated sediment transport.”
   Richards (1987)

“Geomorphology is the study of Earth surface forms and processes; fluvial phenomena those related to running water.”
                                                                                        Graf (1988)

“The science that seeks to investigate the complexity of behavior of river channels at a range of scales from cross sections to catchments;it also seeks to investigate the range of processes and responses over a very long time scale but usually within the most recent climatic cycle.”
                                                                                                            Newson and Sear (1998),                            


Concept:
Fluvial Geomorphology considered is a most significant discipline in modern period for its’ The term “fluvial geomorphology” is combined with two words Fluvial and Geomorphology where Fluvial produced by a river; from Latin fluvius and from Greek, Geo - earth, morphs - form and -ology – science. So Geomorphology is the science dealing with the nature and origin of the earth's topographic features.
Fluvial geomorphology is a science devoted to understanding rivers, both in their natural setting as well as how they respond to human-induced changes in a watershed. One goal is to predict what changes will occur to a stream channel in response to alterations in watershed conditions; and, in turn, how these changes will impact human infrastructure and fish habitat.
The Bradshaw Model is a geographical model which describes how river's characteristics vary between the upper course and lower course of a river. It shows that discharge, occupied channel width, channel depth and average load quantity increases downstream. Load particle size, channel bed roughness, and gradient are all characteristics which decrease downstream.
 
Figure 1: Stream Morphology Monitoring Stations in the Credit River Watershed and their Status (2012).

The Scope of Fluvial Morphology:
Scope of a science may be defined as - extent or range of view, outlook, application, operation, effectiveness, etc.
Interestingly different scholars have described the scope of fluvial morphology differently. This is because they all define fluvial morphology in a different light. These definitions set the parameters for the nature of river landform studies by Geomorphologists .
In Present time, there are many portions of fluvial geomorphology for more transparency and analysis is used in the world. There are some fluvial geomorphologic objectives are given below-

1. Qualitative fluvial geomorphology: Here this subject discusses abut traditional Fluvial Geomorphology. Such as-
    • River system
    • Catchments area
    • Water flow flood management
    • River features
    • Flood control etc.
2. Quantitative Fluvial Geomorphology:
    • Water Technology
    • Water Quality treatment
    • Stream discharge
    • Changing nature of river
    • Quantitative analysis of river depth, width, length etc.
Some particular scopes and objectives of Fluvial Geomorphology which are found in modern period are given bellow-
      • River channels and drainage basin
      • River Management System
      • The engineer sees the river
      • The Geomorphologist sees the river
      • Channel types
      • Flood plains and terraces
      • Bankfull flow
      • Types of river
River channels and drainage basin
A channel has two basic functions within a drainage basin. It must convey all of the— WATER, and  SEDIMENT  that the drainage basin delivers by the various runoff and hill slope processes. In order to accomplish these tasks, any channel must take on a particular form, by which we mean its width, depth, sinuosity, and distribution of such small-scale features as pools and bars.
River Management System:
Activities and processes, linked through economics and human actions—irrigation, navigation, etc are shown through the following figure.
Fig: River management.



River engineering:
Adjacent sets of isolated, independent processes and problems—bank erosion, flooding, etc…
Fig: River engineering.
River Channel system:
River Channel system is most important object of fluvial geomorphology. Such as-

(1) Landscape is a system that produces and transports runoff and sediment.
(2) Channel network is like the veins of the landscape.
(3) Channels collect sediment produced on hill slopes and transport it to basin outlets.
(4) Channels influenced by sediment production, transport, routing, and storage processes.



 



Fig: River Channel system
Flood plains System:
To a Geomorphologist, a floodplain is the surface that has been built by a river channel under the current hydrologic and sediment logical regime. It is composed of alluvium, the sediment carried by the river. An alluvial channel is bounded by a floodplain; conversely, a channel formed within a true floodplain is by definition alluvial.
Fig: Floodplain system

Importance of Fluvial Morphology
Fluvial geomorphology is developing rapidly with the expansion of modern technology in present time. If this development process continue, this discipline will mere advance within few years. The importance of fluvial geomorphology is increasing day by day. There are about 72.5% areas of world is water body and 65 - 70% elements of human body are water. For this importance all living things are directly depended on water as well as Fluvial geomorphology. So we can say that the future of fluvial geomorphology will be so much developed and highly speeded each areas of the world. There are great possibilities to develop in future following things of fluvial geomorphology.
Fluvial morphology is particularly important to the hydraulic engineer as many of his greatest problems arise because of the form of streams brought about by the transportation and deposition of sediment by them. For the proper solution of these problems, a knowledge of t he principles of fluvial morphology is often necessary. Among the problems in which fluvial morphology is a very important factor are many of those dealing with water resources development and include some of the most important river problems in the world. Examples of these are flood control on the Lower Mississippi and on the lower Colorado Rivers, the development of the hydraulic resources of the Missouri and Arkansas Rivers, the Yellow and Huai River flood problems in China, the Iiosi River floods in India. A s stream s become more highly developed, and changes in sediment movement due to stream developments slowly become evident, the importance of the morphological aspect of river control problems will be increasingly appreciated.
One of the best contributions made by the geomorphologists to the science of fluvial morphology is the nomenclature which they have introduced.
As previously mentioned, the Geomorphologist is interested in fluvial morphology principally as a tool in explaining the origin of the present form of the surface of the earth. The science appears to be of comparatively recent origin. Although many able men contributed to its early development, the outstanding work is that of W. M. Davis. According to the Davis conception, the primary action in the formation of the earth by moving water is the geographical or geomorphic cycle which is a cycle of erosion passing through several stages.


Conclusion:
Geographic research on a broadened range of resource use and specific inquiry into the spatial and ecological linkages of various technologies appears to be required. The more important natural water is related with every steps of our life. For this fluvial geomorphology considered a significant discipline in modern period. A framework for assessing social desirability still needs devising but it could be hastened by careful assessment of that actually follows water resource development. Geographers freed from the traditional distraction between human and physical geography and with their sensibility towards water, earth and man, have in these both opportunity and challenge.               

References:
  •   Doyle, M.W., C.F. Rich, J.M. Harbor, and A. Spacie. 2000. Physical Geography 21: 155-181
  •   Charlton, Ro (2008). Fundamentals of fluvial geomorphology. London: Rutledge. p. 234
  •  Leopold, L.B., Wolman, M.G., Miller, J.P., 1964, Fluvial Processes in Geomorphology, San Francis
  •   Thornberry, D.W., 1958, Principles of Geomorphology, London: John wiley & sons Publications.
  •   Lobeck, A. L.; 1939; Geomorphology; McGraw-Hill Book Company
  •  Trimble, S.W. 1997. Science, 1442-1444.
  •  FluvialGeomorphology http://www.facstaff.bucknell.edu/brh010/research/fluvial_geomorphology.html


Friday, February 21, 2014

Social Norms and Social Values

“Wash your hands before dinner.” “Thou shalt not kill.” “Respect your elders.” All societies have ways of encouraging and enforcing what they view as appropriate behavior while discouraging and punishing what they consider to be inappropriate behavior. They also have a collective idea of what is good and desirable in life—or not.Two fundamental concepts within sociology are those of norms and values. They help to describe the framework of perceptions and ideas which influence an individual's or group's behaviour.

Social Norms

Every society has expectations about how its members should and should not behave. A norm is a guideline or an expectation for behavior. Each society makes up its own rules for behavior and decides when those rules have been violated and what to do about it. Norms change constantly.
Norms are the established standards of behavior maintained by a society. For a norm to become significant, it must be widely shared and understood. For example, in movie theaters in the United States, we typically expect that people will be quiet while the film is shown. Of course, the application of this norm can vary, depending on the particular film and type of audience. People who are viewing a serious artistic film will be more likely to insist on the norm of silence than those who are watching a slapstick comedy or horror movie.

Types of Norms

Sociologists speak of at least four types of norms: folkways, mores, taboos, and laws. Folkways, sometimes known as “conventions” or “customs,” are standards of behavior that are socially approved but not morally significant. For example, belching loudly after eating dinner at someone else's home breaks an American folkway. Mores are norms of morality. Breaking mores, like attending church in the nude, will offend most people of a culture. Certain behaviors are considered taboo, meaning a culture absolutely forbids them, like incest in U.S. culture. Finally, laws are a formal body of rules enacted by the state and backed by the power of the state. Virtually all taboos, like child abuse, are enacted into law, although not all mores are. For example, wearing a bikini to church may be offensive, but it is not against the law.

Social Values

Values are the ideas which define what is good, right or fair. They are held by individuals and groups and are a product of the culture they find themselves within. A person's values may be tied to their religious or political beliefs, influenced by their family, heritage and upbringing, or by their social environment. Specific to an individual, they differ from person to person. An example of which could be the level of altruism or selfishness they show to others.

A group's values are determined by the values of it's members. They define what is important to the group and can be demonstrated in those individuals a group chooses to praise or condemn. The brave fire fighter, the compassionate hospice nurse, the evil drug dealer or soulless murderer all show traits and behaviours regarded by the society as inherently good or evil.
Norms and values are closely linked, with norms outlining acceptable behaviour in a situation while values determine what should be considered good or bad.

Wednesday, November 20, 2013

Trade and Commerce

trade and commarce


Trade

Trade is the transfer of ownership of goods and services from one person or entity to another. Trade is sometimes loosely called commerce or financial transaction or barter .A network that allows trade is called a market. 
The original form of trade was barter, the direct exchange of goods and services. Later one side of the barter were the metals, precious metals (poles, coins), bill, paper money Modern traders instead generally negotiate through a medium of exchange, such as money. As a result, buying can be separated from selling, or earning.
The invention of money (and later credit, paper money and non-physical money) greatly simplified and promoted trade. Trade between two traders is called bilateral trade,
while trade between more than two traders is called multilateral trade.

Principle and characteristics of trade

• Trade exists for man due to specialization and division of labor, most people concentrate on a small aspect of production, trading for other products. Trade exists between regions because different regions have a comparative advantage in the production of some tradable commodity, or because different regions' size allows for the benefits of mass production. As such, trade at market prices between locations benefits both locations. between locations benefits both locations.

• Retail trade consists of the sale of goods or merchandise from a very fixed location, such as a department store, boutique or kiosk, or by mail, in small or individual lots for direct consumption by the purchaser. Wholesale trade is defined as the sale of goods or
merchandise to retailers, to industrial, commercial, institutional, or other professional business users, or to other wholesalers and related subordinated services.

• Trading can also refer to the action performed by traders and other market agents in the financial markets.

Commerce

While business refers to the value-creating activities of an organization for profit, commerce means the whole system of an economy that constitutes an environment for business. The system includes legal, economic, political, social, cultural, and technological systems that
are in operation in any country . Thus, commerce is a are in operation in any country . Thus, commerce is a system or an environment that affects the business prospects of an economy or a nation-state. We can also define it as a second component of business which includes all activities, functions and institutions involved in transferring goods from producers to consumers.
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Sunday, November 10, 2013

Ancient Geography of India

Ancient Geography of India

The first text in Greek devoted entirely to India was written by Ctesias in the fourth century BC. Only fragments of it survive. Yet he was probably the most widely quoted author on India, although Aristotletreated him with contempt. However, soon after Aristotle drew upon Ctesias’ writings, as did Plato,Xenophon and Plutarch. From all these account India became a happy land, a kind of utopia. Pliny (AD 24-79) put forth the age-old notion that India covered one-third of the surface of the earth. Indian kings from Father Tiber to Alexander had reigned 6451 years and three months.
Anaximander of Miletus, born in 610 BC, was the first Greek to draw a map of the earth. It was shown there that the earth was shaped like two half moons of land. The one on the north was Europe and the southern one consisted of Asia and Africa. Together these two half moons enclosed an inland sea – theMediterranean, truly meaning the middle (medi) of the land (terra). Herodotus drew upon such an authority of the past and put forth his idea of the inhabited world – oikoumene. His notion of the earth was an oblong one, running from west to east. This was divided into three continents – Europe, Asia and Libya. He inform in one place in his writings that the boundaries of Europe were unknown and there was not a man who could say whether any sea girdled it round either to the north or to the east. He thought the farthest settled land in this world reached out to the Persian province of Punjab. Aristotle added that between the Pillars of Hercules (modern Gibraltar) and India there was nothing but ocean.
World Map of Herodotus
This was the sum of knowledge when Alexander began his conquests from Macedon, the tiny kingdom in distant Greece. With all the details given by the advanced parties through marches before the great expedition began across Europe, Alexander believed India to be a peninsula of no great depth, which just jutted eastward to the sea, and which on its northern flank was bordered by the chain of mountains. North of this, at no great distance beyond the River Jaxartes was the ocean. To Alexander India meant the land of the Indus River. Whether that mighty river was the source of the Nile or whether it flowed into the ocean was beyond his interest. He must have questioned the local interpreters on arrival with his vast army on the other side of the Indus. Most of the local people did not even know the meaning of the term ocean.
   
Ptolemy (AD 90–168) was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet. His second book is the Geography, which is a thorough discussion of the geographic knowledge of the Greco-Roman world. In it he says that the true shape of India, the most striking feature of the land, is the acute angle formed by the meeting of the two coasts of the peninsula in a single coastline running almost straight from the mouth of the Indus to the mouth of the Ganga River.
   
Xuanzang (Hsüan-tsang AD 602 – 664) was a famous Chinese Buddhist monk, scholar, traveller, and translator who described the interaction between China and India in the early Tang period. The same division of five provinces – Five Indies – continue in his description of the land he travelled. He packs together the shape of India to a half moon with the diameter or broad side to the north and the narrow end to the south. This is not unlike the configuration of India in Ptolemy’s Geography; yet much more accurate. In fact the Chinese pilgrim author brings in a touch of humour when he says rather wryly that the people’s faces are the same shape as the country – narrow downward and broad on the top.

Friday, November 8, 2013

Amazon

Amazon

Definition

In Greek mythology, the Amazons were a race of warlike women noted for their courage and pride who lived at the outer limits of the known world, sometimes specifically mentioned as the city of Themiskyra on the Black Sea. Their queen was Hippolyta and although Homer tells us they were ‘the equal of men’, they fought and lost separate battles against three Greek heroes:Hercules, Theseus and Bellerophon. Scenes from these battles were popular in Greek art, especially on pottery and in monumental sculpture adorning some of the most important buildings in the Greek world.
In mythology, the Amazons were daughters of Ares, the god of war. They were a women-only society where men were welcomed only for breeding purposes and all male infants were killed. In legend, the Amazons burnt off their right breast in order to better use a bow and throw a spear, indeed, the word amazon may signify ‘breastless’. Interestingly though, Amazons are not depicted in Greek art with a missing breast. They are most often depicted wearing hoplite armour and frequently ride a horse. The most common weapon is the bow and spear but there are also examples where Amazons carry axes.
The first meeting between Greeks and Amazons was when Hercules was sent by Eurystheus, the king ofMycenaeTiryns and Argos on one of his celebrated twelve labours, this time to fetch the girdle of the Amazon queen Hippolyta. The girdle was given by her father Ares and the task was set by Eurystheus precisely because it was an impossibly dangerous endeavour. In some versions of the story Hercules goes alone but in other accounts he first assembles an army led by the finest Greek warriors, including Theseus. In some versions, the taking of the girdle turned out to be rather easier than expected when Hippolyta willingly handed it over but in other versions, Hera - always against Hercules because he was the fruit of her husband’s illicit affair with Alkmene - stirred up the Amazons to give the Greek hero and his army a hot reception. Fine fighters though the Amazons were, they were no match for the invincible Hercules who took the girdle back to Eurystheus. Intriguingly, our earliest depictions of the story in pottery predate the literary sources for the tale by two centuries and they sometimes show Hercules fighting an Amazon named Andromache or Andromeda and in none is a belt ever depicted. This is, once again, evidence that the oral myths were more complicated and varied than the literary versions that have survived. A more definite plot element is that during this expedition Theseus fell in love with and abducted (or eloped with) the Amazon Antiope, an action which would lead to a second encounter between Greeks and Amazons.   
Hercules fighting Amazons was represented in sculpture on the frieze of the Treasury of the Athenians atDelphi (490 BCE), on the Temple of Apollo at Bassae, on the Hephaisteion of Athens (449 BCE) and on metopes on the Temple of Zeus at Olympia (470-456 BCE). The throne of the cult statue of Zeus, one of the Seven Wonders of the ancient world, was also decorated with scenes from this famous myth.
Theseus eventually became the ruler of Athens but the Amazons had not forgotten the loss of one of their members and so launched an expedition to rescue Antiope. Theseus defeated the barbarian invaders but during the battle, Antiope was killed. Theseus abducting Antiope is the subject of the pediment from the Temple of Apollo at Eretria (c. 510 BCE) and on the metopes of The Treasury of the Athenians at Delphi. 
Bellerophon was involved in a third meeting between Greeks and Amazons. He was another hero who had to perform impossible tasks in service to a king. This time Proitos, king of Argos, outraged at (false) accusations from his wife that Bellerophon had attacked her, the king sent the hero to serve Iobates. It was he who set the hero the task of killing the Chimera - a fantastic creature which was a fire-breathing mix of lion, snake and goat - and when Bellerophon managed that feat he was told to go off and fight the Amazons. Naturally, the Greek hero won the day and was even made heir to Iobates’ kingdom in Lycia on his victorious return.
A fourth and final meeting with Amazons came towards the end of the Trojan War. In the Epic Cycle we are told that the Amazon Penthesilea aided the Trojans but was killed in battle by Achilles. In some accounts Achilles fell in love with his victim when he removed her helmet and the scene is captured on a celebrated black-figure vase by Exekias (c. 540 BCE).
More general Amazonomachies (battles with Amazons) were present on the shield of the cult statue ofAthena Parthenos in the Parthenon (438 BCE), on the west pediment of the Temple of Asklepios atEpidaurus (395-375 BCE), on the Temple of Athena Nike on the Athenian Acropolis (c. 425-420 BCE), on the Tholos of Delphi (380-370 BCE) and on the Temple of Ares in the Athens agora. The oldest depiction of a warrior fighting an Amazon is on a terracotta votive shield from 700 BCE. Hercules fighting Amazons is the hero’s second most popular labour depicted on Greek black-figure pottery (after the Nemean lion) with almost 400 surviving examples. Amazons fighting unnamed warriors were common throughout the 6th and 5th centuries both on black and red-figure pottery.
In particular, during the 5th century BCE in Athens, these mythological battles with Amazons came to represent contemporary events, i.e. the battles between Greeks and the invading Persian Armies of Darius at Marathon (490 BCE), Xerxes at Salamis and the Persian attack on Athens itself in 480 BCE. In this sense, Amazons came to represent barbarous foreigners; indeed depictions of Amazons on pottery in this period are shown actually dressed in Persian costume. Public buildings and their accompanying sculpture were, without doubt, an important method of mass communication and depictions of heroes fighting Amazons reminded ordinary people that the political leaders had successfully defended Greek culture against the threat of foreign, and in Greek eyes less civilized, invaders.

Wednesday, November 6, 2013

Observation : Advantages and Disadvantages

observation method

What is observation?

Observation is way of gathering data by watching behavior, events, or noting physical characteristics in their natural setting. Observations can be overt (everyone knows they are being observed) or covert (no one knows they are being observed and the observer is concealed). The benefit of covert observation is that people are more likely to behave naturally if they do not know they are being observed. However, you will typically need to conduct overt observations because of ethical problems related to concealing your observation.

Observations can also be either direct or indirect. Direct observation is when you watch interactions, processes, or behaviors as they occur; for example, observing a teacher teachinga lesson from a written curriculum to determine whether they are delivering it with fidelity. Indirect observations are when you watch the results of interactions, processes, or behaviors; for example, measuring the amount of plate waste left by students in a school cafeteria to determine whether a new food is acceptable to them.
newton

What are the advantages of observation?


 >>  Collect data where and when an event or activity

       is occurring.
>>  Does not rely on people’s willingness or ability
      to provide information.
>> Allows you to directly see what people do rather
      than relying on what people say they did.

What are the disadvantages of observation?

 >>  Susceptible to observer bias.
 >>  Susceptible to the “hawthorne effect,” that is,
       people usually perform better when they know
       they are being observed, although indirect
       observation may decrease this problem.
 >>  Can be expensive and time-consuming compared
        to other data collection methods.
 >>  Does not increase your understanding of why
        people behave as they do.

Tuesday, November 5, 2013

Solar System

planets in solar system

Solar System

The Solar System comprises the Sun and its planetary system of eight planets, their moons, and other non-stellar objects. It formed 4.6 billion years ago from the gravitational collapse of a giant molecular cloud. The vast majority of the system's mass is in the Sun, with most of the remaining mass contained in Jupiter. The four smaller inner planets, Mercury, Venus, Earth and Mars, also called the terrestrial planets, are primarily composed of rock and metal. The four outer planets, called the gas giants, are substantially more massive than the terrestrials. The two largest, Jupiter and Saturn, are composed mainly of hydrogen and helium; the two outermost planets, Uranus and Neptune, are composed largely of substances with relatively high melting points (compared with hydrogen and helium), called ices, such as water, ammonia and methane, and are often referred to separately as "ice giants". All planets have almost circular orbits that lie within a nearly flat disc called the ecliptic plane.
The Solar System also contains a number of regions populated by smaller objects.The asteroid belt, which lies between Mars and Jupiter, is similar to the terrestrial planets as it mostly contains objects composed of rock and metal. Beyond Neptune's orbit lie the Kuiper belt and scattered disc, linked populations of trans-Neptunian objects composed mostly of ices. Within these populations are several dozen to more than ten thousand objects that may be large enough to have been rounded by their own gravity. Such objects are referred to as dwarf planets. Identified dwarf planets include the asteroid Ceres and the trans-Neptunian objects Pluto, Eris , Haumea, and Makemake. In addition to these two regions, various other small-body populations includingcomets, centaurs and interplanetary dust freely travel between regions. Six of the planets, at least three of the dwarf planets, and many of the smaller bodies are orbited by natural satellites, usually termed "moons" after Earth's Moon. Each of the outer planets is encircled by planetary rings of dust and other small objects.
The solar wind, a flow of plasma from the Sun, creates a bubble in the interstellar medium known as the heliosphere, which extends out to the edge of the scattered disc. The Oort cloud, which is believed to be the source for long-period comets, may also exist at a distance roughly a thousand times further than the heliosphere. The heliopause is the point at which pressure from the solar wind is equal to the opposing pressure of interstellar wind. The Solar System is located within one of the outer arms of the Milky Way galaxy, which contains about 200 billion stars.

source : wikipedia

 

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