This document provides an overview of fluvial geomorphology and floodplains. It discusses how rivers erode, transport, and deposit sediment, forming various fluvial landforms like alluvial fans, floodplains, and deltas. Floodplains are formed through vertical accretion, lateral accretion, and channel abandonment. They support rich ecosystems but also experience flooding that interacts with human settlements. India has several major flood-prone river basins, and floods annually cause billions in damage, affected millions of hectares and thousands of lives.
Sea Water Intrusion(SWI) in coastal areas :
1. Occurrence of seawater intrusion
2.Factors that affect coastal aquifer
3.Changes by hydrological regime
4.Problems due to SWI
5.Ghyben-Herzberg relation
6.Methods to detect SWI
7.Control measures
Fluvial Morphology handbook for students.
Contents are: definition, scope, importance of Fluvial Morphology, sediment load, channel pattern and process, role sediment to build delta, Reynolds number, Froude Number, channel pattern of Tista and Jamuna River, causes and consequences of flood, benefit of flood, flood and floodplain, hydraulic geometry, water resource management (in Bangladesh), hydrograph, origin and development of river, tributary and distributary and many more.
River bank erosion, its migration, causesNazim Naeem
Riverbank Erosion is an endemic natural hazard in our country.
When rivers enter the mature, they become sluggish and
meander or braid. These oscillations cause extreme riverbank
erosion. It is a perennial problem in our country.
• It has been estimated that tens of thousands of people are
displaced annually by river erosion in Bangladesh, possibly up to
100,000. Many households are forced to move away from their
homesteads due to riverbank erosion and flood.
• As per different sources, 500 kilometres of riverbank face
severe problems related to erosion. The northwest part of the
country is particularly prone to riverbank erosion, which has
turned the region into an economically depressed area.
Sea Water Intrusion(SWI) in coastal areas :
1. Occurrence of seawater intrusion
2.Factors that affect coastal aquifer
3.Changes by hydrological regime
4.Problems due to SWI
5.Ghyben-Herzberg relation
6.Methods to detect SWI
7.Control measures
Fluvial Morphology handbook for students.
Contents are: definition, scope, importance of Fluvial Morphology, sediment load, channel pattern and process, role sediment to build delta, Reynolds number, Froude Number, channel pattern of Tista and Jamuna River, causes and consequences of flood, benefit of flood, flood and floodplain, hydraulic geometry, water resource management (in Bangladesh), hydrograph, origin and development of river, tributary and distributary and many more.
River bank erosion, its migration, causesNazim Naeem
Riverbank Erosion is an endemic natural hazard in our country.
When rivers enter the mature, they become sluggish and
meander or braid. These oscillations cause extreme riverbank
erosion. It is a perennial problem in our country.
• It has been estimated that tens of thousands of people are
displaced annually by river erosion in Bangladesh, possibly up to
100,000. Many households are forced to move away from their
homesteads due to riverbank erosion and flood.
• As per different sources, 500 kilometres of riverbank face
severe problems related to erosion. The northwest part of the
country is particularly prone to riverbank erosion, which has
turned the region into an economically depressed area.
Over the last decade, demand for spring management has increased as traditional spring sources have started drying up or becoming contaminated. In response, communities, NGOs and state agencies began dedicated spring protection programmes. In the Himalayas, the State of Sikkim and organizations such as Central Himalayan Action and Research Group (CHIRAG) and People Science Institute (PSI) started identifying and protecting spring recharge areas around 2007. The difference between these programmes and many other previous efforts is that they went beyond supply-side improvements to focus on the use of hydrogeology to map springsheds for targeted interventions.
The Advanced Centre for Water Resources Development and Management (ACWADAM), a research and capacity-building organization comprised of hydrogeologists and other experts began lending their expertise and building capacity of stakeholders. ACWADAM provides technical support, training and materials in hydrogeology to all network partners as well as others in India and the region. Similar programmes began independently in most of the mountain regions of India. Arghyam, a funding organization that was supporting many of these programmes, noticed that these disparate initiatives shared commonalities despite geographic diversity. They thus organized and funded a meeting of these various organizations in June 2014, and the Springs Initiative was born.
The springs initiative aims to tackle the current water crisis and to ensure safe and sustainable access to water for all, by promoting responsible and appropriate management of aquifers, springsheds, and watersheds and conserving ecosystems in partnership with communities, governments and other stakeholders.
This presentation has been developed as a part of the springs initiative to promote an understanding of springs and their role in mountainous areas.
How streams are classified? The most popular measurable terms classifying the flowing water body into "the stream order" are discussed in this presentation. .
This presentation will help students to know about the basic concept and understanding about the rivers that What is river? What is the flow of river? What are the types of river or its drainage pattern? Rivers Erosional and Depositional Landforms.
Over the last decade, demand for spring management has increased as traditional spring sources have started drying up or becoming contaminated. In response, communities, NGOs and state agencies began dedicated spring protection programmes. In the Himalayas, the State of Sikkim and organizations such as Central Himalayan Action and Research Group (CHIRAG) and People Science Institute (PSI) started identifying and protecting spring recharge areas around 2007. The difference between these programmes and many other previous efforts is that they went beyond supply-side improvements to focus on the use of hydrogeology to map springsheds for targeted interventions.
The Advanced Centre for Water Resources Development and Management (ACWADAM), a research and capacity-building organization comprised of hydrogeologists and other experts began lending their expertise and building capacity of stakeholders. ACWADAM provides technical support, training and materials in hydrogeology to all network partners as well as others in India and the region. Similar programmes began independently in most of the mountain regions of India. Arghyam, a funding organization that was supporting many of these programmes, noticed that these disparate initiatives shared commonalities despite geographic diversity. They thus organized and funded a meeting of these various organizations in June 2014, and the Springs Initiative was born.
The springs initiative aims to tackle the current water crisis and to ensure safe and sustainable access to water for all, by promoting responsible and appropriate management of aquifers, springsheds, and watersheds and conserving ecosystems in partnership with communities, governments and other stakeholders.
This presentation has been developed as a part of the springs initiative to promote an understanding of springs and their role in mountainous areas.
How streams are classified? The most popular measurable terms classifying the flowing water body into "the stream order" are discussed in this presentation. .
This presentation will help students to know about the basic concept and understanding about the rivers that What is river? What is the flow of river? What are the types of river or its drainage pattern? Rivers Erosional and Depositional Landforms.
River is a most Important agent in geological field and most important roll of the physical, Chemical and biological erosion. It is common factors of river.
Geological action of river or Fluvial processes
The geological action of river is divided chiefly into three parts as Erosion, Transportation and Deposition.
Erosion: River erosion is mainly due to mechanical breaking down of rock fragment. The chemical action of
rivers is minimal. A wide variety of processes are involved in river erosion as follows;
a. Hydraulic action: It is the process of mechanical loosening or removal of the material by the action of the water
alone. The effectiveness of hydraulic action of a river is depends on gradient, velocity of the stream, width, depth
and shape of the channel and discharge.
b. Abrasion: The process of wearing-away of bed rock surfaces by mechanical processes such as rubbing, cutting,
scratching, grinding and polishing etc. is known as abrasion.
c. Attrition: The process of mechanical wearing and tearing of the transported rock fragments into smaller fragments
due to mutual impact and collision.
d. Cavitation: Highly turbulent rivers in rocky channels erode their beds by hydraulic plucking, in which pieces of
bed rocks are lifted out by strong eddies spiraling up around vertical axes. This sucking out of the rock pieces
produces cavities or depressions within the rock. This type of process is called cavitation.
e. Corrosion: The chemical processes of rock erosion by river water are known as corrosion or solution.
Important erosional features:
a. Potholes: These are cylindrical or bowl-like depressions in the rocky beds of streams, which are excavated in the
floors of the streams by extensive, localized abrasion. These are commonly found in softer bedrocks.
b. Water fall: These are defined as magnificent jumps made by stream or river water at certain specific parts of their
course where there is a sudden and considerable drop in the gradient of the channel.
c. River valleys: The river channel carved out by the flow of running water is commonly known as a river valley.
d. Gorges or canyons: During the river erosion, down cutting of its cannel gives rise to a deep narrow valley with
vertical or steep walls. Such a valley is termed as a gorge or canyons.
e. Escarpments: These are erosional land forms produces by rivers in regions composed of alternating beds of hard
and soft rocks. During river erosion soft rocks erode much faster than hard rocks, leaving behind steep slopes on
one side and a gentle slope on the other. The steep slope side is known as the escarpment.
Hog’s back: This is a sharp ridge like structure with high angle sides on two sides formed by harder rocks in an
inclined series of beds.
Mesa and butte: In regions of horizontal strata in which isolated portions of land is capped by a hard, erosion-
resistant bed, the erosional landforms produced will have an isolated flat-topped land area with seep sides,
commonly known as mesa. Isolated masses without flat tops are called buttes.
Transportation: A river is a most powerful agent of transportation. All the material being transported by a
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
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The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
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The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
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2. CONTENT
• INTRODUCTION
• FLUVIAL
DEPOSITIONAL FEATURES
ALLUVIAL FANS AND CONES
PIEDMONT ALLUVIAL PLAINS
FLOOD PLAINS
DELTA
NATURAL LEEVES
FLUVIAL TERRAIN
• FLOOD PLAINS
• ECOLOGY
• INTERACTION WITH SOCIETY
• FLOOD PLAIN IN INDIA
• REFERANCES
3. INTRODUCTION
The word geomorphology (Greek, Geo – earth, morph – form/shape and
logos- scientific study) is used for a systematic scientific study to
explains the exterior from or features of the earth surface.
Mc Gee (1888-96) defined geomorphology as a ‘genetic study of
topographic forms’.
Geomorphology is based on the analysis of geological facts
( agencies, processes and factors) that are continuously shaping the
earth’s surface.
Geomorphology can not only describe the mechanism of development of
landforms but also the agencies that are responsible for the processes.
4. FLUVIAL
The fluvial processes are associated with rivers and streams and the deposits and
landforms created by them
FLUVIAL PROCESSES
It included the motion of sediments and erosion or deposition on the river
bed.
The river carries significant quantities of sediments, this material can act as
tools to enhances wear of the bed ( abrasion).
Sometime the fragments that themselves are ground down, becoming smaller
and more rounded ( attrition)
Sediments in rivers is transported as either bed load ( the coarser fragments
which move close to the bed ) or suspended load ( finer fragments carried in
the water). There is also a components carried as dissolved material.
By draining the land surface they dispose the superfluous water brought by
precipitation.
5. They are responsible for much of the denudation of the land surface over
large parts of the earth.
Area where more particles are dropped are called alluvial/floodplain and the
dropped particles are called alluvium.
Examples :-
‘Mississippi River’ annually carries 406 millions tons of sediments,
‘Huang He’ carries 796 millions tons of sediments.
‘Po River’ Italy 67 millions tons of sediments.
Ganga- Brahmaputra- Meghna annually carries 38,897 lakh sediments.
Indus annually carries 23,56 lakh sediment
6.
7. A TYPICAL RIVER SYSTEM HAS THREE SUBSYSTEM
Collecting System
Transporting System
Depositing system
8.
9. DEPOSITION BY RIVER
Wherever the velocity of the river water is reduced, some of the load is
deposited; a decrease in turbulence may also bring about the same effect.
The heavier and coarser materials are first deposited followed by fine silt and
mud.
It is not only confined to the lower course, it can even occur on the upper
course, but here it is temporary and can be removed sooner or later.
10. CAUSES OF DEPOSITION
Break in slope : where the streams leaves the hills and enters a plain.
Widening of valley floor allows flooding to occur.
Contact with quiet water when swift flowing streams enters quiet waters or
lakes.
Where stream peters out as in arid and desert regions causing a decrease in
river energy and allowing sediments to be laid.
Where rivers debouch into the sea.
12. FLOOD PLAINS
It is a depositional features.
Floodplains is an alluvial surface adjacent to a channel that is frequently
inundated.
Its size is generally related to the discharge of the river.
The Three ways in which Floodplains may be formed-
By vertical accretion
By Lateral accretion
By island formation and channel abandonment
13. VERTICAL ACCRETION
When the stream is at the brink of overflowing (flooding) the state of flow of
the river is known as bank full. If the flood spills over, there is overbank.
The large rivers, with gentle gradient and a predominantly suspended load ,
flood they spread out both sides depositing a thin sheet of fine sediments
material previously carried in suspension.
It is the process in which the river Deeping downwards.
14. LATERAL ACCRETION
The rivers naturally tend to flow in a sinuous pattern, this I because of the
turbulent flow of water and irregularity or bend in the channel, which
deflects the flow of water to the opposite bank.
The forces of water that strikes the streams bank and leads to erosion, under
cutting which initiate small bends in the river channels.
With time due to the continues strike of the current it lead to growth of
bends and known as MEANDERS BEND.
On the side of the meanders the velocity is minimum so some sediments load
is deposited. since there deposit occur in the point of the meanders is called
POINT BAR DEPOSITES.
Erosion on the outside of the meanders and depositional on the inside of
meanders it helps the meanders to migrate laterally.
Lateral accretion of this point bar result in floodplain formation.
15.
16. ISLAND FORMATION AND CHANNEL
ABANDOMENT
Island formation and abandonment of channel are commonly associated with
BRAIDING.
Due to lack of competence and capacity, the load that the river carried is
dumped in the mid- channel to form island.
As the river continuously shifting, the side channels on the landward side
become progressively filled with sediments until they are abandonment and it
get incorporated into the floodplain.
17.
18. FLOODS PLAINS CHARACTERISED BY MANY DISTINCTIVE
FEATURES THAT INCLUDE:-
LEEVES ( ‘lever’ – to raise) are ridges lying parallel to the streams channel.
This are formed by rivers in times of flood when overbank flow causes a
decrease in streams velocity after it has left the confining channel walls.
CREVASSE SPLAY it is a sedimentary fluvial deposit which forms when a
stream breaks its natural or artificial levees and deposit sediments on a
floodplains. Once the levees has been reached the water flows out of its
channel the water spreads onto the flood plain sediments will starts to fall
out of suspension as the water loses energy, The resulting deposition can
create graded deposits.
BACKSWAMPS the low lying floodplain adjoining a natural levee may contain
marshy areas called back swamps.
BAYOU is a body of water typically found in a flat, low lying area and can be
either an extremely slow- moving streams or rivers or a marshy lake or
wetlands.
YAZOO STREAM is a geologic and hydrologic term for any tributary stream
that runs parallel to, and within the floodplain of a large river for
considerable distance, before eventually joining it.
19. OX BOW LAKE it is a U shaped body of water that forms when a wide
meander from the main stem of a river is cut-off, creating a free- standing
body of water. This landforms is so named for its distinctive curved shape,
resembling the bow pin of an oxbow.
Its form when a river creates a meander, due to the river’s eroding the bank
through hydraulic action, abrasion and erosion. After a long period of time, the
meander becomes very curved, and eventually the neck of the meander becomes
narrower and the river cuts through the neck during a flood, cutting off the
meander and forming an oxbow lake. E.g. ‘KANWAR LAKE BIRD SANCTUARY’
20. FLOODPLAINS ARE OF TWO BASIC TYPES
CONVEX FLOODPLAINS – Are convex in cross section i.e. the land slopes away
gently from the river bank to the sides of the valleys
e.g. – Tigris , Mississippi,Ganga
FLAT FLOODPALINS – A large majority of river plains are flat or gently
concave in cross section. Natural levees is inconspicuous or absent and the
alluvial flat rise very gently to the outer margins of the floodplains
21. ECOLOGY
Floodplains can support particularly rich ecosystem, both in quantity
and diversity. Tugay forests form an ecosystem associated with floodplains,
especially in central Asia.
a floodplains can contain 100 or even 1000 times as many species as rivers.
Wetting of the floodplains soil release an immediate surge of nutrients: those
left over from the last flood, and those that result from the rapid
decomposition of organic matter that has accumulated since then.
It has importance because of storage and conveyance, protecting of water
quality and recharge of ground water.
This makes floodplains particularly valuable for agriculture and support forest
and livelihoods.
22. RIVERINE FLOODPLAINS
These riverine floodplains typically flood during the springs, but are
subject to periodic flooding due to excessive rainfall. The floodplains brings
erosion and deposition of soils and can determine considerably the shape of the
floodplain, the depth the composition od soil, the type and density of vegetation,
the presence and extent of wetlands, richness and diversity of wildlife, and the
depth of ground water.
COASTAL FLOOPLAINS
Marshes, near-shore ocean bottoms, beaches, bays costal dune
lakes, tidal flats and estuaries are all components that make up the costal
floodplain.
They recognised for their importance to estuarine and marine fisheries. Estuarine
wetland are important for breeding, nursery, and feeding grounds for marine
fisheries and are important to waterfowl and other wildlife.
23. INTERACTION WITH SOCIETY
Historically many towns have been built on floodplains, for
number of reasons :-
(1) Access of freshwater
(2) The fertility of floodplain land for farming
(3) Cheap transportation, via river and railroads, which often followed
rivers
(4) Ease of development of flat land.
River flood has been one of the worst natural disaster In history –
Particular in – Yellow river in china the world natural disaster in 1931 china flood
and 1887 flood killed millions of people respectively.
In the united states the
FEDERAL EMERGENCY MANAGEMENT AGENCY (FEMA) manages the NATIONAL
FLOOD INSURANCES PROGRAM ( NFIP). The NFIP offers insurances to properties
located within a flood prone area, as defined by the FLOOD INSURANCE RATE MAP
(FIRM) which depicts various flood risk for a community.
24. FLOODPLAINS IN INDIA
THE GANGA BASIN :-
The ganga basin gets flooded mostly in the northern part by its
northern tributaries.
The badly effected states of ganga basin are West Bengal, Bihar and Uttar
Pradesh
The Yamuna famous for flooding Haryana and Delhi.
In West Bengal like Mahayana, Bhagirathi, Damodar etc. causes flood because of
tidal effect and insufficient river channels.
BRAHMAPUTRA AND BARAK BASIN :-
The river banks of Brahmaputra and Barak get flooded due to
the surplus water found in the Brahmaputra basin and Barak basin. This rivers
along with their tributaries flood the northern states like West Bengal, Assam and
Sikkim. Jaldakha, Testa and Torsa in northern West Bengal and river in Manipur
often overflow the Bank.
25. CENTRAL INDIA AND DECAN RIVER BASINS :-
Southern and Centre India observes flood caused by
Narmada, Godavari, Tapi, Krishna and Mahanadi even floods coastal region of
Andhra Pradesh, Orissa and Tamil Nadu occasionally
26.
27. AVERAGE ANNUAL FLOOD DAMAGE ( 1953- 2001)
STATE DAMAGE AREA LIABLE TO FLOODS( million Ha)
Total Damage Rs 13,400 millions
Area Affected 8.11 million hectare
Crop Area Affected 3.57 million hectare
Human Lives Lost 2057 Nos
Cattle Lost 95,000 Nos
India receives an annual rainfall of 400 millions hectare meters, of which 75 percent
is received in four months. Flood generally follow, bringing devastation with them.
As death tolls mount, damage reaches unimaginable scales .
12.5% area of the country covers flood prone area.
28. REFERANCES
The earth Dynamic surface – A textbook of Geomorphology
- K . Siddhartha
Principles of Geomorphology – 2nd Edition
- William D. Thornbury
Principles of Engineering Geology
- K.M Bangar
Textbook of Physical Geology
- G.B Mahapatra
www. Wikipedia.com
www.britinica.com