Land as a Resource: Fluvial Landforms

SUSTAINABLE SITE PLANNING AND LANDSCAPE

AR. SYED ZAHID

Land As a Resource : Geophysical Esther Kiruba | 19171NB002

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CONTENTS

Introduction Definitions Types of Rocks Types of Landforms Origin & Process & Examples of Landforms Fluvial Landforms Introduction to Fluvial Landfroms Types of Fluvial Landforms Origin of Fluvial Landforms Process of Fluvial Landforms Examples of Fluvial Landforms Conclusion

INTRODUCTION A landform is a feature on the Earth's surface that is part of the terrain. Landforms can exist under water in the form of mountain ranges and basins under the sea. Tectonic plate movement under the Earth can create landforms by pushing up mountains and hills. Erosion by water and wind can wear down land and create landforms like valleys and canyons. Both processes happen over a long period of time, sometimes millions of years.

03 REFERENCES National Geographic Society

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Geology Geology is the science of studying the earth's structure. The Oxford Dictionary defines it as "The science that deals with the earth's physical structure and substance, its history, and the processes that act on it."

Geo Morphology The study of Landfroms is geomorphology. The Oxford Dictionary defines it as "The study of the physical features of the surface of the earth and their relation to its geological structures".

REFERENCES National Geographic Society Oxford Dictionary

DEFINITIONS

TYPES OF ROCKS There are three main types of Rocks IGNEOUS SEDIMENTARY METAMORPHIC

05 REFERENCES National Geographic Society

FIRE OPAL

IGNEOUS ROCKS Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust.

Intrusive igneous rocks crystallize below Earth's surface, and the slow cooling that occurs there allows large crystals to form.

Examples of intrusive igneous rocks are diorite, gabbro, granite, pegmatite, and peridotite.

Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals. Some cool so quickly that they form an amorphous glass. These rocks include andesite, basalt, dacite, obsidian, pumice, rhyolite, sco ria, and tuff.

OBSIDIAN

SCORIA

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REFERENCES National Geographic Society Common Intrusive and Extrusive Igneous Rock Types by: Hobart M. King

COAL

SEDIMENTARY ROCKS

The most important geological processes that lead to the creation of sedimentary rocks are erosion, weathering, dissolution, precipitation, and lithification.

Clastic sedimentary rocks such as breccia, conglomerate, sandstone, siltstone, and shale are formed from mechanical weathering debris.

Chemical sedimentary rocks, such as rock salt, iron ore, chert, flint, some dolomites, and some limestones, form when dissolved materials precipitate from solution.

HALITE

IRON ORE

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Organic sedimentary rocks such as coal, some dolomites, and REFERENCES some limestones, form from the accumulation of plant or National Geographic Society animal debris.

Common Clastic, Chemical, and Organic Sedimentary Rock Types.Article by: Hobart M. King

ANTHRACITE

METAMORPHIC ROCKS A metamorphic rock, begins as a rock (sedimentary or igneous or another metamorphic rock). Then, due to various conditions have been modified by heat, pressure, and chemical processes, usually while buried deep below Earth's surface. Exposure to these extreme conditions has altered the mineralogy, texture, and chemical composition of the rocks.

Foliated metamorphic rocks such as gneiss, phyllite, schist, and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure.

Non-foliated metamorphic rocks such as hornfels, marble, quartzite, and novaculite do not have a layered or banded appearance.

LAPIS LAZULI

MARBLE

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REFERENCES National Geographic Society Common Foliated and Non-Foliated Metamorphic Rock TypesArticle by: Hobart M. King

AOLIAN

COASTAL

TYPES OF LANDFORMS There are 8 Major types of landforms:

VOLCANIC

TECTONIC

LACUSTRINE

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FLUVIAL

TECTONIC

VOLCANIC

AOLIAN

GLACIAL

MASS WASTING

LACUSTRINE

COASTAL

GLACIAL

REFERENCES A Geomorphic Classification System U.S.D.A. Forest Service

MASS WASTING

FLUVIAL

VOLCANIC

MASS WASTING

Origin Origin Volcanic eruptions pull Loose rock and soil, up materials. called regolith Process Process Volcanic processes are soil, sand, regolith, and related to the eruption rock move downslope of molten rocks, known typically as a solid, as magma, through continuous or central vents or fissures discontinuous mass onto the surface Example: Example: AVALANCHE LAVA DOME

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REFERENCES A Geomorphic Classification System U.S.D.A. Forest Service Geomorphology of Desert Environments pp 597-627

LAVA DOME

COASTAL

AOLIAN

Origin Origin At the interface of land Erosive or constructive and sea action of the wind Process Process erosional factors and deflation (removal of depositional features loosened material and that are often its transport in influenced by local to suspension) and regional controls on abrasion (mechanical wave energy wear) Example: Example: BEACH BARCHAN

AVALANCHE

BEACH

BARCHAN

TECTONIC

LACUSTRINE

GLACIAL

FLUVIAL

Origin Origin Origin Origin Earth's tectonic Plates relating to drained lakes landforms created by landforms created by Process and fresh water bodies the action of glaciers rivers and streams Relief features that are Process Process Process produced chiefly by plains formed when Erosion: Abrasion, stream overflows its banks, uplift or subsidence of lakes filled with Plucking, Freeze-Thaw, water flows over the the Earth’s crust or by sediments are drained Sediment Transport, floodplain and deposits upward magmatic often rich in fineDeposition: Till, sediment. Abrasion, movements. grained sediments Outwash Attrition, Corrasion Example: Example: Example: Example: MOUNTAINS DRY LAKE STRIATIONS CANYON

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REFERENCES A Geomorphic Classification System U.S.D.A. Forest Service Geomorphology of Desert Environments pp 597-627

MOUNTAIN

DRY LAKE

STRIATIONS

CANYON

12 FLUVIAL LANDFORMS AÂ Thorough Study

INTRODUCTION

Fluvial is derived from the Latin " fluvius ", meaning river.

Fluvial geomorphology is the study of the interactions between river channel forms and processes at a range of space and time scales.

The influence of past events is also significant in explaining the present form of river channels. Rivers are found in many different environments and show a huge variety diversity of form.

The landforms either carved out(due to erosion) or built up(due to deposition) by running water are called fluvial landforms and the running water which shapes them are called fluvial process

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REFERENCES R. Charlton 2007 - Fundamentals of fluvial geomorphology

MORPHOLOGICAL

TYPES

There are two ways to categorise the types of fluvial landforms:

PROCESS based

SYSTEMS based

EROSIONAL EG. POT HOLES, RIVER VALLEYS, WATERFALLS ETC DEPOSITIONAL EG. ALLUVIAL FANS, FLOOD PLAINS, DELTAS

MORPHOLOGICAL EG. FLOOD PLAINS, HILLS SLOPES, CHANNELS CASCADING EG. WATER FALLS PROCESS RESPONSE EG. RIVER BASIN, DELTAS

EROSIONAL

DEPOSITIONAL

CASCADING

PROCESS RESPONSE

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REFERENCES R. Charlton 2007 Fundamentals of fluvial geomorphology

MORPHOLOGICAL

TYPES

Without categorising them these are all the types of fluvial landforms

Channel Confluence Cut bank Crevasse splay Drainage basin Esker Floodplain Fluvial terrace Canyon Gully

Levee Meander Oxbow lake Pendant bar Plunge pool Point bar Riffle River River delta River island

Shoal Spring (hydrology) Stream Stream pool Valley Waterfall Yazoo stream Island

CASCADING

PROCESS RESPONSE

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REFERENCES Wilson, W.E. & Moore, J.E..

Glossary of Hydrology, American Geological Institute

ORIGIN

The fluvial system can be subdivided into three zones on the basis of the dominant processes operating within each zone.

These are the sediment production zone, sediment transfer zone and sediment deposition zone.

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REFERENCES Schumm, 1977

An example, showing a cross section of a fluvial landform. This helps understand the origin of a fluvial landform. (a) Bedrock channels are cut directly into the underlying bedrock. (b) Alluvial channels are formed in alluvial deposits that have been deposited on the valley floor by fluvial processes. (c) Rivers exist on a continuum from bedrock to alluvial.

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REFERENCES Niekirk et al. (1999)

PROCESS

EROSION

There are 3 types of processes that fluvial landforms may undergo

EROSION Abrasion, Corrosion, Quarrying, Attrition are all different ways that erosion of the particles happen and particles are formed TRANSPORTATION Whether or not a given particle is set in motion depends on the balance between the forces driving and resisting its movement. These are the forces that transport the erodes particles.

DEPOSITION Sediment particles are deposited when there is a reduction in the competence and capacity of the flow. The process takes place at a very small scale and involves individual grains and can be observed over a wide range from the smallest bed forms to vast floodplains and deltas.

TRANSPORTATION

DEPOSITION

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REFERENCES R. Charlton 2007 - Fundamentals of fluvial geomorphology

EROSION

TRANSPORTATION

DEPOSITION

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REFERENCES R. Charlton 2007 - Fundamentals of fluvial geomorphology

ZONE 1

ZONE 2

ZONE 3

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REFERENCES R. Charlton 2007 - Fundamentals of fluvial geomorphology

DRAINAGE PATTERNS Some typical examples of selected drainage patterns. A major control on drainage network morphology is the underlying geology, although topography, soils, tectonic history and climate are also influential drainage patterns are used in the interpretations of tectonic influences and underlying structural controls .

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REFERENCES River Systems and Fluvial Landforms NPS Trista L. Thornberry-Ehrlich, Colorado State University

22 EXAMPLES Fluvial Landform illustrations to help understand them better

CHACO CANYON Origin and Process

Located in NEW MEXICO, USA, it started as a flood plain, which during floods, when the stream overflowed its banks, water flowed over the floodplain and deposited sediments. Through fluvial processes, streams constructed floodplains that accommodated their maximum flood capacity.

Geomorphic features of the floodplain include:Natural Levees—River may be immediately flanked by a buildup of sediment that forms natural levees, yazoo, bars, dunes, flood-plain splays, Oxbows and oxbow lakes

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REFERENCES River Systems and Fluvial Landforms NPS Trista L. Thornberry-Ehrlich, Colorado State University

ITKILLIK RIVER Located in ALASKA, USA. The picture on the top shows the evolution of the river in the form of river meander and ox bow lake.

This is called meandering stream development.

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REFERENCES R. Charlton 2007 - Fundamentals of fluvial geomorphology

NIAGARA Located in NY, USA. The Niagara Falls retreats at about 1.3 m per year. But the horseshoe falls keeps flowing even when upstream water is shut off during inspections.

There is a formation of a nickpoint in the Niagara falls, which is caused by erosional process.

The nickpoints are the morphological features which make the different layers of the waterfalls apart from the horse shoe falls

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REFERENCES R. Charlton 2007 - Fundamentals of fluvial geomorphology

CONCLUSION

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Fluvial geomorphology is important for several reasons. As environmental designers we have to be aware of the various origins and processes 1. It helps make sense of the enormous variety of rivers and streams 2. It reveals how stream channels are shaped and suggesting useful ways.

3. It helps us study river side settlements.

4. it helps us identify ecological parameters during research and development stages.

5. Modern study of fluvial geomorphology focuses on the linkages among different landforms and diverse approaches and experimental studies.

6. Knowledge of fluvial landforms is critical for modern land use as the nature of a landform determines its slope stability, permeability, whether it is prone to flooding etc.

BIBLIOGRAPHY

1. Christopherson, Robert W, Elemental Geosystems 2. Wadia, D.N., Geology of India 3. Paul W. Williams, New Zealand Landscape 4. Molnar, Peter H., Tectonic landform 5. Charlton, Ro, Fundamentals of Fluvial Geomorphology 6. worldatlas.com/articles/a-complete-list-of-fluvial-landforms 7. nps.gov/subjects/geology/fluvial-landforms 8. David Love, Late Neogene drainage developments on the southeastern Colorado Plateau 9. Fluvial Landscapes, Geography.name 10. Geology.com 11. National Geographic Society 12. Oxford Dictionary 13. Encyclopaedia Britannica 14. National Park Services, USA

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