The Features and Processes of a River Along Its Profile
Introduction ------------
Along the path of a river, from source to mouth, the river shows many different features and is affected by several different processes. These processes are going to be described and explained in the course of this essay and diagrams will be used to back-up and justify my ideas.
A river can be simply divided into an upland or lowland river environment. Upland features and processes occur at a higher altitude, closer to the source of the river; lowland features and processes occur at lower altitudes near the mouth of a river. A river's course can be better divided into a young, mature and old stage.
…show more content…
Erosion, for example, wears rocks away through 4 sub-processes:
* Corrasion or abrasion
* Attrition
* Corrosion or erosion by solution
* Hydraulic action
Transportation can be further divided into:
* Traction
* Saltation
* Suspension
* Solution
A description of these processes and diagrams showing how they affect the river are shown below:
Erosive Processes
Corrasion or abrasion
This is when smaller material which is suspended, rubs against the river banks. This is more common in lowland areas, where the river is at a low altitude and has a low gradient.
Attrition
This is when boulders are being transported along the river bed collide and smash up into smaller pieces. This is likely to occur where river velocity is high in upland areas.
Corrosion or erosion by solution
This is when acids in the water dissolve soft rocks such as limestone.
Hydraulic action
This is when the sheer force of the river breaks up and dislodges particles from the rivers banks and bed.
Transportation Processes
Traction
Saltation
Suspension
…show more content…
When there is high discharge, the high amounts of energy in the river can transport large amounts of material in suspension. In high discharge, the river often floods, spreading out across any nearby flat land. This land causes sudden increase in friction, and so velocity decreases causing much deposition of fine silt. Every time a river floods, another thin layer of silt is deposited, and a flat floodplain is formed. The heaviest material will be deposited first when a river floods, forming an embankment next to the river, called a levees. This levees acts as a natural flood defence, and are sometimes strengthened. If these levees are broken, then huge floods occur over great areas of land.
A diagram showing Floodplains and Levees
(iii) Deltas
Description
A delta is a small area of land formed from deposition when a strong current meets a weaker current.
Explanation
As a river gets closer to its mouth and the sea, the current is dramatically reduced, and its material deposited. This deposited material can block the rivers path. The river must then divide into
An increase in pebble roundness in the direction of long shore drift. The process of attrition will erode the pebbles. c) A decrease of pebble size in the direction of long shore drift, again attrition is involved. d) Undercutting (active erosion of the cliffs at one end of the bay).
Yes this feature is the result of erosion and depositional processes however, it is not associated with the current water course. This feature may be the result of a Gilbert type delta that once occupied this area. Gilbert type deltas have three main components; topsets, foresets and bottomsets. Topsets are fluvial sediments (primarily sandur deposits) that were deposited on the subaerial delta surface. Erosive events occurring on the upper forslope can result in downslope channels and chutes. These features are then eroded by either strong currents or by debris flow resulting in these channels and chutes to become filled. Foresets are a combination of sand and gravel facies. The are deposited by gravitational processes on the delta foreslope and the grains tend to become finer and more angular downslope. Bottomsets consist of fine grained silts and clay and are deposited at the foot of the delta front.
Hydrosphere of the Mississippi River A Case Study of * River management * People interfering in the hydrosphere * A flood management scheme River Basin / Catchment area The source of the river is the eastern side of the Rocky Mountains and the Appalachian Mountains to the north. There are many hundreds of tributaries including the Red River, Missouri river and the river Ohio. The mountains form the river's watershed. From Minneapolis the river flows South-East into Iowa where it flows south as far as Davenport. At Davenport it is joined by more small tributaries.
When I started to reading this book, I do not imagine what it was about .I am an international student, and I have been living in the U.S for a short time , so many of the issues regarding of American history are new for me. The Erie Canal was part of the unknown subjects. It has been interesting to know, and learned that the Americans have had intension of shaping and preserve its history. And great historians, they would give out even the smallest details that helped make this nation what it is today.
Longshore drift influences the deposition and erosion of sediments. Waves erode the coast and transport the eroded material along the coastline. Over a period of time, the material will be deposited on a beach or form a larger feature such as a spit. Groynes are structures built at equal intervals along the coastline. Their purpose is to restrict longshore drift, preventing coastal erosion.
Fly fishing is not what this story is all about, although it might seem so at first. Neither is it about religion, even though the father’s first line is: "In our family, there was no clear line between religion and fly fishing." Yes, these two things are themes that run through the story and add to its power. But there is so much more. It depicts a place of beauty, history, myth, and mystery, it is a triangle of earth in Montana where the writer grew up. And it captures a space of time in the not-so-distant past with a sensitivity that is both witty and poetic. Robert Redford loved this story and turned it into a handsome movie. Read it yourself or watch the movie, and you will learn something about fly fishing, but you wil...
In today’s civil society, we are taught to show compassion and tolerance towards one other, yet the media portrays society in a different perspective, as being intolerant. In the book The Other Side of the River, writer Alex Kotlowitz reflects on the story of a young black male whose lifeless body was found in the St. Joseph river of Michigan. In this story, Kotlowitz reflects on two communities that are opposite from the other in regards to ethnic background and financial well-being, yet both appear to share the same lack of tolerance towards the other. There is a paragraph were Kotlowitz writes,
The water moves at a faster rate since there is nothing to absorb the water, which could cause flooding.
The Mississippi River is one of the world 's extraordinary rivers. It is the longest in the United States, more than twenty-three hundred miles in length, as it structures the outskirts of ten states, just about bisecting the mainland (Currie,2003, 8). This waterway has a long history also, and it has touched the lives of numerous individuals. The Mississippi is said to start at Lake Itasca in Minnesota. In 1832, pilgrim Henry Schoolcraft named this lake, not after any neighborhood Indian name, but rather from the Latin words for "genuine head" which are veritas caput abbreviated to "Itasca" (Currie, 2003, 4). In any case, much sooner than its source was named it was a navigational waterway. The Indians who initially lived on the banks of the stream were known as the Mississippians. From 800 to 1500, these people groups utilized the waterway for exchange. They dug out
It is important to look at the geography of the Yellow River as well as the characteristics. The Yellow River is given its name due to the vast quantities of soil that are suspended in the water which turn the
"Step 1. Characterizations of the Watershed." Forest Service: 17 pars. Viewed 7 Nov. 2002. <http://www.fs.fed.us/r2/psicc/spl/south_platte_web/step_1.htm>.
The usage/control of waterways has many political and economic effects on societies today and in the past. One way that the usage/ control of waterways has an effect politically and economically is by the control/ usage of waterway helped civilizations sprout. Another way is by the control/usage of waterways creates easier trade routes. The next way is by the control/ usage of waterways helps agriculture do well. These are some of the ways that the control/ usage of waterways had effects politically and economically on societies today and in the past.
which can be used as a river, and also attracts people as it can be
All lives revolve around decisions and instances from ones past. In A River Runs Through It (1992), director Robert Redford uses this idea and applies it to a true story of two brothers from Montana, Norman and Paul Maclean (Craig Sheffer and Brad Pitt, respectively). Based on the autobiographical novel by Norman Maclean himself, River uses Maclean’s metaphysical beliefs about life and nature to present its many themes. Using a longing score, various film devices, and a story line involving themes of youth, loss, and the pitfalls of pride, Robert Redford crafts a film about the beauty of the past.
Mudslides usually occur in hilly areas, for an example, when there was a mudslide in Bangladesh few months back, it occurred at Chittagong. Mudslides occur when a portion of a hill side becomes too weak to hold up its own weight. This is generally caused by an intense amount of rain fall. With all of the new water introduced into the slope the content of liquid makes it so heavy that gravity pulls it downward. Although water plays a major factor in creating the mud that flows in a mudslide the real reason that the land begins to slide is gravity. What happens is mudslides redistribute soil and sediments in a process that can be in abrupt collapses or in slow gradual slides.