Explain where and why depositional landforms occur along the course of a river.

Explain where and why depositional landforms occur along the course of a river. Rivers have three courses. The course is the journey the river makes to reach the sea. Rivers never have a straight course from source to mouth. Their course is always irregular. Along this course depositional landforms can occur. Landforms can be formed from the deposition of weathered and eroded surface materials. On occasion, these deposits can be compressed, altered by pressure, heat and chemical processes to become sedimentary rocks. This includes landforms with some of the following geomorphic features: beaches, deltas, floodplains, and glacial moraines. The upper course is found in the mountains and hills where the river rises from its source and often waterfalls and rapids are also found in this course. The river is usually fast flowing in the upper course; also there are lots of stones and boulders for the water to flow over. Furthermore, the river starts as a stream in the upper course and flows through valleys. The middle course, however, is where the river starts to become wider and deeper. The land, which the river flows over, is becoming flatter and this is where the river starts to meander or bend in the middle course. The lower course is where the river becomes its widest and deepest. This course is found closest to the sea where the river has its mouth. The flat area of land by

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  • Level: AS and A Level
  • Subject: Geography
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Discus to the extent to which you believe Carlisle floods 2005 were the result of intense rainfall rather than the physical characteristics of the drainage basin

Discus to the extent to which you believe Carlisle floods 2005 were the result of intense rainfall rather than the physical characteristics of the drainage basin January 2005 was a major even for Carlisle, as there was a major event. The rainfall was immensely high from the 6th to the 8th of January, during which two months of rainfall, although the previous days had high rainfall. During the flood, the rivers such as Eden, Kent and Derwent were the highest on record. The flood peaked in the upper parts of the Eden and Derwent catchments in the early hours of January 8th. In Carlisle, the River Eden peaked at an estimated 1520 m3/s at the Sheepmount Gauging Station at 140hrs on the 8th of January. This flow had returned again after approximately 175 years. Many geologists and people could say that the floods were cause by human impact, but in reality, that would be unlikely, but not impossible. It would not have been one of the major factors that cause the floods in Carlisle. However for example if, the vegetation in the river or around the river basin was removed or cut down, for the use of more land, or materialistic things, this could have affected the velocity of the river, as vegetation such as trees, act as an interception in the river causing its velocity to slow down. Also the land around the river basin is grassland and arable farming, especially in the valleys, so

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  • Level: AS and A Level
  • Subject: Geography
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Assess the costs and benefits of one river management scheme you have studied

Assess the costs and benefits of one river management scheme (15 Marks) There are various arguments for and against the management of the Mississippi and in particular the method of hard engineering used. The Mississippi drains approximately one third of the USA and is a major transport route therefore it is essential that the river is managed efficiently in order to protect jobs, businesses and homes. Although the management failed in 1993 the volume of water was not accounted for, the sporadic volume was not designed to be matched by the management. In effect the budget was set out to prevent specifically flood of a lower volume of water, it can be argued that up until the 1993 floods it was working perfectly. In addition an argument against the management of Mississippi that floods have gotten worse was proved false as records at the time were inaccurate. It was also suggested that some levee's breaking may have saved towns further upstream. Furthermore the jobs created by the construction of levees, flood walls and wing dykes and other management techniques have boosted the economy. There was also extremely hazardous antecendent conditions that could not be predicted, there was 200% more rain than usual for the particular time of year and people were unprepared in the west were flooding is uncommon, this could not be accounted for when managing the floods for the

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  • Level: AS and A Level
  • Subject: Geography
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Analyse How the Inputs and Outputs from a River Basin Can Vary Over Time

Analyse How the Inputs and Outputs from a River Basin Can Vary Over Time Both the inputs to and outputs from a river basin can vary both spatially (in different areas) and temporally (over time), due to daily, seasonal and annual occurrences. Precipitation mainly reaches the grounds surface from the atmosphere as snow and rain. Heavy snow is often intercepted and stored on the tops of hills and mountains and may lead to a decrease in river levels. Some rainfall may fall directly into the stream or river and some may fall onto the land and flow into the river basin through a variety of routes including throughflow, stemflow and overland flow. The intensity and duration of precipitation has a short term but regular effect upon both the inputs and outputs of a river basin due to the weather patterns. Over a short period of time, for example a week, the precipitation levels over the river basin can significantly vary, as on some days of the week the total precipitation can be extremely high and the next it could be virtually zero. Long periods of rainfall are the main cause of flooding as the soil has become saturated it reaches its infiltration capacity and infiltration is reduced, therefore increasing the frequency of surface run off and the risk of flooding. In addition to the weather having a large impact on the inputs over a short period of time in and around the

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  • Level: AS and A Level
  • Subject: Geography
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Examine the factors influencing the movement of glaciers.

Examine the factors influencing the movement of glaciers. Glacier is defined as, 'a mass or river of ice moving very slowly'. Glaciers range in size considerably, Antarctica being the largest ice mass at 12.5 million km and a smaller ice mass of 12km existing in Africa. Glaciers move due to the force of gravity from areas of high altitude to lower areas. There are different mechanisms of glacial movement depending on the type of glacier. Cold (polar) glaciers are frozen to the underlying rock surface. These are found in high-latitude locations where the relief is low and basal temperatures are below the pressure melting point. Cold glaciers have very slow rates of movement, e.g. The Meserve glacier in Antarctica moves only 3-4 metres per year. Warm (temperate) glaciers on the other hand are not frozen to their bed. This type of glacier is found in high-altitude locations where the relief is steep and basal temperatures are at or near the pressure melting point. Temperate glaciers move very rapidly, e.g. The Franz Josef glacier in New Zealand moves approximately 300m per year. It is the basal temperature that determines the mechanism of movement. In what follows I will explain the factors influencing different mechanisms of movement. Temperate glaciers move mainly by basal sliding. If the basal temperature is at or above pressure melting point, a thin layer of meltwater

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  • Level: AS and A Level
  • Subject: Geography
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