Questions - EQ4 & EQ5 Flashcards
What is meant by the long profile of a river?
The long profile of a river shows changes in the height (altitude) of the course of a river from its source to its mouth. A long profile is usually concave and the slope becomes more gentle towards the mouth of the river.
How does the river Eden’s landscape change along its long profile
(upper/middle/lower). Consider: channel shape, valley profile, gradient,
discharge, velocity and sediment size and shape?
Along the upper course of the river eden the river would be at a increased gradient and the river would generally be flowing slower and down to the middle course of the river it would be a little larger but not too big and the velocity of the water would be a little bit faster due to there being more mass of water and the river discharge would be more. Towards the bottom of the river there would be a larger and increased area of the river, the river discharge would be a lot grater however there would be smaller sediment within the river with a larger velocity of the water flowing in the lower courses.
What are the reasons for these changes?
These changes could be due to the change in altitude and the change in the amount of rain and amount of water that comes down from the river source changing the sediment size and river discharge within the river.
Compare hydraulic action with abrasion
hydraulic action and abrasion both occur within rivers, hydraulic action is where the rocks are slowly eroded by the means of water smashing into it, on the other hand abrasion is the way of water holding rocks which smash into rocks to erode them.
Define weathering
Weathering is the act of the landscape being eroded by the weather and weather eroding this via many different types of erosion, such as rain eroding a mountain of rock, it is usually physical and not related to humans when it is the weather eroding the rock.
Compare freeze thaw and biological weathering
Freeze thaw is the process of water freezing, and expanding where as the biological weathering is where plants may have expanding roots which is why they grow, freeze thaw is similar to biological weathering as it is both the expansion of mass in cracks in the rock which would eventually break the wrong into smaller and different parts which is how these types of erosion can break down rocks.
Compare traction with suspension transport
traction is where sediment is pulled along the bed of the river whereas suspension transport is where the sediment is small and light enough to be moved along the surface of the water and transported along the rivers courses and downstream towards the place where the sediment will rest.
Explain the stages and processes responsible for waterfall formation, v
shaped valleys and interlocking spurs, meanders, ox-bow lakes, flood plains, levees and deltas. Do each of these in turn – this is a big question!!
waterfalls are formed when rivers move from a hard rock to a soft rock, this happens when the rock which is soft breaks and erodes downwards, after this the waterfall would carry on the process and retreat backwards along the river forming a gorge, V shaped valleys are formed by rivers when the river runs through the valley and the valley would be eroded into a V shape. Interlocking spurs are mixes between hard rock and soft rock, when this happens a river runs around the hard rock to form the spurs within the river. Ox bow lakeside formed when a river meander becomes so large that it can no longer flow and cuts through to form the new river, the old part of the river would form to become the oxbow lake. Flood plains are formed when a river overflows and the discharge of the river would overflow onto the flood plain, this is the area where it is most likely to flood. A levee is an embankment on a river which would stop water from flooding within a river. A delta is where a river deposits sediment so that the water creates land around the river.
Explain two ways climate, geology and slope processes change the river landscape
the climate could change the river landscape as it changes where the water molecules may be expanding or get smaller which could affect the amount the river floods and the floodplains increase in size. The slope processes changes the landscape from being flat, to a valley all the way to waterfalls and gorges which are all formed this way.
Label the key features (lag time, rising limb and peak discharge) of a flood hydrograph
In a flood hydrographic the main features of lag time, rising limb, peak discharge of the graph, lag time would be the amount of time it takes from rain to flood, if it is short this could mean a flash flood has occurred or it has happened over a short time. Peak discharge would be the total amount of water which has been output when the flood occurred.
Compare a flashy and subdued hydrograph
A flashy hydrographic is different to a subdued hydrographic, this is because a flashy hydrographic would show a flood coming in a short period of time whereas a subdued hydrograph winked show us a flood which may be greater but over a longer period of time making it seem even worse.
Explain how physical factors (geology, soil, slope, basin type,
antecedent conditions) can affect flood hydrographs.
A physical factor such as the type of basin and how large it is would affect the flood hydrograph as if it is a larger basin then more water would enter the flood plain, the soil type may also affect the flood hydrography as a more solid soil type may allow less water to permeate through the ground therefore causing more surface run off and larger flood risk.
Explain how human factors (urbanisation, land-use change and deforestation) can affect flood hydrographs.
Human factors such as a urbanisation would affect the flood hydrograph because the city and concrete would be impermeable as the water would not be able to go through the ground which could lead to an increase in flood risk .
Explain how physical and human factors cause river flooding in the River Eden.
Physical factors can affect river flooding for example the amount of water that precipitates from the rain would increase the amount of flooding that occurs as if it rains too much it could be increasing the flood risk as more water could affect the surface run off and make the risk of flood occurring within the river alot greater.
What are the effects of flooding on people and environment? What problems were caused?
The affects of flooding are often very great, it could damage the land, cause increased erosion, sediment from the river may be scattered along the floodplain and even worse animals and humans habitats would be damaged, the towns and villages of the affected by the flood would be damaged badly and could be even destroyed as well in the worst possible scenario.
