rivers Flashcards
figure 17, photo showing river straightening along river cuckmere in east sussex
using figure 17 describe the relief (height and shape of land) on either side of the straightened river
floodplain surrounding is quite flat but gets steeper further away
figure 17, photo showing river straightening along river cuckmere in east sussex
suggest how the strategy shown in figure 17 helps to manage the river
channelisation means water leaves the area quicker rather than building up so flood risk is lower
figure 18, graph showing maximum discharge for a river between 2000 and 2018
using figure 18, calculate the range of maximum discharge
22 - 7
= 15
figure 19, info about cockermouth and the impact of storm desmond in december 2015
explain how physical and human factors may affect flood risk using figure 19 and own understanding (6)
in figure 19, an urbanised area is displayed and firstly this creates impermeable surfaces (concrete and buildings made from impermeable materials) which consequently increases surface run off as less water infiltrates into the ground. as well as this cockermouth is located around steep hills and this means that water will reach the river channel quicker because it can flow faster down the steep slopes, rapidly increasing discharge. on the other hand in figure 19, trees are shown all down the street and trees intercept rainwater on their leaves which then evaporates, as well as storing water from the ground. this means that the volume of water entering the nearby river channel is decreased
figure 15, long and cross profile diagram
describe how the cross profile of the river valley changes downstream
the river widens as well as the valley sides decreasing in height
figure 16, velocity data for meandering river
complete table in figure 16 by calculating median velocity in metres per second at point Y
1.3
figure 16, velocity data for meandering river
suggest one reason for the difference in river velocity between point X and point Y
Y is on the outer bank where there is no deposition slowing the water down
which of these is a process by which a river transports sediment?
A) abrasion
B) traction
C) deposition
D) hydraulic power
B) traction
explain how soft engineering strategies can help reduce the impact of river flooding using figure 17 a diagram showing floodplain zoning and your own understanding (4)
floodplain zoning can help reduce the impact of river flooding by putting restrictions to prevent buildings on parts of a flood plain that are likely to be affected by a flood. this means that flood risk is reduced as fewer impermeable surfaces are created and there are no buildings to damage, reducing impact. this means less money is needed for repairs of buildings. afforestation can also help reduce the impact as it increases the interception of rainwater and reduces soil erosion so less water reaches the river meaning the impacts of flooding are reduced as less water bursts from the banks so less areas are flooded.
