Draw a sketch to show the shape of the long profile of a river.
1.1 On the sketch, label the source and the mouth.
1.2 At the correct stage of the river on the long profile, draw simple sketches
to show the transverse profiles in the upper, middle and lower courses of
the river.
2 Explain why erosion changes from vertical erosion to more lateral erosion
from the upper to middle course.
3 In which stage of the river course is flooding more likely to occur? Explain
why.
4 List three things that you think people living along the river can do to protect
themselves against flooding.
1.1 Sketch of the long profile of a river:
[Source]--->(Upper Course)--------->(Middle Course)--------->(Lower Course)----->[Mouth]
1.2 Transverse profiles sketches:
- Upper course: V-shaped valley with steep sides and narrow channel
- Middle course: Wider channel with more meandering flow
- Lower course: Wider, flatter valley with a broad floodplain
2. Erosion changes from vertical erosion to lateral erosion because in the upper course, the river has more energy and gravitational potential energy causing it to erode vertically, creating a V-shaped valley. As it moves towards the middle course, the river has less energy and starts to erode laterally, widening its channel and creating more meanders.
3. Flooding is more likely to occur in the upper and middle courses of the river. This is because in the upper course, the river has a steeper gradient and therefore flows faster, eroding deeper channels. In the middle course, meandering rivers can burst their banks during times of heavy rainfall or snowmelt.
4. Three things people living along the river can do to protect themselves against flooding are:
- Building levees or flood walls to contain floodwaters
- Implementing better land use management practices to prevent erosion and sedimentation
- Developing early warning systems and emergency response plans to evacuate areas at risk of flooding