Component 2 EQ 4 Flashcards
What are the characteristics of a river in the upper course?
The upper course usually has V shaped valleys and interlocking spurs. They also have waterfalls in the upper valley
What are characteristics for rivers in the middle valley?
The river is in gentle sloping valley. There are oxbow lakes and lots of meanders.
What are characteristics of a river in the lower course?
It is very flat and wide along with the floodplain, there aren’t many features
How are waterfalls formed?
More resistant rock lies on top of less resistant rock. The less resistant rock is eroded quicker. This rock leaves a ledge behind which water flows over. This process continues over along period of time, and the waterfall keeps getting pushed further and further back.
How are ox-bow lakes formed?
The mender bend of a river starts to get closer and closer due to erosion. Eventually , when the neck is very thin, water flows over the neck, often in a flood, and water continues to flow this way. Eventually the lake is cut off from the rest of the river.
How are interlocking spurs formed?
In the upper course, the river bends and meanders to avoid areas of hard rock, thus creating interlocking spurs
What is river discharge and what is it measured in?
It’s the amount of water in a river measured in cumecs
What are some factors that impact discharge?
- The location of the drainage basin
- The weather and temperature
- The size of the drainage basin
- The size of the river
- Obstacles in the drainage basin
- The permeability of soil
What is a flashy hydrograph?
A graph with a big peak discharge and short lag time
What is a subdued hydrograph?
A hydrograph with a small peak discharge and a big lag time
How does urbanisation increase river discharge?
If the drainage basin is full of concrete, the amount of surface runoff will increase dramatically. If there are also purpose built drains for the water to go in to, the river discharge will increase a lot.
What other human factors increase the river discharge?
- Deforestation
- Global warming
- Removing gardens
What are human factors that affect river discharge in Sheffield?
- Urbanisation
- Lack of defences
- Old drainage system
What are physical factors that effected flooding in Sheffield?
- It sits at the foot of the Pennines
- There had been lots of rain before the flood
- A depression caused lots of rain
- It is a very hilly city with lots of steep sides