S-Cool Revision Summary

S-Cool Revision Summary

  • The drainage basin acts as an open system, with a number of inputs, outputs, stores and transfers.
  • The drainage basin system forms an important part of the overall water cycle.
  • As water flows downhill into rivers it can create a number of different drainage patterns. These are called cenripetal, dendritic, parallel, radial and trellis patterns.
  • The long profile of a river looks at its full length. It is steep in the upper stages, a more gentle slope in the middle section and almost flat in the lower reaches.
  • The cross profile of a river looks at the shape of the river channel. In the upper reaches it is narrow and not very deep. In the middles stages it was widened but is still not particularly deep. By the lower stages it is very wide and deep.
  • Fluvial erosion occurs vertically and laterally, using the processes of attrition, abrasion, corrasion corrosion and hydraulic action.
  • Which type of erosion occurs depends upon where in the river you are looking at.
  • Fluvial transportation occurs through the processes of traction, saltation, suspension and solution.
  • Which type of transportation occurs depends on where in the river the material is.
  • Fluvial deposition occurs when the water slows down, losing energy and causing it to drop what it is transporting.
  • Erosional features include interlocking spurs, meanders, ox-bow lakes, V-shaped valleys and waterfalls.
  • Depositional features include deltas, flood plains and levee's.
  • For thousands of years rivers have been the focal point of people's activities, including fishing, as a source of drinking water, for dumping waste, for navigation and for power production.
  • As humans have increasingly used and abused river basins so management and planning of them has become increasingly important.
  • Flooding is the most common thing to have to plan around.
  • Rivers are used for the dumping of waste, such as sewage, agricultural waste, chemicals and oil, causing water pollution, which may affect the natural environment and humans.
  • A river regime is the difference in the discharge of the river throughout the year.
  • Flooding occurs due to a sudden increase in the amount of water travelling down a river.
  • The discharge of a river is shown on a graph called a flood or storm hydrograph. By looking at the peak rainfall and comparing it with the peak discharge you can work out the lag-time (the time between the two peaks). Flood hydrographs are very important in predicting how a certain river will behave in a time of intense rainfall.