Rivers Topic

Mind Map by lucywolford, updated more than 1 year ago
Created by lucywolford over 5 years ago


AS - Level Geography Mind Map on Rivers Topic, created by lucywolford on 04/04/2016.

Resource summary

Rivers Topic
  1. Drainage Basin
    1. The catchment area from which a river system obtains its water. An imaginary line called the WATERSHED delimits one drainage basin from another.
      1. Storm hydrographs
        1. FLASHY
          1. Short lag time
            1. steeper drainage basin
              1. lots of surface runoff
                1. underlying rock
                  1. less percolation
                  2. urban areas
                    1. less trees
                      1. less interception
                      2. ploughing fields downhill
                        1. more tributaries
                        2. SUBDUED
                          1. Labelling
                            1. lag time
                              1. the time delay between maximum rainfall amount and peak discharge.
                              2. rising limb
                                1. As the water enters the drainage basin the discharge rises- there's a delay due to overland flow and interception
                                2. base flow
                                  1. the starting and finishing level
                                  2. receding limb
                                    1. shows the fall in the discharge back to the base level
                                    2. peak discharge
                                      1. indicates the highest flow in the channel
                                    3. type of hydrograph is determined by relief, rock and soil type, vegetation, land use, weather, urbanisation, drainage basin density, drainage basin shape and size
                                    4. Long profile
                                      1. River rejuvenation
                                        1. significant breaks in slopes (knick points) along a river's long profile- may be due to rejuvenation
                                        2. illustrates the changes in the altitude of the course of the river from its source, along the entire length of its channel to the river mouth.
                                          1. UPPER COURSE
                                            1. LANDFORMS
                                              1. small waterfalls
                                                1. due to change in rock type
                                                2. rapids
                                                  1. potholes
                                                    1. large boulders
                                                      1. uneven steep river beds
                                                      2. TRANSPORTATION
                                                        1. mostly large boulders
                                                          1. some suspension and little in solution
                                                          2. PROCESSES
                                                            1. hydraulic action, attrition, mostly vertical erosion
                                                            2. DEPOSITION
                                                              1. bedload is too heavy so limited deposition
                                                            3. MIDDLE COURSE
                                                              1. LANDFORMS
                                                                1. rapids
                                                                  1. small meanders
                                                                    1. small floodplain
                                                                    2. PROCESSES
                                                                      1. lots of attrition
                                                                        1. little hydraulic action
                                                                          1. more lateral erosion- start of meanders
                                                                          2. TRANSPORTATION
                                                                            1. less traction
                                                                              1. suspension increases
                                                                              2. DEPOSITION
                                                                                1. in slow waters
                                                                                  1. floodplains built in times of flood
                                                                                2. LOWER COURSE
                                                                                  1. LANDFORMS
                                                                                    1. Large meanders
                                                                                      1. levees
                                                                                        1. floodplains
                                                                                        2. PROCESSES
                                                                                          1. erosion reduced, just small lateral erosion
                                                                                            1. slower waters
                                                                                          2. TRANSPORTATION
                                                                                            1. small bedload
                                                                                              1. mostly suspension
                                                                                              2. DEPOSITION
                                                                                                1. mostly fine particles,
                                                                                                  1. forms levees, slip off slopes and floodplains
                                                                                              3. BRADSHAW MODEL
                                                                                            2. PROCESSES
                                                                                              1. EROSION
                                                                                                1. Hydraulic action
                                                                                                  1. power of moving water removing materials from the channel bed leading to collapsing
                                                                                                  2. corrasion
                                                                                                    1. rubbing actions of material carried along the river bed
                                                                                                    2. corrosion
                                                                                                      1. minerals in rock dissolved by weak acids
                                                                                                      2. attrition
                                                                                                        1. particles striking against one another into smaller pieces
                                                                                                      3. TRANSPORTATION
                                                                                                        1. Solution
                                                                                                          1. dissolved particles
                                                                                                          2. suspension
                                                                                                            1. fine materials (sand and silt) carried in water flow
                                                                                                            2. saltation
                                                                                                              1. small stones bounce along the river bed
                                                                                                              2. traction
                                                                                                                1. stones and boulders roll downstream in fast water
                                                                                                              3. Deposition
                                                                                                                1. Hjulstrom curve
                                                                                                                  1. velocity and deposition relationship shows when particles are eroded deposited or transported in relation to particle size
                                                                                                                Show full summary Hide full summary


                                                                                                                Using GoConqr to study geography
                                                                                                                Sarah Egan
                                                                                                                Geography Quiz
                                                                                                                All the Countries of the World and their Capital Cities
                                                                                                                River Processes and Landforms
                                                                                                                The Rock Cycle
                                                                                                                GCSE Geography - Causes of Climate Change
                                                                                                                Beth Coiley
                                                                                                                Tectonic Hazards flashcards
                                                                                                                Geography Coastal Zones Flashcards
                                                                                                                Zakiya Tabassum
                                                                                                                Plate Tectonics
                                                                                                                Globalisation Case Studies