Fluvial Processes and Landscapes

August 29, 2003

 

1.      Drainage Density – The number of streams within a specific area.

 

2.      Some key water terms

a.       Infiltration – water is absorbed by the soil.

b.      Evaporation – water is returned to the atmosphere

c.       Transpiration -- water is returned to the atmosphere by plant respiration.

d.      Runoff – amount of water left over from Precipitation minus all of the above.

 

3.      Differential Erosion – different rocks weather differently based on their makeup.

a.       permeability – the ability of a rock to transmit water.

 

4.      Drainage Patterns (Fig. 11.2, p. 184)

a.       Dendritic – no structural control on drainage courses and uniform bedrock.

b.      Rectangular – streams flow along zones of weakened rocks adjacent to faults or joints. Streams usually meet at right angles.

c.       Trellis – resistant and non-resistant rocks form valleys and ridges. Streams will have sub-parallel orientation.

d.      Radial – Streams “radiate” from an isolated topographic high.

 

5.      Drainage system terms and parts of the river

a.       Discharge

b.      Longitudinal profile

c.       River parts

i.                     Drainage Basin

ii.                   Divides

iii.                  Headwaters

iv.                 Floodplain

v.                   Terraces

vi.                 Natural Levee

vii.                Yazoo Stream

viii.              Meander

ix.                 Point Bar

x.                   Downstream Bar

xi.                 Oxbow lake

xii.                Mouth

xiii.              Delta

xiv.              Distributaries

xv.               Headward Erosion

xvi.              Piracy

xvii.            Alluvium

 

9. Floods

a.       Gauging station – measuring point on a stream

 

b.      Stage – elevation of the water surface

 

c.       Recurrence Interval – Average interval (in years) between floods of a particular size.