physical- changes along the river WEY

• HYPOTHESIS- WIDTH, DEPTH, VELOCITY WILL INCREASE AS YOU GO DOWNSTREAM
• Why has this been a suitable topic-

  studied it in class- linked to bradshaws model
• why is this location suitable?

  river is close to where we stayed on the field trip - easily accessible

  river is around 9 km long- shows variation but can study it in a day
• data collection method 1- river velocity sampling method aimed at systematic sample size 7 sample sites
• data collection method 1 river velocity-

  measured 5m of the river with tape measure

  dropped a rubber duck and timed how long it took for it to travel the 5m
• data collection method 1 river velocity

  justification

  provides a measure of velocity at the same sites as width and depth so can calculate discharge

  can be used to show how and why a rivers characteristics are changed downstream
• data collection method 1 river velocity

  weaknessess

  rubber duck can get stuck in weeds on bank

  can be dropped at different heights- measurements are inaccurate

  human error when using stop watch
• data collection method 2 river depth sampling method aimed at systematic ( equal spacing of sites) sample size : 7 sample sites
• data collection method 2 river depth

  tape measure taught across surface of river from bank to bank

  every 50 cm measure depth of water (surface to bed) using verticle ruler

  / width by six
• data collection method 2 river depth

  justification

  provides a measure of river depth at same sites as the other characteristics

  can be used to show how and why river features are changing
• data collection method 2 river depth strengths

  quite quick to do

  only needs 3 people

  gets reasonably accurate measurments
• data collection method 2 river depth weaknessess

  ruler may not be vertical so inaccurate measurements

  tape measure may not be taught so inaccurate measurments
• risks- drowning due to deep/fast flowing water- teachers stand at either end of river stretch and supervise and not allowed in deeper ends

  weil's disease - can get into open wounds so wear plasters and wash hands when back

  cuts from broken glass- wellies with thick soles
• date collection method 3 river width

  tape measure taught across the surface of a river from bank to bank
• data collection method 3 river width

  justification- provides a measure of width at same sites as the other characteristics

  can be used to show how and why a rivers features are changed as you go downstrea,
• data collection method 3 river width weaknesess- vegetation in the way and might not be taught enough = invalid results
• data representation method 1 river velocity- scatter gragh

  strengths

  shows relationship between distance downstream

  can assess strength of corelation (line of best fit) clear and visual record

  identify outliars
• data representation method 1 scattergragh velocity- weaknesess

  plotted on a small scale so reading may be difficult

  interpretation is subjective
• data presentation method 2 river depth and width- cross sectional graph

  strengths

  visual shows by comparing which sites are deeper

  put graphs next to eachother makes it easy to compare

  identify overall pattern

  easy to draw
• WHAT OTHER METHODS CAN BE USED TO PRESENT DATA?

  SPEARMANS RANK CORRELATION - STATISTICAL METHOD
• ANYALASIS- why it proved the brad shaw method
• analysis- river velocity increased overall with distance downstream
• velocity analysis- velocity

  AT SITE 1 THE RIVER VELOCITY WAS 0.030 METERS PER SECOND BUT BY SITE 7 IT WAS 0.625
• analysis- velocity

  anomalies- at site 5 where there had been some human management it was slower ( old mill which means there was less water in the channel)
• velocity generally increases downstream due to channel shape becoming more semi circular- more water in river (fed by tributaries)

  increased volume has eroded the channel into a more efficient semi circular shape. linked to hydraulic radius downstream.
• analysis river depth- river depth increased with distance downstream- the depth increased from 1.6cm at site 1 to site 7 61.6cm
• analysis river depth- at site 5 it became slower- river has been split in order to flow past a now defunct mill this channelling was to prevent flooding and erosion.
• analysis river depth - as the river flows downstream more tributaries joining it adding volume of water in river. + surface run off. erodes a wider and deeper channel
• analysis river width- at site 1 the width was 0.42 and increased to 11.02 by site 7 (meters)
• conclusion- overall we found out that river velocity and depth both increased downstream. this fitted the bradshaw model