2: PHYSICAL FIELDWORK Flashcards
title of fieldwork
investigating downstream changes in river characteristics down loughtoon brook considering the bradshaw model
where and why
loughtoon brook which is a tributary of river roding which is a tributary of river thames
accessible, safe (not deep or wide)
the three data collection techniques used
velocity: place a metre rule on bank. place a cork upstream of rule. start stopwatch when cork reaches the reading “0”, stop it when the cork has reached 1m
depth: place a metre rule 1/4, 1/2 and 3/4 of the way across a river. stand it at 90 degrees and get at eye level with the rule
width: bring a tape measure from one side of the river bank to the other
pros and cons of each method (j vel and depth)
velocity: cheap to do, little equipment
if someone is standing upstream, could change velocity, snapshot in time
could use flowmeter, could compare at different times of year
depth: metre rule does not bend, easy to do
metre rule may not be exactly 90, bedload size could change depth
measure more intervals along drainage basin
risk assessments: (2)
Weils disease - tape cuts, wear gloves
falling into river - appropriate footwear
data presentation methods (vel and depth)
velocity - line graph
depth - bar chart
pros and cons of each data presentation method
line graph: continuous data set, clearly shows trend, easy to spot anomalies
snapshot in time, weather could alter velocity
add data taken with flow meter to compare accuracy, have three or four lines to see comparative trends
bar chart: easy and simple to read, easy to compare site by site changes
doesn’t geo-locate to actual sites
proportional circles could be used to make this cartographical
what secondary data is there for this fieldwork
flow rates of seasons, weather conditions
random vs stratified vs systematic
random - random
stratified - regular intervals
systematic - site best representative of an area
