Physical Fieldwork Techniques Flashcards
What is involved in a beach profile or slope analysis?
• measure the length of the beach or slope and determine sampling points to carry out systematic sampling.
• use ranging poles at the top and at the first sampling point/visible change in the landscape. then use a clinometer to measure the gradient (x2 and take average).
• other data can be taken at each sampling point - this includes soil samples which can be lab tested or compared to a flow chart, or quadrats to assess vegetation.
What are the limitations of a beach profile/slope analysis?
• Tide times can affect data collected on the beach
• ranging poles MUST be straight for an accurate reading
• user error with clinometer
• measuring tape must be tight to ensure sampling points are accurate
What is involved in a stream analysis?
• Systematic sampling is used to take the depth at regular intervals across the river (divide river width for sampling points)
• pebbles can be collected and compared to the roundness index chart and the longest axis of the pebble can be measured.
• the wetter perimeter can be collected using a chain or by pushing a measuring tape along the banks and bed of the river.
• velocity can be taken at 3 points on the river using a flow meter or a float device.
What are the limitations of a stream analysis?
• tape measure must be held tight to get accurate readings and sampling points.
• when taking depth, you should stand upstream and use a wooden measuring stick which will not bend for accurate readings.
• place stick on riverbed (i.e not a large rock)
• roundness index chart is subjective
• float device could get stuck
What is involved in a micro-climate analysis?
• a compass should be used to find North.
• a wind vane or sock should be used to find wind direction.
• an anemometer should then be used to find wind speed.
• take several readings for average.
• digital or analogue thermometer to take temp.
• cloud coverage assessed against the okta scale.
• precipitation is measured using a rain gauge (scaled glass funnel).
• readings recorded at each location.
What are the limitations of a micro-climate analysis?
• wind strength can be hard to measure at ground level.
• each temp. must be taken at same height to keep the study standard.
• it should be noted that cloud coverage can influence heat.
• okta scale is subjective - take different opinions and average.
• rain gauge must be kept away from anything that could affect readings e.g buildings and vegetation.
