The Abney Level
Useful for simple slope profiles, horizon diagrams and height measurements
Level bubble
Rotating
Arm
Eyepiece
Scale (in
degrees)
The Abney Level
View Through The Eyepiece
Viewing side
Align bubble
with this line
Target eg staff
Rotate arm to
align Level
bubble
Mirror side
Slope Profiling
Measured
angle 
Equal length
poles
Abney level
Useful Notes For Profiling

Take measurements at changes in slope and at points
of interest (eg swampy areas, erosion sites etc)

Follow the line of steepest slope (this will mean your
line is not straight) – but do avoid dangerous slopes or
cliffs

Try to keep the staffs vertical when measuring

Take care when winding the tape measures or they
will jam or break

Use tape to measure slope distance

Use Trig to calculate horizontal and vertical distances
for plotting cross sections
Horizon Diagrams



Used at specific sites to quantify the shape of the
horizon
When matched with sun path, gives indication of
possible light levels at a site (therefore
susceptibility to frost, suitable plants for a site etc)
Can be a useful way of considering how
topography may affect wind patterns
Horizon Diagrams
Outer ring rep.
horizon
000o
315o
Centre rep.
Straight up, ie
045o 90o elevation
270o
090o
Azimuth = 270
Elevation = 030
225o
135o
180o
Measuring the height of a tree
Measured
angle 
Abney level
Ht
Measured distance (d) eg 20m
Hint: use a larger distance for a
taller tree to make things easier
Htree = hpole + (tanθ.d)
hpole