Geoscience Reference
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(a)
150
mm
150
mm
1.2m
1.2m
Horizontal
C
C
B
B
300mm
D
D
1.5m
1.5m
Turf wall for use at exposed rain gauge sites
(b)
(c)
Nipher precipitation gauge
Figure 12.2 Some methods used to minimize the effect of turbulence around a gauge: (a) a turf wall surrounding the
gauge; (b) a covered pit into which the gauge is put; (c) a Nipher gauge with shield to break up the local wind field. (From
Sumner, 1988, published with permission.)
arguably superior method for achieving horizontal flow across the top of the gauge
is to place it in a pit which is as deep as the gauge is tall, with a (plastic) grid over
the remainder of the pit that simulates the aerodynamic properties of the sur-
rounding ground (Fig. 12.2b).
At some locations gauges must be mounted relatively high above the ground to
ensure they are not buried by accumulating snow in winter months. To do this,
gauges are mounted on poles above the ground with, for example, the top of the
gauge at 31 inches in the USA and 2 m in the USSR. Clearly, mounting at height
exacerbates the problem of loss of catch due to wind flow and, to minimize this,
shields can be mounted around the gauge with the purpose of slowing the wind
 
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