Environmental Engineering Reference
In-Depth Information
A further complication with heat transfer into soils is that air is a poor conductor of
heat. If there is a large amount of air between the soil particles, heat transfer into the soil
is slow. This means that on a hot, sunny day the heat is trapped in the upper layers, so the
surface layers warm up more rapidly. Because of this, dry sandy soils can get very hot
when the sun shines. Water conducts heat more easily than air, so soils which contain
some moisture are able to transmit warmth away from the surface more easily
Plate 8.1
Aspect effects on snow survival. The south-facing
slope has lost its snow through melting, apart from the area
in shadow at the base of the slope; the north-facing slope in
the foreground is still deeply snow-covered. Photo: Peter
Smithson.
Figure 8.1
(above) Diurnal temperature changes over a dry
soil and a moist soil.
