Dunes and People - Dune Worlds: How Windblown Sand Shapes Planetary Landscapes - page 261

Fig. 23.2 Fences installed to guide drifting sand away from the railroad in the Columbia river gorge, near Grant, Oregon. Similar fences are
sometimes found elsewhere to prevent blowing snow from blocking roads. USGS photo by G.K. Gilbert

One approach (which can be seen applied in satellite
images) (Fig. 23.8 ) is to have two roads, separated by a
little over a dune length. Thus when one road is blocked by
a dune (this usually occurs with barchans, which are the
fastest-moving

between them), the other is not. As the months and the dune
go by, the traffic is simply diverted to the other road, and
then back again when the next dune hits.
This approach is of little use for irrigation canals, which
can get silted up and blocked by sand flow. Still other dunes and usually have some spacing