Dunes and People - Dune Worlds: How Windblown Sand Shapes Planetary Landscapes - page 260

Fig. 23.1 A photograph by G.K. Gilbert in 1899. This is the last
house in Biggs, Oregon, torn down shortly after this photo was taken.
The town was abandoned because it was being overrun by dunes. Note

the abundant ripples and the almost completely buried railway track. A
similar abandoned house is still visible today as a tourist attraction at
Kolmanskop near Luderitz in Namibia. Photo credit USGS

way. Note that in some locations, even though the near-
surface is dry, once a tree can become established, its roots
might reach deep enough to find moisture. Surrounding
seedlings and their roots with a plastic barrier may reduce
evaporation enough for artificial irrigation to be carried out
for a year or so while the tree grows, and then it can keep
itself going (e.g., Rognon 1999). How well these efforts
succeed remains to be seen: fixing a dune by these methods,
or the less sustainable approach adopted sometimes in the
Middle East of spraying oil on it, does not change the fact
that more sand is still coming from upwind and it will have
to go somewhere.
A well-tried approach predating Meunier's approaches is
to 'plant' a grid of grasses, straw or permeable fabric
(Fig. 23.6 ). With a grid spacing of about 1 m and a fence
height of about 1/10th of that, sand movement becomes

substantially suppressed. This approach was introduced into
China (e.g., Zheng 2009) by Russian advisers—notably to
the Baotou-Lanzhou railway across the Tengger Desert.
Some of the challenges of engineering roads and other
infrastructure in arid lands are discussed in Dauncey et al.
(2012). In richer countries, it is of course possible to keep
specific sites like roads clear of sand simply by shoveling it
or bulldozing it, especially if the sand transport rate is
modest (e.g., Fig. 23.7 ). Alghamdi and Al-Kahtani (2005)
discuss these measures, quoting costs of $2/m 3 for manual
removal and $0.5/m 3 for bulk (mechanized) removal. Given
that small barchan dunes 2 m high wide can move at
*50 m/year, this means a 200 m sector of road crossed by
a barchan corridor may cost $10,000 a year to keep clear.
This is clearly not a preferred solution, but in some settings
is the most straightforward.