AEOLIAN LANDSCAPES - Fundamentals of Geomorphology - page 313

of 625 g/m 2 /yr. A lower rate of deposition will lead to
dilution by weathering, by mixing by burrowing ani-
mals, by mixing with other sediments, and by colluvial
reworking. During the late Pleistocene in North America
and Western Europe, loess accumulated at more than
2 mm/yr, equivalent to 2,600 g/m 2 /yr.

containing seeds, damage crops by sandblasting them,
and block ditches and roads. Blowing is recorded as long
ago as the thirteenth century, but the problem worsened
during the 1960s, probably owing to a change in agri-
cultural practices. Inorganic fertilizers replaced farmyard
manure, heavy machinery was brought in to cultivate and
harvest some crops, and hedgerows were grubbed to make
fields better-suited to mechanized farming. Intensively
cultivated areas with light soils in Europe are generally
prone to wind erosion and the subject of the European
Union research project on Wind Erosion and European
Light Soils ( WEELS ) (e.g. Riksen and De Graaff 2001).
This international project began in 1998 and looked at
sites in England, Sweden, Germany, and the Netherlands
where serious wind-erosion problems occur. The damage
recorded depended very much on landscape factors and
land-use. Most on-site damage, mainly in the form of
crop losses and the cost of reseeding, occurred in sugar
beet, oilseed rape, potato, and maize fields. In the cases
of sugar beet and oilseed rape, the costs may be as much
as

HUMANS AND AEOLIAN LANDSCAPES

Wind erosion may bring about long-term impacts on
humans and human activities. It may damage agricultural
and recreational lands, and, on occasions, impair human
health. As Livingstone and Warren (1996, 144) put it:

There has been and continues to be massive investment across
the world in the control of aeolian geomorphological processes.
It has happened in Saharan and Arabian oases for thousands
of years; on the Dutch coast since the fourteenth century; on
the Danish sandlands particularly in the eighteenth and nine-
teenth centuries; in the Landes of south-western France from the
nineteenth century; in the United States since the Dust Bowl of
the 1930s; on the Israeli coast since shortly after the creation
of the State in the late 1940s; on the Russian and central Asian
steppes since the Stalinist period; since the 1950s in the oil-rich
desert countries of the Middle East; since the early 1970s in the
Sahel, North Africa, India and China; and less intensively but
significantly in other places. In most of these situations, applied
aeolian geomorphology won huge resources and prestige.

500 per hectare every five years, although farmers
are fully aware of the risk of wind erosion and take pre-
ventive measures. In Sweden, measures taken to reduce
wind erosivity include smaller fields, autumn sowing,
rows planted on wind direction, mixed cropping, and
shelterbelts. And measures taken to reduce soil erodibil-
ity include minimum tillage, manuring, applying rubber
emulsion, watering the soil, and pressing furrows.

E

The chief problems are the erosion of agricultural soils,
the raising of dust storms, and the activation of sand
dunes, all of which may result from human disturbance,
overgrazing, drought, deflated areas, and the emissions
of alkali-rich dust (see Livingstone and Warren 1996,
144-71).

Modelling wind erosion

Researchers have devised empirical models, similar in
form to the Universal Soil Loss Equation (p. 179), to pre-
dict the potential amount of wind erosion under given
conditions and to serve as guide to the management prac-
tices needed to control the erosion. The Wind Erosion
Equation ( WEQ ), originally developed by William S.
Chepil, takes the form:

Cases of wind erosion

The Dust Bowl of the 1930s is the classic example of
wind erosion (Box 12.2). Even greater soil-erosion events
occurred in the Eurasian steppes in the 1950s and 1960s.
On a smaller scale, loss of soil by wind erosion in Britain,
locally called blowing, is a worse problem than erosion by
water. The light sandy soils of East Anglia, Lincolnshire,
and east Yorkshire, and the light peats of the Fens are the
most susceptible. Blows can remove up to 2 cm of topsoil

= E f ( I , C , K , L , V )

where E is the soil loss by wind, I is the erodibility of
the soil (vulnerability to wind erosion), C is a factor
representing local wind conditions, K is the soil surface
roughness, L is the width of the field in the direction of