Controlling Sand Movement Through Mechanical Measures: China’s Experience - Combating Desertification in Asia, Africa and the Middle East - page 24

Fig. 2.3 The cross section of covering sand dune with earth

3.1.1 Technique of Covering Sand Dune with Earth

This technique uses the following steps:

• The sand top is pushed down the leeward slope to make the sand dunes gentle so

that the earth can stay on the sand dunes.

• The surface of the sand dune is covered with clay or piled from the top to the

foot of the sand dunes. The depth of the clay or pile covering on the sand dune
is around 6-15 cm. Under normal conditions; it is deeper on the windward slope
and the upper part of the sand dunes. The sand dune must be completely covered
and the clay or piled soil is left loose. Some plants such as Artemisia arenaria
and Agriophyllum squarrosum , can be sown after the sand dunes are covered. At
the same time, several lines of trees or shrubs should be planted along the foot of
the sand dunes so as to stabilize the sand dune permanently. See Chap. 3 .

Covering sand dunes with mud is often practiced in areas where plants survival
is problematic due to extreme shortages of rainfall. The function of the mud is to
reinforce the sand surface and protect the sand dunes from erosion.

3.1.2 Technique of Covering Sand Dunes with Mud

The technique of covering the sand dunes with mud is basically the same as that
of covering the dune with earth. Generally the steps of employing the earth or mud
barrier are as follows:

• Cover the sand dunes with earth or damp soil

• Cover the earth or damp soil with mud alone or mud mixed with broken straws

• Daub plaster on the sand dunes from the top to the foot of the sand dunes.

A protective crust, on which there will be no plants, will be formed. Finally, trees
and shrubs can be densely planted along the foot of the sand dunes. Although this
method can consume a lot of man-hours it can save many useful materials and it can
control moving sand dunes immediately.