Successful Biological Methods for Combating Desertification at Degraded Areas of China - Combating Desertification in Asia, Africa and the Middle East - page 67

Fig. 3.15 Mechanical barriers made of clay have proved to be successful in some areas. Clay
'tablets' of various sizes are used in mixtures (as shown)

6.5 Control of Sand Hazard Around Factories or Mines

The control of blowing, shifting sand around Jilantai Salt Lake is taken as an
example here. The Jilantai Salt Lake lies in the southwest part of Ulan Buh Desert
around which the shifting longitudinal dunes and sand mound covered by Nitraria
tangutorum prevail. The northwest is the main wind direction in this area. The area
covered by sand reached 10.8 km 2 , making up 29 % of the total salt lake area. In
view of this situation, a comprehensive shelter system around the Lake has been
established. The measures adopted are follows.

6.5.1 Enclosure Method for Protecting Factories

In the spring of 1984, the wire fence of 27 km in length was installed, the closed
area reached 16 km 2 . An investigation in 1985 showed that the vegetation coverage
of the closed area increased from 20 to 39.4 %; the sand quantity (0-10 cm above
ground surface) in the air current in the closed area, compared with the check plot,
decreased by 75 %. A great amount of sand was kept in the closed area. Sprinkler
irrigation was used to reclaim the surface of sand dunes in this area. This improved
the rehabilitation and regeneration of vegetation cover in the closed area.

6.5.2 Adopting Engineering Measure

The clay checkerboard barriers (1 1 m) should be built at the feet of mobile

longitudinal dunes (Fig. 3.15 ) close to the Lake, and combine with closing and