Successful Biological Methods for Combating Desertification at Degraded Areas of China - Combating Desertification in Asia, Africa and the Middle East - page 65

Main Wind Direction

Sand-breaking Belt Sand-breaking Belt

Sand-closing
Bed

Sand-closing
Belt

Road Bed

40m 15m 25m 50m

600-700m 200m 10m 300-400m

Fig. 3.12 Structure of the shelter belts in Ganqika section of the Dalushan-Zhongjiatun railway
line, Inner Mongolia

6.3 Control of Sand Hazards Along Railway Line in Dry Steppe

There are some railway lines running across mobile sand areas and fixed and semi-
fixed sand dunes in steppe, e.g. Dalushan-Zhengjiatun line through Horqin Sandy
Land in Inner Mongolia and Laoning. Where the railway line traverses an area with
mobile sand dunes, various Populus trees are planted on the swales between dunes
and flat sand lands are planted with sand binders (e.g. Salix gordejevii, Artemisia
halodendron, Caragana microphylla etc.) The shelter belt on the windward side is
200 m wide, and divided into 3 forest belts with width of 25 m per belt of first
to fourth forest belts, 40 m of fifth from road bed, and distances of 15 m between
neighboring belts. The widths of 600-700 m on windward side and 300-400 m on
leeward side as closing belt exist (Fig. 3.12 ).

6.4 Control of Sand Hazard Along Highways

For highways that pass through desert areas where the conditions are favorable for
sand-fixing plants to grow, measures such as planting road-protective forest belts
along the line and fixing sand dunes by planting shrubs ( Artemisia ordosica, Salix
psamophilla etc.) should be adopted and properly combined. For sectors of fixed
and semi-fixed sand dunes, the best and easiest way is to fence off the dunes to
grow grasses and forests. This method has been widely adopted on most highways
in Mu Us Sand Land, Inner Mongolia.
In areas where sand source is rich and shifting sand dunes prevail a combination
of mechanical and biological measures is adopted. A wind-leading panel is erected
at the shoulder of highway on the windward side of highway. It may be perpendic-
ular or lean forward (angle of inclination is 60 ı -80 ı ). There is a wind exit between
the ground and the panel. The recommended width of a panel is 1.5-2.0 m, and the