Introduction to Deserts and Desertified Regions in China - Combating Desertification in Asia, Africa and the Middle East - page 13

all situations. In that sense, desertification, which has been called the 'cancer of
drylands' can affect any area which has been made vulnerable enough by climatic
stress or human overexploitation, or both.
The area of land affected by wind erosion exceeds the total area tilled. Annually,
there are about 13 million ha (Mha) of cropping lands threatened by wind and
severe dust and sand storms causing a decrease in crop yield, loss of livestock
and property damage. It is also estimated that nearly 100 million ha of rangeland
has been impacted by the severe wind erosion incidents (Ci and Yang 2010 ;Wang
et al. 2012 ). Over a thousand water conservation facilities were destroyed by sand
movements. Similarly, a total of 800 km. of railway lines and several thousand km
of highways in desert regions are impacted by sand accumulation and wind hazards.
Economic loss is estimated at 6.5 billion USD annually and affects 400 million
people (Wang et al. 2012 ).
Water erosion is also serious. It is estimated that 430,000 km 2 of the Loess
Plateau is affected by soil loss and water erosion. The other negative consequences
caused by desertification include rapid reduction of the area of arable lands, and
subsequent impact on human populations; rapid decrease in land productivity, the
degradation of ecosystem and decline of biodiversity. Other impacts are constraints
to economic and social sustainable development and unemployment in the affected
areas; aggravated poverty and poor quality of life, outward migration, and hunger in
the affected areas; imbalance and shortage of water resources and frequent changes
in the ecosystem complex and influences of sand transport and long-distance dust
carried in the atmosphere to the east and the southeast parts of China (Squires 2007 ).

5 Combating Desertification in China

Combating desertification is essential to ensuring the long-term productivity of
inhabited dry lands. Unfortunately, past efforts have too often failed, and all around
the world the problem of land degradation continues to worsen although some
countries are making progress in arresting and reversing it (Yang et al. 2011 ).
As a large country with dense population and complex environmental conditions,
China is aware that desertification combating is also of importance to global
sustainable development of environment and economy. Through a long period of
hard efforts to combat desertification, capacity has been built through technology
know-how whereby technicians and scientists have been trained. Combating deser-
tification includes activities which are part of the integrated development of land
in arid, semi-arid and dry sub-humid areas for sustainable development which are
aimed at: (i) prevention and/or reduction of land degradation; (ii) rehabilitation of
partly degraded land; and (iii) reclamation of desertified land.
In the 1950s, the Government of China conducted scientific surveys and studies
on affected lands and has given priority to combating desertification in seriously
impacted regions. Since 1970s, China has initiated and implemented successfully
such major ecological restoration projects such as the Three North Regions Shelter