Introduction to Deserts and Desertified Regions in China - Combating Desertification in Asia, Africa and the Middle East - page 10

Fig. 1.4 Riparian areas like this one on the lower reaches of the ShiYang river in the Hexi corridor
of China have died as a result of over enthusiastic water conservation projects that prevented annual
flooding after the spring snow melt and the cessation of ground water recharge

by human activities since recorded history (Fig. 1.4 ) rather than taking the deserts
formed and developed in natural process during prehistorical or geological periods
as desertification. Therefore, desertification combating cannot be equated to sandy
desert prevention and control, or even simply take the areas with drought index
ranging between 0.05

0.65 as desertified area.
That being said, there is an important role for preventing and controlling desert
encroachment and the chapters that follow will outline measures being taken to do
this important work.

4.1 Status and Causes of Desertification

China is one of the developing countries with vast deserts and desertified areas and
60 % of her population is living in the affected areas. The status of desertification is
very serious (Ci and Yang 2010 ). It is mainly caused by climatic variations and
human factors. It is estimated that 13 Mha of arable land has been threatened
by disasters of wind and sand storms; about 100 Mha of steppe, desert steppe
and pasture lands have been seriously degraded; thousands of water conservation
facilities and systems have been threatened by wind and sand hazards and the
benefits of the drainage system have been reduced; around 800 km of railway
has been threatened and thousands km of highways have been destroyed by the
accumulation of sands.