China is one of the developing countries with vast deserts and desertified areas and 60% of its population is living in the affected areas. China has been severely hit by persistent drought and desertification. Although drought and desertification must be distinguished, they can amplify each other's impact.
The status of desertification in China is very serious and is caused by human activities and climate variations. Factors such as population growth, unsustainable economic development, inadequate environmental and ecological awareness, over-cultivation and rangeland encroachment for cropping productivity and overgrazing all played important roles. In addition, mismanagement of water resources and over exploitation of ground water leading to a lowering of water tables and salinization/alkalization also caused widespread desertification. All these factors have led to recurrent movements of sand dunes, sand and dust storms to an extent that settlements, water bodies, farmlands, road and rail networks can be totally submerged in the sand and oases area greatly reduced, and affecting the economic and social fabric of China.
It is estimated that annually 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 by severe wind erosion; thousands of water conservation facilities and systems have been threatened by wind and sand hazards and the benefits of drainage systems have been reduced; around 800 km of railway has been threatened and thousands of km of highways have been destroyed by the accumulation of sands and wind hazards. Annual economic cost is high, estimated at USD 6.5 billion and affects 400 million people.
China deserts covers a large area, about 2.674 million square km, which is 30% of the land areas, in more than 750 counties and in 13 provinces and autonomous regions. China's sand, gobi (gravel) and stony deserts have an area of 1.57 million square km. Sand deserts covering an area of 684,000 square km of shifting deserts are mostly in western China. The existing desertified land is 861,000 square km. Water erosion induced and wind erosion induced desertified lands accounted for 45.7% and 44.1% of all desertified areas respectively.
As a large country with dense population and complex environmental conditions, China is fully aware that desertification is also of importance to global sustainable development of environment and economy. China's strategic objectives to combat desertification are in three phases:
Since 1970s, China has initiated and implemented successfully major ecological restoration projects including the Three North Regions Shelter Belt Development Project, The Coastal Protection Shelter Belt Project, The National Action Program to Combat Desertification (NAP) etc. In particular, the Chinese government has set up a Chinese National Committee comprising of 16 ministries and commissions for the sound implementation of the NAP. Since 1990s, the NAP and the Three North Regions Shelter Belt Development Project have brought more than 16 Mha of farmland and 10 Mha of rangeland under effective protection.
China has also worked together with international organizations in various projects as part of the effort to combat desertification. Some notable examples are: a water saving irrigation project together with Israel in 1988; a Sino-Korea cooperation project that started in 1996 which focused on the observation and research of desert control technologies and protective effect of windbreak; a Sino-Holland project that started in 1999 (still ongoing) which monitors water balance in Minqin desert area.
While desertification is closely related to human activities and therefore desertification combating cannot be equated to sandy desert control and prevention, there is an important role for the latter work in China as shifting sand has been a serious contributor to desertification.
China's successful experience in fixing shifting sands is the result of two very successful complementary measures - the biological or plant measures to protect the vegetation on the sand dunes, or where such vegetation has deteriorated, to plant trees, shrubs and grasses; and the mechanical measure to set up barriers on sand dunes or to cover the surface of sand dunes to prevent sand dune encroachment.
Of the two measures, biological methods are the ultimate way to rehabitate sandy land and a fundamental approach to the development and proper utilization of desert. These technologies have been tested and proven under extremely difficult conditions in China’s arid northwest and are now adopted and used with equal success elsewhere in the world.
In the arid part of northwest China, transport routes links are very important for the economic development of the region and the welfare of the people. Effective prevention and control measures have been applied to 50% of the rail lines in the desert region. Furthermore, there are lots of major highways including the Taklamakan Desert Highway that pass through the arid areas. Taklamakan Desert is the largest in China and the second largest in the world. Eighty-five percent of the area is drifting dunes and ninety-two percent of such dunes are mobile dunes of different shapes and heights. Building a highway in this desert marked the study of measures in controlling sands and designers took part in the design of road beds. The prevention method together with mechanical measures along the highway assures that the highway remains open, accelerating oil exploitation and development in the hinterland. The Taklamakan Desert reclamation program has been a great success and received the National first prize for progress in science and technology in 1996.
On the other hand, some successful and biological measures for different land uses were developed for such as agricultural areas, highways, railways, roads, cities, industrial factories, reservoirs and mining areas. Suitable plant species were chosen on the basis of their capabilities in these kinds of harsh environments. Plantation techniques and the seed treatments like sowing, seedling, air seeding were perfected and successfully used for protecting people and property. Shelter belt systems and practical models for the hilly and flat desert areas are available for application in desertified areas worldwide.
China has gone through a long winding road in her battle against desertification. Even though a wealth of knowledge and skills has been accumulated on the subject, other environmental threats like global warming and pollution are becoming more and more pressing in the 21th century. There certainly is still a long way to go before the threat of desertification can become a subject of the past.
Combating Desertification in Asia, Africa and the Middle East - Proven practices, G. Ali Heshmati, Victor R. Squires (editors), Springer Netherlands, 2013, ISBN 978-94-007-6651-8, 476 pp.