This is a typical example of the Javons
paradox, which occurs when technological
progress facilitates exploiting a resource and
thereby increases the rate of consumption of
that resource. With advances in pumping and
irrigation technology to improve efficiency, there
is an increase in the consumption of limited water
resources in arid regions such as Turpan. The
repercussion is that the groundwater reserve is
being mined much faster than the aquifer is being
replenished.
However, the karez system has its own
limitations that curb its ability to compete with new
technologies, such as a low discharge rate and —
despite its low level of technology — intense labour
requirements and high costs for construction and
maintenance.
Preserving the Karez System
With karezes disappearing at an alarming speed,
the United Nations and national Governments
have raised concerns about their preservation.
To protect the historic and cultural value of the
karez system, multiple measures have been
undertaken by agencies in Turpan. These include
establishing and implementing Government
rules and regulations for the protection of karez
systems, designating select karez systems as
protected areas, controlling the development
of surface water systems at the headwaters of
a karez, and curtailing the exploitation of deep
groundwater in areas where the karez system will
be preserved.
Efforts have also been made to preserve the
karez system as a UNESCO World Heritage Site.
Nowadays, the karez systems in Turpan attract
thousands of Chinese and international tourists. In
fact, a museum has been established to showcase
the karez system in Turpan. Because karezes
constitute a global heritage of human civilization,
such international co-operation to protect karezes
and to formulate strategies and technologies for
their continued utilisation should be encouraged.
The karez is an impressive hydraulic
engineering project as well as a cultural
achievement. In China it is recognised as one of
three major ancient engineering projects, along
with the Great Wall and the Beijing-Hangzhou
Grand Canal. Because the karez system has
provided a safe and reliable water supply over the
centuries, the communities that rely on it have
referred to it as the “mother river” and “spring
of life.” This is particularly true in the Turpan and
Hami prefectures in Xinjiang, where most of the
region’s karez systems are located.
However, karez systems have faced great
challenges over the past several decades,
including drying up, abandonment, damage,
and pollution as a result of over-exploitation of
groundwater through deep wells, the construction
of reservoirs upstream, the development of oil
fields, and other human and natural activities.
In recent years, the United Nations and national
Governments have raised concerns about and
recognised the importance of karez systems.
Plans have been drawn up and implemented to
revitalise some karezes for use and to preserve
some for cultural purposes.
In most cases, the karez system is not only
a structure to extract groundwater, but also an
integration of the history, culture, and unique
knowledge of its builders. Karezes have created
strong cohesion in their communities owing to the
traditions and beliefs attached to them. Religious
beliefs and cultural traditions also helped the
karez system to be handed down as a legacy. In
the past, the social arrangements in karez-based
communities were directly related to the karez
system. Essentially, people’s importance and value
were judged according to their water ownership
rights in the system. A household’s proximity to
the system was a good indicator of the social or
economic status of its residents.
The karez system is an important part of the
ecosystem as well, as karezes provide water for
native vegetation and play an important role for
the survival of wildlife by providing water to these
habitats through underground tunnels, shafts, and
pools.
REFERENCE
Middle East Institute (Chunliang Cui, Shalamu
Abudu, Zhuping Sheng, Donghai Guan)
Journal of Arid Land
China Highlights
UNESCO
79