Groundwater (Mis)Management in Northern China

In a recent study out of Northern China analyzing groundwater use, it has been found that over-exploitation and mis-management has led to serious problems in the quality and quantity of available groundwater.

Often an under-appreciated resource, groundwater exists in porous soil and underground geologic functions underneath the Earth’s surface. It is in constant balance with surface freshwater systems. Rain and snow seep into the ground to recharge the groundwater, which discharges to springs and rivers, becoming surface water (CTIC 2009). Because groundwater cycles are complex and not fully understood, they constitute difficult problems for government. Modern groundwater management must counter-act exploitative and pollutive actions from the past, as well as deal with increased demand in the form of industry, agriculture, and domestic use.

China in particular has had it’s share of change in the past few years; it’s sizable population has moved from the rural to the urban, it’s standard of living (and therefore water use) has increased, and industry continues to expand. The area of Zhengzhou, in Northern China, has been facing these challenges, and was the subject of a recent study published in Hydrogeology Journal.

The area of Zhengzhou, which consists of Zhengzhou city and surrounding rural land, is a perfect area to study typical groundwater management in China. Zhengzhou gets 70% of its water from groundwater, and over-exploitation and mismanagement of this resource is leading to three main problems: a decline in the water table, groundwater pollution, and formation of depression cones around urban areas.

Urban areas are using more groundwater than rural areas, and the high intensity of use is creating cones of depression underneath the city of Zhengzhou. These are generally circular areas of depleted aquifers, where groundwater has been overused and has run out. Deeper and deeper wells are being dug to compensate for the loss, but according to the study a better solution would be to restore the aquifers with treated wastewater and rainwater, or to alleviate urban groundwater use by using more surface water (from the nearby Yellow River).

The rural areas around Zhengzhou have quite different problems. Wastewater is generally dumped untreated into rivers, and so farmers cannot use surface water because of the bad quality. This makes them use more groundwater, which is unsustainable and discouraged because it lowers the water table. According to the study, agriculture should re-use treated wastewater, rainwater, and river water, as it does not need the same high quality as domestic use.

None of the problems faced by governments who manage groundwater use have easy solutions. Depression cones, lowered water tables, and groundwater contamination, are all wide-reaching and complex problems and require the same kind of solutions. Presently the institutes involved in China’s groundwater management are uncoordinated and the functions and responsibilities of each overlap, but water management has such wide influence that communication and coordination between government agencies and institutes are necessary. The importance of groundwater to society is truly being realized, and problems identified; the only thing left to do is find solutions.

References

Sun, Ronglin, Jin Menggui, Mark Giordano, and Karen Villholth. "Urban and Rural Groundwater Use in Zhengzhou, China: Challenges in Joint Management." Hydrogeology Journal. 17.6 (2009): 1495-1506.

Groundwater & Surface Water: Understanding the Interaction. (2009) Conservation Technology Research Center. Accessed Oct 13 2009 from http://www2.ctic.purdue.edu/KYW/Brochures/GroundSurface.html.