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“Groundwater has been overextracted in more than 300 regions of China, over a total area of 190,000 square km,” said Yu Qiyang, Vice Minister of the Ministry of Water Resources at a press conference on October 28. Approximately 2 percent of the country’s total area is affected.
The excessive withdrawal of groundwater causes a host of problems including lowering the groundwater table and land subsidence. “Aquifers may become compressed and their capacity to hold water may diminish; in China’s eastern plains, seawater may intrude contaminating both land and ground water,” said Shi Jiansheng, Director of the Institute of Hydrogeology and Environmental Geology under the Chinese Academy of Geological Sciences.
Damage associated with the overuse of groundwater is now seen in many parts of China, particularly in north China.
Vanished lake
Angulizhuo, a freshwater lake in Zhangbei County, Zhangjiakou City of Hebei Province, dried up in 2004. The parched and cracked lakebed is now exposed to the sun. Covering an area of 6,000 hectares at its height, the lake was one of the largest inland lakes in north China.
Ye Bin, a 49-year-old resident in Shibagu Village, which sits on the erstwhile lake’s bank, was nostalgic about fishing in its waters. Ye started fishing there when he was in his 20s. He said that at the time the residents of the 20 villages surrounding the lake made a living primarily on fishing.
“Several meters from the bank, the water was up to my chest. In the lake’s center, the water was about seven to eight meters deep,”Ye said.
Local residents still puzzle over how such a huge lake disappeared in just a few years. Experts at the local hydrological department believe that dry weather and the overexploitation of groundwater were the main culprits.
A dry spell starting from 1999 set in over the region and lasted four years. Traditionally, farmers in the region mainly planted drought resistant crops such as wheat, flax and potatoes. But from 1997, the region began to promote vegetable cultivation, which consumes more water. Groundwater was drawn to irrigate vegetables, especially during the drought.
Large-scale well boring started in 1998.“In 2000, the good profits from growing vegetables motivated farmers to sink more wells,” a staff member at the hydrological department of Zhangjiakou City told Hebeibased Yanzhao Evening News.
“The local government regarded well drilling as a means to alleviate poverty and improve the yield of unproductive land,” said an official at the agricultural development office of Zhangjiakou City.
An Lei, a team leader of a China-Australia joint water and agricultural management program in Hebei Province said they had been monitoring the water table in more than 100 wells in several counties in the area and found the water table dropped rapidly.
For instance, he said, the water in a well in Deyanqingmiao Village of Zhangbei County was less than five meters from the ground in June 2003, but in October 2006, it dropped to 12 meters below the surface.
“With the water table falling by several meters, water in the lake permeated into the ground to replenish lost groundwater, causing the lake to vanish,” said An.
In 1999, water in the lake decreased perceptibly; two years later, the water could no longer keep a large sightseeing boat buoyant; and in August 2004, the lakebed was exposed.
In fact, not only Angulizhuo, but many smaller lakes and rivers in north China have disappeared for more or less the same reasons.
Sinking plain
Not all the consequences of groundwater overdraft are as obvious as vanished lakes. Land subsidence, except for sinkholes, may go unnoticed for years.
Land subsidence can occur when a large amount of groundwater has been withdrawn from an aquifer, and then the land above will sink into the empty aquifer.
Groundwater overexploitation has created many groundwater funnels in north China. In the North China Plain, groundwater funnels cover a total area of 73,288 square km, or 52.6 percent of the plain’s total area, said a research report published early this year by Zhang Zhaoji, deputy director of the Institute of Hydrogeology and Environmental Geology.
Nearly half of the North China Plain has sunk by more than 200 mm since 1959, and in the vicinity of Tianjin Municipality, land has sunk by 3.25 meters, according to China Geological Survey, an organization under the Ministry of Land and Resources.
Although land subsidence is usually not directly observable, it is nonetheless damaging.
A report released by the China Geological Survey in 2008 showed that the direct economic losses from land subsidence
in the North China Plain amounted to 40.4 billion yuan ($6.2 billion) as of the end of 2007, while the indirect economic loss to the area was 292.4 billion yuan ($43.4 billion).
The North China Plain, with megacities such as Beijing and Tianjin, has traditionally been China’s cultural, political and economic center. Currently, it is home to one fifth of China’s population and arable land.
In spring, the major crop growing season, the weather in this area tends to be dry. “Over the past two decades, precipitation in north China has decreased by 10-15 percent,” Shi said.
Natural rainfall on the plain is not sufficient to sustain the population increase and industrial and agricultural development. Too much groundwater has been extracted.
Wu Ai’min, an official with the China Geological Environmental Monitoring Institute, said that groundwater supplies between 75 percent and 80 percent of the water consumed in the North China Plain.
Groundwater used to be within the reach of a biandan, a 2 to 3-meter shoulder pole used for carrying water. Farmers once ladled water from wells with a bucket hooked to one end of the biandan. Now, they have to drill dozens or even hundreds of meters to reach groundwater.
Shen Yanjun, a researcher in the Key Laboratory of Agricultural Water Resources at the Chinese Academy of Sciences (CAS), found that the average annual precipitation on the North China Plain is about 500 mm, whereas agriculture in the area consumed the equivalent of 870 mm of precipitation each year, and the shortfall, which amounts to 370 mm of precipitation, is made up by groundwater.
Wu said that it would take the natural water cycle more than 10,000 years to replenish the 100 billion cubic meters of groundwater that has been overexploited, to date, in the North China Plain.
“Moreover, the over 1,600 reservoirs built in the upper reaches of rivers flowing across the North China Plain will increase water evaporation and reduce natural underground water replenishment in the lower reaches of these waterways,” Shi said.
Water-saving agriculture
In terms of replenishing the overused groundwater, Jia Shaofeng, a researcher with the Institute of Geographic Science and Natural Resources Research of the CAS, pinned a lot of hope on China’s ambitious South-to-North Water Transfer Project.
He told the Guangdong-based Time Weekly magazine that in recent years, water consumption in north China has declined
and the water transferred from the south will make it unnecessary to overexploit groundwater in the north, so aquifers will gradually be replenished.
But, Fei Yuhong, a researcher with the Institute of Hydrogeology and Environmental Geology, was skeptical of Jia’s point.
Fei believes that although the water transfer project may supply drinking water to cities, it will not meet agricultural demand for water, and hence will not significantly rectify the damage from overexploitation.
“Because the North China Plain is so big, transferred water will only be available to farmers close to the transfer routes; even so, the water price will be too high for farmers,”Fei said.
Fei believes that a better way to tackle land subsidence is to plant drought resistant crops and use more efficient irrigation methods such as dripping and sprinkling.
Efficient irrigation methods such as dripping and sprinkling were promoted in Zhangbei County after the Angulizhuo Lake dried up in 2004. The county used national subsidies for water conservation projects to promote water-saving agriculture.
As of the end of 2010, efficient irrigation methods had been used in 63.7 percent of the total irrigated land in Zhangbei County, said the county government. The new irrigation methods consume 30-50 percent less water than traditional methods.
To limit groundwater extraction, the county government now requires those who dig wells to have a permit. In addition, the county has also converted 61,000 hectares of arable land to forest. Similar efforts have been reported in Zhangbei’s neighboring counties, such as Shangyi, Kangbao and Guyuan counties.
Zhangbei County is also piloting innovative water-saving reform in its Mantouying Township. Tiered water prices have been introduced and groundwater consumption is inferred from the electricity used to pump water. The reform is expected to be implemented countywide in 2013, reported hebei.com.cn, a local news portal.
In September 2010, after heavy rain, some water in fact returned to Angulizhuo Lake, for the first time in six years. Staff members at the local hydrological department found that water covered an area of 1,212 hectares, about one fifth of the lake’s previous area, and the maximum depth of water was about 50 to 100 cm.
Local hydrological experts believed that the improvement of the ecological environment in the county and its neighboring areas will eventually help the lake retain water and once again become a place of outstanding natural beauty.
The excessive withdrawal of groundwater causes a host of problems including lowering the groundwater table and land subsidence. “Aquifers may become compressed and their capacity to hold water may diminish; in China’s eastern plains, seawater may intrude contaminating both land and ground water,” said Shi Jiansheng, Director of the Institute of Hydrogeology and Environmental Geology under the Chinese Academy of Geological Sciences.
Damage associated with the overuse of groundwater is now seen in many parts of China, particularly in north China.
Vanished lake
Angulizhuo, a freshwater lake in Zhangbei County, Zhangjiakou City of Hebei Province, dried up in 2004. The parched and cracked lakebed is now exposed to the sun. Covering an area of 6,000 hectares at its height, the lake was one of the largest inland lakes in north China.
Ye Bin, a 49-year-old resident in Shibagu Village, which sits on the erstwhile lake’s bank, was nostalgic about fishing in its waters. Ye started fishing there when he was in his 20s. He said that at the time the residents of the 20 villages surrounding the lake made a living primarily on fishing.
“Several meters from the bank, the water was up to my chest. In the lake’s center, the water was about seven to eight meters deep,”Ye said.
Local residents still puzzle over how such a huge lake disappeared in just a few years. Experts at the local hydrological department believe that dry weather and the overexploitation of groundwater were the main culprits.
A dry spell starting from 1999 set in over the region and lasted four years. Traditionally, farmers in the region mainly planted drought resistant crops such as wheat, flax and potatoes. But from 1997, the region began to promote vegetable cultivation, which consumes more water. Groundwater was drawn to irrigate vegetables, especially during the drought.
Large-scale well boring started in 1998.“In 2000, the good profits from growing vegetables motivated farmers to sink more wells,” a staff member at the hydrological department of Zhangjiakou City told Hebeibased Yanzhao Evening News.
“The local government regarded well drilling as a means to alleviate poverty and improve the yield of unproductive land,” said an official at the agricultural development office of Zhangjiakou City.
An Lei, a team leader of a China-Australia joint water and agricultural management program in Hebei Province said they had been monitoring the water table in more than 100 wells in several counties in the area and found the water table dropped rapidly.
For instance, he said, the water in a well in Deyanqingmiao Village of Zhangbei County was less than five meters from the ground in June 2003, but in October 2006, it dropped to 12 meters below the surface.
“With the water table falling by several meters, water in the lake permeated into the ground to replenish lost groundwater, causing the lake to vanish,” said An.
In 1999, water in the lake decreased perceptibly; two years later, the water could no longer keep a large sightseeing boat buoyant; and in August 2004, the lakebed was exposed.
In fact, not only Angulizhuo, but many smaller lakes and rivers in north China have disappeared for more or less the same reasons.
Sinking plain
Not all the consequences of groundwater overdraft are as obvious as vanished lakes. Land subsidence, except for sinkholes, may go unnoticed for years.
Land subsidence can occur when a large amount of groundwater has been withdrawn from an aquifer, and then the land above will sink into the empty aquifer.
Groundwater overexploitation has created many groundwater funnels in north China. In the North China Plain, groundwater funnels cover a total area of 73,288 square km, or 52.6 percent of the plain’s total area, said a research report published early this year by Zhang Zhaoji, deputy director of the Institute of Hydrogeology and Environmental Geology.
Nearly half of the North China Plain has sunk by more than 200 mm since 1959, and in the vicinity of Tianjin Municipality, land has sunk by 3.25 meters, according to China Geological Survey, an organization under the Ministry of Land and Resources.
Although land subsidence is usually not directly observable, it is nonetheless damaging.
A report released by the China Geological Survey in 2008 showed that the direct economic losses from land subsidence
in the North China Plain amounted to 40.4 billion yuan ($6.2 billion) as of the end of 2007, while the indirect economic loss to the area was 292.4 billion yuan ($43.4 billion).
The North China Plain, with megacities such as Beijing and Tianjin, has traditionally been China’s cultural, political and economic center. Currently, it is home to one fifth of China’s population and arable land.
In spring, the major crop growing season, the weather in this area tends to be dry. “Over the past two decades, precipitation in north China has decreased by 10-15 percent,” Shi said.
Natural rainfall on the plain is not sufficient to sustain the population increase and industrial and agricultural development. Too much groundwater has been extracted.
Wu Ai’min, an official with the China Geological Environmental Monitoring Institute, said that groundwater supplies between 75 percent and 80 percent of the water consumed in the North China Plain.
Groundwater used to be within the reach of a biandan, a 2 to 3-meter shoulder pole used for carrying water. Farmers once ladled water from wells with a bucket hooked to one end of the biandan. Now, they have to drill dozens or even hundreds of meters to reach groundwater.
Shen Yanjun, a researcher in the Key Laboratory of Agricultural Water Resources at the Chinese Academy of Sciences (CAS), found that the average annual precipitation on the North China Plain is about 500 mm, whereas agriculture in the area consumed the equivalent of 870 mm of precipitation each year, and the shortfall, which amounts to 370 mm of precipitation, is made up by groundwater.
Wu said that it would take the natural water cycle more than 10,000 years to replenish the 100 billion cubic meters of groundwater that has been overexploited, to date, in the North China Plain.
“Moreover, the over 1,600 reservoirs built in the upper reaches of rivers flowing across the North China Plain will increase water evaporation and reduce natural underground water replenishment in the lower reaches of these waterways,” Shi said.
Water-saving agriculture
In terms of replenishing the overused groundwater, Jia Shaofeng, a researcher with the Institute of Geographic Science and Natural Resources Research of the CAS, pinned a lot of hope on China’s ambitious South-to-North Water Transfer Project.
He told the Guangdong-based Time Weekly magazine that in recent years, water consumption in north China has declined
and the water transferred from the south will make it unnecessary to overexploit groundwater in the north, so aquifers will gradually be replenished.
But, Fei Yuhong, a researcher with the Institute of Hydrogeology and Environmental Geology, was skeptical of Jia’s point.
Fei believes that although the water transfer project may supply drinking water to cities, it will not meet agricultural demand for water, and hence will not significantly rectify the damage from overexploitation.
“Because the North China Plain is so big, transferred water will only be available to farmers close to the transfer routes; even so, the water price will be too high for farmers,”Fei said.
Fei believes that a better way to tackle land subsidence is to plant drought resistant crops and use more efficient irrigation methods such as dripping and sprinkling.
Efficient irrigation methods such as dripping and sprinkling were promoted in Zhangbei County after the Angulizhuo Lake dried up in 2004. The county used national subsidies for water conservation projects to promote water-saving agriculture.
As of the end of 2010, efficient irrigation methods had been used in 63.7 percent of the total irrigated land in Zhangbei County, said the county government. The new irrigation methods consume 30-50 percent less water than traditional methods.
To limit groundwater extraction, the county government now requires those who dig wells to have a permit. In addition, the county has also converted 61,000 hectares of arable land to forest. Similar efforts have been reported in Zhangbei’s neighboring counties, such as Shangyi, Kangbao and Guyuan counties.
Zhangbei County is also piloting innovative water-saving reform in its Mantouying Township. Tiered water prices have been introduced and groundwater consumption is inferred from the electricity used to pump water. The reform is expected to be implemented countywide in 2013, reported hebei.com.cn, a local news portal.
In September 2010, after heavy rain, some water in fact returned to Angulizhuo Lake, for the first time in six years. Staff members at the local hydrological department found that water covered an area of 1,212 hectares, about one fifth of the lake’s previous area, and the maximum depth of water was about 50 to 100 cm.
Local hydrological experts believed that the improvement of the ecological environment in the county and its neighboring areas will eventually help the lake retain water and once again become a place of outstanding natural beauty.