The turbidity of the water in the Shihmen Reservoir (
The recent water supply problem in Taoyuan County came in the wake of Typhoon Matsa on Aug. 5, and it was a recurrence of the problems caused by Typhoon Mindulle last July.
Also, flash floods bringing turbid water into the Touchien River (
By the same token, certain cities and counties in the south, such as Kaohsiung and Pingtung, are facing similar problems. But the public has a short memory for such problems.
After a prolonged drought last month and this one, southern Taiwan was looking forward to rain showers to relieve the drought.
Unfortunately, what came after were the devastations of the June 12 flooding and Typhoon Haitang on July 18.
The turbidity of water in the Kaoping River (
The turbidity of the off-stream Nanhua Reservoir (
Despite the Taiwan Water Corp's (TWC) all-out efforts to restore the water supply at an early date, hundreds of residents in Kaohsiung City's Tsuiping Borough recently had their water cut off for as long as seven days.
TWC officials have already announced that water shortages will be a recurring problem in Taoyuan because of a high water turbidity level resulting from typhoons and torrential rains.
The Pingting Water Treatment Plant (
It was found that the silt content was between 45,360 tonnes to 90,718 tonnes a day, accounting for one-fifth of the total volume.
How could such turbid water be used? Would building more sedimentation tanks be of any help?
About 80 years ago during the Japanese period, a Japanese engineer used hydraulic engineering techniques to construct the Erfeng Ditch (
The thinking behind the construction of the ditch in the region originated from the recurring flooding and drought problems in areas near the Taiwan Sugar Corp's Wanlung Farm (
The Erfeng Ditch, an underground water intake structure, was built at the headwater of the Linpien River, which is currently located 100m upstream of the Laiyi Bridge (
The construction of the Erfeng Ditch was completed within two years, and its water intake structures include four different parts: trapezoid water diversion weirs, semi-circle underground watersheds, arched channels, and water-gathering towers.
The complex constructions cannot be seen above ground since they are under the riverbed.
During the first decade after the completion of the Erfeng Ditch, the water supply was as much as 228,610 tonnes during the rainy season.
Although the ditch was partially damaged, its water supply can still reach 74,390 tonnes per day, an amount higher than the Ahgungtien Reservoir (
Basically, the Erfeng Ditch is an underground water diversion weir under the riverbed.
Since surface water goes through permeable sand and gravel as a natural filtration process, even during periods of heavy rainfalls or typhoons causing high water turbidity, the Erfeng Ditch can still have supply clear water.
Faced with the long-term failure to reduce the turbidity of the water supply during periods of heavy rainfall, the government should reflect on the reason why even after a large expenditure of money on large-scale hydraulic engineering projects, such as constructions of dams and water diversion weirs, the water shortages remain a recurring problem.
There are two other possibilities to help gather clean water: building the Kaotai Reservoir (
But would these two projects simply be high-investment projects that yield low returns?
My purpose in this article is not to praise the successful hydraulic techniques used in constructing the Erfeng Ditch.
Instead, I want to use the Erfeng Ditch as a reminder that if the water turbidity problems after heavy rain continue, the government's stubborn belief in the construction of weirs and dams should be discarded.
Instead, the government should find a way for effective water resource management that can truly benefit the nation.
Also, it would probably be a way to stop future water stoppages during the rainy season.
Lee Ken-cheng is the chief of the Kaohsiung Teachers Association's Ecological Education Center.
TRANSLATED BY LIN YA-TI
As India’s six-week-long general election grinds past the halfway mark, Indian Prime Minister Narendra Modi’s messaging has shifted from confident to shrill. After the first couple of phases of polling showed a 3 percentage point drop in turnout, Modi and his party leaders have largely stopped promoting their accomplishments of the past 10 years — or, for that matter, the “Modi guarantees” offered in the Bharatiya Janata Party’s (BJP) manifesto for the next five. Instead, making the majority Hindu population fear and loathe Muslims seems to be the BJP’s preferred talking point. Modi went on the offensive in an April 21
As Ukraine leads the global fight for democracy, Taiwan, facing a potential war with China, should draw lessons from Ukraine’s cyberwarfare success. Taiwan has been enhancing its arsenal with advanced weapons from the West in anticipation of a possible full-scale invasion. However, Taipei should also consider Ukraine’s effective digital warfare, notably the “IT [information technology] Army,” a decentralized force instrumental in Kyiv’s cybercampaigns. In February 2022, Russia’s invasion of Ukraine marked the onset of a significant cyberwar, where fears of a “digital Pearl Harbor” in Ukraine were unmet, thanks to robust cyberdefenses backed by Western public and private support. This led
Chinese President Xi Jinping (習近平) is attempting to create an alternative international world order to the US-dominated model. China has benefited hugely from the current order since former Chinese leader Deng Xiaoping (鄧小平) opened up its economy five decades ago. Countries can be categorized as continental or maritime, and to a great degree this determines their optimum foreign policy. China is continental, as is Russia. The US initially followed a continental foreign policy, before it settled on a maritime model. The British empire was so successful because a tiny island kingdom built a formidable naval presence. The US-dominated world order, stabilized by
With the addition this year of Sweden and last year Finland to NATO, the Baltic Sea has been dubbed a “NATO lake” by some analysts. A glance at a map shows that is largely (but not completely) true — the coastline has a couple of slivers of Russian territory. The rest of the coastal littoral is in NATO hands: Sweden, Finland, Estonia, Latvia, Lithuania, Poland, Germany and Denmark. Russia controls a bit of coast between Lithuania and Poland because of its strange enclave of Kaliningrad. Russian President Vladimir Putin remains in control of the far eastern corner of the Baltic Sea