By June Tsai
Typhoon Morakot ravaged Taiwan over a week ago, and devastated the southern region of the island with torrential rainfall, causing floods and landslides that destroyed homes, roads and bridges. Many people quickly recalled the flood of exactly 50 years ago: Aug. 7, 1959, a tropical storm dealt a grave blow to Taiwan and cost it around 11 percent of the national income at the time. People are asking: have we really learned nothing from all past calamities?
The island has always been vulnerable to natural disasters, but decades of man-made errors contributed to the destruction brought on by Typhoon Morakot, said Ting Cheh-shyh, a professor in the Department of Civil Engineering at National Pingtung University of Science and Technology and director-general of the Blue Donggang River Conservation Association, a civil organization based in Pingtung County.
Mean annual rainfall in Taiwan over the past 70 years is 2,286 millimeters, but the typhoon brought around 2,000 millimeters of rainfall to many places on the island just between Aug. 7 and Aug. 8. The pounding rains caused landslides, some of which created barrier dams that then collapsed and buried towns and villages in mud. According to the latest estimates, the typhoon claimed up to 650 lives and brought about a total loss of US$3.4 billion.
“Granted, the rainfall was too overwhelming for citizens and all levels of government to prepare for and respond to properly,” Ting said Aug. 13. “Yet the core problem is that we have never really understood what Taiwan’s geological characteristics mean, or how to live with our high mountains and swift rivers.”
Most rivers on the island flow down steep slopes, creating fast currents and limited capacity for water drainage, Ting explained. In addition, frequent tectonic underplating and tropical weather make the earth and soil easily weathered and susceptible to the elements.
Instead of trying to cope with these geological, topographical and terrain features, what the island people have been doing over the past decades is “reclaiming land from the water,” the professor said.
Take for example the plains of Taiwan’s southernmost Pingtung County, a major agricultural region, which suffered heavily from Typhoon Morakot. The Pingtung Plains are flood plains created by four major rivers. Ting said the plains have supplied residents with sufficient underground water and helped absorb torrential waters during stormy seasons. In conjunction with Taiwan Sugar Corporation’s development of 1,000 hectares of land for sugarcane cultivation starting almost 40 years ago, several rivers have been banked.
“Building embankments made water flow swifter and stronger,” Ting explained. Water catchment areas in the mountains were also exploited; and in the coastal area, the pumping of underground water for aquaculture led to serious land subsidence. In recent years, the county’s Linbian River basin has never managed to avoid floods following heavy rainstorms.
Experts argue that decades of improper water management policies are responsible for the large-scale damage, which many believe to be as deadly as that from the major earthquake of Sept. 21, 1999.
In Taiwan, the job of river management falls entirely on the Ministry of Economic Affairs’ Water Resources Agency, which is in charge of nine river management offices throughout the country. “The agency is mainly staffed with engineers, and their minds turn to blocking rivers when it comes to flood control,” said Hsu Chan-chuan, a spokesperson for Taiwan’s Water Watch Alliance.
The alliance, comprising dozens of nongovernmental green groups, was established in 2007 to oversee the implementation of the “Special Act for Flood Management.” The Executive Yuan proposed a “Regulation Project of Flood-Prone Areas” in 2005, planning to spend NT$80 billion to control rivers. When the special act was passed in 2006, the Legislative Yuan raised the funding to NT$141 billion, which would be spent between 2006 and 2013.
According to Hsu, “90 percent of the regulation project is devoted to building and strengthening dikes or similar projects, and the remaining 10 percent is earmarked for creating water detention facilities.” Recent cases show, however, that “building dikes, setting up pumps and so on just doesn’t work anymore,” she said. “If the direction is wrong, no matter how skillful the driver or how excellent the car, we will never get to the destination,” she said.
“Policymakers must face the reality that containing water is not going to meet the challenge of climate change,” Hsu said. In recent years a single tropical storm often brings over 1,000 millimeters of rainfall, belying flood-frequency estimates on which various hydraulic engineering works have been based, she said. During Typhoon Kalmaegi in 2008, for example, floods in more than 14 places already exceeded the predicted 200-year flood frequency. This did not lead to soul-searching regarding the flood control plan. This time, an internal WRA report revealed the flood frequency gauged at several places in the Zengwen, Bajhang and Gaoping river basins exceeded the forecast for 2,000 years. Reports abound on the collapse of dikes and debris barriers built not only on major rivers but also on unnamed streams, exacerbating the mudslides that occur following heavy rainfall.
“Increasingly extreme weather demands new thinking and water management methods,” Ting stressed. “What is happening is making the reckoning of flood frequency a myth,” Ting said. “It is time to stop exploiting land and rivers, and for people to learn again to live with water rather than try to conquer it.”
The best policy for flood control is “returning land to rivers,” or replenishing old alluvial plains, Ting said, citing ancient flood-control genius Jia Rang’s “three strategies for harnessing the Yellow River.” The second best policy is to divert floods by building channels, but the worst is to construct dams, reservoirs and levees to hold extra water.
“Over the past decades, the government has been pursuing exactly the worst policy,” the Dutch-educated professor lamented. With public urging, a sophisticated project that combines the first and second strategies was started to manage the Donggang River, said Ting, who was been heavily involved. The project, the first of its kind in Taiwan, aims to replenish underground water while diverting floodwater, he said, but it is yet to be completed due to intermittent government funding.
Ting suggested integrated water management methods must eventually be implemented. They involve water and soil conservation, as well as hydraulic engineering and water resources management. At present, these fall under different government agencies, with the Ministry of Agriculture responsible for the use and conservation of upstream lands, and the MOEA handling the management of water resources in the middle and downstream areas. “This division is highly problematic,” Ting said, stressing that for successful flood control, land and mountain and water management should be considered together as a whole.
A proper national land recovery plan with non-populist policymaking and implementation is essential for reducing damage brought by about natural disasters, experts urged.
Gloria Hsu, a professor of atmospheric sciences at National Taiwan University, pointed out in particular that the lack of national land use planning has led both the government and ordinary people to seek short-term industrial gains while ignoring the long-term costs to the land and the safety of the populace.
For example, “irrigation water is appropriated for environmentally unfriendly industrial developments, leaving the cost to the environment and public health for all people to bear,” Hsu stated in an article. A responsible government should not try to please influential people by allowing improper development plans to continue in sensitive land areas, she added.
A government must be honest and transparent with all information and explain clearly why certain locations cannot be built upon or used, and what the impact would be if they are,” said Liao Pen-chuan, an associate professor of urban planning at National Taipei University.
“The torrential rainfall dealt a decisive blow to an overdeveloped land,” he said.
This article is first published in Taiwan Today Aug. 21, 2009.
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