A few days ago the Taiwan News reported global warming is causing Taiwan’s sea level to rise:
Sea levels around the world are gradually on the rise due to global warming, said the report. In his research several years ago, Fan discovered that Taiwan’s sea level was rising at an annual average of 0.32 cm, higher than China’s 0.26 cm and the global average of 0.1 to 0.2 cm.
The tidal land in central and southern Taiwan suffers from constant flooding, said Fan. If the sea level keeps rising at such a fast speed, it is feared the land will be swallowed up by the end of the century, Fan cautioned.
Today’s Taipei Times has a good feature article which looks at the issue of coastal erosion and the various factors involved. It quantifies some of the levels of beach erosion.
A survey of coastal areas conducted by National Cheng Kung University’s (NCKU) Department of Hydraulic and Ocean Engineering showed that many of the country’s coastal areas have been suffering from severe beach erosion for decades.
Among the worst of these cases, the coast of Kezihliao (蚵子寮) in Kaohsiung County retreated 266m between 1958 and 1987, with a total of 53 hectares of land disappearing. The shore just south of the central port of Taichung retreated 212m between 1983 and 1996, with land totaling 189 hectares disappearing.
The coast along Tainan County’s Chiku Township (七股), meanwhile, retreated 429m between 1961 and 2000.
In eastern areas, retreats of 100m were seen along the coast of Ilan County’s Toucheng Township (頭城) between 1999 and last year, 84m along Hualien County’s coast of Nanbin (南濱) and Beibin (北濱) between 1984 to 1992 and 78m south of Taitung County’s Dawu fishing port between 1978 and last year.
The article also details some of the causes of the problems.
While waves are the primary natural force leading to erosion, some geologists believe the situation has been exacerbated by rising sea levels — a result of global warming.
Another culprit is the sharp decline in sediment volume in estuaries, the result of excessive river sand extraction and the building of reservoirs and dams that have blocked the transport of sediment needed to replenish beaches.
The key point is that development plans in low-lying coastal areas need to take into account the effects of future sea level rises and coastal erosion. Increased frequency or intensity of storms will also have negative impacts. Last year a planning tribunal in Australia set a precedent by rejecting a proposal to build new homes on coastal farmland because of the future impacts of climate change.
Here in Taiwan there are still some people in government who don’t take the issue so seriously. KMT Legislator Wu Yu-sheng (吳育昇) while questioning the EPA Minister about plans for highway development in Danshui said mangroves were unimportant and they should make way for roads.
Mangroves and other coastal vegetation provide an important buffer against storms and rising sea levels. They are far more important than poorly thought out infrastructure projects that may be washed away by the rising seas in decades to come.