The nation’s shoreline has been eroding over the past three decades, sometimes at a rate of more than 15m per year, academics said.
Numerous fishing wharfs dotting the coastline are the primary cause of shoreline erosion as they have caused a “jetty effect,” said Ling Tsung-yi (林宗儀), an assistant professor of geography at National Taiwan Normal University who was commissioned by the Central Geological Survey to conduct research on changes to the nation’s coastline.
The “jetty effect” refers to hard coastal structures — such as jetties and breakwaters — placed on sedimentary coastlines, which causes erosion of the down-drift shoreline.
The research team conducted the study by overlaying a photo of Taiwan’s shorelines taken in 1978 with a satellite photo taken in 2009, for the first time showing how much the shoreline has receded in 31 years.
A common feature wherever shorelines have receded is that the northern edge of the receded area has dikes perpendicular to the shoreline, which has caused sand to deposit north of the dikes and form beaches, but resulted in erosion to the south, Lin said.
Eroding shorelines have been observed at beaches near the Tatan Power Plant (大潭電廠) in Taoyuan County, the Hsinchu fishing wharf, the Jincheng (金城) and Siangshan (香山) coastlines and Lungfung Port (龍鳳港) in Hsinchu County.
The erosion rate south of the Tatan plant was as high as 6.2m per year.
At the Jincheng to Siangshan areas, the report found that heavy sand extraction from riverbeds in recent years had disrupted the sand balance. The extension of breakwaters at Hsinchu Harbor has cut off sand deposit to the southern shores of the two areas, causing erosion rates at the Jincheng area of up to 15.4m per year, with a total of 500m during the past three decades.
Lin said that stretching the timeline of the study over 30 years clearly showed progressive erosion of the western coastline.
While the eastern shorelines does not exhibit such evident erosion, breakwater reefs erected along the east coast to protect road foundations along Highway No. 11 point to the present danger of shoreline erosion, Lin said.
Statistics from the Council of Agriculture show there are 225 fishing wharfs across the country, with 139 in Taiwan proper.
Compared with the total length of the nation’s coastline, which spans 1,349km, there was roughly one fishing wharf per 9.7km, statistics showed.
Writer and nature enthusiast Liu ko-hsiang (劉克襄) said the density of fishing wharfs and breakwaters in Taiwan is probably a world record.
Green Formosa Front (GFF) said there were multiple factors causing coastline erosion, including changing weather patterns, rising sea levels, blockage and extraction of sand deposits, overpumping of groundwater causing land subsidence and the felling of windbreaks, which has caused sand to be blown inland.
The illegal extraction of riverbed sand and construction of tourism facilities and restaurants on former windbreaks pointed to a failure of land planning policies, GFF acting director Lin Chang-mao (林長茂) said.
The Tatan coastal area once had a thriving and self-sufficient ecosystem and was a breeding ground for sharks and rays, Lin Chang-mao said, adding that after the “jetty effect” began following construction of the power plant, sand deposits covered and killed off vast patches of algae that were a source of food for aquatic species.
It is now rare to see sharks and rays in the area, Lin Chang-mao said.
Chien Lien-kwei (簡連貴), dean of the department of harbor and river engineering at National Taiwan Ocean University, said one of the major reasons contributing to receding coastlines was the increase in extreme weather patterns.
Using the Fulong coastal region in New Taipei City (新北市) as an example, Chien said Fulong beach’s shoreline was receding because of an overabundance of extreme weather patterns and a decrease in sand deposited by Shuangsi River (雙溪河), as well as a “jetty effect” caused by nearby breakwaters and the pier of the Fourth Nuclear Power Plant.
Chien said abnormal weather patterns had increased typhoon erosion rates on beaches and the construction of reservoirs has stopped rivers from depositing sand in river deltas, causing shores to erode.
The government should actively monitor water depths and ocean weather patterns, Chien said, adding that officials should also implement “beach growing” policies to keep beaches from disappearing.
ADDITIONAL REPORTING BY WU LIANG-YI AND TANG JIA-LING TRANSLATED BY JAKE CHUNG, STAFF Writer
‘DENIAL DEFENSE’: The US would increase its military presence with uncrewed ships, and submarines, while boosting defense in the Indo-Pacific, a Pete Hegseth memo said The US is reorienting its military strategy to focus primarily on deterring a potential Chinese invasion of Taiwan, a memo signed by US Secretary of Defense Pete Hegseth showed. The memo also called on Taiwan to increase its defense spending. The document, known as the “Interim National Defense Strategic Guidance,” was distributed this month and detailed the national defense plans of US President Donald Trump’s administration, an article in the Washington Post said on Saturday. It outlines how the US can prepare for a potential war with China and defend itself from threats in the “near abroad,” including Greenland and the Panama
The Chinese Nationalist Party (KMT) is maintaining close ties with Beijing, the Democratic Progressive Party (DPP) said yesterday, hours after a new round of Chinese military drills in the Taiwan Strait began. Political parties in a democracy have a responsibility to be loyal to the nation and defend its sovereignty, DPP spokesman Justin Wu (吳崢) told a news conference in Taipei. His comments came hours after Beijing announced via Chinese state media that the Chinese People’s Liberation Army’s Eastern Theater Command was holding large-scale drills simulating a multi-pronged attack on Taiwan. Contrary to the KMT’s claims that it is staunchly anti-communist, KMT Deputy
RESPONSE: The government would investigate incidents of Taiwanese entertainers in China promoting CCP propaganda online in contravention of the law, the source said Taiwanese entertainers living in China who are found to have contravened cross-strait regulations or collaborated with the Chinese Communist Party (CCP) could be subject to fines, a source said on Sunday. Several Taiwanese entertainers have posted on the social media platform Sina Weibo saying that Taiwan “must be returned” to China, and sharing news articles from Chinese state media. In response, the Mainland Affairs Council (MAC) has asked the Ministry of Culture to investigate whether the entertainers had contravened any laws, and asked for them to be questioned upon their return to Taiwan, an official familiar with the matter said. To curb repeated
Myanmar has turned down an offer of assistance from Taiwanese search-and-rescue teams after a magnitude 7.7 earthquake struck the nation on Friday last week, saying other international aid is sufficient, the National Fire Agency said yesterday. More than 1,700 have been killed and 3,400 injured in the quake that struck near the central Myanmar city of Mandalay early on Friday afternoon, followed minutes later by a magnitude 6.7 aftershock. Worldwide, 13 international search-and-rescue teams have been deployed, with another 13 teams mobilizing, the agency said. Taiwan’s search-and-rescue teams were on standby, but have since been told to stand down, as
RSS