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
The manufacture of the remaining 28 M1A2T Abrams tanks Taiwan purchased from the US has recently been completed, and they are expected to be delivered within the next one to two months, a source said yesterday. The Ministry of National Defense is arranging cargo ships to transport the tanks to Taiwan as soon as possible, said the source, who is familiar with the matter. The estimated arrival time ranges from late this month to early next month, the source said. The 28 Abrams tanks make up the third and final batch of a total of 108 tanks, valued at about NT$40.5 billion
Two Taiwanese prosecutors were questioned by Chinese security personnel at their hotel during a trip to China’s Henan Province this month, the Mainland Affairs Council (MAC) said yesterday. The officers had personal information on the prosecutors, including “when they were assigned to their posts, their work locations and job titles,” MAC Deputy Minister and spokesman Liang Wen-chieh (梁文傑) said. On top of asking about their agencies and positions, the officers also questioned the prosecutors about the Cross-Strait Joint Crime-Fighting and Judicial Mutual Assistance Agreement, a pact that serves as the framework for Taiwan-China cooperation on combating crime and providing judicial assistance, Liang
A group from the Taiwanese Designers in Australia association yesterday represented Taiwan at the Midsumma Pride March in Melbourne. The march, held in the St. Kilda suburb, is the city’s largest LGBTQIA+ parade and the flagship event of the annual Midsumma Festival. It attracted more than 45,000 spectators who supported the 400 groups and 10,000 marchers that participated this year, the association said. Taiwanese Designers said they organized a team to march for Taiwan this year, joining politicians, government agencies, professionals and community organizations in showing support for LGBTQIA+ people and diverse communities. As the first country in Asia to legalize same-sex
MOTIVES QUESTIONED The PLA considers Xi’s policies toward Taiwan to be driven by personal considerations rather than military assessment, the Epoch Times reports Chinese President Xi Jinping’s (習近平) latest purge of the Chinese People’s Liberation Army (PLA) leadership might have been prompted by the military’s opposition to plans of invading Taiwan, the Epoch Times said. The Chinese military opposes waging war against Taiwan by a large consensus, putting it at odds with Xi’s vision, the Falun Gong-affiliated daily said in a report on Thursday, citing anonymous sources with insight into the PLA’s inner workings. The opposition is not the opinion of a few generals, but a widely shared view among the PLA cadre, the Epoch Times cited them as saying. “Chinese forces know full well that
RSS