Coastal Erosion in Taiwan

Coastal erosion is a problem present in the majority of countries with coastline. Wind and water mechanically whether the coastlines, though rising oceans are also largely responsible for much of the erosion taking place. As ⅔ of the world is covered in ocean, it is important that the land that is available for use is protected, and that as much of the coastal environments can be maintained.
Taiwan, an island country in the Pacific, is a perfect example of a country that is facing coastal erosion as having the potential for becoming a major problem. Currently, the average vertical displacement velocity is estimated somewhere between 1-3 cm/year (Hsu). Though this is an average, there are a number of areas that have been the subject of much more substantial erosion and displacement, such as in Kaohsiung County, where more than 50 hectares of land being displaceds between 1958 and 1987 (Low 1-4).
One of the major contributing factors is human development along the shorelines as well as inland. As sand is mined out of the rivers and human constructs such as dams are built, the sediment levels drop. For example, Toucheng Beach in Ilan, once 2 Km in length, though as a result of jetties being built to protect a fishing area north of the beach, it has been rapidly disappearing over the past 10 years (Low 1-4).
Constant wave action and typhoons are also a concern in coastal erosion. Ideally, waves will transport sediment away from the beaches and shoreline, while rivers and sediments in runoff collect and stabilize the coast. However, the construction of dams and the removal of sand from rivers causes a severe decline in the replenishing of sediment by holding it from reaching the beach. This causes the waves to remove sediment that is not being replaced. Typhoons greatly accelerate this process with much more extreme conditions.
Steps are being taken, slowly, to help deter coastal erosion from occuring. For example, the Water Resources Agency passed a measure to ensure that a maximum of 40% of sand used for construction can be gathered from the local rivers and shorelines. Although this will not have an effect as easily seen as others, it will still slow the erosion rates in the coming years (Low 1-4). Additionally, research is being conducted on ‘soft’ barriers, barriers that are capable of allowing sediment to be moved up from the seafloor while catching sand being pulled away from the beaches (Peng and Jan).

“It takes time. But at least we can see that the situation is not worsening,” Hsu said. “The retreat of the coastline, while continuing over the last 10 years, is not as drastic as during the previous decade. (Low 1-4)”

Taiwan is generally a mountainous country, roughly ⅗ of the island is considered mountainous. As a result, the majority of the population is concentrated around the perimeter of the island, and a large portion of the population is dependent on the ocean directly or indirectly to support their livelihood (Hsu). As jetties and other structures are continuing to be built, its a fair assumption that the general population that will be directly affected by coastal erosion is largely unaware of the danger that exists in the structures.


Peng, Ta-Hsiung, and Chyan-Deng Jan. "FIELD EXPERIMENTAL STUDY ON A SOFT PROTECTING METHOD FOR COASTAL EROSION PREVENTION." SlideShare. East Asian Workshop on Marine Environments, 09 Nov 2009. Web. 31 Oct 2010. .

Low, Stephanie. "FEATURE: Battle of trenches in shoreline erosion war." Taipei Times March 22 2009: 1-4. Web. 31 Oct 2010. .

Hsu, Tai-Wen. "Human impact on coastal erosion in Taiwan.." Journal of Coastal Research (2007): n. pag. Web. 31 Oct 2010. .