Coastal Structures as Beach Erosion Control and Sea Level Rise Adaptation in Malaysia: A Review

Abstract

The shoreline of Malaysia is exposed to threats of coastal erosion and a rise of sea level. The National Coastal Erosion Study, 2015 reported that 15% of an 8840 km shoreline is currently eroding, where one-third of those falls under the critical and significant categories that require structural protection. The Study of Sea Level Rise in Malaysia, 2017 presented a sea-level increase of 0.67–0.74 mm on average yearly. This study reviewed selected coastal protection structures along the shoreline of Malaysia as an erosion control and sea-level rise adaptation based on coastal management strategies. Hard structures such as rock revetment and breakwater are commonly used as erosion protection systems in the “hold the line” strategy. Increased platform level of seawalls and earth bunds, considered as an “adaptation” approach, are effective in erosion protection and are adaptive to sea-level rise. Mangrove replanting is suitable as a “limited intervention” approach in minimizing the long-term impact of both threats. However, offshore breakwater, groyne, and geotextile tubes are solely for protection purposes and are not as effective for sea-level rise adaptation. As the sea level is continuously increasing, their function as coastal protection will also become less effective. In summary, this comprehensive review on coastal protection in Malaysia will benefit the related agencies on the future assessment.

Coupling Relationship of Human Activity and Geographical Environment in Stage-Specific Development of Urban Coastal Zone: A Case Study of Quanzhou Bay, China (1954–2020)

“…Notably, natural factors are still an important factor affecting the topography of urban coastal zones. Excessive erosion of the coastline will lead to the failure of flood protection facilities in coastal cities and will thus, increase the risk of flood disasters in the city (Mohamed Rashidi et al, 2021).…”

Analysis of Long-Term Shoreline Observations in the Vicinity of Coastal Structures: A Case Study of South Bali Beaches

“…If the oblique angle of waves towards the coastline is more than 45°, it will cause an unstable shoreline to form a sand spit [14]. Shoreline perpendicular coastal protection structures are found on the Java coast, Indonesia, Wonpyeong and Wolcheon beach, Korea, and Cahaya beach, Malaysia [11,24,25]. At Wonpyeong beach, South Korea, the presence of Gungchon's Port has impacted the coastal erosion, changing the wavefield in the study area and forming a new shoreline [11].…”

“…Detached breakwaters have been proven to be able to form new salient (Figure 1a) in the sheltered zone of the structure and to reduce erosion in the downcoast area compared to groins, but they have other problems, such as increased water circulation in the sheltered basin, and rip currents between detached breakwaters installed in the same place Shoreline perpendicular coastal protection structures are found on the Java coast, Indonesia, Wonpyeong and Wolcheon beach, Korea, and Cahaya beach, Malaysia [11,24,25]. At Wonpyeong beach, South Korea, the presence of Gungchon's Port has impacted the coastal erosion, changing the wavefield in the study area and forming a new shoreline [11].…”

“…Detached breakwaters have been proven to be able to form new salient (Figure 1a) in the sheltered zone of the structure and to reduce erosion in the downcoast area compared to groins, but they have other problems, such as increased water circulation in the sheltered basin, and rip currents between detached breakwaters installed in the same place [26]. In Kuala Terengganu coastline, Malaysia, the placement of breakwaters protects the shore from erosion but blocks longshore sediment transport such that it disrupts hydrodynamic processes in this area [25]. In Yeongrang Beach, South Korea, the presence of double headland on both sides of the coast encourages significant erosion in the center area [11].…”

Environmental impact of submerged and emerged breakwaters

“…Breakwaters, both submerged and emerged, represent a common approach to shoreline defense and provide substantial protection against severe storm conditions, reducing risks to coastal communities and local economic activities ( Mohamed Rashidi et al., 2021 ; Silva et al., 2017 ). In Thailand, it has been used to protect harbors and eroded coastlines ( Prukpitikul et al., 2019 ).…”