11:30 〜 11:45
[HQR04-09] Landscape evolution of the coastal dunes in the southwestern Taiwan
キーワード：Coastal dunes, Aeolian activity, Ground-penetrating radar, Tainan Plain
Coastal dune is an important part of the coastal system. When confronting the impacts of climate change, understanding the dynamic environment and long-term evolution of the coasts can lead to sustainable use of the coastal areas.
Previous studies of coastal dune in the East Asia have shown that the Holocene coastal dunes of Fujian mainly developed in the regression period since 3 ka, and the main accumulation period was 0.8 ka. Moreover, the coastal dunes in the southwestern of Korea and Japan were mainly formed between 8 ka and 5 ka. In particular, according to the dating results of the Tottori sand dunes in Japan, it was found that there was an aeolian interruption in the late Holocene, and the accumulation began again after the 15th century, and the dunes began to move landward after the 17th century.
Furthermore, there are also many coastal dunes in Taiwan, but the research on the evolution of sand dunes mostly focuses on the eastern Taiwan. For example, the Fulong dunes in the northeastern Taiwan were formed between 3 ka and 0.7 ka, while the Feng-Chuei-Sha and Gangkou dunes in the southeastern Taiwan began to form 4 ka and 2.5 ka, respectively. However, these sites are all adjacent to hilly areas with limited coastal hinterland, so it is difficult to observe the migration of coastal dunes during the Holocene regression period. However, the Tainan alluvial plain in the southwestern part of Taiwan is flat and vast. In addition to many developing coastal dunes, previous studies also observed many remnants of old sand dunes in the inland area, but the evolution process of these old sand dunes is still unknown.
This study will use UAVs and ground penetrating radar to build the landscape and subsurface structure of old sand dunes, and use sediment characteristics and OSL dating to explore the cause and age to discuss the evolution of sand dunes in the Tainan Plain, attempts to reconstruct the evolution of paleo-coastline along the southwestern coast of Taiwan during the late Holocene, and even further to compare with other coastal dunes in East Asia.
Previous studies of coastal dune in the East Asia have shown that the Holocene coastal dunes of Fujian mainly developed in the regression period since 3 ka, and the main accumulation period was 0.8 ka. Moreover, the coastal dunes in the southwestern of Korea and Japan were mainly formed between 8 ka and 5 ka. In particular, according to the dating results of the Tottori sand dunes in Japan, it was found that there was an aeolian interruption in the late Holocene, and the accumulation began again after the 15th century, and the dunes began to move landward after the 17th century.
Furthermore, there are also many coastal dunes in Taiwan, but the research on the evolution of sand dunes mostly focuses on the eastern Taiwan. For example, the Fulong dunes in the northeastern Taiwan were formed between 3 ka and 0.7 ka, while the Feng-Chuei-Sha and Gangkou dunes in the southeastern Taiwan began to form 4 ka and 2.5 ka, respectively. However, these sites are all adjacent to hilly areas with limited coastal hinterland, so it is difficult to observe the migration of coastal dunes during the Holocene regression period. However, the Tainan alluvial plain in the southwestern part of Taiwan is flat and vast. In addition to many developing coastal dunes, previous studies also observed many remnants of old sand dunes in the inland area, but the evolution process of these old sand dunes is still unknown.
This study will use UAVs and ground penetrating radar to build the landscape and subsurface structure of old sand dunes, and use sediment characteristics and OSL dating to explore the cause and age to discuss the evolution of sand dunes in the Tainan Plain, attempts to reconstruct the evolution of paleo-coastline along the southwestern coast of Taiwan during the late Holocene, and even further to compare with other coastal dunes in East Asia.