Japan Geoscience Union Meeting 2024

Presentation information

[E] Oral

H (Human Geosciences ) » H-QR Quaternary research

[H-QR04] Deep time perspective on the geological response to climate change

Tue. May 28, 2024 9:00 AM - 10:15 AM 303 (International Conference Hall, Makuhari Messe)

convener:Liang-Chi Wang(National Chung Cheng University, Taiwan), Neng-Ti Yu(National Tsing Hua University), Kaoru Kashima(Estuary Research Center, Shimane University, Department of Earth and Environmental Sciences, National Chung Cheng University Taiwan), Yusuke Okazaki(Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University), Chairperson:Liang-Chi Wang(National Chung Cheng University, Taiwan), Yusuke Okazaki(Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University)

9:00 AM - 9:15 AM

[HQR04-01] Sediment dynamics and coastal environments in the Holocene of southwestern Taiwan

★Invited Papers

*Jiun-Yee Yen1, Lihung Lin2, Neng-Ti Yu5, Shyh-Jeng Chyi3, Liang-Chi Wang4, Jia-Hung Ren3, Jia-Hung Chen3 (1.National Dong Hwa University, 2.National Taiwan University, 3.National Kaohsiung Normal University, 4.National Chung Cheng University, 5.National Tsing Hua University)

Keywords:Taiwan, coastal environment, sediment dynamics, Holocene

In 2009, Typhoon Morakot brought unprecedented rainfall to southern Taiwan, triggering a massive landslide in the mountainous terrain. Extensive research has been carried out on the landslide processes, in particular the catastrophic event at Hsiaolin village.

The staggering volume of sediment generated by Typhoon Morakot raises several questions: 1. Is this typhoon an outlier in terms of rainfall and sediment production? 2. Beyond the immediate sediment transport during the event, does sediment cascade from upstream to the coast? 3. Are these two questions related?

The coastal plain, which is vulnerable to sea level rise and land subsidence, has significant societal implications due to its high population density. While previous studies indicate a gradual seaward shift of our coastline over the past millennium, evidence linking sediment-generating events to coastal change remains scarce, partly due to limitations in the existing literature.

Our research efforts focus on upstream sediment dynamics, coastal environmental changes and their intricate interrelationships. By studying extreme events in the upper reaches of the Lao-Non River and establishing an age-controlled borehole near the mouth of the Kaoping River, we reveal a sedimentary evolution - from a pre-Holocene braided river to an estuarine environment and finally to a barrier island and lagoon around 7.5 thousand years ago.