Holocene changes in flooding frequency in South Korea and their linkage to centennial-to-millennial-scale El Niño–Southern Oscillation activity

Abstract

To trace past changes in flooding frequency, we investigated fluvial sediments in the middle reach of the Nakdong River, South Korea. Sediments with larger grain size, lower total organic carbon percentage, and depleted δ13C values in the recovered sediment cores were interpreted as periods of more frequent flooding. Patterns of decreased long-term flooding frequency and vegetation changes during the early to late Holocene were similar to the decreasing regional summer monsoon intensity. Multicentennial frequent flooding periods in the study area (2900–3400 cal yr BP, 3600–3900 cal yr BP, 4600–5300 cal yr BP, and 5800–6400 cal yr BP) corresponded to stronger El Niño–Southern Oscillation (ENSO) activity periods. Based on previous studies showing that high-frequency tropical typhoon-driven coastal inundation along the western coast of Japan during the middle to late Holocene was coupled with stronger ENSO activity, it is likely that the observed centennial-to-millennial-scale flood frequency change in South Korea was influenced mainly by changes in the genesis and tracks of tropical typhoons at centennial-to-millennial time scales. This suggests that the centennial-to-millennial-scale hydrologic changes in East Asia were linked to the remote atmospheric-oceanic circulation changes represented by an ENSO-like pattern.

Magnetic Properties of a Holocene Sediment Core from the Yeongsan Estuary, Southwest Korea: Implications for Diagenetic Effects and Availability as Paleoenvironmental Proxies

“…yr BP (∼4,750-5,000, ∼5,900-6,000, and ∼7,900-8,000 cal. yr BP; green shaded regions in Supplementary Figure S2), and such ENSO peaks are being considered to be related to high frequency and magnitude of flooding or freshwater input from inland at least in the southern part of the Korean Peninsula (Lim et al, 2017, Lim et al, 2019. However, we did not find any of our magnetic property variability data that could be well correlated to those ENSO peaks (Supplementary Figure S2).…”

“…It is generally thought that sedimentation during Holocene at estuaries and coastal lines are sensitive to not only their catchment (terrestrial) environmental changes and extreme hydrologic events such as heavy rainfalls and storms, which are closely associated with regional and global climate changes, but also regional sea-level change (e.g., Lim et al, 2017, Lim et al, 2019. Hence, such estuarine-coastal sediments are of potential use for reconstructing records of paleoenvironmental changes during Holocene.…”

“…Along the west coast of South Korea, facing the eastern Yellow Sea, estuaries of large rivers such as the Han, Geum, and Yeongsan Rivers are widely distributed from north to south; these are tide-dominated depositional environments (Chough et al, 2004) forming a variety of deposits during the Late Pleistocene and Holocene (Park et al, 1998;Choi et al, 2003;Lim and Park, 2003;Nahm et al, 2008;Nahm and Hong, 2014;Moon et al, 2018). During the Holocene, these western coastal areas would have experienced dramatic environmental changes due to e.g., sea-level changes such as the Holocene transgression (Stanley and Warne, 1994;Kim and Kennett, 1998), the El Niño Southern Oscillation (ENSO) activity (e.g., Lim et al, 2017;Lu et al, 2018;Lim et al, 2019), the eastern Asian Monsoon (EAM; e.g., Chang, 2004;Dykoski et al, 2005;Selvaraj et al, 2007), and the Holocene climate optimum (HCO; e.g., An et al, 2000;Zhou et al, 2016;Park et al, 2019).…”

History of Mid- and Late Holocene Palaeofloods in the Yangtze Coastal Lowlands, East China: Evaluation of Non-Pollen Palynomorph Evidence, Review and Synthesis

“…While moderate annual seasonal Yangtze flooding has been a constant factor, introducing fine-grained minerogenic sediment into the floodplain sequence, major floods have occurred regularly throughout the Holocene, continuing into modern times [34,35], with periods during which very extreme flood events affected the Taihu lowlands as well as many other parts of the Yangtze valley [36,37]. Such extreme flooding events were not confined to the Yangtze, although the huge Yangtze catchment and river water discharge rates would exacerbate them, and have been recorded throughout eastern Asia, as in north China [38][39][40][41][42][43][44][45], Japan [46,47] and Korea [48][49][50]. As the timings of the major flooding phases in all these places correlate closely, it is clear that a regional external driver of extreme freshwater flooding has been involved, with some periods during the Holocene particularly affected.…”

Pollen record of early- to mid-Holocene vegetation and climate dynamics on the eastern coast of the Yellow Sea, South Korea

“…Some studies suggest that the main factors involved are solar output at the decadal to centennial scales and the Atlantic meridional overturning circulation at the millennial scale (Dykoski et al, 2005; Wang et al, 2005). Other research suggests that coastal areas may be influenced by changes in El Niño-Southern Oscillation (ENSO) at the centennial to orbital timescales (Jia et al, 2015; Lim et al, 2017; Lim and Fujiki, 2011; Park et al, 2016; Wu et al, 2012; Yang et al, 2014). Stebich et al (2015) suggested that the combined monsoon precipitation and insolation-driven changes in temperature determined the environmental dynamics in northeast (NE) China at the suborbital to orbital timescales.…”