High-resolution records of anthropogenic activity and geohazards from the reservoir of Sun Moon Lake, Central Taiwan
Journal
Elementa
Journal Volume
9
Journal Issue
1
Date Issued
2021
Author(s)
Chen H.-F
Wei K.-Y
Huang J.-J.S
Lin C.-C
Su C.-C
Song G.-S
Li H.-C
Lee T.-Q
Song S.-R
Abstract
Sun Moon Lake is the first dam reservoir constructed in Taiwan with the capability of generating hydroelectricity satisfying the whole Taiwan need during the Japanese colonial period since 1934 CE. Now, the Sun Moon Lake is one of the biggest hydropower stations in Taiwan and has become an important touring area. During World War II (1944–1945 CE), the hydroelectric power plant at Sun Moon Lake was bombed by the U.S. air force, which caused severe damage to the dam structure. More recently, the dam structure was also damaged during the 1999 CE Chi-Chi earthquake whose epicenter is nearby in the Nantou County. A suite of cores were taken from both Sun Lake and Moon Lake, and two selected cores, Sun 2–1 and SM 16 4–3, from Sun Lake were detailed studied with multiple analyses, including X-ray imaging, magnetic susceptibility, visible spectrophotometry, X-ray fluorescence (XRF) scanning, and mineral analysis. We discovered that the increase of Ca content in the sediments not only clearly indicates when the dam was constructed at Sun Moon Lake but also records evidence of structure repairs after both the World War II bombing and the Chi-Chi earthquake. Additionally, the yellow turbidite, X-ray image, and low-Ca signals in Core Sun 2–1 strongly correlate to the typhoon events that caused severe floods in the watershed of Zhuoshui River. The turbidite layers caused by the 1963 Gloria Typhoon are also characterized by conspicuous high peak of Fe/Mn in both cores. This study shows that XRF scanning results are useful for recognition of human activity and for high precipitation event correlation. Moreover, the appearance of charcoal layers shows evidence of forest burning and slash-and-burn activities by humans during the past 4,000 years back to the Middle Neolithic Age. ? 2021 The Author(s).
Subjects
Dam
Disaster
Human activity
Sediment
Typhoon
XRF
charcoal
Chi-Chi earthquake 1999
civil war
earthquake epicenter
geological hazard
human activity
hydroelectric power plant
Neolithic
Sun Moon Lake
Taiwan
Zhuoshui River
Type
journal article