Seasonal variation of SPM concentration in the Taiwan Strait using satellite data / 以衛星資料探討台灣海峽懸浮沉積物之季節特性

碩士 / 國立中山大學 / 海洋環境及工程學系研究所 / 104 / The Taiwan Strait is located in the part of the Western Pacific, and is an important trade route in history. The interaction between wind and wave is causing a series of changes in the Taiwan Strait. Also the climate change caused the record-breaking precipitation, landslide and seabed erosion or deposition.
Surface SPM concentration data from MODIS satellite together with wind, wave and current data from operational results have been used to assess the seasonal variations in SPM dynamics in Taiwan Strait. The Strait is characterized by strong tidal currents and a distinct seasonal pattern in wind climate. During summer monsoon winds are generally blowing from the south and warm water with low SPM concentration is entering the Strait from the South China Sea. Higher SPM concentrations are found along the coasts and in the shallow areas of the Strait. These higher turbidity areas are caused by local resuspension and by high river runoff. Indeed, mountain rivers from Taiwan may carry huge amount of sediments into the Strait during short periods of heavy rains associated with typhoons during the summer season. These sediments are, however, rapidly dispersed in the sea and result in a relatively small increase in the surface SPM concentration during a limited period of time. Surface SPM concentrations in winter are higher than in summer. During winter monsoon winds are generally blowing from the NE and the China coastal current flows towards the SW. The higher SPM concentrations in winter are caused by higher wave induced resuspensions, but also by the larger import of SPM from the Chinese coastal current into the Strait.
Especially, there are the extreme events in summer, such as typhoon. The heavy rainfall caused by typhoon induced the river discharge increasing. The terrigenous sediment following the river discharge flowed into the Taiwan Strait and gathered at Tanshui and Zhaoshui river estuary. The maximum of precipitation and river discharge happened in typhoon period and SPM concentration peak happened after typhoon period. Consequently, after typhoon one month, the sediment caused by typhoon would dispersal. It represented the extreme event will not effect the SPM averaged distribution.

Identiferoai:union.ndltd.org:TW/104NSYS5282007
Date January 2015
CreatorsTzu-yin Chou, 周姿吟
ContributorsJason C.S. Yu, 于嘉順
Source SetsNational Digital Library of Theses and Dissertations in Taiwan
Languagezh-TW
Detected LanguageEnglish
Type學位論文 ; thesis
Format87

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