| 摘要: | 葉綠素 a (Chlorophyll-a) 是海水中生物量生產的主要指標之一，對人類生活可能有利亦可有害。首先，其為魚類和相關營養鏈的食物，但同時如果因葉綠素過多而導致之生物量增長過度以及優養化，則可能對海洋生物和漁業有害。 隨著地球同步衛星的出現，我們可以利用其提供之高時間解析度影像對地表進行更詳盡的動態分析，例如颱風等特定情景下沿海地區的養分和沈積物循環的運作過程。2016 年 9 月梅姬颱風 (Typhoon Megi) 作為本研究之研究對像，造成了宜蘭地區因強降雨和狂風而遭受相當大的災害損失。本研究旨在分析
該颱風事件對沿海水域之總懸浮固體 (Total Suspended Solids, TSS) 和葉綠素 a 之濃度相關性。
本研究收集地球同步海洋彩色成像儀 (Geostationary Ocean Color Imager )之葉綠素 a 和Rrs 555 (波長為 555 nm 之反射率)影像資料，其中 Rrs 555 為用以推估總懸浮固體濃度。
本研究針對梅姬颱風侵台 (2016 年 09 月 22 日至 30)之前、中、後(各為三日)分別分析兩者之相關性變化。由於颱風期間之雲霧影響，使得影像資料之應用受限，本研究應用以一三維影像(空間與時間)修復技術來重建影像資料，以利後續分析。結果顯示，整體來說颱風前Chl-a 與 TSS 之間有較高的相關性(R2=0.5)，Chl-a 可透過 TSS 與三次多項式進行推估，而颱風後兩者相關性較低(R2=0.27)，且此相關性不僅在時間上有所變化，在距海岸、河口距離不同時亦有不同的關係變化，需要綜合颱風動態、降雨特性、河川流量等問因素進行解釋。
本研究突顯了使用之地球同步衛星資料於分析颱風等災害的生態動力過程的優勢。儘管如此，本研究仍有部分限制，特別是在時序影像中，遺失數據的重建方面應可進行改進，特別是颱風期間雲層覆蓋率很極高的情形，而針對此問題的改進或解決，或許可成為未來
針對颱風動態等相關多時序分析的研究方向。
;Chlorophyll-a (Chl-a) is one of the main indicators of biomass production in ocean waters, which can be beneficial or detrimental for human activities, as they serve as food for fish and trophic chains. On the other hand, if biomass growth is excessive it can induce eutrophication, etrimental
to sea life and fishery. With the advent of geostationary satellites, now it is possible to have better temporal and spatial resolutions and thus have more data to analyze local contexts such as how nutrient and sediment cycles work in coastal areas during specific scenarios such as typhoons. In
September 2016, Typhoon Megi caused severe damage in the area of Taiwan, especially on Yilan Bay due to heavy rainfall and strong winds. This study aims to explore the effect of this typhoon on the correlation behaviors in concentrations of Total Suspended Solids (TSS) and chlorophyll-a in coastal waters during Typhoon Megi.
In this study, data of Chlorophyll-a and Rrs 555 (used for TSS estimation) were obtained from the Geostationary Ocean Color Imager (GOCI) corresponding to the period from September 22th to 31st. Corresponding to three days respectively for the period before, during, and after Typhoon Megi. Due to the cloud coverage which impedes the application of the optical data, in this study, all images were preprocessed to produce reconstructed images using a data-driven 3D (spatial and temporal) technique to reconstruct contaminated images. Results show a higher R2
value of 0.5 was obtained using pre-event scenes, and Chl-a can be effectively estimated using a cubic regression model, while a lower R2 (=0.27) is derived using data after Typhoon Megi. In addition to the variation in time, the correlation patterns varying in different coastal zones were also observed, which can be subjective to typhoon dynamics, precipitation, flow discharge, and so on.
This study shows the advantages of using geostationary satellites for the analysis of ecological dynamics in the case of disasters such as typhoons due to their higher temporal and spatial |
