| 摘要: | 桃園海岸的藻礁若受泥沙覆蓋，會改變礁體的地形、棲地狀態和藻礁生物的生存狀況，因此，藻礁的海沙覆蓋比例為藻礁棲地監測的重要科學資料。本研究利用傳統地形測量及無人機建模方式，量化覆沙的面積與體積變化，並分析碎形特徵，以理解研究區的地形變遷以及碎形特徵差異。
本研究針對桃園海岸觀塘工業港的藻礁區域，蒐集2021年8月至2024年7月黃志誠老師研究團隊的無人機空拍建模資料，以及環評監測報告2001年至2024年的人工RTK單點測量資料及正射影像，以了解研究區較長期的覆沙狀況。通過對無人機空拍建模後的數值地表模型和人工單點RTK測量數據進行對比，評估不同測量技術的適用性和分析地形高程變化，以及使用正射影像分析覆沙面積變化。同時，利用碎形維度分析藻礁區域在不同尺度下的幾何特徵，探討礁體與沙體的區別性以及多重碎形的可能性。
結果顯示，G1區在2001年至2024年間，2018年後的平均覆沙面積變化較2018年前小，介於67% ~ 80%，在2021年至2024年間，G1區的覆沙面積與體積變化相關性較G2區高；而G2區覆沙體積在2001年至2024年間，2018年後的平均覆沙面積變化較2018年前小，介於39% ~ 48%，在2021年至2024年間近陸側的覆沙呈現增加的趨勢，但潮間帶中潮位以下變動不明顯，覆沙面積與體積變化相關性較G1區小。碎形分析的部分，礁體的碎形維度值平均高於沙體的碎形維度值，但僅能區分較大的礁體與沙體之間的邊界，沙體本身的表面高程可能和礁體過於類似而導致錯誤分類。
;The algal reefs along the Taoyuan coastline, when covered by sediment, can alter the reef′s topography, habitat conditions, and the survival status of the reef organisms. Therefore, the proportion of sediment coverage on algal reefs is an important scientific data for habitat monitoring. This study utilizes traditional topographic measurement and drone modeling methods to quantify the changes in the area and volume of sediment coverage, and analyzes the fractal characteristics to understand the topographical changes and the differences in fractal features within the study area.
This research focuses on the algal reef area at Guantang Industrial Port along the Taoyuan coast. It collects drone aerial modeling data from The research team of Professor Huang Zhi-Cheng from August 2021 to July 2024, along with artificial RTK single-point measurement data and orthophoto images from environmental monitoring reports from 2001 to 2024, to understand the long-term sediment coverage situation in the study area. By comparing the Digital Surface Models (DSM) generated from drone aerial photography with the artificial RTK single-point measurement data, this study evaluates the applicability of different measurement techniques, analyzes terrain elevation changes, and uses orthophoto images to analyze changes in sediment coverage area. Simultaneously, fractal dimension (FD) analysis is employed to study the geometric features of the algae reef area at different scales, exploring the distinctions between reef and sand and the possibility of multiple fractals.
The results show that in the G1 area, from 2001 to 2024, the average change in sediment coverage area after 2018 was smaller than before 2018, ranging from 67% to 80%. Between 2021 and 2024, the correlation between the changes in the sediment coverage area and volume in the G1 area was higher than that in the G2 area. In the G2 area, the average change in sediment coverage area after 2018 was smaller than before 2018, ranging from 39% to 48%, and between 2021 and 2024, the sediment coverage on the landward side showed an increasing trend, but changes below the mid-tide level in the intertidal zone were not obvious. The correlation between the changes in sediment coverage area and volume was smaller than in the G1 area. As for the fractal analysis, the fractal dimension value of the reef body was higher than that of the sand body, but it could only distinguish the boundaries between larger reef bodies and sand bodies. The surface elevation of the sand body might be too similar to that of the reef body, leading to misclassification. |
