本研究以不同時期之航遙測影像偵測宜蘭海岸濱線變遷，影像來源包含1947年之舊航照影像、1971年的美國Corona衛星影像、1985年的像片基本圖、2003年的SPOT-5衛星影像及2009年以Z/I DMC(Digital Mapping Camera)航空數位相機所拍攝之高解像力航照影像。 由於影像獲取的時間與感測器皆有所差異，故本研究透過不同的方式處理資料，將影像地理對位，並利用地理資訊系統(Geographic Information Systems, GIS)軟體數化濱線及沙灘(丘)，且以套疊分析觀察不同時期濱線與沙灘變遷之情形，最後收集宜蘭地區的自然或人文資料如潮汐、降雨量與輸沙量等，分析宜蘭海岸變遷的原因。而在濱線萃取方面，由於以人工數化方式太耗時間與人力，故嘗試以半自動化方式如影像分類或影像分割萃取濱線，並與人工數化結果比較。研究結果顯示，利用多時期之遙測影像，並結合GIS之空間分析功能，確可有效掌握濱線與沙灘(丘)的歷史變化概況。 / This study used multi-temporal remote sensing images to detect shoreline changes along the Yilan coast. Various types of remote sensing images were used in this study, including old aerial images taken in 1947, Corona satellite images acquired in 1971, photo base map produced in 1985, SPOT-5 satellite images obtained in 2003, and high-resolution aerial images taken in 2009 by using Z/I DMC (Digital Mapping Camera). Because these images were taken in different time using different sensors, different procedures were applied to process the data and georeference the images to a common coordinate system. GIS (Geographic information Systems) software was used to digitize shoreline and the beach area, and overlay analysis was applied to find the shoreline changes in different time periods. Then various ancillary data such as tides, precipitation, and sediment load was collected to analyze the causes of coastal changes in Yilan. For shoreline extraction, manual digitization required a lot of time and manpower. Therefore, semi-automatic method such as image classification and image segmentation was applied to extract shoreline. The results show that, by using multi-temporal remote sensing images and spatial analysis functionalities of GIS, the historical changes of shoreline and beach area can be detected effectively.