海岸後退為花東海岸明顯的破壞性地質作用，本研究經多年持續觀察、測量 和訪談，並採集標本定年，進行不同年代航照和地形圖對比等工作，發現長濱以南至台東段 海岸至少有九處嚴重後退的地點。南石寧橋至鳥石鼻，成功以南至福德橋、都蘭沖積扇南緣 、宜灣等地三、四十佃來累計後退量可達 50-100 公左右，許多地點在有颱風侵蝕的年度有 2-3 公尺不等的後退量。 夏秋雨季由東部登陸的颱風所帶來的暴風激浪高度可達 5 至 15 公尺，帶來強大的侵蝕力，發育不佳的低窄海灘緩衝海浪的侵蝕力有限，以及組成海崖的岩 性鬆軟易蝕，容易產生崩壞，當地河川短小，輸沙量少，海岸沉積物收支不平衡，皆為造成 海岸後退的主因。

　　　　　The dominant morphological process along the Huatung coast is cliff retreat. Analysis of two epochs of aerial photographs taken forty years apart and by field investigations have identified nine coastal sections that have experienced severe retreat along the Changpin to Taitung section. Many of these sites have retreated 50-100 meters during the last forty years and at least 2-3 meters during the typhoon period every year. The interaction of high-energy typhoon induced storm waves with heights of 5-15 meters, low-resistant cliff-forming materials, narrow beaches with low buffering capacity, mass wasting after typhoon induced heavy rainfalls and small rivers with limited sediment carrying capacity, result bin an unbalance sediment budget along the coast. These combination of processes are believed to be the main factors that influence the rate of coastal recession.