台灣北部海成壺穴的地形學研究

陳翰霖

慈濟技術學院醫務管理系

摘　要

台灣北部海岸海成壺穴地形發達，本研究以文獻探討、室內計測、野外實察、統計分析等方法，發現壺穴群主要分布在老梅、野柳、和平島、深澳、大社、蝙蝠洞、濂洞及南雅等處海岸濱台，受地殼隆升運動影響，最高者離水已有12m。穴口形狀以橢圓形、圓形較多，其穴口長徑走向主要受節理走向所影響。穴壁形態大致有直立、傾斜、過懸三形態，其中以直立形穴壁較為常見。壺穴演育形態以單一壺穴最為普遍，顯示壺穴演育時期尚屬年輕。壺穴規模特徵中平均穴徑及穴深分別為56及47cm，其中以南雅及野柳、和平島等區規模較大。根據統計分析結果得知，穴徑與穴深呈顯著正相關；穴口形狀與演育形態、穴壁形態有顯著相關，橢圓形及圓形多為演育時期較年輕的單一壺穴；穴壁過懸者多呈橢圓形穴口，而穴壁傾斜者趨向於其他形穴口。

台灣北部海成壺穴發達，為水流渦蝕作用的明證，是自然教室的活教材，相關單位應積極選擇規模較大或較具典型者設置自然保護區，以收自然環境保育教育之效。

關鍵字：海成壺穴、台灣北部、渦蝕



A Geomorphological Study of Marine Potholes in Northern Taiwan
Chen, Han-Lin

Department of Health Administration

Tzu-Chi College of Technology

Abstract

Marine potholes are noted in northern Taiwan, which distributed mainly on Laomei, Yeilui, Hopingdao, Hsienao, Tahsieh, Pienfutung, Lientung and Nanyia. This study investigates the caracteristics of shape and occurrence of potholes by the methods of document reviewed, geometery, field excursion and statistics. The elevations of pothole are located mostly lower than 12m, that is an evidence to estimate the amount of the emergence of platforms. The shape of potholes is almost round and elliptical, while the inner walls are straight. The average diameter and depth is about 56 and 47cm. According to statistical analysis, both diameter and depth are positive correlations notably. The shapes of pothole are highly correlation with stages and walls.

Marine potholes in northern Taiwan is much notable than other areas, due to the strongly evorsion energy, that is an active natural classroom. The authorities should construct outdoor educational sites for sustainable management.

Key: marine pothole, northern Taiwan, evorsion