澎湖桶盤嶼地質公園基準資料庫建置之研究

Abstract

Columnar basalt landscapes hold a fascination that transcends geographical and cultural boundaries. It is because of this that they feature so prominently on the global register of significant geomorphosites. Arguably the most iconic of these basalt landscapes in Taiwan is Tongpan Island, a status recognized by its inscription as a GeoPark. Recognition at this level invariably brings visitor pressure, and with it concern as to the impact they exert on site integrity. Rarely, however, is the same overt concern expressed for the risks that such sites pose to the visitors – or not at least until disaster strikes. Yet, the very features that make these sites attractive – tall, exposed, largely unconstrained columns – render many of them intrinsically unstable, prone to catastrophic collapse and potentially hazardous to visitors. In this presentation we highlight the nature of these slope instability issues and we create a baseline for Tongpan. The results show that the method of baselining is effective and identifies some of the key controls.