巨大灾害后的脆弱性:台湾集集地震后中部地区土地利用与覆盖变迁

Vulnerability after a Devastating Hazard: An Interpretation of Land Use and Land Cover Change in Central Taiwan Since 1999 Chi-Chi Earthquake

自2004年底的南亚大海啸、美国遭受飓风侵袭以来,人类社会如何采取应对措施以降低灾害的冲击成为国际科学界的一个重要议题。台湾在几年前也遭遇巨大的地震灾害,1999年9月21日凌晨,震中发源于台湾中部、芮氏规模7.3级的巨大地震,造成全台湾2 000多人死亡,8 000多人受伤,除了造成直接的经济社会损失外,也造成山区土石松滑、地层松动与山崩,直接改变了地表的覆盖状况。在后续几年台风所带来的强风豪雨下,丰沛的降雨量使原本因地震而松滑的土石大量滑落,造成严重的土石流灾害,河床也因土石泥沙的堆积而被提升,形成严重的洪患。这些自然环境的变化不仅再次改变地表的覆盖,也使重建后的小区面临极大的灾害风险。此次冲击促使当地居民重新思考人地关系之意义,通过重建过程凝聚小区意识,发展有别于过去的土地利用形态。因此为检验当地居民对灾害的暴露程度、敏感性与适应能力,本研究采用近年来在国际环境灾害研究课题备受重视的脆弱性研究途径,并利用野外调查以及遥测与地理信息系统分析呈现地震后的土地覆盖变化。希望通过分析人与环境系统的变化,以及人类社群的社会内部固有特质,归纳出重要机制以发展降低脆弱性的策略。研究结果显示,灾害是人与环境耦合系统(coupled system)共同形成的结果,非单一的独立事件,也不是不可避免的;且地方的脆弱性具有演化与多元化的特性,同一地方下不同族群与个体对灾害的脆弱性皆不同,因此灾害研究必须更关注于灾害发生的机制,相关的政策与策略也必须建立在更小的社会与空间单元上。

Since the Indian Ocean tsunami took place on December 26, 2004, the significant outcome of a devastating hazard has occurred. Strategies that we can mitigate the impacts have been the central research theme of the international academic communities. A similar event had happened in Taiwan several years ago. On September 21, 1999, a devastating earthquake measured 7.3 on the Richter scale struck central Taiwan, and caused over 2 400 deaths and 8 000 injuries. After the earthquake, a lot of landslides occurred and had made the land use and land cover transformed. The purpose of this research is to interpret how people perceive a hazard and through what kind of personal, social and political mechanisms that can help them construct the resilience and adapt to the impact. It＇s especially significant that after the devastating earthquake, people in the impacted areas have not only adapted to the impacts, but also changed the previous land uses. Most of these areas were economically-weak agricultural and aboriginal regions, before the earthquake occurred, these areas had had high percentage of illegal and inappropriate land uses which often induced serious landslides after heavy rains. Now, six years after the earthquake, most of the previous land uses have been abandoned ; environment-friendly agriculture and eco-tourism now become the major liveli- hood. In this research, well use remote sensing and GIS to express land use and land cover changing process during different stages, and will examine the endowment, entitlement and the social capital of the local people to deal with the impact. Our aims are to analyze the mechanism and to develop a conceptual model that could strengthen people＇s resilience and adaptive capacity to cope with the impacts and reduce the vulnerability.