土砂灾害敏感区位考量之山坡地发展规划评估研究

台湾地区近年来交通建设发展大幅缩短城乡之间的距离，复因经济产业发展、人口密度提高、周休二日、岛屿型土地资源先天限制等因素，土地价格成本较低之非都市土地开发乃成为必然之趋势。其中，山坡地因开发导致环境劣化问题，使山坡地中部分具有缓冲天然土砂灾害之区位功能逐渐丧失。以大安溪上游双崎部落为例，分析区内影响土砂灾害之环境敏感区位，透过G IS图层套叠及差异分析，建立环境开发规划合理性评估模式，进而对照检讨现行山坡地开发管理法令、保育利用法规、相关土地使用及管制计划、开发许可审议机制等。研究分析发现，相关法令及管制配套因修订迟缓，导致部分既存开发区位空间结构不合理，亟须调整；其次，早期坡地土地开发利用零散，未考量景观生态、水土保持、生态等因素，致使景观不协调、水土灾害不断、生态自净自愈功能降低；同时，分析结果亦发现，因整体资源利用之区域土地使用计划订定不周详、山坡地土地开发利用规划评估机制与架构未确实建立，导致部分资源保育管制法规，所划设之区位有过度粗放、条件简化、或虽有划设却无因应保育复育作为、甚至错置情形，将可能导致环境生态之浩劫。最后本研究并建议，山坡地农村聚落发展应考量山坡地水土保持安全与景观资源、自然生态间之合理保育利用，建立以单元集水区中土砂环境特性考量之山坡地农村聚落规划发展评估模式。

The Study of Slopeland Development Planning and Evaluation Based on the Consideration of Debris Hazard Sensitivity

Because of recent infrastructure, the transportation distances between rural and urban areas are reducing significantly. In the meantime ,economic development ,population density ,new labor hours and land resources restriction force the suburban area development resulted in unavoidable. Among these landuse patterns, some slopeland containing debris hazard buffering capacity became unable to maintain the natural functions for deteriorating environment. The Shuangqi native tribal area located on the headwater Daan Stream was used as an example study. The debris hazard analysis was used to distinguish the environmental sensitive areas. The rational evaluation model for the development planning was established by the GIS layer overlapping and variation analysis. Furthermore, the current slopeland regulations, conservation rules, related landuse and restriction planning, and development approval processes can be verified and discussed. From the analysis, the revision for the related regulations and control methods need speed-up for existing inappropriate developed area spatial distribution. Moreover,the slopeland development and utilization are scattered for the former stage ,the concepts of landscape ecology, soil and water conservation, and environmental ecology are not considered. These reasons may cause unattractive landscape,continual debris hazards ,and lower ecosystem functions, Also from the results ,some appointed reservations are too rough, simple or without restoration measures based on the uncompleted landuse planning and inappropriate landuse evaluation system. The above scenarios may result in environmental catastrophes. This study suggested slopeland village development need consider safety, landscape resources and conservation. The established evaluation model for slopeland development need consider watershed debris hazard characteristics.