宜蘭海岸永續經營之沙丘劣化評估指標

Assessment Indices of Dune Degradation for Sustainable Management: An Example from Yilan Coast, Taiwan

林宗儀(Tsung-Yi Lin)

《地理研究》 55期 (2011/11) Pp. 69-87

https://doi.org/10.6234/JGR.2011.55.04

摘要

宜蘭海岸因有適當地形條件、沙粒來源及盛行向岸強風的配合，原有寬闊綿延的沙丘地形發育，形成海岸的自然防禦屏障，並兼具景觀及生態的高度價值。然近年來除了許多沙丘在颱風事件中受到波浪的強烈侵蝕，形成沙丘崖，且崖面逐年崩滑後退外，更多不當規劃的人為開發和毫無經營管理理念的土地利用方式，也使整體沙丘環境被破壞而轉趨劣化，使其原有的環境功能漸漸消失，連帶引起周遭的環境災害，危及附近居民生命財產的安全。本研究以沙丘的海岸防禦、生態棲地及視覺景觀等環境功能的退化，來定義「劣化」。根據野外實地調查、監測及透過不同時期的航照及衛星影像資料的比對分析，總共歸納宜蘭海岸地區沙丘的十一種劣化破壞型態，並進一步據以討論適當的量化評估指標，例如沙丘崖線的變化量、植生覆蓋變化量及穿越沙丘道路分佈密度等，總計研提七項環境劣化指標，並針對其中幾項指標進行實際的監測與調查，以檢驗這些環境劣化指標的可執行性，建立宜蘭沙丘環境指標的基礎資料，提供未來環境永續經營管理分析的重要參考。

關鍵字

海岸沙丘 ； 環境劣化 ； 劣化評估指標 ； 宜蘭

並列摘要

Coastal dune is a dynamic and biodiversified, yet vulnerable, environment. These dunes act as a buffer to extreme waves and winds, as well as, a freshwater aquifer to provide habitats to plants and animals. In addition, the dune landscapes also have high aesthetic values that can attract tourists. However, many coastal dune systems in the world are suffering degradation either from the natural environmental pressures or from the interference of human activities. In our case study from the northeastern coast of Taiwan, some different types of dune degradation are identified. Many beaches are narrowed; erosion dune scarps are formed; and the recession of dune scarp continues. Dunes have been removed artificially for the construction of new roads or industrial parks. Low dune slacks are reclaimed as fish or duck breeding ponds. The continuous and increased intensity of human use has resulted in extensive and irreparable damages on the dunes ecologically and morphologically. Thus, there is an urgent need to develop an assessment index of dune degradation for the sustainable management. The discussion for developing the assessment indices for practical management that can evaluate the environmental quality is centered on three basic services provided by the coastal dune: coastal defense, ecology and aesthetic landscape. The intention is to provide environment managers a tool that can collect the information of dune conditions quickly and to be helpful for decision making.

並列關鍵字

Coastal Dune ； Environmental Degradation ； Degradation Assessment Indices ； Yilan

參考文獻

()。

石再添、張瑞津、林雪美、張政亮、連偵欽(1992)。台灣北部海岸沙丘之地形學研究。國立台灣師範大學地理研究所地理研究報告。18，193-240。

李友平、賴鴻成、孫培基、林家祺、林璟翔、韓光恩、蔡萬宮()。

林宗儀(2002)。沙丘重建與海岸保育。海洋技術季刊。12(4)，36-40。

林宗儀()。