九九峰自然保留區地覆變遷之監測與分析

Monitoring and Analyzing Land-cover Change in the Jeou-Jeou-Fen Natural Reserve

九九峰在921 地震後，即劃定為自然保留區，崩塌地任其植生自然恢復，引來多方論戰。本研究應用地理資訊系統結合四期SPOT 影像、全球定位系統與其他空間資料，評估九九峰崩塌地植生自然恢復之狀態。歷經兩年多，四期同態化差異植生指標顯示崩塌地植生稍有恢復，然多出現在基腳至近山腰處，而山腰至坡頂稜線區則較少。本研究推測是地形陡峭，土層淺薄且貧瘠，水分極易流失，入侵植物易因乾旱而枯萎。因監測期短，尚難推斷恢復之植生能否朝峰頂與稜線區拓殖，有待後續研究之觀察。因此，崩塌地除急需處置者外，對生育地條件差者，仍以自然恢復為宜，另以非入侵式且所費不多之遙感技術長期監測植生恢復之狀態。 Jeou-Jeou-Fen has been designated as a natural reserve after Chi-Chi earthquake. The decision has been controversial because only natural recovery of plants for the landslide scars at Jeou-Jeou-Fen is allowed in the area. The objective was to evaluate plant recovery of the bare lands in the study area. The study applied GIS technique to combining four-date SPOT images, GPS mapping data, and other spatial data to achieve the goal. For the two-year period, plants have been recovered over the bare lands based upon four-date NDVI statistics, which appear on the belts from the mountain bases to flanks rather than from flanks to peaks because of thinner, drier, and less fertile soils on ridges and peaks. However, the monitoring period was too short to determine if plants would colonize upward into ridges and peaks. Further research will be needed to continue the monitoring. Hence, natural recovery of plants is better suited for landslide scars with poor habitat conditions, except urgent cases. The study suggests that longterm monitoring plant recovery using remote sensing with low cost and non-invasive characteristics over the bare lands be continued.

Jeou-Jeou-Fen has been designated as a natural reserve after Chi-Chi earthquake. The decision has been controversial because only natural recovery of plants for the landslide scars at Jeou-Jeou-Fen is allowed in the area. The objective was to evaluate plant recovery of the bare lands in the study area. The study applied GIS technique to combining four-date SPOT images, GPS mapping data, and other spatial data to achieve the goal. For the two-year period, plants have been recovered over the bare lands based upon four-date NDVI statistics, which appear on the belts from the mountain bases to flanks rather than from flanks to peaks because of thinner, drier, and less fertile soils on ridges and peaks. However, the monitoring period was too short to determine if plants would colonize upward into ridges and peaks. Further research will be needed to continue the monitoring. Hence, natural recovery of plants is better suited for landslide scars with poor habitat conditions, except urgent cases. The study suggests that longterm monitoring plant recovery using remote sensing with low cost and non-invasive characteristics over the bare lands be continued.