應用遙測技術與地理資訊系統輔助考古遺址探坑抽樣試掘之研究──以台中市國家歌劇院為例

Application of Remote Sensing and Geographic Information System in Archaeological Excavation and Pits sampling –A Case Study in Taichung Metropolitan Opera House

考古工作中的探坑挖掘費時費力，往往趕不上都市發展與開發的腳步，使得史前遺址在還來不及發現之前已先遭受破壞，因此利用遙測技術進行大面積調查分析並推測遺址可能的分布地點，確有其必要性。本研究以遙測技術，進行考古遺址潛在地區分析，並輔以現地探坑挖掘，以了解遙測技術和地理資訊系統在輔助考古遺址探坑抽樣位置選擇的可行性。研究過程中，由於台中都市已屬高度開發地區，對於遺址的探勘有很大的干擾，導致衛星影像分析應用受限，因此除了衛星影像之外，另以像片基本圖進行河川的判定，以確認遺址的分布和地理環境之間的關聯性，並建議可能的遺址分布線作為人工抽樣挖掘的參考地。最後配合考古專業人員的經驗，修正上述探坑抽樣建議樣線，進行現場考古挖掘及探坑抽樣分佈。研究結果顯示史前文化選擇聚落的地點的確落在建議樣線之間，可供探坑抽樣之參考，若配合考古人員之經驗及專業判斷，可降低探坑試掘的工作量。出土遺址最豐富的探坑距抽樣建議線約60 公尺，可能因本研究區地形環境大致帄坦，但是仍有些微的地形起伏差異，且區域內東、北下層含有豐富的有機物質和較細的質地，顯示過去是一水域的沉積環境，由於黎明溝支線貫穿「公3」基地，故可知基地經歷流水活動影響甚大，進而影響推估遺址分布位置的正確度。未來可經由舊環境資料的重建及完整遺址分布資料，提高推估遺址潛在分布地點的準確度。

Test pitting in archaeological excavation is time consuming and not keeping pace with urban development, therefore, the prehistoric sites are virtually destroyed before they are found. The technique of remote sensing can be applied to large area survey for analyzing and predicting possible site distributions. Based on the technique, this study analyzes potential site areas with the assistance of on-site test pitting. It also examines the feasibility of the technique and geological information system in determining alternative test pitting in archeological excavation. The city of Taichung is a highly developed area which might interfere with site exploration and consequently lead to the limitation of satellite image analysis. Therefore, orthophoto base maps are included to evaluate the rivers and determine the correlation between site distributions and geographical environment. Suggestions about possible site distributions as reference for randomized manual digging. Based on archeological experts' experiences, the suggested distributing lines be revised and the on-site archeological excavation and the loction of the pits sampling can be initiated. The study results indicate that the location of the chosen prehistoric cultural settlement is within the range of suggested line sampling which can be used as a reference for trial pitting. With archaeological experts' professional judgment the workload of digging can be reduced. Possibly due to the flat terrain, the most abundant exposed site is 60 meters from the suggested sampling line. However, the slope variation of the terrain and the underground sphere on the north and the east contains rich organic materials and fine soil texture, the evidence of a sediment environment. Li-ming ditch branch stretches across the site of 'public land number 3', therefore, the effects of water flowing through the area are enormous and further influence the accuracy of the predictions on site distribution. It is suggested that future study should include reconstructing information on archaic environment and complete site distribution to improve the accuracy of predicting potential site distributions.