地圖概括化對環境變遷研究之影響 以臺灣地圖資料為例

Abstract

Being the documents of historical environment, maps provide valuable information for research of environmental change. Many previous studies have explored problems regarding map data accuracy, coordinate system and projection. However, the influence of cartographic generalization has often been overlooked. This article discusses cartographic principles and the impact of cartographic generalization on environmental change research. In order to identify such influences, major Taiwanese map data were analyzed. Findings of this case study suggest that environmental changes based on overlapping maps are not necessarily reliable. Therefore, researchers must use maps of similar scales and purposes, or even re-generalize map data when necessary.地圖是歷史環境的文件記錄，在環境變遷研究上具重要參考價值。許多研究已指出地圖資料準確度、坐標系統與投影於地圖套疊時所產生的問題，然而有關地圖概括化的影響層面則未受到相同的重視。本文主旨在於探討地圖概括化對環境變遷研究之影響，並以重要的臺灣地圖資料為例，驗證此種影響的性質及程度。藉由此一個案研究的結論，本文發現直接套疊地圖所獲得之環境變遷訊息未必可靠。因此研究者應盡量選擇比例尺與使用目的相近的地圖資料，必要時可針對所使用的地圖資料進行再概括化處理