臺灣地區地圖海岸線簡化之研究

目前國內地圖編繪作業的情況，仍以人爲簡化處理爲主，除了受制於人爲因素造成不一致外，處理過程亦相當費時。至於數值地圖簡化作業，雖有相關簡化軟體輔助，卻由於特徵物複雜程度不一，而無法有效的掌握簡化參數。本研究擬以海岸線爲例，先針對海岸線型態進行分類研究，以瞭解其細部特徵。進而再利用Intergraph公司所發展之模組化地理資訊系統環境地圖簡化軟體(Modular GIS Environment Map Generalizer, MGMG)，進行簡化實驗，除採用Douglas & Pcucker演算法之外，並應用其餘演算法如第n點法、Lang演算法、Reumann-Witkam演算法、Point Relaxation演算法及VectGen演算法等進行測試。做法上係採用現有之系列地形圖爲基準，將五萬分之一地形圖不同簡化參數之測試結果與較小比例尺地形圖套疊比對，決定適合的簡化參數。從測試比對中進行歸納分析，並結合上述特徵物之分類結果，擬制訂出一套適合台灣地區海岸線之簡化參數，此項成果除了解決傳統地圖編製中可能發生品質不一致的問題外，並能加速地圖編製作業的流程。

關鍵字

地圖簡化；線形特徵物；運算因子；模組化地理資訊系統環境地圖簡化軟體

並列摘要

Currently, the generalization of map compilation still primarily depends on the manual operation, except the inconsistency caused by the operators, the procedure is also time-consuming. As for the digital generalization, there is some available software. However, because of the different complexities of features, we still could not have effective control on the parameters. By this research, we try to classify the different types of coastline and to figure out their detailed characteristics. Then by adopting the MGE Map Generalizer (MGMG) developed by Intergraph Co., with the algorithms such as Douglas & Peucker, the Nth Point Thinning, Lang, Reumann-Witkam, Point Relaxaton and VectGen to test the generalization of coastline. The series topographic maps are adopted as the standard maps, and the generalization is performed from the scale 1:50000 with different parameters, then the generalized maps are compared with those of smaller scale to decide suitable parameters. From the test and comparison, we tried to analyze and induce a set of generalization parameters which is suitable for the coastline of Taiwan area. The outcomes could not only solve the quality inconsistency in the conventional map compilation, but also shorten the time for map production.