由於地圖編繪處理的過程相當複雜，目前雖有各種的電腦製圖軟體，但是仍然沒有一套能完全自動化的編圖系統。其主因在於地圖中各特徵物之簡化模式不易取得，加上特徵物間關係的錯綜複雜，使得地圖簡化作業帶來不少困難，因此，現階段研究對象大都著重於單一特徵物的簡化，至於地圖簡化整體作業，以目前的技術，只能利用交談式的方法處理。基此，本文根據筆者對臺灣地區近五十條流域水系進行之研究，建立一套適合於該區的地圖水系網簡化模式。爲落實自動化製圖之應用，以自行研發之水系網簡化系統(RNGS)，經由資料的獲取、處理至圖形資料的輸出，完成國內首件可以處理河流自動選取的簡化系統。

Because of the complexity on the process of map compilation, although there are many kinds of CAD software presently, there is still not a full-automatic map compilation system. It's main reason is that it's not easy to get the generalization mode for varied features on the map, plus the complicated relation among the features that cause many difficulties for map generalization. Therefore, the present research object almost focuses on the generalization of single feature, as to the whole operation of map generalization, only could use interactive approach as the current skill. Upon this point of view this text is according to the writer's research on the drainage basin of near 50 rivers in Taiwan area to establish a set of map river network generalization mode which is suitable that area. In order to concrete the application of automatic cartography, use the River Networks Generalziation System (RNGS), which is researched and developed individually, through the acquisition and processing of information to the graphic output to accomplish the first generalization system in Taiwan which could manage the river automatic selection.