任何區域地形發育的背景，都包含了氣候與地質兩項因子。氣候因子和當地的地理位置有關，它決定了侵蝕力的種類，也影響侵蝕力的強度；地質因子則是反應地形發育的基礎。因此，不同地形區演育出之水系亦不相同，間接地也影響地圖水系網之簡化。基此，本文擬以地形特性中最易察覺之起伏性（高度、坡度及相對高度），以流域為地形單位，進形流域地形分類，探討地形區與水系網簡化之關係。

Any background for the topographic growth of any area includes two factors: climate and geology. The factor of climate is concerned with local geographic location which decides the kind of erosion, and affects the strength of erosion as well; as to the factor of geology is the base which reflects the growth of topography. Therefore, different topographies create different river networks that affect the generalization for map of river networks indirectly. Upon this point of view, this text intends to take the relief (altitude, slope and relative height) which is most aware of among the topographic features and to take the drainage basin as the topographic unit to make the geomorphological classification to discuss the relationship between topographic area and river networks generalization.