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A draw (US) or re-entrant (international), is a terrain feature formed by two parallel ridges or spurs with low ground in between them. The area of low ground itself is the draw, and it is defined by the spurs surrounding it. Draws are similar to valleys on a smaller scale; however, while valleys are by nature parallel to a ridgeline, a draw is perpendicular to the ridge, and rises with the surrounding ground, disappearing up-slope. A draw is usually etched in a hillside by water flow, and often contains a stream or loose rocks from eroded rockfall. A draw differs from a valley or an arroyo, in that the ground always slopes downward from a draw in only one direction, and upward in the other three;〔http://www.globalsecurity.org/military/library/policy/army/fm/3-25-26/ch10.htm〕 while in a valley or arroyo there is noticeable upward slope in only two directions. 〔http://www.armystudyguide.com/content/Prep_For_Basic_Training/Prep_for_basic_land_navigation/draw-minor-terrain-featur.shtml〕 The slope on a draw is generally quite sharp, with a clearly established fall line and characterized by a generally steep vertical drop over a short horizontal distance. ==See also== *Arroyo (creek) *Canyon / Gorge *Chine *Couloir *Defile (geography) *Mountain pass *Riparian zone *Salients, re-entrants and pockets 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Draw (terrain)」の詳細全文を読む スポンサード リンク
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