大陆漏斗 · CONTINENTAL FUNNEL
The River That Drains a Nation — United States · Mississippi Basin
密西西比流域排水面积约占美国本土连续州的 41%。这个大陆漏斗塑造了粮食与河运经济：上游草原，下游驳船，入海处沉积三角洲。
这条河不是一条线，更像一套收集系统。玉米、煤、木材和洪水顺着同一个南向坡度汇集，最后在人工堤防与不安分的三角洲相遇。
The Mississippi basin drains about 41% of the contiguous United States. That vast funnel favored a grain-and-river economy: prairies upstream, barges downstream, delta mud at the Gulf.
The river is less a line than a collection system. Corn, coal, timber and floodwater all find the same southward grade, ending where engineered levees meet a restless delta.