让我先改述你的问题:什么吃惊的是,大陆主要由河流排水,连续流*下坡的*,形成一些湖泊和海洋中结束。两个方面的考虑:1。因为大陆海周围的水平之上,很明显,大陆和海岸之间的任何位置,每条路径,平均下坡的。2。在大陆范围内,流水没有显著的惯性,所以水流后,* * * *最大斜率。河是一条沿着大陆之后的最大局部斜率在任何地方十字架。那么将相反的景观主要由河流?答:有很多地方没有走下坡路。这些被称为盆地,* *湖泊* *形式。所以你的问题减少了这一套:* *”为什么没有更多的湖泊在我们大陆吗?”* *地球上1.17亿个湖泊只占据4%的地表[1]。 The rest of the continents has a downhill slope where, provided the water, a river can flow. Even endorheic drainage basins are drained by rivers, although these drain to close lakes instead of the ocean. Importantly, large lakes are relatively rare because they are ephemeral: once they form by tectonic and geodynamic motions they tend to disappear due to two processes: A) Lake basins tend to fill up with the sediment carried by tributary rivers[2]. B) Lake basins tend to be lowered in level due to the erosion along their outlet river[3]. Consider a landscape formed with a pure random topography. It will contain many lakes because many locations will not have a downhill exit to the sea. Processes A and B would tend to make this topographic minima disappear and establish a *normal* fluvial network. On Earth, erosion is a process trying to remove lake basins in timescales of hundreds of thousands to tens of millions of years. If we still have this 4% of the planet surface occupied by lakes it is because erosion competes with relief-generating mechanisms such as plate tectonics. But that's a different story. [1]: http://voices.nationalgeographic.com/2014/09/15/117-million-lakes-found-in-latest-world-count/ [2]: Carroll, A.R., and Bohacs, K.M., 1999, Stratigraphic classification of ancient lakes: Balancing tectonic and climatic controls: Geology, v. 27, p. 99–102, doi:10.1130/0091-7613(1999)027<0099:SCOALB>2.3.CO;2. [3]: Garcia-Castellanos, D., 2006. Long-term evolution of tectonic lakes: Climatic controls on the development of internally drained basins. In: Tectonics, Climate, and Landscape evolution. Eds.: S.D. Willett, N. Hovius, M.T. Brandon & D.M. Fisher. GSA Special Paper 398. 283-294. doi:10.1130/2006.2398(17)
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