地理漫步·世界地理英语30篇（1）

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维多利亚瀑布侵蚀与赞比西河后退速率

Victoria Falls lies on the Zambezi River between Zambia and Zimbabwe, where basalt cliffs drop 108 meters.
The waterfall erodes upstream at about 1.5 meters per year due to hydraulic action and rock fracturing.
Joint-controlled basalt layers create a series of gorges downstream, each marking past waterfall positions.
Scientists measure retreat rates using radiocarbon dating of river terrace sediments and GPS mapping.
Wet-season flows exceed 10,000 cubic meters per second, intensifying undercutting beneath the lip.
Droughts and hydropower diversions downstream reduce flow variability and may slow erosion temporarily.
The First Gorge hosts the main cataract, while the Eighth Gorge reveals how long-term retreat reshapes valleys.
Rainforest microclimates thrive on mist-fed slopes, contrasting sharply with surrounding savanna woodlands.
Geological time scales show the falls will eventually retreat into softer sandstone upstream.
Understanding this process helps predict landscape evolution and manage tourism infrastructure safely.