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…society, that first brought civilization to the desert. Far from just scraping by in this harsh landscape, the Garamantes were flourishing. They grew crops, such as cereals and grapes. They kept horses and pigs. Clearly, they needed large amounts of water.
So where did they find it, here in the middle of the desert? Now, this is the key to the Garamantians' incredible success. It's vertical1 holes that are sunk deep into the ground. 40 to 50 meter. That's 150 feet. And the purpose of them was pretty simple - it was to bring water up from below ground. In this environment, it must have seemed that it was almost magic. In fact, the Garamantians had discovered ground water.
Beneath the surface of the Sahara, is a surprising part of the great water cycle, a massive store of ground water.
This is water that has seeped2 into the ground and has collected in the poorest layers of rock. The water came from the period thousands of years before when the Sahara was lush and wet. Some of that water percolated3 into the rocks below and remained there, despite the dramatic drying above until the Garamantes found it.
You can dig them down until hit the water table and then you just keep doing the same thing. And there's one after another after another, all in a whole line. But these holes aren't wells that maintain and shaft4. They reach down to tunnels which carry the water. The point is right up there at the end. It’s where the water source is. So the water flows naturally from the escarpment up there, underground, down to the kind of oasis5 over there and that's where the Garamantians’ city was. What they could have done is they could have dug wells down, they lifted the water up but that's a, that's a lot of work for very little return. Much better to use gravity to channel the water in an underground tunnel straight to where they needed. That was the Garamantians’ real ingenuity6.
The Garamantes had managed to tap the same water that the early Saharans had enjoyed thousands of years earlier. By mining ground water, the Garamantians managed to turn the clock back on the Sahara. They made the desert bloom again.
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1 vertical | |
adj.垂直的,顶点的,纵向的;n.垂直物,垂直的位置 | |
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2 seeped | |
v.(液体)渗( seep的过去式和过去分词 );渗透;渗出;漏出 | |
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3 percolated | |
v.滤( percolate的过去式和过去分词 );渗透;(思想等)渗透;渗入 | |
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4 shaft | |
n.(工具的)柄,杆状物 | |
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5 oasis | |
n.(沙漠中的)绿洲,宜人的地方 | |
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6 ingenuity | |
n.别出心裁;善于发明创造 | |
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