I just learned about this last week watching "Seamen" on prime video[0]. It is pretty terrifying.
But one thing I don't get is: once the dam is built and filled up, shouldn't the water be back to flow regularly? It seems the dam should only act as a buffer, but not cause a dramatic decrease in water flow. Is it because evaporation at the water basin is much higher than on the river?
[0] an episode of the show called "The Grand Tour" where they usually drive cars, but here they drove boats on the Mekong.
Persistent unseasonably dry weather. There is no water, even at the top. A lot of the water held at the dams is also diverted to local farms so it never continues 'down the hill'...
Then what happens is that the water is further away (lower) and people build houses closer... a big rain comes in and wipes away the houses. That is why in the wet season, you see stories in the news about all the landslides... which are a combination of building and deforestation for farming.
The artificial lakes cause a lot of water absorption to surrounding land and air. Grounswater levels can go down when the river bottom deepens downstream of the dam.
But one thing I don't get is: once the dam is built and filled up, shouldn't the water be back to flow regularly? It seems the dam should only act as a buffer, but not cause a dramatic decrease in water flow. Is it because evaporation at the water basin is much higher than on the river?
[0] an episode of the show called "The Grand Tour" where they usually drive cars, but here they drove boats on the Mekong.