Of course this had nothing at all to do with natural climate variability, like when the “wet band” shifted North and South of the equator, making the lands closest to the equator dry (Sahara Desert and The Land of Milk And Honey are pretty parched now when they once were fertile). This MUST be caused by the hand of Man.
Aficianados of Pisco will understand that a so-called "man-made natural disaster" may be God's way of permitting Evil in the attainment of a greater Good!
I thought that a Korean martial art.
Say, that's the same rough time frame for the collapse of the Anasazi and the classic Mayan civilizations too. Were they all bad farmers then? /s
I found some other stories about this place and history.
Scientists write that the place was really agriculturally rich between 100BC and 400AD (especially after 100AD), but an El Nino event trashed the place with a massive flood at or before 500AD, ruining irrigation systems and forests.
They write that human deforestation made the place much more vulnerable to flood damage (but obviously didn’t cause the flood).
Did American farmers cause the Dust Bowl?
It’s not just Peru, the Mayans in Copan, Honduras, and elsewhere throughout Central America, eventually died out due to poor agricultural practices and over population.
New Orleans, LA, Matagorda and Sergents Beach, TX learned the hard way about the dangers of hurricanes when marsh, grass lands were destroyed with development. Both Matagorda and Sergents are restoring the marsh and grass lands...and I’ve read NO’s is doing the same.
The Nile valley is a fertile floodplain even today.
That doesn't mean it gets much rain.
Farming the Ica Valley was possible because of the huarango tree woodland, which literally held the floodplain together. The roots of the tree physically anchored the soils and protected the ground from erosion. The trees also maintained fertility by fixing nitrogen from the air and keeping moisture in the soil.
But as more land was cleared for crop production, so much of the woodland was cleared that the huarango's benefits were lost. The land was then exposed to floods from El Niño events and strong winds parched the land when it wasn't flooded.
This was a river valley in a dry area that got its moisture from melting snow in the distant mountains. It was at risk for desertification for a long, long time.