Are we certain these aren’t lithium extraction pools? Based on the color and variation in color between them and the fact that they’re in the desert, it could be a lithium mine.
Not sure what lithium pool look like, but this is called center-pivot irrigation, https://en.wikipedia.org/wiki/Center-pivot_irrigation, and it’s how crops are typically done in the desert where there is no river or canal to pull from. Water is piped from wherever, or drawn up from a well and pumped into the irrigation arm. It’s on wheels and slowly rotates around the point where water is being pumped in. I see these all the time in southern Arizona and California deserts.
They likely have them everywhere because it’s a dead simple solution to watering crops. I just live in the desert, so this is where I see them all the time. I figured you wouldn’t need them in place it rained, but it makes sense as different crops have different needs.