We use high school physics. We apply vacuum to sea or river water. At only 1m of vacuum head, the water boils, losing all salts and contaminants.
We pump the water vapour to the edge of arable land, and vent it over an artificial lake. The water vapour condenses to form water drops, and fills the lake.
Local wells that were running dry, now fill with water. And the air gets moist, and filled with water vapour. As the afternoon heat dies away, we get cloud, and natural rain.
We dredge soil from the sea bed, and wash it in river estuaries. And we erect a new network of new soil, seeded with grass seed.
In time, we plant field boundaries of trees, so stabilising the new soil. We mow the grass, and feed it to animals in fenced off areas. We collect their waste and urine, and fertilise the new grass with animal waste. What was desert is now lush fields.
Every year, we push the deserts back by 5km – so soon the deserts will vanish.
At the Atacama, we pump the water vapour to the centre of Chilli, and soon have a massive animal farming project, that engulfs the driest desert of Earth.
In only 20 year the deserts vanish.In India, we break the dependence on natural rain. We have limitless fresh water all year. The monsoon loses its importance, as we have lush life all year.
Where ever farmers need fresh water, they can use a vacuum pump to turn river of sea water into fresh, nearly free water.