How about: it being a desert, the air is very dry. The limited moisture in the air can only support a limited amount of vegetation in a given space (an X foot circle).
Accordingly, you would end up with clumps of grass in a fairly regular pattern like that in the photo.
You’re welcome.
Yep, Just the way God planned it........................
It’s not clumps of grass, it’s “clumps” of NO grass.
‘Life will find a way’
Perhaps the roots of a circle of grass grow outward and absorb water between the circles. The cohesive nature of water then pulls water from the surface. Seeds that land in that area may germinate but don’t have enough water to last long.