DayZ 2 + Badlands · Nasdara
Sefid & Siyah Darya
Named water
Short answer
Dev blog names: Sefid Darya and Siyah Darya — greenery around the rivers. Desert is not a blank.
Also: sefid darya · siyah darya · dasht-e sarman
What we know
Week-63 style blogs mention those rivers and the Dasht-e Sarman desert. They are flavour landmarks, not a fishing table.
What to do
Use the names when talking. Don't pin them as if iZurvive had a layer already.
Don't
Don't invent villages on the banks.