The calculated distance (air line) between Nāḩiyat ash Shināfīyah and As Samawah is approximately 42 miles respectively 68 kilometers.
By car or train, the actual journey to As Samawah is certainly longer, as only the direct route (as the crow flies) between Nāḩiyat ash Shināfīyah and As Samawah has been calculated here.
Air line (approximately)
68 kilometers
36 nautical miles