The calculated distance (air line) between Ksar El Kebir and Oued Zem is approximately 153 miles respectively 246 kilometers.
By car or train, the actual journey to Oued Zem is certainly longer, as only the direct route (as the crow flies) between Ksar El Kebir and Oued Zem has been calculated here.
Air line (approximately)
246 kilometers
133 nautical miles