All equally likely. Deposition of sediment constantly rechannelizes the stream. Sheet flow occurs over the whole area during storms. Slumping spreads sediment out evenly in all directions. The stream meanders across a broad floodplain.
Wind reworks the stream deposits over a wide area.
All water entering them evaporates, leaving its salt behind. Extensive evaporite deposits are being eroded in desert regions. Playa lakes are areas that were previously part of the ocean. The wind blows fine salt particles into playa lakes. Meteoritic accumulates in great volumes in deserts.