A mathematical model of spit growth and barrier elongation: Application to Fire Island Inlet (USA) and Badreveln Spit (Sweden)

► A mathematical spit model was developed based on the model proposed by Kraus (1999). A new formula was introduced to estimate the sediment portion feeding spits. ► The model was successfully applied to unique field data at Long Island coast, USA. ► An analytical solution to the model was validated via data at Badreveln Spit, Sweden.