Barrier Spits

Synonyms

Barrier; Spits

Definition

Barrier spits are long narrow strips of depositional bodies emerging from water (Evans, 1942), with one end attached to a coast that serves as the source of sediment supply (proximal end) and the other end jutting into open water (distal end), forming a shelter for its inner water.

Introduction

Offshore waves normally approach the surf zone of a coast in an oblique angle. A combination of shore-oblique swash caused by the incoming waves and shore-normal backwash caused by gravity creates a longshore drift, which is further strengthened by longshore currents generated by wave breaking. Sediment is entrained by strong turbulence induced by wave breaking and transported down-drift along the coastline by longshore currents. Longshore sediment transport rate remains constant if there exists a uniformity of waves and nearshore isobaths along the coastline (USACE, 1984). Net deposition occurs where the longshore uniformity is broken by a decrease of the...