Instruments for investigating shore and nearshore processes

Abstract

Abstract On shingle beaches, changes in foreshore elevation and sediment distribution landward of the break point are produced largely by variations in the uprush and backwash of waves. However, very little is known about the forces active in this zone. A field instrument system which senses and records some of the parameters thought to influence beach erosion and deposition in this zone has been constructed. The equipment is also suitable for the investigation of a number of other shore and nearshore processes including erosion on sandy and rocky shores, and flow processes affecting littoral biological communities. In the swash zone two sensing heads, a dynamometer and a depth recorder, sense variations in uprush and backwash velocities, energies, discharges, and depths of flow. Both devices are electromechanical and are coupled to a recording unit on land by PVC‐insulated cable. The dynamometer (two force plates mounted back‐to‐back on a compression spring and coupled to variable resistances) has been c...