TY - GEN

T1 - Morphological evolution around a groyne structure at Cleveleys beach, Northwest England, during a range of wave conditions

AU - Miles, Andrew

AU - Ilic, Suzana

AU - James, Michael

AU - Whyatt, Duncan

PY - 2013

Y1 - 2013

N2 - This paper outlines the detailed short-term morphological evolution around a single composite wood and rock groyne during a range of wave and tidal conditions. Analysis of morphological data based on beach profile surveys and waterlines created using an Argus imaging system identify five distinct phases of morphological evolution during a 17 day study period. These are related to the growth and infilling of a scour pool located close to the toe of the groyne and the migration of its associated drainage channel. By comparing the evolution with nearshore hydrodynamic data a conceptual model has been developed to explain the evolution of scour around the groyne. It is hypothesised that the scour pool largely dependent upon wave driving conditions, exhibiting growth during high wave conditions (Hs>0.8 m) which is hypothesised to be related to wave breaking around the groyne tip and the possible formation of rip currents alongside the groyne, infilling during moderate wave conditions (Hs 0.4-0.8 m) which are associated with onshore sediment transport by shoaling waves and stability during low wave conditions (Hs<0.4 m) when the system is dominated by tidal currents. The position of a drainage channel exiting the scour pool is influenced by longshore currents, migrating northward during spring tidal conditions when tidal currents are increased and larger waves may reach the nearshore region resulting in northward directed transport of the channel as well as during other periods of energetic wave activity when longshore currents are great enough to initiate movement.

AB - This paper outlines the detailed short-term morphological evolution around a single composite wood and rock groyne during a range of wave and tidal conditions. Analysis of morphological data based on beach profile surveys and waterlines created using an Argus imaging system identify five distinct phases of morphological evolution during a 17 day study period. These are related to the growth and infilling of a scour pool located close to the toe of the groyne and the migration of its associated drainage channel. By comparing the evolution with nearshore hydrodynamic data a conceptual model has been developed to explain the evolution of scour around the groyne. It is hypothesised that the scour pool largely dependent upon wave driving conditions, exhibiting growth during high wave conditions (Hs>0.8 m) which is hypothesised to be related to wave breaking around the groyne tip and the possible formation of rip currents alongside the groyne, infilling during moderate wave conditions (Hs 0.4-0.8 m) which are associated with onshore sediment transport by shoaling waves and stability during low wave conditions (Hs<0.4 m) when the system is dominated by tidal currents. The position of a drainage channel exiting the scour pool is influenced by longshore currents, migrating northward during spring tidal conditions when tidal currents are increased and larger waves may reach the nearshore region resulting in northward directed transport of the channel as well as during other periods of energetic wave activity when longshore currents are great enough to initiate movement.

KW - hydrodynamics

KW - sediment transport

KW - morphodynamics

KW - groyne

KW - scour

KW - coastal structures

M3 - Conference contribution/Paper

SP - 1195

EP - 1206

BT - Proceedings of Coastal Dynamics 2013

T2 - Coastal Dynamics 2013

Y2 - 24 June 2013 through 28 June 2013

ER -