- Created by: C.H.A.R.L.O.N.A.T.O.R. and David :)
- Created on: 09-06-12 13:32
The gradient of the managed section is higher than the unmanaged section.
Walton on the Naze, Essex, U.
Characteristics of the area,
The beach is split into two sections managed and unmanaged as shown below, there was a cost benefit analysis done and it was found the area in front of the houses would benefit from coastal defences this is because things like houses and Naze tower which have higher value so needed to be protected whereas in the unmanaged section there is limited things located there so it is not worth protecting. The Naze tower is a tourist attraction and also a marker for where the Harbour is located for ships coming into the Harwich Harbour. The managed section and unmanaged section is shown below with the Naze tower and houses that need to be protected shown. Where the area is not been managed the cliff is retreating at a rate of 2 metres a year.
Groynes in the managed section mean that they capture more sediment due to longshore drift. Longshore drift is the process which sediment is moved along a shoreline as the backwash goes out to sea parallel to the coast, the swash then goes onto the beach in the direction of the waves which is often at an angle to the beach so does not goes back in the same place so is moved up the shoreline as shown in the image above. This is more common in the unmanaged side so sediment gets removed due to nothing to the stop the sediment form being removed, but in the managed sides stop the sediment getting to the unmanaged side which is then deprived of sediment so is more easily eroded due to the sediment being “captured” by the groynes which helps build up the beach in the managed section of the shoreline. So from this we would expect the managed section of the beach to have a big change of height due to the build-up of sediment whereas the unmanaged have little change in height. The wave fetch is not that long meaning that the waves have a weak swash so they act like constructive waves so they help build-up the beach but only when there is sediment present, this also means that the gradient of the beach would be quite shallow as the sediment is moved up the beach. Whereas in the unmanaged section the wave cut platform is likely to be exposed due to the lack of sediment on the beach so would have a fairly flat beach. There has also been some cliff re grading in the managed section of the beach where the gradient of the slope is made gentler so it is less prone to slumping or landslides as shown in the image left.
Ranging pole: Used with the theodolite to measure the height of the beach from a particular point
Theodolite: Helps view the ranging pole from a level point