Case Study - Holderness Coast

Location

 61km coastline from Flamborough head in north to Spurn Head in south. North East England in Yorkshire

Geology

mainly soft glacial drift cliffs. Made of more resistant chalk and soft boulder clay. Concordant coastline.

Sediment cell activity (inputs, transfers, outputs)

Subcell of sediment cell 2. most rapidly eroding coastline in Europe. Inputs: erosion particularly from boulder clay, transfers: longshore dirft, outputs: deposition of Spurn Head, some sediment continues south into rest of cell 2

physical factors affecting rapid erosion

winter storms, destructive waves, longshore drift, chalk and clay (clay easilt eroded), tide (very high - canr each 7m)

human factors affecting rapid erosion

interfering with natural processes eg downdrift impacts of groynes at hornsea/mappleton/withernsea mean sediment being prevented building beaches elsewhere, global warming eg sea level rise and more storms - Spurn head and humber estuary at risk from coastal flooding and erosion; by 2050 holderness predicted to sink by 9cm and sea level rise predicted to be 30cm in next 50yrs for holderness 

impact of erosion

up to 14m of land can disappear in single storm. holderness coast cliffs retreating at avg rate of 1.5-2m/yr

rate of growth of spurn head spit

10cm/yr

Mappleton rate of erosion

rate before of 1.7m now 3.3m /y

Skipsea erosion

stormy weather + rising sea levels = over 10m of cliff to disappear from a 2-mile stretch of coast in 9 months in 2020, compared to annual avg of 4m

Hornsea cost of groynes

£5.2 million

Mappleton sea defences

1991 defences built - £2mill