50m segment database The database contains for every 50m segment between Brigthon and Margate the following details (some only available for certain sections). The data is based on information digitised and calculated by Uwe Dornbusch during the Beaches at Risk Project at the University of Sussex. Location Where a segment can be associated with a place name this is given ID Unique identifier starting at Black Rock Distance Distance along the coast starting at Black Rock X_Centr x-coordinate (longitude) of the centre of the segment polygon Y_Centr y-coordinate (lattitude) of the centre of the segment polygon Cl_min_ele Minimum cliff elevation along the 50m segment. Cliff elevation was measured along a line 5m landwards of the 2001 cliff line. Elevation data was taken from point data based on the 2001 air photographs made available by the Environemt agency. Cl_max_ele Maximum cliff elevation along the 50m segment. Cliff elevation was measured along a line 5m landwards of the 2001 cliff line. Elevation data was taken from point data based on the 2001 air photographs made available by the Environemt agency. Cl_mean_ele Mean cliff elevation along the 50m segment. Cliff elevation was measured along a line 5m landwards of the 2001 cliff line. Elevation data was taken from point data based on the 2001 air photographs made available by the Environemt agency. Dist_1899 Average distance between the cliff position on the 1st Edition Ordnance Survey map and the 1st Revision in 1899 Rate_1899 Average rate of cliff retreat between the 1st Edition Ordnance Survey map and the 1st Revision in 1899 Dist_1910 Average distance between the cliff position on the 1st Edition Ordnance Survey map and the 2nd Revision in ~1910 Rate_1910 Average rate of cliff retreat between the 1st Edition Ordnance Survey map and the 2nd Revision in ~1910 Dist_1929 Average distance between the cliff position on the 1st Edition Ordnance Survey map and the 3rd Revision in 1927-1929 Rate_1929 Average rate of cliff retreat between the 1st Edition Ordnance Survey map and the 3rd Revision in 1927-1929 Dist_1973 Average distance between the cliff position on the 1st Edition Ordnance Survey map and the air photographs in 1973 Rate_1973 Average rate of cliff retreat between the 1st Edition Ordnance Survey map and the air photographs in 1973 Dist_2001 Average distance between the cliff position on the 1st Edition Ordnance Survey map and the air photographs in 2001 Rate_2001 Average rate of cliff retreat between the 1st Edition Ordnance Survey map and the air photographs in 2001 !!!!!!!!!!!!!!!!! Note, that where cliffs have been protected, the rate of retreat declines as the distance remains the same but the time increases !!!!!!!!!!!! Lwl_1870s_landline Change in the position of the LWL as shown on the 1st Edition Ordnance Survey map and in the OS landline data. Negative values indicated movement landwards, positive a movement seawards. !!!!!!!!!!!!!!!!!!!!!!!!! Though both map data claim to show the position of mean low water this hsa been shown not to be the case !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! HWL_1870s_landline Change in the position of the LWL as shown on the 1st Edition Ordnance Survey map and in the OS landline data. Negative values indicated movement landwards, positive a movement seawards. Net_wat_ cha Net narrowing (negative values) or widening (positive values) of the distance between LWL and HWL between the 1st Edition Ordnance Survey map and in the OS landline data. !!!!!!!!!!!!!!!!!This calculation included the change in LWL position (see above) and is therefore to be interpreted with great caution !!!!!!!!!!!!!!!!!! Net_res Net narrowing (negative values) or widening (positive values) of the distance between LWL and HWL between the 1st Edition Ordnance Survey map and in the OS landline data. !!!!!!!!!Data adjusted for wrong location of LWL on the 1st Edition Ordnance Survey map and in the OS landline data. See Dornbusch, U et al (submitted to Journal of Coastal Research) Intertidal shortening along the coast of Southeast England, UK - a re-evaluation.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! This data is only available for stretches with rock shore platform. 1870s_SD Survey year for the 1st Editions Ordnance Survey map (1:10,560) R_rte_01 Mean annual rate of retreat of chalk cliffs between the 1st Editions Ordnance Survey map (1:10,560) and the cliff line in 2001. R_are_01 Area of cliff top lost between the 1st Editions Ordnance Survey map (1:10,560) and the cliff line in 2001. R_seg_01 Length of the segment. 'Retr-area_1870-2001' divided by 'Retr-seg-length_1870_2001' divided by ('1870s_SD' minus 2001) = rate of cliff retreat A_rte_01 Mean annual rate of advance of chalk cliffs between the 1st Editions Ordnance Survey map (1:10,560) and the cliff line in 2001. A_are_01 Area of cliff top gained between the 1st Editions Ordnance Survey map (1:10,560) and the cliff line in 2001. !!!! This is not physical possible so that it indicates teh quality of the map. A_seg_01 Mean annual rate of retreat of chalk cliffs between the 1st Editions Ordnance Survey map (1:10,560) and the cliff line in 2001. 1870lwlT Type of sediment cover on the 1870s maps plat = rock platform rubb = rubble and boulder from cliff falls sand = sandy intertidal shin = shingle and gravel (only at Cuckmere Haven) 2001lwlT Type of sediment cover interpreted from 2001 ortho photos harbour = intertidal covered by harbour ouse = segements covering the Ouse River peat = peat outcrop at Cliff End plat = rock platform in chalk sand = sandy intertidal sandstone = rock platorm in sandstone shing = shingle and gravel 2001wall Existing seawall in 2001 is indicated by 'y' 2001beac Existing beach in 2001 is indicated by 'y' 2001groy When a groyne existed in the segment in 2001 this is indicated by 'yes' Beach_1873 Beach width in metres between the beach toe and seawall/ cliff on the 1st edition OS map Beach_1899 Beach width in metres between the beach toe and seawall/ cliff on the 1st revision OS map Beach_1910 Beach width in metres between the beach toe and seawall/ cliff on the 2nd revision OS map Beach_1929 Beach width in metres between the beach toe and seawall/ cliff on the 3rd revision OS map Beach_2001 Beach width in metres between the beach toe and seawall/ cliff on the 2001 Ortho photos THE FOLLOWING 4 COLUMNS contain abbreviated information that is contained in more detail in the point data "2004 Grain size" LARGEST_b_ B-axis of largest clast found in the sample D50ALL_MM D50 in mm for the whole sediment sample D50GRAV_MM D50 in mm for the subsample >2mm %sand % of sand in sample LWL-OS-el Average elevation of the Ordnance survey Landline 'mean low water line' taked from EA LIDAR survey in 2005. Along the Landline LWL a point was created every 1m (that is ~50 points per segment) and the elevation of this point was taken from the LIDAR data. The figure shown is the average of all points in the segment. Note that Mean Low Water at Newhaven is -2.3m Uwe Dornbusch 21-12-2006