Volumetric changes of a soft cliff coast 2008-2012 based on DTM from airborne laser scanning (Wolin Island, southern Baltic Sea)

A comparison of DTMs off a 2 km-long section of the southern Baltic Sea cliff coast at Wolin Island, composed of unconsolidated Pleistocene sediments with NW exposure and maximum height of 93 m, prepared on the basis of airborne laser scanning (ALS) data collected in 2008, 2009, 2011 and 2012 allowed the magnitude and spatial distribution of changes to be determined. Morphodynamic processes were spatially and temporally diverse. The time period 2008-2012 is dominated by erosion expressed by a negative sediment balance of -33,000 m(3). The volume of eroded material was 49,080 m(3), while the volume of accumulated material - 15,678 m(3). The largest changes were observed in the upper parts of active cliff as a result of mass wasting triggered by loss of the slope stability due to erosion of the lower part of the slope. Significant erosion also occurred on the lower part of the cliff and on the beach. The accumulation is a consequence of material deposition on the beach and at the cliff base. Erosion could be correlated with the number of storm events and with water levels. The results confirm previous studies on the role of factors that regulate the magnitude of coastal erosion, the first being water level rise during the storm events as well as the influence of a series of storms.