Multi-decadal shoreline change in coastal natural world heritage sites – a global assessment

作者：Salma Sabour, Sally Brown, Robert J. Nicholls, Ivan D. Haigh, Arjen Luijendijk · 发表于：Environmental Research Letters · 年份：2020 · DOI：10.1088/1748-9326/ab968f · 被引用次数：29 · 研究领域：Coastal wetland ecosystem dynamics、Coastal and Marine Dynamics、Coastal and Marine Management

Abstract Natural World Heritage Sites (NWHS), which are of Outstanding Universal Value, are increasingly threatened by natural and anthropogenic pressures. This is especially true for coastal NWHS, which are additionally subject to erosion and flooding. This paper assesses shoreline change from 1984 to 2016 within the boundaries of 67 designated sites, providing a first global consistent assessment of its drivers. It develops a transferable methodology utilising new satellite-derived global shoreline datasets, which are classified based on linearity of change against time and compared with global datasets of geomorphology (topography, land cover, coastal type, and lithology), climate variability and sea-level change. Significant shoreline change is observed on 14% of 52 coastal NWHS shorelines that show the largest recessional and accretive trends (means of −3.4 m yr −1 and 3.5 m yr −1 , respectively). These rapid shoreline changes are found in low-lying shorelines (<1 m elevation) composed of unconsolidated sediments in vegetated tidal coastal systems (means of −7.7 m yr −1 and 12.5 m yr −1 ), and vegetated tidal deltas at the mouth of large river systems (means of −6.9 m yr −1 and 11 m yr −1 ). Extreme shoreline changes occur as a result of redistribution of sediment driven by a combination of geomorphological conditions with (1) specific natural coastal morphodynamics such as opening of inlets (e.g. Río Plátano Biosphere Reserve ) or gradients of alongshore sediment tra...