NSW Coastal Erosion - 2025

This dataset provides regional-scale mapping of coastal erosion hazards for the New South Wales (NSW) coastline. It represents the modelled range of potential beach erosion for baseline conditions (2020) and projected future periods at decadal intervals through to 2150, under a range of sea level rise (SLR) scenarios associated with the Intergovernmental Panel on Climate Change Shared Socio-economic Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5 medium confidence, and SSP5-8.5 low confidence).\r\nThe present-day (2020) hazard extents relate to storm erosion volume and any existing sediment budget imbalance. The future (2030-2150) hazard extents represent the impacts of these two processes, along with the migration of the shoreline due to SLR and local sediment movements that vary between beaches. To address uncertainty in present and future coastal processes and shoreline responses, the erosion model was run using a statistical sampling approach for each scenario and forecast year to simulate different combinations of the driving processes that contribute to erosion. This approach enables the mapping of potential shoreline position as percentiles or cumulative probabilities of the distribution of hazard projections (50, 90, 99, and 99.9%). These are respectively equivalent to the relative likelihood of erosion exceeding each mapped position within the modelled range – i.e. 50%, 10%, 1%, and 0.1%.\r\nThe methodology considers variability in the morphology and drivers of coastal change between individual beaches while maintaining a consistent, state-wide approach. The mapping supports comparative exposure assessment and prioritisation of adaptation needs at regional and state scales. As a regional-scale assessment, it does not incorporate all local-scale influences and fine-scale variability, and it is not intended for site-specific erosion risk assessment, and where additional details may be needed.\r\nFurther details on the methodology are available in the NSW Coastal Erosion and Inundation Hazards and Exposure Assessment – Technical Report, 2025. Information on data structure, file naming conventions, folder organisation, shapefile attributes, and layer descriptions is provided in the accompanying ReadMe documentation.

本数据集针对新南威尔士州（New South Wales, NSW）海岸线开展海岸侵蚀灾害的区域尺度制图，涵盖基准情景（2020年）下潜在海滩侵蚀的模拟范围，以及截至2150年以十年为间隔的未来时段情景。所有情景均基于政府间气候变化专门委员会（Intergovernmental Panel on Climate Change, IPCC）共享社会经济路径（Shared Socio-economic Pathways, SSP）对应的一系列海平面上升（Sea Level Rise, SLR）方案，包括SSP1-2.6、SSP2-4.5、SSP3-7.0、中等置信度下的SSP5-8.5以及低置信度下的SSP5-8.5。
当前（2020年）的灾害影响范围与风暴侵蚀量及现有沉积物收支失衡相关。2030年至2150年的未来灾害影响范围则综合了上述两类过程的影响，同时纳入海平面上升引发的海岸线迁移，以及不同海滩间存在差异的局地沉积物运动过程。为应对当前及未来海岸过程与岸线响应的不确定性，本研究针对每种情景与预测年份采用统计采样方法运行侵蚀模型，以模拟贡献于侵蚀的各类驱动过程的不同组合。该方法可基于灾害预测分布的百分位数或累积概率（50%、90%、99%、99.9%）实现潜在岸线位置的制图，分别对应侵蚀超过各制图位置的相对可能性——即50%、10%、1%与0.1%的概率。
本方法兼顾了各独立海滩间海岸变化的形态特征与驱动因子差异，同时维持了全州统一的研究框架。该制图成果可支撑区域与州尺度下的海岸暴露度对比评估与适应需求优先级排序。作为区域尺度评估，本数据集未纳入所有局地尺度影响因素与精细尺度变异，且不适用于场地特定的侵蚀风险评估，若需补充细节可另行获取相关信息。
有关方法学的更多细节可参阅2025年发布的《新南威尔士州海岸侵蚀与淹没灾害及暴露度评估技术报告》。数据集的结构、文件命名规范、文件夹组织方式、形状文件（shapefile）属性及图层说明等信息，详见随附的ReadMe文档。