Wave power atlas for South Africa

The spatial dataset is provided as a point shapefile and indicates the average annual and seasonal wave power (kW/m of wave crest). Model outputs were produced on a 500m resolution (nested numerical grid approach) and written out at the 7m and 15m bathymetry contour lines. False Bay is the exception, with output on a 200m resolution. The numerical code, Simulating WAves in the Nearshore (SWAN) was used for the present study. Averages are based on stationary, coastal, spectral wave model computations. The simulation period is at a three-hourly resolution spanning from 1997 until 2013. Saturated, wind wave computations and swell computations were executed separately. The combined product presented here were thus the result of total wave energy addition.

The wave power averages are also presented in terms of coastal wave exposure classifications. Through this classification the South African coastline can thus readily be understood in terms of total and seasonal experienced wave exposure. These range from fully sheltered to fully exposed and is based on widely accepted literature.

These data were originally produced during a Research and Development contract between the Council for Scientific and Industrial Research (CSIR) and the Department of Environmental Affairs (DEA). The scope of the project was to determine the coastal wave run-ups for the entire South African coastline (Theron et al., 2014*). These data were then used as input for post-processing and thus producing the wave power atlas data for South Africa, as presented here. *Theron, A., Rossouw, M., Rautenbach, C., Page, P., von Saint Ange, U., van Niekerk, L., & Luck-Vogel, M. (2014). DEA-CSIR Coastal Vulnerability Phase 2 Wave Report.

本空间数据集以点矢量形状文件（point shapefile）格式提供，表征年均与季均波浪能功率，单位为千瓦/米波峰长度。模型输出采用500米分辨率的嵌套数值网格法生成，并在7米与15米等深线处输出数据；福尔斯湾（False Bay）为特例，其输出分辨率为200米。本研究采用近岸波浪数值模拟（Simulating WAves in the Nearshore, SWAN）模型开展计算。所有平均值均基于稳态近岸谱波浪模型的计算结果得出。模拟时段为1997年至2013年，时间分辨率为3小时。研究分别对饱和风浪与涌浪进行了独立计算，本数据集最终呈现的合成结果为两者叠加后的总波浪能功率。

本数据集同时按照海岸波浪暴露等级对年均波浪能功率进行分类呈现。通过该分类体系，可清晰认知南非海岸线的总波浪暴露与季候波浪暴露状况，其分级覆盖从完全遮蔽到完全暴露的全谱系，分级标准基于学界公认的权威文献。

本数据集最初源自南非科学与工业研究理事会（Council for Scientific and Industrial Research, CSIR）与南非环境事务部（Department of Environmental Affairs, DEA）签订的研发合同项目。该项目的核心目标是测算南非全境海岸线的沿岸波浪爬高（Theron等，2014*）。后续研究以该项目产出的数据作为后处理输入，最终生成了本数据集所呈现的南非波浪能功率图集。*Theron, A., Rossouw, M., Rautenbach, C., Page, P., von Saint Ange, U., van Niekerk, L., & Luck-Vogel, M. (2014). DEA-CSIR海岸脆弱性第二阶段波浪报告。