Morphological characteristics of the positive relief features forming Broken Bank and Swarte Bank.

aMany mobile sandy sedimentary bedforms are asymmetrical in vertical cross-section. For tidal sandbanks, sand may be transported over the bedforms in different directions at different times, and may circulate around it in the long term. Nonetheless, there is often a long-term net direction of movement of the bedform, indicated by its asymmetry. Sand is generally transported (obliquely) up the longer shallower stoss slope, over the crest and down the shorter steeper lee slope, which faces the overall direction of movement of the sandbank.
Morphological characteristics of the positive relief features forming Broken Bank and Swarte Bank.

多数活动砂质沉积床沙形体（mobile sandy sedimentary bedforms）在垂向剖面中呈不对称形态。对于潮流沙坝（tidal sandbank）而言，泥沙可在不同时段沿不同方向越过床沙形体，并可长期绕其循环运动。尽管如此，床沙形体通常仍存在长期的净移动方向，该特征可由其不对称性体现。泥沙通常以斜向方式沿更长且更缓的迎流坡（stoss slope）向上搬运，越过沙脊顶（crest）后，从更短且更陡的背流坡（lee slope）向下滑落——该背流坡朝向潮流沙坝的整体移动方向。
构成布罗肯沙洲（Broken Bank）与斯瓦特沙洲（Swarte Bank）的正地形地貌单元的形态特征。