Keijsers Joep G S, Poortinga Ate, Riksen Michel J P M, Maroulis Jerry
Soil Physics and Land Management Group, Wageningen University, Wageningen, The Netherlands.
Soil Physics and Land Management Group, Wageningen University, Wageningen, The Netherlands; School of Science, Education and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia.
PLoS One. 2014 Mar 6;9(3):e91115. doi: 10.1371/journal.pone.0091115. eCollection 2014.
Depending on the amount of aeolian sediment input and dune erosion, dune size and morphology change over time. Since coastal foredunes play an important role in the Dutch coastal defence, it is important to have good insight in the main factors that control these changes. In this paper the temporal variations in foredune erosion and accretion were studied in relation to proxies for aeolian transport potential and storminess using yearly elevation measurements from 1965 to 2012 for six sections of the Dutch coast. Longshore differences in the relative impacts of erosion and accretion were examined in relation to local beach width. The results show that temporal variability in foredune accretion and erosion is highest in narrow beach sections. Here, dune erosion alternates with accretion, with variability displaying strong correlations with yearly values of storminess (maximum sea levels). In wider beach sections, dune erosion is less frequent, with lower temporal variability and stronger correlations with time series of transport potential. In erosion dominated years, eroded volumes decrease from narrow to wider beaches. When accretion dominates, dune-volume changes are relatively constant alongshore. Dune erosion is therefore suggested to control spatial variability in dune-volume changes. On a scale of decades, the volume of foredunes tends to increase more on wider beaches. However, where widths exceed 200 to 300 m, this trend is no longer observed.
根据风沙沉积物的输入量和沙丘侵蚀情况，沙丘的大小和形态会随时间变化。由于海岸前沙丘在荷兰海岸防御中起着重要作用，深入了解控制这些变化的主要因素非常重要。本文利用1965年至2012年荷兰海岸六个区域的年度高程测量数据，研究了前沙丘侵蚀和堆积的时间变化与风沙输运潜力和风暴活动指标之间的关系。研究了侵蚀和堆积相对影响的沿岸差异与当地海滩宽度的关系。结果表明，在狭窄海滩区域，前沙丘堆积和侵蚀的时间变异性最高。在这里，沙丘侵蚀与堆积交替出现，变异性与风暴活动（最高海平面）的年度值显示出很强的相关性。在较宽的海滩区域，沙丘侵蚀频率较低，时间变异性较小，与输运潜力时间序列的相关性较强。在侵蚀主导的年份，侵蚀量从狭窄海滩到较宽海滩逐渐减少。当堆积占主导时，沙丘体积变化在沿岸相对恒定。因此，沙丘侵蚀被认为控制着沙丘体积变化的空间变异性。在几十年的时间尺度上，较宽海滩上前沙丘的体积往往增加得更多。然而，当宽度超过200至300米时，这种趋势不再明显。
