Primary and secondary dunes in the Waal: Data set corresponding to the publication: Coexistence of two dune scales in a lowland river

This data set provides information on primary and secondary dune characteristics in the river Waal. The bathymetric data and methods are described in:Zomer, J. Y., Vermeulen, B., and Hoitink, A. J. F.: Coexistence of two dune scales in a lowland river, Earth Surf. Dynam., 11, 1283–1298, https://doi.org/10.5194/esurf-11-1283-2023, 2023<br>Two scales of dunes were identified based on analysis of a large biweekly multibeam echo sounding dataset from the river Waal, a lowland sand-bedded river. The objective of the study was to better characterize and understand how two dune scales coexist in fluvial systems and how both scales adapt over time and space, considering their interdependence. <br>BM170 and BM181 include data over a range of 34 km at two separate timesteps. km34, 35, 36 include data at specific locations (one kilometer per file) over a range of time steps. <br>Coordinates (x, y) are provided as RD new (EPSG:28992). Coordinates correspond to the location of a dune crest. datetime: Serial date, UTC+1H: Dune height, vertical distance between crest elevation and average elevation of the up- and downstream trough. L: Dune length, horizontal distance between the up- and downstream dune trough. Lee: Average lee side slope [m/m]. maxLee: Lee side slope determined as described in Zomer et al. (2023) [m/m].

本数据集提供了瓦尔河（Waal）中一级与二级沙丘的特征信息。其水深测量数据与方法详见如下文献：Zomer, J. Y., Vermeulen, B., and Hoitink, A. J. F.: Coexistence of two dune scales in a lowland river, Earth Surf. Dynam., 11, 1283–1298, https://doi.org/10.5194/esurf-11-1283-2023, 2023
本研究基于对低地砂质河流瓦尔河的大规模每两周一次的多波束测深（multibeam echo sounding）数据集的分析，识别出两种尺度的沙丘。本研究的目标在于更精准地表征并阐明河流系统中两种尺度沙丘的共存机制，同时考虑二者的相互依存关系，解析两种尺度沙丘如何随时间与空间发生适应性调整。
BM170与BM181包含了两个独立时间步长下、跨度34公里范围的数据集。km34、35、36则包含了多个时间步长下特定区域（每个文件对应1公里范围）的数据集。
坐标（x, y）采用RD新坐标系（EPSG:28992），对应沙丘脊（dune crest）的位置。datetime：序列日期，时区为UTC+1。Dune height（沙丘高度）：沙丘脊高程与上下游沙谷平均高程之间的垂直距离。L：沙丘长度，即上下游沙丘沙谷之间的水平距离。Lee（背坡）：平均背坡斜率 [m/m]。maxLee：依照Zomer等人（2023）所述方法确定的背坡斜率 [m/m]。