Tide2Topo: A new method for mapping intertidal topography accurately in complex estuaries and bays with time-series Sentinel-2 images
Tide2Topo: A new method for mapping intertidal topography accurately in complex estuaries and bays with time-series Sentinel-2 images
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DOI：
10.1016/j.isprsjprs.2023.05.004
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发表时间：
2023-06
影响因子：
12.7
通讯作者：
C. Chen;Ce Zhang;B. Tian;Wenting Wu;Yunxuan Zhou
中科院分区：
文献类型：
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作者：
C. Chen;Ce Zhang;B. Tian;Wenting Wu;Yunxuan Zhou
潮间带是陆地和海洋之间的重要过渡地带，并定期被潮汐淹没。它们对沿海社区极其重要，因为它提供了多样化的栖息地和抵御海洋灾害的缓冲区。然而，河流泥沙减少、海平面上升和沿海围垦导致潮间带地区广泛消失。可靠、高分辨率和最新的潮间带地形图是沿海脆弱性评估和恢复的关键信息。现有的潮间带地形重建方法涉及大量的地面调查，但空间覆盖范围、准确性和效率有限，因此限制了其在全球范围内推广的潜力。为了解决这些问题，我们提出了一种基于像素的方法，从密集的 Sentinel-2 卫星时间序列和有限的地面实况调查中构建潮间带地形，称为 Tide2Topo。 Tide2Topo 在概念上与广泛使用的水线法不同，因为它将潮汐淹没频率视为地形指标而不是瞬时水线。因此，Tide2Topo不涉及手动选择不同潮位的图像。潮间淹没频率与海拔之间的关系是使用基于一些样线测量而不是潮汐高度的线性和多项式模型来校准的，从而防止由不准确的潮汐数据引入的误差。拟议的 Tide2Topo 在英国和中国的几个复杂的河口和海湾以及大面积的泥泞平坦或沙滩上进行了应用和验证。结果表明，与激光雷达或无人机摄影测量观测结果相比，根据潮间带淹没频率得出的地形的均方根误差范围为 16 至 38 厘米。在潮汐河道区域，淹没频率计算容易出现不确定性，误差较大。密集的Sentinel-2时间序列观测确保了对潮汐周期更精细的采样，从而不仅消除了空间插值引起的误差，而且保持了像素级高程估计的准确性。 Tide2Topo 是一种稳健、便携且快速的方法，非常适合大规模潮间带地形重建。未来的工作可以使用Sentinel-1 SAR作为Tide2Topo的替代数据源，实现对潮间带地貌变化的季节性或年度监测。
Intertidal zones serve as a critical transition between land and ocean and are periodically inundated by tides. They are extremely important to coastal communities as it provides diverse habitats and buffers against marine hazards. However, the reduced river sediment together with sea level rise and coastal reclamation have caused the widespread loss of intertidal areas. Reliable, high-resolution, and up-to-date intertidal topography maps are key information for coastal vulnerability assessment and restoration. Existing approaches to intertidal topography reconstruction involve significant ground surveys, with limited spatial coverage, accuracy, and efficiency, thus, restricting their potential to generalize globally. To address these issues, we propose a pixel-based approach to construct intertidal topography from dense Sentinel-2 satellite time-series and limited ground truth surveys, named as Tide2Topo. Tide2Topo differs conceptually from the widely used waterline method since it considers tidal inundation frequency as a topographic indicator rather than instantaneous waterlines. Therefore, Tide2Topo does not involve manual selection of images at different tide levels. The relationship between intertidal inundation frequency and elevation is calibrated using linear and polynomial models based on a few transect measurements instead of tidal height, preventing errors introduced by inaccurate tidal data. The proposed Tide2Topo was applied and validated in the UK and China over several complicated estuaries and bays with extensive muddy flats or sandy beaches. The results demonstrated that the topography derived from intertidal inundation frequency compared to LiDAR or UAV photogrammetric observations has a root mean square error ranging from 16 to 38 cm. The large errors were found in the tidal channel areas where the inundation frequency calculation was prone to uncertainty. Dense Sentinel-2 time-series observations ensure finer sampling of the tidal cycle, thereby not only eliminating errors caused by spatial interpolation but also maintaining the accuracy of elevation estimations at pixel level. Tide2Topo is a robust, portable and rapid method that is well suited to large-scale intertidal topography reconstruction. Future work could use Sentinel-1 SAR as an alternative data source for Tide2Topo, realizing seasonal or annual monitoring of intertidal geomorphological changes.