Testing a novel sonar-based approach for measuring water depth and monitoring sediment storage in beaver ponds
Testing a novel sonar-based approach for measuring water depth and monitoring sediment storage in beaver ponds
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测试一种基于声纳的新型方法，用于测量海狸池塘的水深和监测沉积物储存量
DOI：
10.1002/rra.4082
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发表时间：
2022
影响因子：
2.2
通讯作者：
Bradbury G
中科院分区：
文献类型：
--
作者：
Bradbury G
随处可见的“探鱼仪”回声探测仪正开始被用于水深研究，以估计地貌变化。然而，到目前为止，还没有在浅水和复杂的湿地中应用，因为在这些湿地中，沉积物储量的变化在时间上是出了名的动态的，在空间上很难准确描述。因此，在这项研究中，我们测试了一种现成的用于测绘浅水河狸池塘水深的寻鱼器的性能。我们测试了21个最小深度为0.31 m，平均深度为0.65 m的成对采样点的探鱼仪声纳深度读数，并与传统的测深导线方法进行了对比。该装置的空间精度也与经过差分校正的全球导航卫星系统接收器进行了测试。从探鱼器测量到池底的深度平均在5%以内，尽管比铅线法测得的深度少0.015 m(SD=0.034)。然而，与修正后的GNSS接收器读数相比，空间精度差别很大，平均误差为2.7米(SD=0.15)，但最高可达6.2米。鉴于两种方法之间深度读数的密切匹配，我们得出结论，与现有技术相比，声纳是一种合适、成本效益高、侵入性较小的方法，即使在中等植被的浅水水体中也是如此。确实需要采用一些方法来解决“现成”探鱼仪模型空间精度不高的问题，但这可以通过勘测设计或使用二次GNSS来解决。这项技术的应用将允许在其他难以进入或对干扰敏感的湿地，如河狸池塘和水处理或水流衰减湿地，进行快速一次性调查或重复监测深度、河床形态和沉积物积累。
Widely available ‘fish‐finder’ echo‐sounding devices are beginning to be used in bathymetric studies to estimate geomorphic change. To date, however, there have been no applications in shallow and complex wetlands, where changes in sediment storage are notoriously dynamic in time and difficult to describe accurately in space. Therefore, in this study, we tested the performance of an ‘off‐the‐shelf’ fish‐finder for mapping bathymetry in a shallow beaver pond. We tested fish‐finder sonar depth readings against a traditional‐sounding lead‐line method across 21 paired Sampling Points with a minimum depth of 0.31 m and a mean of 0.65 m. Spatial accuracy of the unit was also tested against a differentially corrected Global Navigation Satellite System (GNSS) receiver. Measured depths to pond bottom from the fish‐finder were on average within 5%, although significantly 0.015 m (SD= 0.034) less than those obtained by the lead‐line method. Spatial accuracy, however, varied greatly compared to the corrected GNSS receiver readings, with a mean discrepancy of 2.7 m (SD= 1.5) but up to 6.2 m. Given the close match of depth readings between the two methods, we conclude that sonar is a suitable, cost‐effective, and less‐intrusive method than existing techniques, even in moderately vegetated shallow waterbodies. Methods do need to be adopted to account for poor spatial precision with ‘off‐the‐shelf’ fish‐finder models, but this can be rectified with survey design or using a secondary GNSS. Application of this technology will allow rapid one‐off surveys or repeated monitoring of depth, bedform and sediment accumulation in otherwise hard‐to‐access or disturbance‐sensitive wetlands, such as beaver ponds and water treatment or flow attenuation wetlands.