EVALUATING SHALLOW‐WATER BATHYMETRY FROM THROUGH‐WATER TERRESTRIAL LASER SCANNING UNDER A RANGE OF HYDRAULIC AND PHYSICAL WATER QUALITY CONDITIONS
EVALUATING SHALLOW‐WATER BATHYMETRY FROM THROUGH‐WATER TERRESTRIAL LASER SCANNING UNDER A RANGE OF HYDRAULIC AND PHYSICAL WATER QUALITY CONDITIONS
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在一系列水力和物理水质条件下通过水陆地面激光扫描评估浅水水深
DOI：
10.1002/rra.2687
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发表时间：
2014
影响因子：
2.2
通讯作者：
D. Vericat
中科院分区：
文献类型：
--
作者：
Mark W. Smith;D. Vericat
河流环境中水-沙边界的细尺度结构是动态的和复杂的，影响近床流动、泥沙输运和非稳定生态。然而，精确的高分辨率测量河道的边缘或部分淹没区域是有问题的。先前的工作表明，使用标准绿色波长设备通过相对较浅的水柱进行地面激光扫描（TLS），在静态、清澈的水柱中引入了<5 mm的误差。本文介绍了在不同流速、深度、悬浮泥沙浓度、水色水平和扫描范围下的七项穿水TLS实验室和现场测试。流速仅会降低超临界流的点精度，而点密度则会随着水深和悬浮泥沙浓度的变化而降低。一个类似的点返回阈值观察到的水色变化，没有颗粒悬浮液。相反，点的精确度和准确度仅是悬浮泥沙浓度的函数（观察到的阈值为0.11 g L−1）。现场试验表明，较大的误差（<10 mm）和较低的点精度。确定了0.68 m的清水深度穿透极限。通过水TLS获得的河流水深是为砾石/卵石床到达。尽管观察到的限制，这些实验表明，我们的方法提供了厘米分辨率的测深和子航空调查在一个综合的数据集，而不需要以下：（i）额外的财政资源;（ii）同时进行深度测量;（iii）深度测量。或（iii）额外的实地工作以获取测深数据，从而使定期调查能够表征河床的精细结构，并限制单个洪水事件的地貌影响。版权所有© 2013约翰威利父子有限公司.
The fine‐scale structure of the water–sediment boundary in fluvial environments is dynamic and complex, influencing near‐bed flows, sediment transport and instream ecology. However, accurate high‐resolution surveying of marginally or partially inundated areas of river channels is problematic. Previous work has shown that terrestrial laser scanning (TLS) through relatively shallow‐water columns using standard green‐wavelength equipment introduces errors of <5 mm in a static, clear water column. This paper presents seven laboratory and field tests of through‐water TLS under variable flow velocities, depths, suspended sediment concentrations, water colour levels and scan ranges. Flow velocity decreased point accuracy only for supercritical flows, whereas point density decreased as a function of both water depth and suspended sediment concentration. A similar point return threshold was observed for water colour variations with no grains in suspension. Conversely, point precision and accuracy were a function of suspended sediment concentration alone (a threshold of 0.11 g L−1 was observed). Field tests showed larger errors (<10 mm) and lower point precisions. A clear‐water depth‐penetration limit of 0.68 m was identified. Fluvial bathymetry acquired from through‐water TLS is presented for a gravel/boulder bed reach. Despite observed limits, these experiments demonstrate that our approach provides centimetre‐resolution bathymetry and sub‐aerial survey in an integrated dataset without the need for the following: (i) additional financial resources; (ii) concurrent depth measurements; or (iii) extra field effort for bathymetry acquisition, thereby enabling regular surveys to characterize the fine‐scale structure of channel beds and to constrain the geomorphic effect of individual flood events. Copyright © 2013 John Wiley & Sons, Ltd.
影响因子：
5.4
作者：
Brasington, J.;Vericat, D.;Rychkov, I.
通讯作者：
Rychkov, I.