Hyperscale terrain modelling of braided rivers: fusing mobile terrestrial laser scanning and optical bathymetric mapping
Hyperscale terrain modelling of braided rivers: fusing mobile terrestrial laser scanning and optical bathymetric mapping
复制标题
DOI：
10.1002/esp.3437
复制
发表时间：
2014-02
影响因子：
3.3
通讯作者：
R. Williams;J. Brasington;D. Vericat;D. Hicks
中科院分区：
文献类型：
--
作者：
R. Williams;J. Brasington;D. Vericat;D. Hicks
辫状河形态的定量化是了解辫状河行为的关键任务。在过去的十年中，地理信息技术和相关数据处理方法的发展已经改变了精确的，范围尺度地形数据集的生产。然而，生成精确的数字高程模型（DEM）仍然是一项艰巨的任务，特别是在河流系统。本文确定了一个三重的挑战与调查这些动态地貌：复杂的救济，淹没浅渠道和高速率的泥沙运输，这些挑战的“形态”，“湿通道”和“流动性”的问题，分别。为了直接面对这些问题，本文提出了一种新的调查方法，该方法将移动的地面激光扫描和非测量航空摄影与数据简化和表面建模技术相结合，以从产生的非常高的分辨率数据集绘制DEM。该方法是用来生成和模拟一个精确的，密集的地形数据集为2.5公里的编织里斯河，新西兰。在高流量事件之间快速采集数据，并在暴露的沙洲和水道表面上结合超过5 x 109个原始调查观测值，点密度为1600 pts m-2。详细的误差分析所产生的亚米分辨率描述量化DEM质量在整个表面模型。这表明，对于这样一个大型和复杂的表面模型，垂直误差是无与伦比的，在模型的暴露和淹没区域分别为0.03和0.12米之间。版权所有© 2013约翰威利父子有限公司.
Quantifying the morphology of braided rivers is a key task for understanding braided river behaviour. In the last decade, developments in geomatics technologies and associated data processing methods have transformed the production of precise, reach‐scale topographic datasets. Nevertheless, generating accurate Digital Elevation Models (DEMs) remains a demanding task, particularly in fluvial systems. This paper identifies a threefold set of challenges associated with surveying these dynamic landforms: complex relief, inundated shallow channels and high rates of sediment transport, and terms these challenges the ‘morphological’, ‘wetted channel’ and ‘mobility’ problems, respectively. In an attempt to confront these issues directly, this paper presents a novel survey methodology that combines mobile terrestrial laser scanning and non‐metric aerial photography with data reduction and surface modelling techniques to render DEMs from the resulting very high resolution datasets. The approach is used to generate and model a precise, dense topographic dataset for a 2.5 km reach of the braided Rees River, New Zealand. Data were acquired rapidly between high flow events and incorporate over 5 x 109 raw survey observations with point densities of 1600 pts m‐2 on exposed bar and channel surfaces. A detailed error analysis of the resulting sub‐metre resolution is described to quantify DEM quality across the entire surface model. This reveals unparalleled low vertical errors for such a large and complex surface model; between 0.03 and 0.12 m in exposed and inundated areas of the model, respectively. Copyright © 2013 John Wiley & Sons, Ltd.