Use of fused airborne scanning laser altimetry and digital map data for urban flood modelling
Use of fused airborne scanning laser altimetry and digital map data for urban flood modelling
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DOI：
10.1002/hyp.6343
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发表时间：
2007-05
影响因子：
3.2
通讯作者：
D. Mason;M. Horritt;N. Hunter;P. Bates
中科院分区：
文献类型：
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作者：
D. Mason;M. Horritt;N. Hunter;P. Bates
城市地区的洪水模拟仍处于早期阶段，部分原因是直到最近，城市地区一直缺乏足够高分辨率和准确度的地形数据。然而，由机载激光扫描测高（LiDAR）生成的具有亚米空间分辨率的数字表面模型（DSM）现在已经可用，并且这些模型能够表示城市地形的复杂性。本文介绍了一个激光雷达后处理器的发展，城市洪水建模的基础上融合的激光雷达和数字地图数据。地图数据与激光雷达数据结合使用，以识别城市地区的不同对象类型，但也采用了模式识别技术。后处理生成数字地形模型（DTM），用作模型水深测量，以及摩擦参数图，用于估计空间分布的摩擦系数。在植被覆盖的地区，摩擦力是从LiDAR导出的植被高度估计的，并且（与大多数植被去除软件不同）该方法处理高度小于1.01米的矮植被，即使是城市洪泛区也可能占据相当大的一部分。DTM和摩擦参数图也可用于帮助生成植被覆盖的城市洪泛区的非结构化网格，以供二维有限元模型使用。网格被分解以反映与周围环境具有不同摩擦特性的洪泛区特征，包括城市特征（如建筑物和道路）和较高的植被特征（如树木和树篱）。这允许更准确地估计局部摩擦。该方法产生了大量的节点密度，由于许多城市功能的小尺寸。版权所有© 2007约翰威利父子有限公司.
Flood modelling of urban areas is still at an early stage, partly because until recently topographic data of sufficiently high resolution and accuracy have been lacking in urban areas. However, digital surface models (DSMs) generated from airborne scanning laser altimetry (LiDAR) having sub‐metre spatial resolution have now become available, and these are able to represent the complexities of urban topography. This paper describes the development of a LiDAR post‐processor for urban flood modelling based on the fusion of LiDAR and digital map data. The map data are used in conjunction with LiDAR data to identify different object types in urban areas, though pattern recognition techniques are also employed. Post‐processing produces a digital terrain model (DTM) for use as model bathymetry, and also a friction parameter map for use in estimating spatially distributed friction coefficients. In vegetated areas, friction is estimated from LiDAR‐derived vegetation height, and (unlike most vegetation removal software) the method copes with short vegetation less than ∼1 m high, which may occupy a substantial fraction of even an urban floodplain. The DTM and friction parameter map may also be used to help to generate an unstructured mesh of a vegetated urban floodplain for use by a two‐dimensional finite element model. The mesh is decomposed to reflect floodplain features having different frictional properties to their surroundings, including urban features (such as buildings and roads) and taller vegetation features (such as trees and hedges). This allows a more accurate estimation of local friction. The method produces a substantial node density due to the small dimensions of many urban features. Copyright © 2007 John Wiley & Sons, Ltd.