Evaluating a topo-bathymetric lidar sensor to map river channels for improved hydrodynamic flood risk mapping

评估地形测深激光雷达传感器以绘制河道地图，以改进水动力洪水风险地图绘制

• 批准号: 486169-2015
• 负责人: StAmour, Wayne
• 金额: $ 1.82万
• 依托单位: Nova Scotia Community College
• 依托单位国家: 加拿大
• 项目类别: Applied Research and Development Grants - Level 1
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=585445
• 关键词: Evaluating; topo; bathymetric; lidar; sensor

The impacts of river flooding have been felt by many communities, most recently in Alberta and the prairies, where these events have caused millions of dollars damage. In Nova Scotia, communities were severely impacted by flooding in 2012. CBCL, a Halifax based engineering company, and NSCC's Applied Geomatics Research Group (AGRG) are proposing to adopt innovative lidar technology to better understand river systems and contributing areas that drain into the river to reduce the impacts of flood events in the future through more informed mitigation strategies. The topography or elevation of the watershed and floodplain and the land use have a lot to do with why and where a river floods. This information on the land use and topography of the watershed can be mapped using a variety of well-established techniques (air photos, satellite imagery, and laser altimetry - lidar). However, in order to understand how much water the river can hold before it spills out onto the flood plain, we must know the elevation of the river bottom and banks. Hydraulic models used to predict river flooding require accurate river cross-section geometry and flood plain elevations. Currently, there is a lack of adequate survey data representing these key model inputs. Traditional survey techniques to collect these data, such as wading across the river or performing shallow water boat based echo sounding surveys are expensive and potentially dangerous. NSCC's new mapping system, topo-bathymetric lidar, utilizes lasers mounted in an aircraft to precisely measure the topography surrounding a river and can also see through the water to measure what is below. The sensor will measure the river bottom topography, bottom roughness, and composition including vegetation which can cause friction and slow the flow of water. The sensor is also capable of accurately measuring anthropogenic features such as bridges which bottleneck the flow of water within the system. With the lidar sensor mounted in an aircraft, large areas can be surveyed quickly and provide more information than traditional methods. This new approach has the potential to improve our ability to map river systems accurately at a cheaper cost when compared to previous methods.

许多社区都感受到了河流洪水的影响，最近一次是在艾伯塔省和大草原，这些事件在那里造成了数百万美元的损失。在新斯科舍省，社区在2012年受到洪水的严重影响。 总部位于哈利法克斯的工程公司CBCL和NSCC的应用地球信息学研究小组(AGRG)正在提议采用创新的激光雷达技术，以更好地了解河流系统和排泄到河流中的贡献区域，以通过更知情的缓解战略来减少未来洪水事件的影响。流域和泛滥平原的地形或高程以及土地利用与河流泛滥的原因和地点有很大关系。可以使用各种成熟的技术(航空照片、卫星图像和激光测高-激光雷达)绘制关于分水岭土地利用和地形的信息。然而，为了了解河流在溢出到泛滥平原之前可以容纳多少水，我们必须知道河底和河岸的高程。用来预测河流洪水的水力学模型需要准确的河流横断面几何形状和洪泛区高程。目前，缺乏代表这些关键模型投入的充分调查数据。收集这些数据的传统调查技术，如涉水过河或进行基于浅水船只的回声探测，成本高昂，而且具有潜在的危险。 NSCC的新地图系统，地形测深激光雷达，利用安装在飞机上的激光来精确测量河流周围的地形，还可以透过水看到下面的东西。该传感器将测量河底地形、海底粗糙度和包括植被在内的成分，这些成分可能会导致摩擦和减缓水流。该传感器还能够准确地测量人为特征，如阻碍系统内水流的桥梁。激光雷达传感器安装在飞机上，可以快速测量大片区域，提供比传统方法更多的信息。与以前的方法相比，这种新的方法有可能提高我们以更低的成本准确绘制水系地图的能力。