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（最近一次是在艾伯塔省和大草原）感受到了河流洪水的影响，这些事件造成了数百万美元的损失。在新斯科舍省，2012年洪水受到洪灾的严重影响。 CBCL是一家位于哈利法克斯的工程公司，NSCC的应用地理研究小组（AGRG）提议采用创新的激光雷达技术，以更好地了解河流系统，并通过更明智的缓解策略来理解河流系统，从而耗尽河流的影响，以减少洪水事件的影响。分水岭和洪泛区的地形或高程和土地使用与河流泛滥和何处有关。可以使用各种公认的技术（空气照片，卫星图像和激光速度计 - LIDAR）对流域的土地使用和地形的此信息进行映射。但是，为了了解河流在洪水平原上溢出之前可以容纳多少水，我们必须知道河流底部和河岸的高度。用于预测河流洪水的液压模型需要准确的河流横截面几何形状和洪水平原海拔。当前，缺乏代表这些关键模型输入的足够的调查数据。收集这些数据的传统调查技术，例如在河上涉水或表演浅水船的回声调查是昂贵且潜在危险的。 NSCC的新映射系统，Topo-Bandymetric LiDAR，利用安装在飞机中的激光器精确测量河流周围的地形，并且还可以在水中看到以测量以下水平。传感器将测量河底地形，底部粗糙度和成分，包括植被，可能导致摩擦并减慢水的流动。该传感器还能够准确测量人为特征，例如桥梁在系统内的水流瓶颈。随着LIDAR传感器安装在飞机中，可以迅速调查大面积，并提供比传统方法更多的信息。与以前的方法相比，这种新方法有可能提高我们以更便宜的成本准确地绘制河流系统的能力。