New approaches to estimating flood flows via surface videography and 2D &3D modelling

在所有能够造成灾害的自然灾害中，洪水是造成生命损失的最常见原因。洪水管理的核心内容是准确确定渠道的洪水输送和水位。 EA 和 DEFRA 发布的报告（2002 年和 2004 年）将由于主河道和洪泛平原的粗糙状况而确定洪水时期水流阻力的不确定性列为高度优先级。流阻的主要不确定性是由于缺乏足够的空间速度和水面高程数据而产生的，因为在洪水期间测量速度极其困难且危险。该提案引入了一种新颖的洪水期间流速和水面高程测量技术（远程控制），在黑水河上的工程两级河道中使用 PIV、DP 和 ADCP 技术。该站点配备了 EA 的基本测量设施，因此是研究溢流水流结构的理想站点。洪泛平原上的植被包含多种植物类型，使其成为调查植被流阻参数以及河流栖息地调查正在开展的新工作的理想场所。 3-D 数值模型用于重建内部湍流结构并研究粗糙度对流动行为、存储容量和洪水风险的影响。

Of all natural hazards capable of producing disasters, flooding is the comst common cause of loss of life. A core component of flood management is accuarte determination of flood conveyance and water level in channels. The reports (2002 & 2004) published by the EA and DEFRA ranked the uncertainty in determining flow resistance in times of flood, due to roughness condition in the main channel and on the flood plains, as of high priority. The main uncertainty in flow resistance arises because of lack of sufficient spatial velocity and water surface elevation data, since it is extremely difficult and dangerous to measure velocity during floods. This proposal introduces a novel velocity and water surface elevation measuring technique (remote control) during floods using PIV, DP and ADCP techniques in an engineered two stage channel on the River Blackwater. This site is well equipped with basic measuring facilities by the EA, so is an ideal site to study flow structures for overbank flow. Vegetation on the flood plains contains many plant types making it a good location for investigating the flow resistance parameters for vegetation, along with new work being developed by the River Habitat Survey. 3-D numerical models are used to reconstruct internal turbulent flow structure and to investigate roughness effects on flow behaviour, storage capacity and flood risk.