3DGIS支持下的洪水淹没模拟与快速损失评估研究

Research on flood simulation and loss evaluation based on 3DGIS

洪水过程模拟和淹没损失计算是防洪会商中的重要环节,快速呈现洪水风险并估算淹没损失是保障决策会商时效性的基础。针对现阶段研究中洪水模拟效果单一且淹没计算耗时较长的问题,基于OpenSceneGraph图形框架搭建3DGIS环境,实现了三维环境下水体的四类淹没表达,提出了三维地形瓦片支持下的3D射线淹没损失计算方法,并以三峡库区洪水为例开展淹没模拟和损失评估。结果表明:在3DGIS环境下利用四类水体表达方法可从多角度反映洪水淹没风险,并可基于三维场景利用GPU性能加速淹没损失计算,在可接受的精度偏差范围内将计算耗时控制在1.5 s左右,较传统方法大幅减少了计算耗时。该研究可提高防洪会商中风险识别与损失计算的效率,为防洪风险评估和应急转移提供支撑。

Flood simulation and loss calculation are important parts in flood control consultation, presenting flood risk and estimating loss quickly can guarantee the timeliness of decision-making consultation. Aiming at the problem of single flood simulation effect and long time-consuming flood calculation, a 3 DGIS scene is built based on the OpenSceneGraph framework, on which four types of water expression are performed for flood simulation, and the 3 D-ray method is proposed for flood calculation, the flood simulation and loss calculation experiments are then carried out using the flood data of the Three Gorges reservoir area. The results show that in the 3 DGIS scene, the four types of water expression methods can reflect flood risk from multiple aspects, and the flood calculation method can be accelerated using GPU, thus can reduce calculation time to 1.5 s within the acceptable accuracy deviation range compared with traditional methods. This study can improve the efficiency of risk identification and loss calculation in flood control consultations, and provide support for flood risk assessment and emergency transfer.