暴雨洪涝灾情快速监测评估技术框架体系与应用:以2022年6月北江流域洪水灾情分析为例

A technique framework and implementation for rapid survey and assessment of flood disasters:A case study in the North River Basin in June 2022

【目的】暴雨洪涝灾情快速评估在洪灾应急救援和灾后恢复重建中发挥着重要作用,但仍面临诸多挑战。为快速监测和评估洪涝灾情,建立一套集成天空地网多源信息与多种技术的暴雨洪涝灾情快速监测评估技术框架体系,【方法】以2022年6月北江暴雨洪灾为例,综合利用雨量、河道水位、网络淹没图片和视频、卫星遥感影像、地面调研测绘和无人机低空航测等多源数据、水文模型和地理空间分析技术,通过实地调研测绘和无人机航测,结合遥感影像、水力学模型和地理空间分析技术,快速识别本次洪水淹没深度范围、分析淹没区内的受灾人口、房屋、农田等基本灾情,在洪水灾情分析的实战中检验集成天空地网多源信息的暴雨洪涝灾情快速监测评估技术。【结果】结果显示:清远市新增的淹没面积为478 km^(2),其中淹没农田307 km^(2)(64%),淹没区内有74119栋房屋和167306人;韶关市新增的淹没面积为90 km^(2),其中淹没农田46 km^(2)(51%),淹没区内有15629栋房屋和78037人。【结论】结果表明:无人机航测结合地面RTK高程和洪痕测绘,将在洪涝灾情快速调查评估中发挥越来越重要的作用;卫星影像可快速揭示洪水淹没区的总体格局,但受云层遮档和过境时间的影响,难以获取最大淹没范围;洪涝淹没区公众提供的各类网络众包信息是最直接和现时的洪涝灾情信息,需要认真核实和充分利用;结合河道等各类实测水位,HAND模型可以快速估算出淹没深度范围,有很大的推广应用价值。通过对本次北江洪涝灾情的快速模拟和初步分析,充分展示了各类前沿技术在洪涝灾情快速识别中的独特作用,可为洪涝灾情应急监测方案设计和技术准备提供参考。

[Objective]Rapid assessment of flood disasters is crucial in emergency rescue and post-flood reconstruction,but facing many challenges.A technique framework for rapid survey and assessment of flood disasters is presented based on space,air,ground observation and internet information and implemented during flood in the North River Basin in June 2022.[Methods]Multiple sources of observations,including in situ gauge precipitation and water levels,crowd sources of inundation picture and videos,satellite images,ground surveying and mapping,and Unmanned Aerial Vehicle(UAV)drowning,are used together with hydrologic models and GIS to identify the maximum inundation depth,and to compute the inundated areas of farmland,the number of buildings and the affected population in the inundated areas.[Results]In the prefecture city of Qingyuan,the added inundation areas are 478 km^(2),of which farmland is 307 km^(2)(64%),and 74119 buildings and 167306 people are within the inundated areas.In the city of Shaoguan in the upper stream of North River,the added inundation areas are 90 km^(2),of which farmland is 46 km^(2)(51%),and 15629 buildings and 78037 people are within the inundated areas.[Conclusion]The results show that UAV aerial survey combined with ground RTK elevation and flood mark mapping will play an increasingly important role in the rapid investigation and assessment of flood disaster.Satellite images can quickly reveal the overall pattern of flood inundation area,but it is difficult to obtain the maximum inundation area due to the influence of cloud cover and transit time.The various network crowdsourcing information provided by the public in the flooded area is the most direct and current flood disaster information,which needs to be carefully verified and fully utilized.Combined with various measured water levels such as river courses,the HAND model can quickly estimate the range of submergence depth,which has great popularization and application value.The above implementation fully demonstrates the unique functions and shortcomings of various techniques in identifying flood disasters,and offers a reference for emergency surveying,disaster assessment and technique preparations.