基于Sentinel-1数据的巢湖流域洪涝灾害信息提取与分析

2020 Chao Lake basin flood information extraction and analysis based on Sentinel-1 data

洪涝灾害往往会造成巨大损失,分析洪水淹没范围、回溯洪涝灾害演进过程,为洪涝灾害应对提供决策支持十分必要。合成孔径雷达(SAR)具备全天候、全天时、有一定穿透能力的特性,可在有云层时获取地表数据,能为洪涝灾害研究提供数据支撑。本文以2020年巢湖流域洪涝灾害为例,基于灾害期间多期Sentinel-1 SAR影像,使用大津法提取洪水范围,结合巢湖流域内水利工程数据,分析巢湖流域洪水上涨和回落过程,为完善巢湖流域防洪减灾体系提出建议。结果表明,当巢湖水位上涨至11.25 m后,洪灾范围迅速增加,在此水位前即需人工主动干预,启用圩口蓄洪、加速流域内洪水外排。

Flood often cause huge losses.To provide a better support for the decision making during the flood,it is necessary to analyze and trace back the scope and evolution process of the flood.Synthetic aperture radar(SAR)is able to provide certain penetration for all weather and all time.SAR is able to observe the surface in cloudy weather and provide data support for flood research.Taking the flood in Chaohu Basin in 2020 as an example,based on the images taken by multi-phase Sentinel-1 SAR and water conservancy project data,this paper uses the Otsu method to obtain the range of the flood,and analyzes the rise and fall process of the flood.This paper also provide suggestions for improving the flood control and disaster reduction system in Chaohu Basin.The results show that the scope of the flood is increasing rapidly when the water stage of Chaohu Lake reaches 11.25m,it is necessary to require manual intervention before the water stage,such as using the polder mouth to store the flood,accelerating the flood discharge.