Mapping coastal floods induced by hurricane storm surge using ATMS data

ABSTRACT

The coastal floods induced by hurricane storm surge are frequent, costly, and deadly hazards. Accurately and quickly estimating the spatial extent of floods is highly important for relief and rescue operations. In this study, we present an approach to estimate the extent of large-scale coastal floods caused by Hurricane Sandy in late October 2012 using passive microwave remote-sensing data. The approach estimates the water fraction from coarse-resolution Advanced Technology Microwave Sounder (ATMS) data through mixed-pixel linear decomposition. Land and water sample regions generated by river density and land-cover data, the relationship of channels 3, 4, and 16, neighbourhood pixel searching, and the difference of ATMS channels 4 and 3 are all comprehensively taken into account to dynamically determine water and land end members. The difference in the water fraction at the basin scale before and after flooding is calculated to reduce the impacts of soil and vegetation and to avoid pixel-to-pixel errors. Based on the water fraction difference, using the physical characteristics of water inundation that always proceed from the lowest to the highest elevation points in a basin, the flood map derived from the coarse-resolution ATMS measurements was extrapolated to a higher spatial resolution of 100 m using topographic information. Together, these steps represent a water fraction and high-resolution flood (WFHF) mapping process. To evaluate the WFHF mapping methodology presented in this study, the corresponding ground observations (storm-tide sites and high-water-mark data) and the Federal Emergency Management Agency 3 m resolution Hurricane Sandy storm surge flooding (SSF) products are used. The results show that 88% of the storm-tide and high-water-mark sites were located within the WFHF-mapped flood area. There was also good agreement between our WFHF and the SSF areas, with an accuracy of 88% and a correlation of 0.94. Overall, the proposed WFHF methodology was able to produce high-quality and high-resolution flood maps over large-scale coastal areas.

Acknowledgements

The work was supported by NASA Disaster Program:[Grant Number NNX12AQ74G]. The manuscript’s contents are solely the opinions of the authors and do not constitute a statement of policy, decision, or position on behalf of NASA or the USgovernment. Part of this work was supported by National Nature Science Found of China:[Grant Number 41571425] ‘Research on flood and waterlogging quantitative retrieval and super-resolution mapping based on passive microwave remote sensing data.’ We are grateful to the editor and the reviewers for their helpful and constructive comments and suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work was supported by NASA Disaster Program: [Grant Number NNX12AQ74G]. Part of this work was supported by National Nature Science Foundation of China: [Grant Number 41571425].