Hurricane Maria and Dominica: geomorphological change and infrastructure damage baseline surveys, with verification of mapping from satellite imagery

点击翻译按钮获取中文摘要

During 18-19 September, Category 5 Hurricane Maria devastated the small island developing state of Dominica. Sustained winds of 257 Km/h almost completely stripped the island of its forest cover and caused much destruction of buildings and infrastructure. Intense rainfall and uprooting of trees caused numerous landslides, debris flows and river floods. Debris carried by the floods jammed under bridges, exacerbating overbank flooding and damage to infrastructure. Coarse sediment and tree debris discharged to the sea were transported back onto the coastline by the storm surge, damaging shoreline infrastructure.The impact of Hurricane Maria upon the landscape of Dominica and the consequences for disaster risk reduction in Dominica are the focus of this research. This work is urgent because it must be completed before the landscape is further modified by intense rainfall events in the next hurricane season (June-November 2018). To understand how this either decreases or increases geomorphological hazards, as much survey work as possible needs to be done during the debris clearance phase of the recovery operations. We therefore aim to produce a detailed post-event survey, combining remote sensing and fieldwork, of the geomorphological changes caused by Hurricane Maria and an understanding of their effects on post-hurricane landscape instability, focusing on the damage done to critical infrastructure by flooding, debris flows and storm surge erosion. There are three phases to the project: 1) processing of satellite imagery (both optical and radar), evaluating the effectiveness of remote sensing for damage mapping; 2) Fieldwork and verification survey of slope instability features and damaged infrastructure; 3) Analysis of stakeholder perceptions of vulnerability and resilience, with collation of survey results into an assessment of future geohazards, with recommendations on improved disaster risk reduction and enhanced resilience.The project will have many applications: (i) providing a valuable baseline inventory of hurricane impacts in Dominica's landscape and the ensuing damage to infrastructure; (ii) enabling an accuracy assessment of the hurricane damage maps produced from inspection of satellite remote sensing imagery during the disaster response phase; (iii) enabling an examination of the interaction between hurricane-driven geomorphic processes and ensuing damage to critical infrastructure; (iv) improving our understanding of post-hurricane landscape instability and the DRR implications for reconstruction in Dominica.