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

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.

The primary beneficiaries of this project will be Dominica Government agencies working on recovery and reconstruction after Hurricane Maria, as well as local NGOs and international organisations working with them. The findings of the project will also particularly benefit emergency planning and disaster response organisations by seeking ways of improving the accuracy of the damage maps produced from satellite remote sensing imagery a few days after a disaster event.
We will place data and results from our work in the public domain e.g. as digital maps and associated documents, detailing infrastructure damage distribution, landscape change and hazardous terrain. We will seek to meet stakeholders to convey key results of our work as quickly as possible, in working papers, non-technical summaries and policy briefings.
Here is a summary of impacts for the main beneficiaries:
1. Government agencies responsible for post-hurricane recovery and reconstruction. We will produce a baseline dataset of landscape change and damage to critical infrastructure resulting from Hurricane Maria; ensuring that the data, results and recommendations are made available through our partners in the Dominica Meteorological Service, Ministry of Public Works & Ports, and the Department of Local Government & Community Development.
2. Disaster management organisations, specifically those using satellite remote sensing (RS) for disaster damage mapping and emergency response. That extends from the United Nations (UNITAR), through to international NGOs (e.g. Red Cross, MapAction), all benefiting from our accuracy analysis of the Dominica damage maps produced for the hurricane response and our search for improved methodologies of satellite RS-based feature mapping for disaster management
3. Communities and local NGOs Our NGO partners in Dominica, the Red Cross and the Public Seismic Network, will support our research efforts there, and provide pathways to impact within the country for our findings. Impact opportunities will be maximised by embedding the knowledge generated by this project within the local policy-maker and stakeholder communities.
4. International beneficiaries: the potential benefits are not limited to Dominica, with the project findings likely to be of use in other Small Island Developing States (SIDS) or countries with urban areas in mountainous coastal settings (e.g. Freetown, Sierra Leone). This project maps directly onto Target (d) of the UN Sendai Framework for Disaster Risk Reduction: critical infrastructure and disruption of basic services.
5. The International Research sector will benefit important for dissemination of our findings, via dissemination of our findings by our regional partners: the Centre for Resource Management & Environmental Security at the University of the West Indies, the International Development Research Centre (Canada) and our partners in the DRR and disaster response sectors: UNITAR, ITC and MapAction. We will take every low-cost opportunity to interact with regional and international reconstruction partners, such as the Hurricane Response event of the UK Alliance on Disaster Research (Dec 2017) and the subsequent Overseas Development Institute meeting (Jan 2018). A key aspect of our participation in these international meetings will be to gain input from potential users on priorities for data collection in Dominica.