சுற்றுச்சூழல் & பகுப்பாய்வு நச்சுயியல்

Using Satellite Data Analysing Cyclone Ana in the Mozambique Channel

Abstract

Javed Khan

A simplified impact assessment of tropical cyclones on coastal habitats, particularly in the Mozambique Channel, still lacks sufficient information. We modelled the extent of flooding and its impact following the "severe tropical storm" Ana, which passed over the Mozambique Channel from January 20 to January 25, using data from Sentinel-1 and Sentinel-2 and socio-ecological parameters like mangrove forest health and population density. We adapted a model from the United Nations Platform for Space-Based Information for Disaster Management and Emergency Response (UN-SPIDER) to effectively assess storm impacts at a resolution of up to 10 meters, focusing on areas affected by Ana, the Sofala, Zambezia and Boeny, Melaky, provinces in Mozambique and Madagascar, respectively. Our findings revealed that more than 195,977 people have the potential to be affected by Ana, while this number was reduced to 79, The Boeny province was responsible for the majority of the flooding as a percentage of its total area, but the majority of the flooding occurred in the central region of Zambezia. The Sofala district of Mozambique showed the most noteworthy impacted populace and most elevated impacted metropolitan region, with 108,400 uncovered individuals. However, it was discovered that urban areas accounted for only 1.4% of the flooded areas in all regions of interest (ROIs) that were affected. Despite the presence of degraded mangrove patches in close proximity to barren areas at a fine scale low mangrove normalized-difference vegetation index (NDVI) changes were observed throughout all ROIs prior to the 2021–2022 cyclone seasons. Finally, healthy mangrove forest ecosystems in the Mozambique Channel were found to effectively shield densely populated areas from cyclonic storms for an average of 40 kilometres.