SPATIAL - TEMPORAL ANALYSIS OF VEGETATION COVER DYNAMICS FOLLOWING CYCLONE FREDDY: A CASE STUDY OF BLANTYRE, MALAWI.

Author
Ganetie Assabie GIS-002-20
2025 Undergraduate
Research theme: Environmental Modelling
Department: Earth Sciences
Program of study: BSc Geo-Information and Earth Observation Sciences
District: Blantyre

Abstract

Cyclone Freddy, a severe tropical storm, struck the Southern Region of Malawi in March 2023 causing extensive environmental damage, Blantyre was one of the affected districts. This dissertation focuses on assessing the cyclone’s impact on vegetation cover through geospatial analysis, with the aim of enhancing understanding of ecological resilience following extreme weather events. The study employed high-resolution Sentinel-2 Multispectral Instrument imagery and applied the Normalized Difference Vegetation Index (NDVI) technique to detect vegetation loss across four selected areas within Blantyre: Nyambadwe, Ndirande, Chilomoni, and Soche-Chilobwe. Data processing and analysis were conducted using Google Earth Engine (GEE), ArcMap, and QGIS platforms. NDVI differencing was used to map spatial and temporal vegetation dynamics before and after the cyclone. Results indicated significant declines in vegetation health, with Ndirande and Chilomoni experiencing the most pronounced degradation, while some resilience and regrowth were observed in parts of Soche and Nyambadwe. The findings underscore the impact of Cyclone Freddy, influenced by topographic and urbanization factors. It is recommended that future resilience-building efforts integrate high-resolution vegetation monitoring and ground-truth validation to support disaster preparedness and sustainable land management planning. The methodology presented can serve as a model for future studies assessing post-disaster ecological impacts in cyclone-prone regions.

Research summary

Cyclone Freddy, a severe tropical storm, struck the Southern Region of Malawi in March 2023 causing extensive environmental damage, Blantyre was one of the affected districts. This dissertation focuses on assessing the cyclone’s impact on vegetation cover through geospatial analysis, with the aim of enhancing understanding of ecological resilience following extreme weather events. The study employed high-resolution Sentinel-2 Multispectral Instrument imagery and applied the Normalized Difference Vegetation Index (NDVI) technique to detect vegetation loss across four selected areas within Blantyre: Nyambadwe, Ndirande, Chilomoni, and Soche-Chilobwe. Results indicated significant declines in vegetation health, with Ndirande and Chilomoni experiencing the most pronounced degradation, while some resilience and regrowth were observed in parts of Soche and Nyambadwe.