Flood risk assessment using GIS and remote sensing in Tsholotsho District, Matabeleland North in Zimbabwe

Abstract

Floods are one of the most widely distributed hazards globally, and their management is an essential issue of concern among all stakeholders, especially in developing countries. Flooding is one of the most significant natural hazards affecting the Tsholotsho District, causing widespread damage to infrastructure and the natural environment and endangering people's lives. This study assessed flood hazards and risk areas in the District using remote sensing (RS), Geographic Information Systems (GIS), and analytical hierarchy process (AHP). Six main factors were considered to identify flooding hazard wards in the District: drainage density (DD), flow length, elevation, Normalized difference, vegetation index (NDVI), slope, and distance from the river. The study also identified five flood risk zones: high, moderate, low, and very low. The result of the flood risk map revealed that the low-risk area was 433699.57 hectares (56%), the moderate-risk area was 278328.41 hectares (36%), and the very high risk was 41060.25 hectares (5%) of the District. The results indicate that low-lying areas, mainly adjacent to major rivers such as the Gwayi and Manzamnyama Rivers, are highly susceptible to flooding, exacerbated by land degradation and deforestation. The study highlights the critical role of integrating GIS and remote sensing in flood risk assessment, providing decision-makers with valuable insights for developing early warning systems, flood hazard zoning, and sustainable land management practices. Recommendations for improving flood resilience in Tsholotsho District include community-based disaster risk reduction programs and the implementation of adaptive infrastructure.