Analysis of gully erosion as a hydro-geomorphological hazard in Thulamela Municipality, Limpopo Province, South Africa

Abstract

Gully erosion, a severe form of environmental process, poses significant global environmental and socio-economic challenges, worsened by deforestation, overgrazing and climate change. This study examines gully erosion as a hydro-geomorphological hazard in Thulamela Municipality, Limpopo Province, South Africa. The aim of this research was to investigate the occurrence and intensity of gully erosion in Thulamela Municipality. The study's first objective was to map gully distribution in Thulamela Municipality. The second objective was to map the severity of gullying. The third and last objective was to map factors contributing to gully erosion formation. This study investigated the three objectives across four temporal benchmarks (2008, 2013, 2018 and 2023) using GIS and Remote Sensing techniques. Distribution in gully occurrence was tracked through interpolation. Sampled gullies were overlaid to assess their size and shape transformation over time to determine the severity of gully erosion. Land use/cover changes were classified to track how they influenced gully development over the 15-year period. Topography was analysed based on elevation, terrain characteristics, flow accumulation and flow direction to determine areas that are more prone to gully development. Rainfall was assessed based on its intensity and distribution over the period of the study to determine how it contributes to gully erosion. Soil moisture was analysed to determine susceptibility to gully erosion. The results revealed a significant and exponential increase in gully development influenced by all the analysed factors. The findings highlight that Thulamela Municipality contains areas highly susceptible to gully erosion, presenting severe threats to land stability, safe habitation and sustainable development.