Spatial understanding of historical and future landslide variation in Africa

Abstract

The African natural landscape reshaping in search for housing, food and infrastructure development exposes the slope to failure. However, the entire African landslide characterization is still not well known due to limited studies covering the whole continent. The authors recognize this fact and conduct this study to present the historical African landslide susceptibility and the 2050 predicted occurrence under urbanization practices. Literature identi es 26,211 recent landslides and high number is localized within same areas highlighted by the 2006-2017 NASA landslide inventory. For periodical landslide susceptibility mapping, rainfall, urbanization and LULC are selected as major drivers based on literature and inventory. Each of these factors' historical maps are estimated to date (2022). These factors are combined with elevation, slope, aspects, curvature, distance to roads, distance to rivers, distance to faults, soil moisture, soil texture and lithology as of 2022 to estimate the current ( 2022) spatial landslide susceptibility. The Information Gain Ratio sensitivity analysis highlights urbanization (0.106), LULC (0.097), slope (0.091), elevation (0.088) and rainfall (0.083) as key landslide drivers. The Southern and Horn of Africa record above 80% of high and very high susceptibility classes. This 2022 susceptibility map is then predicted to 2050 and reclassi ed as that of 2050 urbanization (base map). The Southern, Eastern, Northern and Horn of Africa are landslide prone areas. This new study helps policy makers to ensure proper land planning and management practices for sustainable urbanization and lowering loss on human lives, damage on properties and environment.