CLASSIFICATION AND DISTRIBUTION OF RECENT HISTORIC LANDSLIDES IN SOUTHERN NIGERIA

Recent historic landslides in southern Nigeria have been catalogued, c lassified and analysed in terms of their seasonal, geologic and topogr aphic distributions. It is found that 58% of the landslides fall withi n the complex category (mostly slide-debris flows), while only 42% cl assify as ordinary slides. It is also found that, while landslides do not normally occur during the first half of the rainy season (March to June), they can occur in the first month of the dry season (November) after the rains. The peak of the rainy season (September) coincides w ith the greatest number (42%) of the landslides. The distribution reve als that both sedimentary and non-sedimentary (igneous and metamorphic ) terrains are vulnerable with the latter yielding a majority (73%) of the slide-debris flows. Implications of these distributions are discu ssed.