Question

Give a brief background on landslide harzads occurring in south africa

Answer 1

Landslides are a major hazard in most mountainous and hilly regions as well as along steep river banks and coastlines. In many parts of South Africa, landslides continue to be responsible for much damage to infrastructure and land degradation that result in considerable financial losses, as well as some injuries and deaths in the past. The conditions and triggers that lead to landslides form as a result of severe high intensity rainfall events, underlying geology and unstable rock mass conditions in steep terrain, considerable topographic variation, high relief, humid climate, veld fires and/or seismicity. Human activities such as road cutting, slope undermining, and poor farming and silviculture methods also play a prominent contributory role in the frequency of these mass movements.

In response to the needs of local and provincial authorities for effective management strategies regarding the reduction of economic and social losses caused by landslides, the Council for Geoscience has initiated a systematic inventorization and susceptibility mapping of zones prone to slope instability for the entire country. These mapping programs are unique in that no similar systematic studies have been conducted elsewhere in the Southern African region to date. Preliminary susceptibility maps based inter alia on a semi-quantitative, bivariate statistical approach which was aided by the multi-criterion decision-making technique, the Analytical Hierarchy Process (AHP); can now guide planning in the typically hilly areas constraining rural community development in the provinces of KwaZulu Natal and Limpopo as well as parts of the Eastern Cape and Western Cape provinces. Erratic heavy-rainfall events, probably associated with climate change, are increasing in frequency and provide an impetus to rapidly map and define this geo-hazard in the interests of community safety and quality of life.