OCCURENCE OF LANDSLIDES WITHIN MURANG'A COUNTY
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Several cases of landslides, mainly triggered by rainfall and human activities have been reported in the past and of recent in Kenya, mostly along Murang’a, Kisii and Mt Elgon region. Landslides are common in highly mountainous landscapes with ragged terrain. Sediment supplies from storm floods and by over steepening of dispositional slope and water movement triggers the slides. Due to the steep physiography and high sedimentation rates within Murang’a county, slumps, debris flows and turbidity currents are common. The county is the most prone part in Kenya, with the most number of recorded events. This project aimed at zoning hazard areas, In order to reduce subjectivity and quantify the degree of susceptibility. Data treatment techniques have been incorporated. With these techniques, landslide-susceptible areas are determined by correlating some of the main factors that contribute to the occurrence of slope failure, such as steep slopes or presence of weak lithological units, with the past distribution of landslides. The method used for establishment of correlation is, the overlapping of maps of instability factors with the landslide inventory map. Acquired area DEM is used to get the different slope angles, hillshade, curvature and aspect. With the use of a developed inventory map, these factors have been correlated to the landslide scars so as to categorize different slopes according to their degree of failure. This is aimed at minimizing loses caused through availing an easily interpreted map that can give guidance on where to settle and at what point properties are at jeopardy. The clearance of vegetation covering different slope can as well be controlled on slopes considered to fall within the failure margin.