ASSESSING SLOPE STABILITY AND LANDSLIDE HAZARD IN CHAPIMA HEIGHTS, BLANTYRE DISTRICT

Landslide susceptibility is an important topic mainly because its geospatial analysis provides a useful tool for planning, disaster management, and hazard mitigation. In this study, the aim is to identify and analyze landslide susceptibility at a local spatial scale, which is Chapima Heights, Blantyre, using the multi-criteria evaluation (i.e., the analytical hierarchy process technique (AHP) and geographic information systems (GIS)). The following landslide conditioning factors were selected, representing the local terrain predispositions: slope angle, curvature, slope aspect, and elevation. The other factors are rainfall, normalized difference vegetation (NDVI), and land use. The raster-based analysis was conducted on data obtained. After the analysis maps for the chosen factors were created, they were classified and reclassified to risk levels to allow comparability and assigned weights using AHP according to their importance to contribute to the landslides class final map. The AHP results from this research show that the following were the percentages of the contributing factors: slope (42.44%), rainfall (23.84%), NDVI(12.64%), land use (8.67%), elevation (5.82%), aspect (3.89%), and curvature(2.7%). The final map shows that the majority of the area has low to moderate landslide susceptibility, with only the southwestern part being highly susceptible due to the steepness of the area. The validation of the results was based on consistency checks through the pairwise comparison of the chosen landslide contributing factors through consistency index and consistency ratio calculations that are 0.05094 and 0.03859, respectively. Finally, I will recommend people living in the southwest to build waterways that will direct the water to flow to safer sites therefore making almost the whole of the area safe in terms of landslide risks during periods of heavy rainfall.

In this study, the aim is to identify and analyze landslide susceptibility at a local spatial scale, which is Chapima Heights, Blantyre, using the multi-criteria evaluation (i.e., the analytical hierarchy process technique (AHP) and geographic information systems (GIS)). After the analysis maps for the chosen factors were created, they were classified and reclassified to risk levels to allow comparability and assigned weights using AHP according to their importance to contribute to the landslides class final map. The validation of the results was based on consistency checks through the pairwise comparison of the chosen landslide contributing factors through consistency index and consistency ratio calculations that are 0.05094 and 0.03859, respectively. Finally, I will recommend people living in the southwest to build waterways that will direct the water to flow to safer sites therefore making almost the whole of the area safe in terms of landslide risks during periods of heavy rainfall.

It is located in between Chileka Road to the east and M1 Road to the west and makes boundaries with Mussa to its northwest, Mbayani to its southwest, Chirimba to its north, and Nyambadwe to its southeast. The study area is situated within the largest perthite gneiss and perthosite outcrop in the country that covers an area of about 200 square miles, which forms hills of Ndirande, Bangwe, Mikolongwe, Mpingwe, Soche, and many other small hills within the vicinity of the area, which is of the basement complex that formed during the Precambrian to lower Paleozoic and are generally ridge-like in form (Evans, 1965). Geographical Extent: 715237E to 717637E and 8257645N to 8255845N.

Traditional authority: TA Kuntaja

District: Blantyre

Coordinates: -15.6563, 34.907