A COMPARATIVE STUDY OF LANDSLIDES AND GEOHAZARD ...

2.2 Characterisation of the Study Areas
The research was carried out in three study areas, namely; the Ntchenachena Area
and the Chiweta Area of the Rumphi District (Northern Malawi), and Mvai/Livilivi
Catchments in the Ntcheu District (Central Malawi) (Figure 2.1b). The Ntchenachena
and the Mvai/Livilivi areas were the primary sites, with Chiweta as a secondary site.
Landslides in the Ntchenachena, the Mvai and the Livilivi areas occurred on natural
slopes as opposed to those at the Chiweta Area which occurred on modified slopes.
2.2.1 Ntchenachena Area
2.2.1.1 Location
The Ntchenachena Area, a country of rugged topography with interlocking spurs, is
located in Rumphi District in the Northern administrative region of Malawi (Figures 2.5
and 2.1b). The area lies on the foot of the Nyika plateau, west of the Uzumara hills. It is
bounded on the western side by longitude 34 0 05’E and on the south by latitude 10 0 35’S
(Kemp, 1975; and GoM, 1977). It covers an area of approximately 264 hectares. The
Ntchenachena hills are a continuation of the Uzumara hills to the north of the South
Rukuru River and they abut the loftier East Nyika escarpments. The Livingstonia coal field
is separated from the Ntchenachena Area by the Rumphi-Chitimba Road (GoM, 1987).
2.2.1.2 Geology
Geologically, the region consists of a basement complex of Pre-Cambrian to Lower-
Paleozoic rocks which is overlain by young sedimentary formations. In Northern Malawi,
the Pre-Cambrian rocks were affected by both the Ubendian and Irumide Orogenies
(Kemp, 1975). The resulting basement complex is largely composed of gneisses and
muscovite schist of south easterly trend and structurally is the continuation of the
Ubendian Belt of south-western Tanzania. The gneisses experienced a long period of
erosion that was followed by deposition, mainly in the Permian and Triassic times of the
Karoo Supergroup (Cooper and Habgood 1959). The Karoo Supergroup comprises
sandstones, siltstones and shale with some coal seams near the base (Bloemfield, 1968;
and Kemp, 1975). Within the study area, the geology of the Ntchenachena Area
consists of highly jointed muscovite schist and biotite gneisses, with a gneiss foliation
trend varying between 278 0 and 114 0 . The average dipping angle is 45 0 . In some
places, the lithology shows the presence of mica schists (GoM, 1977; and Kemp, 1975).
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