OVERVIEW OF THE IMPACT OF MINING ON THE ... - IIED pubs

The plateaux on both sides of the Lake Malawi Rift Valley are composed of quartzites, sandstones, granites and
gneisses, underlain by sedimentary rocks with coal measures to the east. In the south and north, these rock
formations are intruded by numerous small Greenstone formations that host gold deposits.
In the southern portion of the Shire catchment, extensive deposits of limestone and gypsum are found, as well
as good quality bauxite on Mulanje Mountain. A small deposit of monazite is also found near to Lake Chilwa in
the south.
3.19.1.3 Pedology, agriculture and land use
Soils in the sub-catchment can be divided into three groups:
• Moderately deep to very deep, well-leached ferralitic soils in the wetter northern, western and southeastern
parts of the sub-catchment;
• Moderately deep sandy soils derived from quartzites and sandstones and associated alluvial material along
the floor of the Lake Malawi Rift Valley;
• Moderately deep, sandy loams on areas underlain by limestone deposits; and
• Small areas of sodic soils in the far south of the sub-catchment.
Land use comprises a mixture of densely populated communal lands with extensive subsistence agriculture,
densely populated urban areas of Lilongwe, Zomba, Blantyre, Kotakota and Karonga, with commercial
cultivation of maize, cotton and tobacco. Some stock farming (beef cattle and goats) takes place in the central
and southern portions of the sub-catchment. Tourism on Lake Malawi is extremely important and several
National Parks are located along the length of the rift valley. Numerous small and large communities are
located along the major roads running north south alongside Lake Malawi, and alongside the main roads that
connect Malawi with Zambia, Mozambique and Zimbabwe.
3.19.1.4 Surface water users
Large volumes of water are consumed by small- and medium-scale irrigation agriculture along the banks of
rivers leading to the lake. Most of the water used for domestic consumption in the larger towns is obtained from
nearby streams or dolomite formations.
3.19.1.5 Water management systems
The area falls under the jurisdiction of the Malawi Department of Water Affairs.
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