The Lesotho Highlands are formed by the Drakensberg and Malotimountain ranges in the east and central parts of the country of Lesotho. Foothills form a divide between the lowlands and the highlands. Snow is common in the highlands in the winter.
Location and description
The Highlands are located to the southeast of the Highveld, encompassing the whole eastern part of Lesotho. The average annual rainfall is nearly 1,000 mm in some parts of the high ranges. Temperature is closely related to elevation in the Lesotho Highlands. In general, the mean July temperatures stay around 7 °C. The Lesotho Highlands form a localized high spot on the Central Plateau of the Great Escarpment. This is because it is capped by a 1400 m thick layer of erosion resistant lava which welled up and spread across most of Southern Africa when it was still part of Gondwana. Most of this lava has eroded away together with a layer of Karoo sedimentary rocks several kilometres thick on top of which the lava was poured out 182 million years ago. Only a small patch of this lava remains and covers much of Lesotho. The Lesotho Highlands have been deeply eroded by the tributaries of the Orange River which drain these highlands towards the south-west by means of erosion gulleys which turn into deep valleys further downstream. This gives this high region its very rugged, mountainous appearance. There are so many of these tributaries that the whole terrain of the highlands has a very rugged mountainous appearance, both from the ground and from the air. The eastern Lesotho Highlands contain numerous terraces and scarp faces developed on ancientflood basalt. The form and development of terraces is controlled by rock structure. The terraces are pediments where cryogenic processes are active. The terraces may be referred as cryoplanation terraces albeit this term is controversial. Each scarp represent a flow unit of the flood basalt. During the last glacial periodperiglacial conditions prevailed in the highlands producing landforms such as blockfields, blockstreams and stone garlands. During the coldest period of the last glacial period—the last glacial maximum— the environment was relatively arid with deep seasonal freezing. The area is believed to have been free of both permafrost and large snow accumulations. There is some uncertainty if small glaciers ever developed in the shadowy slopes around the highlands.
The Lesotho Highlands Water Project is an ongoing water supply and hydropower project in the area of the Highlands. Developed in partnership between the governments of Lesotho and South Africa, it comprises a system of several large dams and tunnels throughout the territory of both countries. The project allegedly is said to have had so far negative social and environmental effects.
