Sustainable mountain development in East Africa in a changing climate

a crucial source of water for the whole subregion, providing water for domestic, industrial, irrigation and hydropower uses (UNEP, 2014). In Rwanda, for example, annual precipitation varies from less than 700 mm in the lowland areas in the east to over 1,500 mm in the more mountainous areas of the west (MoNR, 2012). Some of the subregion’s largest cities depend on mountains for their water supply: Dar es Salaam gets its water from the Ulguru Mountains (part of the Eastern Arc Mountains) and Nairobi is supplied by the Aberdare Mountains (Fisher et al., 2011; NEMA, 2011). Mount Kenya alone provides fresh water to about 7 million people (Kohler and Masseli, 2012). Key ‘water towers’ in East Africa include the Albertine Rift, the Kenyan Highlands and the Ethiopian Highlands. Some water towers, such as the Albertine Rift and Mount Elgon, are transboundary. Rivers originating from the mountains cross national borders; these include the White and the Blue Nile, which drain into the Nile River. The transboundary nature of East Africa’s water resources calls for international cooperation for resource use and protection (UNEP, 2010; UNEP, 2014). The impact of climate change on East Africa’s water resources is not yet fully understood. There are a number of uncertainties around future precipitation trends; findings from scientific studies vary significantly – some forecast an increase in water availability, while others a decline. Nonetheless, the majority of studies project that water availability in the subregion will increase due to climate change (Bates et al., 2008; Niang et al., 2014). A study by Döll (2009), for example, predicts that climate change will have a positive effect on groundwater recharge in East Africa. According to some climate change models, most areas in East Africa can expect an increase in groundwater recharge

Water Towers

Major Rivers

Countries

Southern Highlands

Great Ruaha

Tanzania

Albertine Rift

White Nile Congo

Sudan, South Sudan, Rwanda, Tanzania, Uganda, DR Congo

Kenyan Highlands

Tana Ewaso Ng’iro

Kenya Kenya, Somalia (Juba) Ethiopia, Sudan Ethiopia, Somalia Ethiopia, Somalia Ethiopia, into Sudan

Ethiopian Highlands

Blue Nile Juba Shabelle Omo Atbara

Murchison Falls, Uganda

22