Geomorphic and Hydrological challenges in Africa: implications for soil and water conservation

Expected scenarios of climate change and population growth confront Africa with various important challenges
related to food, water and energy security. Many of these challenges are closely linked to the impacts of soil erosion
and other geomorphic processes, such as reduced crop yields, sedimentation of reservoirs and reduced freshwater
quality. Despite the urgency and extent of many of these challenges, the causes and dynamics of these processes
and their impacts remain severely understudied. This becomes apparent when the availability of e.g. soil erosion
and catchment sediment export measurements for Africa is compared to that of other continents. Nonetheless,
a substantial amount of geomorphic research has been conducted in Africa. Many of this work dates back from
several decades ago, and were often only reported in ‘gray literature’ (e.g. internal reports). Here we present
an overview of our current state of knowledge on soil erosion and its implications in Africa. We discuss which
geomorphic process rate measurements are currently available and what can be learned from these with respect
to the challenged raised above. We especially focus on our current understanding about the effectiveness of soil
and water conservation techniques at various spatial and temporal scales. Based on specific case-studies (e.g. in
Ethiopia and Uganda) and a meta-analysis of previous work, we highlight some research gaps, research needs and
research opportunities when aiming to use Africa’s soil and water resources sustainably and efficiently