
Inland
Valleys
Inland valleys are the upper reaches of river
systems, in which alluvial sedimentation processes are completely or almost
absent. Inland valleys comprise the whole valley cross-section, i.e. valley
bottoms, which may be submerged for part of the year, their hydromorphic
fringes, and the contiguous upland slopes and crests extending over the area
that contributes runoff and seepage to the valley bottom.
Inland valleys constitute an important
agricultural and hydrological asset at local and national level, and can make a
major contribution to food security and poverty alleviation. They cover
approximately 190 million hectares in Sub-Saharan Africa, which is about 8% of
the land area. Only a small fraction of the inland valleys, probably less than 15%, is currently utilized, mostly in the sub-humid and humid zones. Crop yields are often low and cultivation is limited by constraints.
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Lack of appropriate water management
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Weed problems
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Lack of
labor
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Human diseases associated with lowland
environments
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Land-tenure arrangements
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Limited access to input
and output markets
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