Trapezoidal bunds are efficient water harvesting structures for crop production in the arid and semi-arid lands with annual rainfall between 200 and 500 millimetres. Trapezoidal bunds are used to enclose large areas of up to 2 hectares in order to impound water for crop production. They are derived from enclosing 3 sides of a plot while the upslope side is left open to allow entry of runoff, with excess being discarged at the tips of the wings. Crops, fodder or trees are planted within the enclosed area.
This video demonstrates the processes and techniques of planning, construction and maintenance of such bunds.
More info: http://www.worldagroforestrycentre.org/
Produced by: World Agroforestry Centre