ABSTRACT
This chapter deals with ways and means of increasing and stabilizing yields through the use of water harvesting techniques, illustrating them with a case in Kenya.
Arid and semi-arid lands (ASAL) occupy approximately one-third of the land surface of our planet and are settled by around 800 million inhabitants. These lands are characterized by low and highly variable rainfall, and the annual precipitation is much lower than the annual evaporative demand of the atmosphere (Lovenstein et al., 1991). The latter is met only during extremely brief periods that occur immediately after rain events. The interannual variability in the total annual precipitation is typically very large (Bruins and Berliner, 1998). In Figure 12.1 these features are presented for a farm located at the border of the arid zone in Israel. This area is characterized by Mediterranean climate with precipitation occurring during the period October-March.
