Runoff (floodwater) farming and rural water supply in arid lands

Abstract

This note provides a brief introduction to a series of 'theme papers' in Applied Geography which describe recent research on runoff or floodwater farming and water supply in rural areas in arid lands (Bruins et al. 1986; Gale and Hunt 1986 ; Nabhan 1986a,b ; Brunner and Haefner 1986 ; Hulme 1986 ; and Davies 1986) . The various terms which have been used to describe the irrigation and farming of marginal arid lands by capturing and concentrating surface runoff are discussed in Bruins et al . (1986) . In the past the term `floodwater farming' has been widely adopted following its use by the geologist Kirk Bryan (1929) to describe the surfacewater harvesting and farming techniques of the Indians of Arizona and adjacent states . In many arid lands the surface water used is often derived largely from a few storms, hence the term floodwater farming is particularly appropriate when the centres of cultivation are in valleys or basins on upland plateaux . Approximately one-half of the world's nations live partly or wholly in arid or semiarid lands . Le Houerou and Lundholm (1976) estimate that 3-5 per cent of the lands in the world's arid zone, which lie beyond those that may be cultivated reliably using conventional dryland farming methods, might be brought under cultivation using the techniques of runoff farming . The significance of these figures in a hungry world is self-evident .