Indigenous Knowledge and Techniques of Runoff Harvesting (Bandsar and Khooshab) in Arid and Semi Arid Regions of Iran

Abstract

Two-thirds of Iran’s landmass is considered a desert-land devoid of forests and green pastures. Such a harsh environmental condition ancient Iranian innovated amazing techniques and knowledge for supplying water, which are recently called indigenous knowledge. Rain water and runoff harvesting techniques are often applied to increase the water recharge and consequently productivity in arid regions. The sizes of runoff harvesting structures are varying form micro to macro landscape. Qanat, Khooshab, Bandsar and Degar are the most famous indigenous techniques of water resources management in Iran. We tried to introduce two methods (Bandsar and Khooshab), their classification and structure as well as benefits. Bandsar is a kind of flood farming structure ground water recharge prevailed in Khorasan province of eastern Iran. Depending on rainfall, land topography and geomorphology of area, different types have been established to use floods and agricultural activities. Their area is about 0.5 to 5 ha in alluvial fans and piedmont plain . Its structure consists of plots, basin and levee along contour lines and dry rivers. The upland generated runoff is stored in the basin to infiltrate. Moreover, the fine trapped sediment in Bandsar as a fertile material cause to improve sandy soils. Khooshab is another traditional method used in southeast of Iran (Sistan va Baluchistan). It is a wall structures built across or along the dry river to catch the summer Monson floods water and cultivation as well as combat to wind erosion. Their areas are about 1 - 10 ha and crops such as wheat, maize and barely are produced through them . Flood plains and piedmont are the best location for Khooshabs which caused aquifer recharging. This work tries to explain about environmental condition affect the outcomes of mentioned techniques and their side effects on decreasing soil erosion, flooding and desertification as well as productivity increasing in some parts of Iran . Our findings revealed that the efficiency of traditional knowledge is closely integrated with environment conditions and socio-economic situation of rural community such as participatory. However, they can act as a good alterative in conjunction of new technological methods .