Rainwater harvesting potential in a semi-arid region of Fars Province

Rainwater harvesting using micro-catchment is one of the water resources development options in arid regions that can partly supply water requirement of rain-fed agriculture. Some operations can be performed for increasing the harvesting rainwater in micro-catchment. In this study, the effect of simple treatments including furrowing, clay cover, furrowing and clay cover and control treatments on runoff production were investigated in the form of a complete randomize design with three replications during 2014 and 2015 in Zarrin-Dasht region of Fars Province. Results confirmed the potential of rainwater harvesting in the region. The highest runoff coefficient was observed in control treatment as 6.5 and 9.3% in 2014 and 2015, respectively. Disturbing of surface soil (in various treatments except control) led to average reduction of 11 and 14% runoff amount and coefficient, respectively compared to the control treatment. Threshold Precipitation for Runoff Production (TPRP) was 1 mm in control treatment during two years of the experiment. In other treatments TPRP values reduced in the second year. In view point of the runoff amount and coefficient and also TPRP, control treatment is recommendable in the region. The catchment area varied almost between 15 and 150 m2, respectively, for supply water requirement of 300 and 600 mm with rainfall occurrence probability of 0.50 and 0.67 and runoff storage efficiency of 25 and 50%. In fact, micro-catchment area can be economically determined with crop type.