Determination of Soil Infiltration in Rainwater catchment Areas Using Field Rain Simulator

Soil infiltration is one of the most crucial parts for designing rainwater catchment systems and has an essential role in determining the area for rainwater harvesting. Using the Kamphorst field rain simulator, the infiltration rate of the suitable sites for the rainwater catchment systems has been determined. After selecting the suitable site, the soil was saturated, and the experiments were performed a day later. Simulation experiments have been conducted in two sites. The first site was Pishkamr city in Golestan province and the second site was near Sararood research station in Kermanshah province. The constant slope was at 12%, and the rain intensities were 33, 64, and 110 mm/h for 15 minutes in four repetitions. At the end of the experiment, the total volume of runoff was collected, and the infiltration rate was calculated. The results showed that with increasing rainfall intensity from 64 to 110 mm/h, the runoff volume of Pishkamr and Sararood increased 6.1 and 13.7 times, respectively. The infiltration rate in comparison with rain intensity showed that by increasing rainfall intensity from 64 to 110 mm/h, the infiltration rate increased 16.6% and 25.3% in the Pishkamr and Sararood, respectively. The comparison of the infiltration rate in the two sites also showed that the infiltration rate in the Sararood site was higher than the Pishkamr site. Therefore, with the knowledge of soil Infiltration, suitable rainwater catchment systems can be designed to supply water for plants.