University of Tehran Press Iranian Journal of Soil and Water Research 2008-479X 51 11 2021 01 20 Effect of Slope Angle on Water Harvesting Using Kajaveh Method Effect of Slope Angle on Water Harvesting Using Kajaveh Method 2913 2923 77838 10.22059/ijswr.2020.306234.668670 FA Mohammad Reza Hami Kouchebaghi Department of Irrigation and Development - Campus of Agriculture and Natural Resources - University of Tehran - Karaj - Iran 0000-0002-2865-5928 Teymour Sohrabi Professor, Department of Irrigation and Reclamation Engineering, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. 0000-0001-7571-4604 Arezoo Nazi Ghameshlou Assistant Professor, Department of Irrigation and Reclamation Engineering, Faculty of Agricultural Engineering and Technology, University College of Agriculture and Natural Resources, University of Tehran, P. O. Box 4111, Karaj, 31587-77871, Iran. 0000-0003-2283-8026 Journal Article 2020 07 22 In areas where annual rainfall is less than the crop water requirement, providing water for plant is necessary to grow properly without stress. One of the methods that have least damaging to the environment is rainwater harvesting techniques. The Kajaveh system is a local rainwater harvesting system that can be used in very low-slope areas and can be used in a mechanistic manner for annual crops. In order to investigate the operation of the rainwater harvesting system, computer simulations were performed. Estimating rain infiltration on sloping surfaces is the main part of this simulation. In this research, a semi conceptual- experimental method was used to estimate the infiltration of rainfall on sloping surfaces and find a structure with suitable geometric dimensions to rainwater harvesting. The results of the simulation that was prepared using this method were compared with the experimental data and after calibrating the simulation, it was used to study structures with different wall slopes. The results indicate that there is an optimal slope in which the maximum ability of the Kajaveh system to water concentrate occurs. For the soil whit Sand-Loam type, Aggregate structure, precipitation intensity of 11.49 cm per hour, rainfall duration of 10 minutes and in the conditions of structure formation in this research, a square base structure with 50 cm length and cavity depth of 10 cm (wall slope of about 22 degrees) showed the highest efficiency in water concentrating. In areas where annual rainfall is less than the crop water requirement, providing water for plant is necessary to grow properly without stress. One of the methods that have least damaging to the environment is rainwater harvesting techniques. The Kajaveh system is a local rainwater harvesting system that can be used in very low-slope areas and can be used in a mechanistic manner for annual crops. In order to investigate the operation of the rainwater harvesting system, computer simulations were performed. Estimating rain infiltration on sloping surfaces is the main part of this simulation. In this research, a semi conceptual- experimental method was used to estimate the infiltration of rainfall on sloping surfaces and find a structure with suitable geometric dimensions to rainwater harvesting. The results of the simulation that was prepared using this method were compared with the experimental data and after calibrating the simulation, it was used to study structures with different wall slopes. The results indicate that there is an optimal slope in which the maximum ability of the Kajaveh system to water concentrate occurs. For the soil whit Sand-Loam type, Aggregate structure, precipitation intensity of 11.49 cm per hour, rainfall duration of 10 minutes and in the conditions of structure formation in this research, a square base structure with 50 cm length and cavity depth of 10 cm (wall slope of about 22 degrees) showed the highest efficiency in water concentrating. https://ijswr.ut.ac.ir/article_77838_8a724dffdc7bb9d2dc94c0d228adf5b1.pdf