Optimal use of rainfalls, especially snow and rain in arid and semi-arid regions, can play an important role in providing water requirement for the green space in the dry seasons. On the other hand, poor vegetation can cause erosion and destruction in Sloping lands that can be partially resolved if water and soil resources are properly managed. Rainfall is one of the most important sources of water supply for various uses. One way to collect rainwater is too impermeable the surface of the earth and to maximize runoff from rainfall. Impermeable surfaces can be naturally occurring like rock surfaces or can be artificially covered with materials such as asphalt, concrete, insulating sheets such as plastic, geomembrane and decamond. This study, which was carried out in the northern part of Tabriz, was conducted in four treatments, each with three replications of 4 m2 (2m×2m), including geomembrane cover area, plastic cover with sand protection, natural surface and natural surface with sand mulch. Results of 78 rainfall events over two years showed that in intermediate slopes of 33-38.6%, runoff from rainfall for geomembrane, plastic cover with sand protection, natural surface and natural surface with sand mulch were 84, 67, 3 and 2% of rainfall respectively and rainfall threshold for runoff at mentioned surfaces was 0.28, 2.56, 9.95 and 11.12 mm, respectively. Therefore, with respect to annual normal rainfall (245.7 mm), the volume of runoff accumulated for geomembrane, plastic cover with sand protection, natural surface and natural surface with sand mulch will be 206, 164, 7 and 5 liters /m2 in year, respectively. Comparing the means, the geomembrane cover treatment was identified as a suitable option for runoff production. Also, Sand mulch on the natural surface reduces soil erosion tenfold and reduces soil erosion from 97 gm/m2 to 9.5 gm/m2 in two years. |