| چکیده انگلیسی مقاله |
Runoff components are the most important factors in explaining hydrological behaviour of a system. So that the proper understanding of the runoff processes may effectively help managers and decision makers adopt appropriate measures. In this regard, controlling different factors of runoff processes may consequently allow efficient management of other processes like soil erosion and nutrient loss. Although, there are many ways to handle runoff generation, but the application of environmentally bio-based economic approaches has been rarely reported. The present study has therefore tried to investigate the role of inoculation of cyanobacteria on runoff components under rain simulation conditions at the mid-sized (i.e., 6×1m) plots installed at ≈ 30 % slope steepness. Accordingly, cyanobacteria was inoculated on 6-m2 plots in three replications and filled by erosion-prone marl soil collected from Marzanabad Region, Northern Iran. The treated plots were subjected to a simulated rainfall with intensity of 50 mm h-1 and initial duration of 30 min. A simulated runoff of 2.18±0.32 L was also performed simultaneously on the onset of starting surface runoff. A regular measurement of runoff from the plots was also made with 2-min intervals. The results showed significant differences (P<0.010) in hydrological behaviours in control and treated plots. So that no surface runoff was produced in treated plots up the end of initial duration of 30 min of simulated rainfall. Whilst, the runoff was commenced in control plots just after 2.34±1.09 min. The rainfall simulation was then prolonged for further 30 min to facilitate comparative study of the runoff elements. The volume of runoff, time to peak and runoff coefficient, infiltrated water and seepage in control plots were found 109.10±21.91 L, 14.21±4.69 min, 42.61±8.55 %, 130.90±21.91 L and 0.00 L, respectively. While the similar study variables of volume of runoff, time to peak and runoff coefficient, infiltrated water and seepage in cyanobacteria inoculated plots after commencing runoff at 32.07±3.63 min of rainfall simulation were 63.09±14.11 L, 52.74±3.61 min, 15.17±4.15 %, 228.15±12.38 L and 98.75±5.65 L, respectively. The results of the study clearly revealed that cyanobacterization not only postponed runoff generation but also effectively inhibited runoff components even if the rainfall incident extends for longer periods. The positive effect of cyanobacterization on increasing infiltration and potential storage of water in the beneath of the soil was also verified in the present study, which obviously suggests the profitable application of cyanobacteria for regulating hydrologic components. |
