Leila Gholami; Ataollah Kavian; Abdulvahed Khaledi Darvishan; Azame Alipour; Zahra Besarand
Abstract
Determination of time to runoff and runoff volume in watershed response management against rainfall are the key parameters in watershed system management. Among different factors of effect on time to runoff and runoff volume, the rainfall intensity is one of the most important factors. In this study, ...
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Determination of time to runoff and runoff volume in watershed response management against rainfall are the key parameters in watershed system management. Among different factors of effect on time to runoff and runoff volume, the rainfall intensity is one of the most important factors. In this study, the effect of rainfall pattern on variables of time to runoff, runoff volume and coefficient was studied under simulated rainfall in the southeastern Noshahr city, Mazandaran province. To achieve the study purposes, four rainfall patterns, each with three changes in rainfall intensity (I: Low-Medium-High, II: Low-High-Low, III: High-Medium-Low, IV; High-Low-High) were simulated. Then, the time to runoff, runoff volume and runoff coefficient were measured for each rainfall pattern. The measured data were analyzed in Excel and SPSS 23 softwares to determine the relationship between the rainfall pattern and variables of time to runoff, runoff volume and runoff coefficient. The results showed that there was a significant difference (P≤0.05) in variables time to runoff, runoff volume and runoff coefficient resulted rainfall patterns. Also the results showed that, in all of rainfall patterns between mean amounts were the significant differences on time to runoff, runoff volume and runoff coefficient in level of 99 percent. The results showed that the rainfall pattern I had the longest time to runoff and rainfall pattern III had the largest amounts of runoff volume and runoff coefficient. The average time to runoff in rainfall patterns of I, II, III was 5.90, 4.24, 0.71 and 1.25 min, respectively. Also, the average runoff coefficient in rainfall patterns of I, II, III and IV measured 30.03, 49.63, 88.82 and 75.16 percent, respectively.
Leila Gholami
Abstract
In severely eroded areas, especially steep slopes, establishment of vegetation cover is not possible. The application of organic and inorganic amendments can therefore improve the conditions leading to establish vegetation cover through playing an effective role in runoff control. Accordingly, in the ...
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In severely eroded areas, especially steep slopes, establishment of vegetation cover is not possible. The application of organic and inorganic amendments can therefore improve the conditions leading to establish vegetation cover through playing an effective role in runoff control. Accordingly, in the present study, woodchips as a soil organic amendment was applied to control runoff variables including time to runoff, runoff volume and coefficient. For this purpose, three levels of woodchips treatment of 0.5, 1.0 and 1.5 kgm-2 were used in three replications at in 1 m2- plot scale. The plots were located in 30% slope in accordance with field conditions under simulated rainfall of 60 mmh-1 and duration of 15 min. The results showed that application of woodchips in 0.5, 1.0 and 1.5 kgm-2, time to runoff increased 97.50, 192.38 and 203.31%, respectively. The runoff volume decreased 35.23, 55.11 and 60.43% and runoff coefficient also decreased 42.43, 67.40 and 72.14% in three levels of woodchips treatments, respectively. The results of GLM showed that woodchips treatment had a significant increasing effect on time to runoff (p≤0.01) as well as a significant decreasing effect on runoff volume and coefficient (p≤0.05). The application of woodchips as a conservation treatment on the soil surface showed that this amendment can be used for runoff control especially where large quantities of woodchips are simply available.
