Parviz Abdinezhad; Parviz Moradi
Abstract
In this research, some effective factors on stability and sedimentation of woven-wire check dams within marly areas were studied. For this pupose, data of 380 light-weight metallic dams were collected during field study and Pearson correlation coefficients and regression analysis of variance of SPSS ...
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In this research, some effective factors on stability and sedimentation of woven-wire check dams within marly areas were studied. For this pupose, data of 380 light-weight metallic dams were collected during field study and Pearson correlation coefficients and regression analysis of variance of SPSS statistical software were used in analysis procedures. The results showed that there were significant relation between width, length and volume of dams with stability at confidence level of 99% and according to correlation coefficients, width of dam showed a higher correlation in comparison to two other variables, but length of dam holds the second place. On this respect, dimensions of dams were among the effective factors on their stability. The stability of dams also represents an inversely linear relationship (correlation coefficient of 0.24) with volume of sediment accumulated behind them. The link between length and width to volume of accumulated sediment favors a direct linear relationship, and based on their correlation coefficients (0.69 and 0.23 respectively) the impact of length of dams is greater. In general, to reach a desired stability of these dams, their dimension must be in accordance with standards and must be determined using respective equations.
Farzad Bayat Movahhed; Davood Nikkami; Mohammad Tokasi; Parviz Moradi; Hamideh Daghigh
Abstract
In arid and semi-arid regions the precipitation occurs erratically, and often, with high intensity which causes sediment production and soil loss especially in the areas ploughed parallel to the hill slope direction. In such areas, we can reduce those undesirable effects through employing proper management ...
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In arid and semi-arid regions the precipitation occurs erratically, and often, with high intensity which causes sediment production and soil loss especially in the areas ploughed parallel to the hill slope direction. In such areas, we can reduce those undesirable effects through employing proper management method. In this survey the effect of two treatments of applying straw mulch in standard plots and over three slope classes of 0-12, 12-20, and 20-40 % with three replicates in the split plot format on the base of RCB design were compared. In all plots, the parallel plough to slope direction was done. After wheat cultivation, on the half of plots, straw mulch was applied uniformly by hand on the soil surface. After any rainfall events, the amount of sediment was measured. Results showed that application of straw mulch caused a reduction of about 36.9, 10.8, and 55.4 % soil loss in three slope classes compared to the plots without mulch application respectively. These amounts for organic carbon loss were 33.2, 7.1, and 29.43 %. Statistical analysis by SAS software showed that difference between two treatments for sediment and Organic Carbon was significant at 5% probability. These results show that straw mulch application can highly increase the infiltration and water absorption and reduce soil and O.C. loss. Also, it can prevent the reduction of soil fertility through reducing organic material loss.
