Mohammadreza Fazel Pouraghdaei; Hossein Malekinezhad; Mohammadreza Ekhtesasi; Jalal Barkhordari
Abstract
The main objective of water spreading projects is recharging aquifers. In this study, changes of soil surface permeability in Yazd water spreading projects, including Sirizi in Bafgh, Herat and Miankouh in Mehriz were investigated. Using a double ring, 12 Permeability tests (in first and ...
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The main objective of water spreading projects is recharging aquifers. In this study, changes of soil surface permeability in Yazd water spreading projects, including Sirizi in Bafgh, Herat and Miankouh in Mehriz were investigated. Using a double ring, 12 Permeability tests (in first and fourth strips and three tests for each strip) were performed. Using measured data the performance of permeability equations such as Kostiakov, Kostiakov-Lewis, Horton, SCS, and Philip were compared in estimating cumulative infiltration and infiltration rate in the study areas. Results showed that average permeability for Bafgh, Herat and Mehriz water spreading projects were about 1.06, 1.52 and 2.94 cmhr-1, respectively. The best equation for estimating cumulative infiltration in Bafgh was the Horton equation with RMSE and Nash Sutcliffe coefficients of 0.097 and 0.992, respectively, while in Herat and Mehriz the best equation was the Kostiakov-Lewis equation with Nash-Sutcliffe coefficient and RMSE of 0.385, 0.994, 0.081 and 0.991 respectively.
Jalal Barkhordari; Davood Nikkami; Mohammadbagher Samadi; Monirosadat Tabatabaeizadeh
Abstract
Rainfall erosivity is one of the most important factors in determining soil erosion. This factor is usually expressed as erosion indices that are based on rainfall characteristics. In this study, after construction of 12 runoff-sediment plots in Nir Research Station in Yazd province, the amount of runoff ...
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Rainfall erosivity is one of the most important factors in determining soil erosion. This factor is usually expressed as erosion indices that are based on rainfall characteristics. In this study, after construction of 12 runoff-sediment plots in Nir Research Station in Yazd province, the amount of runoff and sediment from each plot were monitored and measured for 12 rainfall events. Then, based on a world wide literature review, 61 rainfall erosivity indices were identified. The rainfall erosivity indices were determined for each of the storms with extracting the required parameters. In order to determining suitable rainfall erosivity indices, the correlation between the rainfall erosivity indices and soil loss values were determined. The results showed that PI602, PI302, RPI602, RPI302, RI60 with 0.730, 0.713, 0.703, 0.694 and 0.664 percent had highest correlation with soil loss amount. Generally, in the climatic condition of study area, the indices based on rainfall intensity with total amount of rainfall multiply in the square of 60 and 30 minutes rainfall are better than other indices.
