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Showing 3 results for Khaledi Darvishan
Investigation the Effect of Sand and Gravel Mining on Bed Sediment Morphometric Characteristics (Case Study: Zaremrood River, Mazandaran Province)
S. H. Roshun, Gh. Vahabzadeh, K. Solaimani, A. Khaledi Darvishan,
Volume 21, Issue 3 (Fall 2017)
Abstract

Sand and gravel mining from the most of our country rivers causes morphological, hydrological and geomorphological changes in these rivers. This study investigates the effects of removal of sand and gravel from the river bed on sedimentological features of Zaremrood River in Mazandaran province. For this purpose, by determining four sections before and four sections after the sand removing point, the river bed sediments sampling in combined approach and in a plot within the river were performed and sedimentology features such as the large, medium and small diameters (a, b and c), roundness (Rc), form factor (Sf), normal diameter (D), sphericity (S), and width ratio (W), were measured and calculated in the laboratory and analyzed by SPSS software. The results showed that the variations of sediment statistics a, b, c, Sf, D, S and W in the pre- and post- harvest location has a significant difference but the Rc statistic does not show any significant difference. The reduction of the triple diameters after the excavation site is caused by the fracture of the sediments in the mining area, so that the sphericity of grains also decreased in the mining area. Roundness of sediment particles after the excavation site is decreasing up to 600 meters reach and then it tends to increase.
 


Effect of Various Rates of Montmorillonite Nanoclay on Changing Runoff and Soil Loss
N. Hasanzadeh, L. Gholami, A. Khaledi Darvishan, H. Yonesi,
Volume 25, Issue 1 (Spring 2021)
Abstract
Soil erosion is one of the most serious environmental issues in the world, causing soil degradation, reduction of land productivity, increasing flood, water pollution and pollutions transportation; it is also a serious threat to sustainable development in the world. Therefore, the soil conservation and the prevention of soil erosion and use of conditioners as the nanoclay can be considered as a solution to improve   land productivity and protect environment. The present study was, therefore, conducted to address the effect of the application of montmorillonite nanoclay with three rates of 0.03, 0.06 and 0.09 t ha-1 on changing runoff and soil loss variables under laboratory conditions. The results showed that the nanoclay with the rate of 0.03 t ha-1 could decrease the runoff coefficient, soil loss and sediment concentration with the rate of 40.65, 88.38 and 82.19 percent, respectively. The average of soil loss in control treatment and conservation treatments of nanoclay with various rates was measured to be 3.76, 0.44, 1.33 and 3.16 g, respectively. Also, the results showed that the most sediment concentration was the control treatment with the rate of 5.84 g l-1 and the conservation treatments with nanoclay in the applied rates was 1.04, 3.47 and 2.96 g l-1, respectively. Also, the results showed that the nanoclay effect was significant on changing the soil loss and sediment concentration at the level of 99 percent. Finally, due to the effect, the use of this conditioner in natural conditions and investigation of the effects on environment and aggregates stability are recommended.

Evaluation of Erosion Sensitivity of Lithological Units in Vaz Watershed, Mazandaran Province Using Fingerprinting
D. Khatibi Roudbarsara, A. Khaledi Darvishan, J. Alavi,
Volume 27, Issue 2 (Summer 2023)
Abstract
Soil erosion followed by sediment production is the most important phenomenon that causes soil and environment degradation in many areas and is increasing. Sediment fingerprinting is a method to identify sediment sources and determine the contribution of each source to sediment production. The present research was carried out to evaluate the relative erosion sensitivity of lithological units and to determine the contribution of each unit in bed sediment production using geochemical properties in the Vaz River located in Mazandaran province. The 33 soil samples were taken from the whole watershed and one sediment sample at the outlet of the watershed. Then, five tracers of B, Al, Sc, Mo, and Sn were selected as the optimal combination using three statistical tests range tests, Kruskal-Wallis, and discriminant function analysis. Finally, using optimal tracers and a combined multivariate model, the contribution of lithological units with very high (A), high (B), medium to high (C), and medium (D) sensitivity in bed sediment production were obtained using FingerPro statistical package and R software. The results showed that the contribution of lithological units with very high (A), high (B), medium to high (C), and medium (D) sensitivity in bed sediment production were 24.23, 50.77, 15.62, and 9.36%, respectively. Then, the specific contribution of each sensitivity class was also calculated to remove the effect of area on the results. The Qal lithological unit including the Quaternary sediments in the river bed and banks with very high sensitivity to erosion (A) and a specific contribution of 0.0807 % per hectare had the maximum contribution in bed sediment production in Vaz River.

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