A. Talebi, A. H. Charkhabi, H. R. Peyrowan, A. A. Hashemi, H. Mosaddegh,
Volume 16, Issue 62 (3-2013)
Abstract
The Marls are unstable sedimentary formations that contain chemical materials and destructive particles. Marls Erosion processes are very intensive, so different forms of erosion on the marls as badlands are of specific characteristics in marl lands. Hence, recognition of effective characteristics in marls erodibility is necessary to adopt corrective measures and methods. In this research, for assessing marls erodibility in Hablehroud watershed portable rain simulator was used. Runoff and sediment amounts were measured in each marl unit. Then effective Factors were identified using statistical parameters. Finally, by factor analysis we determined the relationship between marls chemical properties and sediment yield. Therefore, effective parameters of erosion and sediment yield were determined. Results showed sediment yield is decreased in gypsum marl, sandy marl, salt marl and limy marl. In addition, erosion and sediment yield are increased with increasing EC, Na, Cl, SAR and with decreasing TNV, HCO3
Hamzeh Saeidian, Hamid Reza Moradi,
Volume 17, Issue 64 (9-2013)
Abstract
The type and intensity of soil erosion in a region generally depend on climatic conditions, ups and downs, soil and land use. Of these, land use is most important. Using different systems of ploughing after unconscious and non-scientific change of land use affects soil physicochemical characteristics. This fact especially in marginal lands and mountainous regions is more visible. In order to investigate sensitivity to soil loss and erosion in various land uses of Aghajary deposits, part of Margha catchment with an area of 1609 hectares in Izeh city was selected. This was to determine the relationship between soil loss by rain simulator and some soil physicochemical characteristics like percentage of very fine sand, sand, clay, silt, pH, Ec, moisture, Calcium Carbonate and organic materials in different land uses. Then, sediment sampling in 7 points, three replicates and in various intensities of 0.75, 1 and 1.25 millimeters in minute in range, residential and agricultural land uses was done using rain simulator. In order to investigate effective factors in sediment production and erosion, samples of soil layers (in depth range of 0-20 cm meters) equal to the number of sediments were taken. For statistical analysis, EXCEL and SPSS 11.5 software were used. In total, the amount of runoff in residential land use was highest and in agriculture land use was lowest. The amount of sediment in agriculture land use was highest and in residential land use was lowest. Then, the most important factors in sediment yield were diagnosed by multi regression. The results showed that sediment yield and erodibility in land uses have meaningful differences in various intensities of precipitation. Regression models showed that in the production of sediment in various land uses, from among the measured factors, silt, sand very fine, lime, Ec, organic materials and pH had the greatest role. Sand percentage in the residential land use, and very fine sand and organic matter in agriculture land use had the most important role in sediment production. But in range land use, moisture percentage and pH had the biggest role in sediment production.
A. Kavian , A. Alipour, K. Soleimani, L. Gholami,
Volume 23, Issue 1 (6-2019)
Abstract
Nowadays, acid rain serves as one of the most serious environmental problems has affected many regions in the world. This phenomenon is characterized by many environmental impacts, such as soil contamination and degradation. Acid rain immediately affects soil, causing soil particles to breakdown and be dispersed; this is the first step to initiate the soil erosion. Therefore, in this study, the effect of different pH levels of acid rain (at different levels) on the soil splash was investigated under laboratory conditions using a rain simulator and a cup splash. In the experiments, acid rains, with the pH values of 3.75, 4.25, 5.25 and normal rains at three intensities of 40, 60 and 80 mmh-1, were studied; finally, a number of 36 samples were taken for statistical analyses. SPSS 23 and EXCEL 2013 software and one way and two-way ANOVA were used for the statistical analysis at a confidence level of 95%. The results showed that at the intensities of 40 and 60 mmh-1, the splash rate was significantly different in all pH treatments, and the acid rain with pH of 3.75 showed the highest splash rate. However, no significant difference was found at the rain intensity of 80 mmh-1, despite the higher splash rate at the pH of 4.25 and 5.25 treatments. Also, the results of the comparison of the means showed that the soil splash rate was also increased with enhancing rain intensity. Finally, the two-way ANOVA test showed that the simultaneous interaction effects of the two factors of pH and rain intensity on soil splash was not significant.
