Atefeh Davari Dolatabadi; Akbar Ghazifard; Kourosh Shirani; Farzad Heidari Morche khorti
Abstract
East of Isfahan City, especially around Segzi Plain is one of the desert areas of the country that due to the flatness and soils sensitivity to wind erosion, there is high susceptibility to wind erosion. The aim of this study is to evaluate the possibility of using saline water of Segzi Plain and its ...
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East of Isfahan City, especially around Segzi Plain is one of the desert areas of the country that due to the flatness and soils sensitivity to wind erosion, there is high susceptibility to wind erosion. The aim of this study is to evaluate the possibility of using saline water of Segzi Plain and its effect on the soil strength properties, crust formation and its stability against wind erosion. In order to conduct this research, five soil samples with different textures were collected from top soil surface and were transferred to the laboratory along obtained saline water sample from surface aquifer. After determining some of the physical and chemical properties of samples, they were examined in wind tunnel with specified velocity for soil erosion tests. The first soil sample was flooded with saline water and the rest were treated with either spraying of undiluted saline water or spraying of diluted saline water with 2 to 1, 1 to 1 and 1 to 2 ratios of saline water to water. In this regard, parameters such as salinity of saline water, erosion threshold velocity of dried treated soil samples, maximum dry density, thickness, strength and sieve analysis of the crusts were determined. The results indicated that, as the salinity of saline water increases, the strength, thickness and maximum dry density of forming crust and wind erosion threshold velocity also increases in the model. Analysis of variance used to investigate the effects of soil texture, salinity of saline water, crust thickness and threshold velocity to control wind erosion showed significant difference in 1% level. Sample C1 with the highest percentage of fine grains had threshold velocity of 11 m.s-1, but sampleE1 with the lowest percentage of fine grains had threshold velocity 6.23 m.s-1. The presence of a high amount of sodium makes restrictions on the possibility of using saline water as mulch scientifically and practically but the results showed that the use of saline water can increase the density of dirt roads.
Farzad Heidari; Razieh Saboohi
Abstract
This research was carried out aiming to investigate positive and negative aspects of watershed practices and their effects on quantity and quality of water resources in Budejan River basin. This river is one of the main branches of Shour-Dehaghan River and its area plays an important role in supplying ...
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This research was carried out aiming to investigate positive and negative aspects of watershed practices and their effects on quantity and quality of water resources in Budejan River basin. This river is one of the main branches of Shour-Dehaghan River and its area plays an important role in supplying water for lower lands. In this regard, meteorological data, hydrology and other information and maps were collected. The volume of dam reservoirs and the amount of rainfall within two years of the project were measured by field studies and hydrology studies were carried out by field measurement and assessment of hydrologic conditions of the basin. Results showed that the water content generated by these practices is enough to recharge groundwater. Construction of dams tended to decrease water flow rate and reduced the destructive effects of seasonal flood and with increasing water infiltration rate, it has increased aquifer recharge in the study area. The low volume of dam reservoirs has not caused irregularity in water supply of downhill lands. However, the lack of proper management of these operations and the excessive development of gardens and agricultural lands, due to the ease of access to water, overshadow positive results of watershed practices and offset it by a very high cost.
Farzad Heidari; Razieh Saboohi
Abstract
Marl formations have problems in watersheds due to high sediment yield. The purpose of this research is the marls classification of Isfahan province according to erodibility indices and their physical and chemical properties. In this regard, region marl units were identified and their sediment yield ...
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Marl formations have problems in watersheds due to high sediment yield. The purpose of this research is the marls classification of Isfahan province according to erodibility indices and their physical and chemical properties. In this regard, region marl units were identified and their sediment yield was measured using rainfall simulator. Then, based on erosion type, they were sampled and soil physical and chemical properties were analyzed. Cluster analysis statistical method was used to classify marl units. Statistical analysis was performed by three sets of data including chemical, physical and both chemical and physical accompanied by slope and measured sediment from six mmh-1 rainfall in each step of the analysis. Results showed that the most important similarity factors in marls are chemical properties and the effect of climate. According to information obtained from investigations, climate is the most effective factor of differences among marl units in this province. In addition to its direct impact on creation and evolution of marls, it affects on other parameters directly and indirectly and choosing either of these parameters is related to climate.
Kourosh Shirani; Farzad Heydari; Alireza Arabameri
Abstract
Landslides are major natural hazards which not only cause damages to human life but also provide economic losses on infrastructures. In order to determination of the most important method of estimation recognizing appropriate method to estimate landslide, in this research, the efficiency of two ...
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Landslides are major natural hazards which not only cause damages to human life but also provide economic losses on infrastructures. In order to determination of the most important method of estimation recognizing appropriate method to estimate landslide, in this research, the efficiency of two methods of landslide hazard zonation including methods of Artificial Neural Network and Multivariate regression were compared. Therefore, in this research, first, landslide inventory map was obtained using aerial photos interpretation, satellite images processing, geology maps review and field surveying. Also, the 9 important effective factors are in occurrence of landslide including lithology, land use, slope angle, slope aspect, elevation, precipitation, distance to fault, distance to road, density of drainage were determined using inspect of field and literature review. After producing of layers and weighting to effective factors using inventory map, landslide hazard zonation was made by Artificial Neural Network and Multivariate regression models. From 200 landslides identified, 140 (≈70%) locations were used for the landslide susceptibility maps, while the remaining 60 (≈30%) cases were used for the model validation. The quality sum (Qs) and precision (P) indices for Artificial Neural Network model are 0.15, 0.08 and for Multivariate regression model are 0.14, 0.05 respectively. This results show that artificial Neural Network is the better model in landslide hazard zonation in this area, therefore an accurate landslide hazard zonation map can be prepared by selecting and applying the proper method.
