Geomorphology
leila aghayary; sayyad Asghari Saraskanrood; Batool Zeynali
Abstract
Text Landslides are one of the types of large-scale processes that cause many human and financial losses in many parts of Iran and the world every year. The increase in population and the expansion of human settlements in mountainous areas, the difficulty of predicting the occurrence of landslides ...
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Text Landslides are one of the types of large-scale processes that cause many human and financial losses in many parts of Iran and the world every year. The increase in population and the expansion of human settlements in mountainous areas, the difficulty of predicting the occurrence of landslides and the numerous factors influencing the occurrence of this phenomenon, reveal the necessity of landslide risk zoning. Identifying the effective factors in the occurrence of this phenomenon and its risk zoning is one of the basic and practical methods to achieve its forecasting, control and monitoring solutions. By using field studies, geological and topographical maps, and by reviewing the researches and studies done in this field, as well as examining the existing conditions in the studied area, 9 factors of elevation, slope, slope direction, lithology, distance from the fault. , the distance from the river, the distance from the communication roads, land use and rainfall were investigated as factors affecting the occurrence of landslides. Therefore, the purpose of this research is to investigate and analyze the most important factors involved in creating the risk of landslides in Garami city and to identify the prone areas that will probably be involved in landslides in the near future. In this research, the zoning of prone areas was done with the Aras multi-criteria algorithm in the Edrisi software environment, and according to the results of landslide risk zoning; The criteria of land use, slope, and lithology are the most important factors involved in creating the risk of landslides in the study area with weight coefficients of 0.187, 0.152, 0.152, and 0.142, respectively, and are 361.99 and 450.32, respectively. A square kilometer of the area has a very high probability of danger. Finally, it can be said that the most important factor involved in increasing the amount and potential of landslides in Germi city is the change of land use and the increase of agricultural land and livestock pastures.
hydrogeology
Zahra Sedghi; Ata Allah Nadiri; Sina Sadeghfam; Somayeh Asadi; Frank Tsai
Abstract
Nitrate is one of the pollutants of drinking water sources in the Maku-Bazargan-Poldasht region as a result of human and agricultural activity. Investigations show that the maximum nitrate content in the water resources of the Maku-Bazargan-Poldasht region has increased from 33 mg/liter to 167 mg/liter ...
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Nitrate is one of the pollutants of drinking water sources in the Maku-Bazargan-Poldasht region as a result of human and agricultural activity. Investigations show that the maximum nitrate content in the water resources of the Maku-Bazargan-Poldasht region has increased from 33 mg/liter to 167 mg/liter at the regional level since 2000, or 15 years ago. Is. This area's drinking water is sourced from a variety of poorly maintained wells, springs, aqueducts, and surface water bodies. The results of this analysis, which collected samples from a number of water sources, show the area's high level of water source pollution. This study is the first to assess the carcinogenic risk of nitrate, which is present at high amounts in the study area. This study is the first to assess whether nitrate, nitrite, and ammonium are carcinogenic due to the high amounts of nitrogen compounds in the study area. The goal of the current study was to evaluate the levels of nitrate, nitrite, and ammonium in the drinking water sources of the Maku-Bazargan-Poldasht region and investigate any potential health issues related to nitrate and nitrite. This was done in compliance with USEPA regulations. An effort was made in this study to present a nitrogen compound risk map that is not carcinogenic, and if such a risk exists, future research by scientists should focus on it and determine the best course of action.
Mohammad Hossein Rezaei Moghaddam; Davoud Mokhtari; Nasrin Samandar
Abstract
Land use change is one of the important factors in changing the hydrological flow, basin erosion and biodiversity destruction. Therefore, knowing the effect of land use change on discharge and suspended load is an inevitable necessity. The main purpose of this study is the efficiency test of the model ...
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Land use change is one of the important factors in changing the hydrological flow, basin erosion and biodiversity destruction. Therefore, knowing the effect of land use change on discharge and suspended load is an inevitable necessity. The main purpose of this study is the efficiency test of the model and its usability as a simulation of the process of land use change on discharge and sediment is from the soil and water assessment model (SWAT) and SUFI2 program. Model simulation was performed for 29 years from 1987 to 2015, the first 5 years of which were selected for model calibration and the last 5 years for model results validation. Four statistical indices, r_factor, P_factor Nash-Sutcliffe (NS) and coefficient of determination (R2), the ratio of squared root-to-standard deviation (RSR) and the percentage of skewness (PBIAS) were selected monthly to evaluate the model. The accuracy of monthly simulation using NS evaluation index in the calibration and validation stage for flow and suspended load is equal to 0.65 and 0.49, respectively. The results of the study were considered acceptable according to the interpretive domains used in previous studies and indicate the satisfactory efficiency of the SWAT model in simulating the components of the impact of land use change on sediment and discharge in the Ojan Chay Bostanabad watershed. The results showed that the height of surface runoff increased by 1.15 mm and the sediment concentration increased by 1.5 tons per hectare per year.
hydrogeology
Mirali Mohammadi; Mahsa Mohtadi
Abstract
The purpose of present research work is to study the hydraulic properties of River Simineh and its process using HEC-RAS model, in a combination with ArcGIS software using HEC-GeoRAS extension to simulate the hydraulic parameters of river having a catchment area of 3726 km2. For that mean, since multi-dimensional ...
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The purpose of present research work is to study the hydraulic properties of River Simineh and its process using HEC-RAS model, in a combination with ArcGIS software using HEC-GeoRAS extension to simulate the hydraulic parameters of river having a catchment area of 3726 km2. For that mean, since multi-dimensional models require long time and high cost in river bends, by using a combination of satellite images and HEC-RAS model a multi-dimensional simulation was prepared. Among those, 58 cross-sections are considered along the river lane that main data required in this research are elevation maps, satellite images, boundary conditions and River Simineh hydrometric stations. The results showed that at the upstream of river, the discharge was 316.3 m3/s and water level was 12.85 m, and at the downstream the flow rate and water level are 313.6 m3/s and 11.52 m, respectively. On the other side of the river bend, the water level variation is around 50 cm and the flow velocity is directly proportion to a distance from the river bank; so that the maximum flow velocity of 2.2 m/s occurred at a distance nearby 1.5 m. To verifying the model, a statistical parameter of NSE coefficient for the water level and flow depth were 0.805 and 0.845, respectively; which shows the accuracy of model. Those results indicate a high accuracy of HEC-RAS model in hydraulic simulation of River Simineh flow. Also, simulations prepared in GIS background have significant impacts on the accuracy of outputs
