Geomorphology
elnaz piroozi; Aghil Madadi
Abstract
AbstractSoil erosion is one of the most important problems in the watersheds of Iran, which causes the loss of thousands of tons of arable soil every year. The aim of the present study is to zoning the risk of soil erosion in Givi Chay watershed (northwestern Iran). In this study, first, the effective ...
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AbstractSoil erosion is one of the most important problems in the watersheds of Iran, which causes the loss of thousands of tons of arable soil every year. The aim of the present study is to zoning the risk of soil erosion in Givi Chay watershed (northwestern Iran). In this study, first, the effective factors for erosion in the region were identified and then the information layers of each criterion were prepared in Geographic Information System (GIS). Valuation and standardization of layers was done using fuzzy membership function and criteria weighting, using critic method. Final analysis and modeling was performed using the Multi-Attributive Border Approximation Area Comparison (MABAC) method as one of the Multi-Criteria Decision Making (MCDM) methods. According to the results of the study, slope, land use, soil and lithology had the highest weight coefficient, respectively. Also, the results of the study showed; 283.89 and 414.93 km-square of the area, respectively, has a very high and high risk potential, and very high-risk and high-risk areas in unstable and erodible formations, agricultural uses and gardens and slopes of 25-40 % are located. It can be said that the results of this study indicate the high potential of the study basin in terms of erosion occurrence and it is necessary to control erosion and conservation measures on the agenda of experts and land managers. In addition, the results of validation of the results showed that the use of MABAC method has a high relative accuracy for studying the risk of erosion.
Zahra Sharifi; Raoof Mostafazadeh; Abazar Esmali Ouri; Zeinab Hazbavi; Mohammad Golshan
Abstract
Daily flow data are a prerequisite for water resources management, but it is not possible to measure it in many upstream watersheds. In this study, different optimization algorithms have been used to evaluate the efficiency of the SIMHYD model. Therefore, the discharge data of Kouzetopraghi rive gauge ...
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Daily flow data are a prerequisite for water resources management, but it is not possible to measure it in many upstream watersheds. In this study, different optimization algorithms have been used to evaluate the efficiency of the SIMHYD model. Therefore, the discharge data of Kouzetopraghi rive gauge station was selected as the study data (805 km2) located in Ardabil province. The daily data of rainfall, evapotranspiration of the meteorological stations in the study area were used to simulate the daily river flow data. Optimization methods including genetic algorithm, comprehensive competitive evolution, search pattern, multi-start search pattern, uniform random sampling, Rosenbrook, multi-start Rosenbrook optimization were evaluated based on statistical efficiency criteria. The mean value of discharge values by genetic algorithms, multi-year pattern search, uniform random sampling, multi-start Rosenbark, Rosenbork, comprehensive competitive evolution, search pattern were 0.031, 0.023, 0.085, 0.032, 0.024, 0.032, 0.031, respectively. The results showed that the change of optimization algorithms has a significant effect on the calibration accuracy of the model, so that the values of the Nash-Sutcliffe efficiency criteria for the employed algorithms were 0.42, 0.31, -8.55, 0.38, 0.56, 0.023, and 0.24, respectively. The Rosenbrook algorithm had higher accuracy in calibrating the SIMHYD hydrological model compared to other algorithms used. A part of the modeling error can be related to the inconsistency of precipitation and runoff data due to the multiplicity of stations.
Nahideh Parchami; Raoof Mostafazadeh; Abazar Esmali Ouri; Rasol Imani
Abstract
During the occurrence of hydrological drought, the river flow will be reduced and the quality of the river ecosystem will be degraded. Determining the temporal and spatial variations of the hydrological drought makes it possible to plan for the optimal use of river water. In this study, temporal and ...
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During the occurrence of hydrological drought, the river flow will be reduced and the quality of the river ecosystem will be degraded. Determining the temporal and spatial variations of the hydrological drought makes it possible to plan for the optimal use of river water. In this study, temporal and spatial changes of river flow index (SDI) in watersheds of Ardabil province were evaluated. In this regard, daily flow time series of 28 hydrometric stations in Ardabil province were analysed. River flow drought index was calculated using DrinC software and then hydrological drought characteristics were analyzed and spatial variations of SDI index were determined in 1-month, 3-month, 6-month and annual temporal scales in GIS software. 1-month SDI values (short-term droughts) showed that severe droughts were more common in rivers with low discharge values. However, most rivers with low and high amounts of river flow discharge have experienced severe seasons. The annual (long-term) hydrological drought index in most stations was in the range of -1.5 SDI greater than or equal to -1, which indicates the occurrence of mild drought. Spatial changes of SDI showed that the spatial variations of drought index on a 1-month scale are completely different from the annual scale. The lowest occurrence of hydrological drought was in upstream stations and flowing rivers in Sabalan hillsides. Severe and very severe droughts occur in low discharge rivers. The higher the river discharge, the lower the incidence of severe droughts, and the greater its flow stability than low-discharge rivers.
hydrogeology
Sina Ziaye Shendershami; Abazar Esmali Ouri; Raoof Mostafazadeh; Ardavan Ghorbani
Abstract
The aim of this study was to investigate the factors affecting the decrease and change of groundwater level in Ardabil plain in two periods 1995 to 2005 and 2005 to 2015. The monthly precipitation data of Ardebil, Nir, Namin, Abi baglo, Hir, Samiyan stations in the Ardabil plain during the statistical ...
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The aim of this study was to investigate the factors affecting the decrease and change of groundwater level in Ardabil plain in two periods 1995 to 2005 and 2005 to 2015. The monthly precipitation data of Ardebil, Nir, Namin, Abi baglo, Hir, Samiyan stations in the Ardabil plain during the statistical period of 1995-2015 and monthly data of the height of the station in 24 Piezometric well ring were chosen for the plain. Landslide OLI and TM satellite imagery was used to prepare land use map for the target periods in June 1993, 2005, and 2015. The results of land use changes in the years 1993, 2005, and 2015 in the Ardabil plain showed the highest watery agriculture with 48156.26, 50678.66, and 58356.68 and area water level, respectively, were with 168.75 ,88.65 and 380.95 ha, lowest level Which indicates the high level of agricultural land involvement in the decline of agricultural land in the Ardebil plain. The study of the process of Piezometric Wells showed that in the plain of Ardabil, the maximum height of the surface of the station (1437 m) is related to the southern parts of the plains around the village - Noshahr-Kargan and the minimum height (1300 m) is related to the village of Khalifaulo Sheikh. The highest level of cultivation is also focused on user plans in these areas.
yaser hoseini
Abstract
1-Introduction Flood is a natural phenomenon, which threatens the life and properties of a large number of people all over the world, yearly. Flood discharge, regarding water resource exploitation, flood control, construction of dams, basin management, and hydrologic studies, is of high importance in ...
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1-Introduction Flood is a natural phenomenon, which threatens the life and properties of a large number of people all over the world, yearly. Flood discharge, regarding water resource exploitation, flood control, construction of dams, basin management, and hydrologic studies, is of high importance in studies. Therefore, the accuracy of these studies and the safety of waterworks and water structures depend on the methods of studies to a large extent. It is impossible to manage water resources in basins without the accurate determination of the peak flood discharge. The advances in flood estimation techniques have made it possible to use rainfall-runoff models to assess the hydrographic properties of the flood in watersheds and decrease the risks of the flood. In studies on water resources, it is of high importance to determine the flood discharge of different basins. Studies of Dile and Srinivasan (2014) and Hoseini et al. (2017) showed that basin level and rainfall can be the most important factor in runoff flow. Consequently, proper simulation and modeling of flood runoff are the important parameters in flood management in the region. However, it is necessary to use new models to determine flood hydrograph parameters. So, this study aimed to determine the peak flood discharge of the Darrehrood basin using regression mode for return periods of 10, 25, 50, and 100 years. 2-Methodology Darrehrood basin is located in Northwest Iran. The basin is surrounded by mountains and is considered the main basin of Ardabil Province. It lies within 47°30' to 48°55' longitude and 37°45' to 39°42' latitude. Its area is approximately 12900 km2. Discharge data were collected from 16 hydrometric stations with a statistical period of 15 years during 2001-2015. Incomplete data related to stations were completed using statistical methods and considering the best statistical distribution of floods in the studied sub-basins, floods with different return periods were calculated then the physiographic characteristics of sub-basins that affect flood rate include: area, slope, shape factor, height average, concentration-time, and curve number achieved using ArcGIS and WMS (watershed modeling system). To evaluate the model, maximum error (ME), root mean square error (RMSE), relative percentage error (ε), mean absolute error (MAE), coefficient of determination (R2), Coefficient of residual mass (CRM), and model efficiency (EF) were used. 3-Results and Discussion The model calibration results showed that the simulated peak discharge and flow volume are in good correspondence with the observed values, so that, the lowest goodness of fit (R2) value in the return periods of 10, 25, 50, and 100 years were estimated to be 97, 96.6, 95.8 and 94.7 %, respectively. The results showed that the linear regression model with very good accuracy can predict the peak discharge in the sub-basins in Darrehrood using the physiographic parameters of the basin and with increasing the return period, the accuracy of the model is slightly reduced. Model evaluation indicators for the return period of 100 years include root mean square error (RMSE), relative percentage error (ε), mean absolute error (MAE), Coefficient of residual mass (CRM), and model efficiency (EF) were calculated 40.75, 52.12, 0.52, 0.92 and 0.62 respectively. Cross-validation diagrams showed that all models were partially underestimated and the scatter of points around the one by one axis was very suitable for the whole return periods. According to the paired t-test of the difference between predicted and actual values in different return periods in the level confidence of 1% are not significant. 4-Conclusions The results of this study show that the model has good accuracy for estimating floods in sub-basins of Ardabil province.
