Mohammad Shabani
Abstract
Estimating instantaneous peak flow in watershed is one of the most important problems that cause hydrologists and experts to work seriously on it. One the new methods in river engineering and suspended sediment estimation is application of artificial neural networks which uses the same algorithm of human ...
Read More
Estimating instantaneous peak flow in watershed is one of the most important problems that cause hydrologists and experts to work seriously on it. One the new methods in river engineering and suspended sediment estimation is application of artificial neural networks which uses the same algorithm of human brain to find the internal relation between data based on the training process. The objective of this study is to compare the efficiency of artificial neural network method and experimental methods for estimating instantaneous peak flow in Fars province watershed. For this purpose, 24 years of daily peak and instantaneous peak flow of seven hydrometric stations were considered and tested for outlier data. Then the estimation was done based on experimental methods including Fuller, Sangal and Fill-Steiner and artificial neural network method and were compared based on RMSE, MAE and R2. Results showed that estimation of artificial neural networks is more accurate than experimental methods in all stations which indicated the lower errors of artificial neural network method compared with experimental methods.
Mohammad Shabani
Abstract
Selection and accuracy of the appropriate methods for zonation and preparing the map of groundwater quality parameters depend on regional condition and availability of data which is an important stage for groundwater management of the region. The purpose of this research is determining the most suitable ...
Read More
Selection and accuracy of the appropriate methods for zonation and preparing the map of groundwater quality parameters depend on regional condition and availability of data which is an important stage for groundwater management of the region. The purpose of this research is determining the most suitable interpolation method for determining salinity (EC), nitrate (NO3), pH and total dissolved salts (TDS) parameters of groundwater and mapping of them by using of geographic information systems in Neyriz plain located in southeast of Fars province. For this aim, different methods of geostatistics including ordinary kriging (OK) and simple kriging (SK) as well as deterministic methods such as inverse distance weights (IDW), radial basis function (RBF), local polynomial interpolation (LPI) and global polynomial interpolation(GPI) were used. The result based on the lowest root mean squared error (RMSe) and mean absolute error (MAE) showed that simple kriging (SK) method is the most appropriate method for salinity (EC) mapping (RMSe=3907.53 and MAE=2911.05), TDS mapping (RMSe=2587.19 and MAE=1936.48), pH mapping (RMSe=0.196 and MAE=0.143) and NO3 mapping (RMSe=4.868 and MAE=3.839) among all the methods in the study area. Finally, the results of this research indicated that geostatistical methods have higher priority than deterministic methods and thus are selected as suitable methods in Neyriz plain.
Seyed Mahmoud Reza Tabatabaei; Mohammad Roghani
Volume 2, Issue 4 , January 2011, , Pages 197-205
Abstract
In calculation of catchments time of concentration, TC, lump equations are often used. Therefore, TC is not accessible for different parts of the catchments. In this research, using object oriented programming in the GIS environment a fully distributed model has been designed and developed. The model ...
Read More
In calculation of catchments time of concentration, TC, lump equations are often used. Therefore, TC is not accessible for different parts of the catchments. In this research, using object oriented programming in the GIS environment a fully distributed model has been designed and developed. The model is able to calculate the time of concentration for any parts of the catchment to its outlet in a raster map. Model input layers are DEM, rainfall intensity, Manning’s roughness coefficient and catchment stream network. The most important outputs of the model are slope, flow direction and flow accumulation layers and isochronal surfaces. In the presented model, catchment cells are divided into two basic classes including channel cells and overland flow cells. Kirpitch and Kinematic wave equations have been used to calculate the time of concentration for the channel and overland flow cells respectively. In addition, rainfall-runoff hydrologic software, RAFTS-XP, has been used to evaluate the accuracy of TC model results. The result of TC model shows that calculated travel time had suitable synchronization to real time, which has been estimated using observed events and the calibration of RAFTS-XP. Considering the point that catchment response for all events which used by RAFTS-XP is based on different rainfall intensities with identical time of concentration, so observing different behaviors in flood hydrographs seems reasonable.
Hamed Nozari; Sahar Alsadat Razavian; Seyed Moezeddin Nabavi Hamedani
Abstract
In order to reduce the losses caused by floods and economize flood control projects in an area, construction of appropriate structures and operating watershed practices in areas with high risk of flooding is essential. One of the approaches to identify high risk flooding regions is watershed simulation ...
Read More
In order to reduce the losses caused by floods and economize flood control projects in an area, construction of appropriate structures and operating watershed practices in areas with high risk of flooding is essential. One of the approaches to identify high risk flooding regions is watershed simulation and evaluation of sub-watersheds participation in outlet discharge. In this research, hydrological units of Hamedan-Bahar basins were simulated using ArcGIS and HEC-HMS hydrological model. Then, flooding indexes were calculated and their changes in all sub-basins were mapped.Effective hydrological units on peak discharge were identified and prioritized for watershed management, by reviewing and comparing these indexes. Site selection of flooding indexes showed that Bahador Beyg and Qareh Aghaj sub-basins had the highest and the lowest effect on flood peak, respectively. Analyzing results demonstrated that sub-basins with large areas or with huge amount of runoff not necessarily cause more effect on flood peak. Performance of management practices and construction of suitable hydraulic structures in studied hydrological units efficiently reduce flood damages in Hamedan-Bahar basin.
Abolghasem Dadrasi; Shahrokh Hakimkhani; Abdolsaleh Ranghavar
Volume 1, Issue 4 , February 2010, , Pages 227-239
Abstract
The fact that there are so many erosion models makes it necessary to critically select one of them as all have some limitations. Models are formulations of processes and logics as represented by the modeler. The formulations may be representations of either simple processes or complicated ones as the ...
Read More
The fact that there are so many erosion models makes it necessary to critically select one of them as all have some limitations. Models are formulations of processes and logics as represented by the modeler. The formulations may be representations of either simple processes or complicated ones as the modeler deems necessary to solve a specific problem. These variables must be derived by a procedure of calibration for a specific case. The Soil erosion model of Morgan, Morgan and Finny (1982) from a large list of soil erosion models, have been applied to test the validity of the model in Sanganeh research station, Mashhad, Iran. After a field survey, plots with sheet erosion, were selected and their data was collected. Rainfall, slope and soil data were derived from station archive, vegetation cover and root depths were determined from field observations and some other parameters were tested on site. Soil loss was calculated by using overland flow for each plot after each rainfall and the measured records were compared with model estimations. The results show that in most plots, predictions deviated from the observations and in 28.21% of plots the results seem acceptable. The final result of present research shows that the model performs reasonably well for plots with lower density of vegetation cover (less than 20%), steep area with more than 40 percent, and soil depths of less than 10 centimeter.
Farhad Shiva; Jalal Attari; Mojtaba Saneie
Abstract
Scour phenomena can impair infrastructures and result in non-reparable damages. Few researches conducted so far show that application of non-cohesive criteria for situations where the bed is formed of cohesive materials, overestimates dimensions of the scour hole and will impose large costs to the project. ...
Read More
Scour phenomena can impair infrastructures and result in non-reparable damages. Few researches conducted so far show that application of non-cohesive criteria for situations where the bed is formed of cohesive materials, overestimates dimensions of the scour hole and will impose large costs to the project. According to the previous researches, type and content of clay also significantly affects scour in the cohesive materials. In this paper, the local scour in the cohesive bed due to a horizontal submerged jet issued from a vertical sluice gate is experimentally studied. Initially, the effective factors were identified and Bentonite clay was selected as cohesive material. A total of 48 tests, considering four different clay contents, three amounts of gate openings and four different tailwater depths, were conducted in a rectangular flume of Soil Conservation and Watershed Management Research Institute laboratory. The results show that by adding Bentonite clay to the erodible bed, effect of cohesion appears in the 10% ratio and with further increase of the clay content the scour depth decreases considerably. So that in a bed containing 20% Bentonite clay the maximum scour depth reduces by 76% on average in relation with a non-cohesive bed. Based on the experimental results, a general equation for predicting the maximum scour depth valid in both conditions of presence and absence of the cohesive materials is presented. A sensitivity analysis on the existing parameters that effect on scour depth was conducted and compared with the results of previous researches. Finally, two types of scour hole profiles were defined which showed a relatively good agreement with previous empirical relationships.
Ali Bagherian Kalat; Gholamreza Lashkaripour; Mohammad Ghafoori; Naser Hafezi Moghadas; Gholamali Ghazanchian; Reza Ghafoorian
Abstract
In recent years, activities on trout fish farming is developed significantly in Ortakand River. Fish production may have huge impact on the river ecosystem if an environmental rule is neglected. This research was carried out in Ortakand River in Kalat city in Khorasan Razavi with the aim of investigation ...
Read More
In recent years, activities on trout fish farming is developed significantly in Ortakand River. Fish production may have huge impact on the river ecosystem if an environmental rule is neglected. This research was carried out in Ortakand River in Kalat city in Khorasan Razavi with the aim of investigation of fish production projects effluent effect on the river water quality. Two fish farms and seven stations were selected and during one year in each season, water samples were collected. The samples were analyzed in the laboratory for determining some physic-chemical and biological parameters of water samples. The results showed that the average of these parameters were within a range between 13.3-15 °C of temperature, 7.9-8.1 of pH, 354-732 mmhos/cm of EC, 8.4-9.6 mg/L of DO, 1-3.7 and 2.5-13.9 mg/L of BOD5 and COD, respectively. The results showed that BOD5 and COD concentration had a significant increasing toward upstream (p<0.01), spatially. Meanwhile, amount of DO showed a significant decrease (p<0.01), temporaly. This research revealed that changes in concentration of BOD5, COD and DO were dominantly due to fluctuations of environmental conditions and activity rates of the farms. Although, the amount of COD and BOD5 in fish farms effluent in current situation are less than the standard environmental amount, but environmental impacts could be increased by activities of new fish farms,.
Ommolbanin Bazrafshan; Azimeh Chashmberahm; Arashk Holisaz
Abstract
Evaporation is one of the most important and effective factors in water resources planning and management in arid and semi-arid areas and examining it's changes in time scales and different years as one of the most important climatic parameters, has an important role in planning and water resource management ...
Read More
Evaporation is one of the most important and effective factors in water resources planning and management in arid and semi-arid areas and examining it's changes in time scales and different years as one of the most important climatic parameters, has an important role in planning and water resource management in agriculture section and determining cultivation pattern and proper water resource management. One of the methods to assess and forecast changes in evaporation is time series models by the generic name of ARIMA models. Therefore, in order to determine the best model to predict pan evaporation, after considering the climate using improved Domarton climatic classification method, in each climatic sample, one evaporation station was selected and standardized pan evaporation index (SPEI) was calculated for each of the stochastic model for estimation the amount of future monthly time series SPEI in the period of 1954-1955 to 2009-2010 over the next 12 months. Results showed that the Auto Regressive Moving Average model (ARMA) and Auto Regressive (AR) had the best performance, in Hormozgan province, so that, in the hot and dry, hyper hot arid and hyper hot hyper arid climates, in the next month, had the highest standard coefficient of determination (R) of 0.83, 0.71, 0.7 and the lowest value RMSE of 0.59, 0.8, 0.88, respectively and the AR model was able to predict the next 11 months, well. The results showed that AR model has better performance compared to ARMA model in estimating monthly pan evaporation in hot and dry climates in coastal wilderness areas.
sohrab jamalpour bergai; hassan ahmadi; Aboalfazl Moeini; mohammad faraji
Abstract
Dust storms is one of the most important environmental hazards, especially in arid and semi-arid climates, which causes irreparable damages to the various dimensions of the environment. The aim of this study was to identify dust sources in south-east Ahwaz, using a remote sensing technique and fuzzy ...
Read More
Dust storms is one of the most important environmental hazards, especially in arid and semi-arid climates, which causes irreparable damages to the various dimensions of the environment. The aim of this study was to identify dust sources in south-east Ahwaz, using a remote sensing technique and fuzzy logic. For this purpose, the satellite images of dust events of Ahwaz City were investigated and the wind characteristic of the study area were studied by plotting the storm rose of Ahvaz Synoptic Station. In the next step, the criteria were categorized into two categories: soil moisture, land surface temperature and vegetation constitute the main layers and land use, spatial data of soil, climate, slope and sedimentology were used as constraint layers. The main layers were extracted from Landsat OLI-TIRS satellite images. The Boolean method were used to standardize the constraint layers, and the fuzzy membership functions were used to standardize the main layers. Also, main layers weighting was done using fuzzy analytic hierarchy process. Finally, the dust sources map was obtained by overlapping the layer. To validate the results, 44 ground control point were selected from the study area that showed high accuracy (81.8%) for identified areas. Based on investigating of satellite image and storm rose of Ahvaz Synoptic Station, the south-east of Ahwaz was recognized as dust-generating source and 145162.01 ha of lands are dust generating sources from which 69343/01 ha (47.77%) belongs to destroyed rangelands and 335.99 ha (0.23%) belongs to Canebrake, contains the highest and lowest level of sources of dust production in the study area, respectively.
Samad Shadfar
Abstract
Gully erosion is a type of water erosion that causes significant sedimentation in watersheds and damages in agricultural lands, rangelands, and infrastructures. This study was conducted to determine the potential of gully erosion by artificial neural network. The Levenberg-Marquardt (LM) ...
Read More
Gully erosion is a type of water erosion that causes significant sedimentation in watersheds and damages in agricultural lands, rangelands, and infrastructures. This study was conducted to determine the potential of gully erosion by artificial neural network. The Levenberg-Marquardt (LM) algorithm and Multi-Layer Perceptron were used employing soil, geology, land use, distance to fault, slope, aspect, distance from roads, distance from drainage, and elevation data as its variables. Results showed that the structure of 1-13-9 with sigmoid activation function in the hidden layer is more suitable for gully erosion potential assessment. Zonation of gully erosion revealed that the watershed area was divided into different classes of different extent, including 70.26% in very low, 1.71% in low, 2.45% in medium, 2.65% in high, and 22.93% in very high potential class. Furthermore, results indicated that slope less than 10%, 50 m distance from the stream, rangeland area, and lithological units of EM and M2 had the greatest impact on the occurrence of gully erosion.
Payam Ebrahimi; Jamileh Salimi Kochi; Mohsen Mohseni Saravi
Abstract
SWAT is a continuous, physically based and distributed hydrologic model which all several hydrological processes like discharge, sediment yield nitrogen are simulated for each one of it. The purpose of this study is to test the efficiency of the Soil and Water Assessment Test (SWAT) and its applicability ...
Read More
SWAT is a continuous, physically based and distributed hydrologic model which all several hydrological processes like discharge, sediment yield nitrogen are simulated for each one of it. The purpose of this study is to test the efficiency of the Soil and Water Assessment Test (SWAT) and its applicability as a flow simulator, and using SWAT-Cup software and the SUFI2 algorithm as a means to calibrate and validate Neka Watershed in Mazandaran Province. Four indices were used to assess the goodness of calibration, viz., P-factor, R-factor, R2 and Nash-Sutcliffe (NS). Runoff data (1995-2004) of four hydrometery stations were used for calibration and (2005-2009) for validation of this watershed. The results of these values for flows at four stations for calibration process in Ablo, Pain zarandin, Karkhane siman and Sefid chah were 0.85, 0.78, 0.78, 0.89 for P-factor; 2.55, 2.03, 1.71, 2.43 for R-factor; 0.76, 0.62, 0.69, 0.71 for Nash-Sutcliffe and 0.71, 0.82, 0.76, 0.63 for R2. The results of validation were 0.87, 0.88, 0.72, 0.72 for P-factor; 3.61, 2.24, 3.56, 1.78 for R-factor; 0.74, 0.66, 0.58, 0.64 for Nash-Sutcliffe (NS) and 0.81, 0.68, 0.73, 0.61 for R2 respectively. In general, the results showed that SWAT could be a proper tool for simulating the flow rate values of the Neka Watershed.
Seyed Ahmad Hosseini; Ahmad Tabatabaei
Abstract
Introduction
Simulating suspended sediment in hydrological systems has always been challenging due to inherent complexities and uncertainties. This issue has led to the use of intelligent models such as Artificial Neural Networks (ANNs) as a suitable approach for predicting suspended sediment load. ...
Read More
Introduction
Simulating suspended sediment in hydrological systems has always been challenging due to inherent complexities and uncertainties. This issue has led to the use of intelligent models such as Artificial Neural Networks (ANNs) as a suitable approach for predicting suspended sediment load. Therefore, the use of intelligent models like ANNs has expanded in this field. However, determining the optimal network structure (including the number of neurons, layers, weights, and biases) is usually done through trial and error, which is both time-consuming and inefficient. In this study, a multilayer perceptron neural network was used to simulate the daily suspended sediment load in the Qarasu Sarab watershed (Quri Chay and Hir Chai rivers) located in Ardabil province, Iran.
Materials and methods
In this research, an Artificial Neural Network (ANN) of the Multilayer Perceptron (MLP) type was utilized to simulate the daily suspended sediment load in the Sarab Qareh Su watershed (including the Quri Chay and Hir Chay rivers) in Ardabil province. The neural network models were trained not only whit the conventional backpropagation algorithm but also using the Particle Swarm Optimization (PSO) algorithm to optimize the weights and biases of the neurons. Furthermore, to increase the models' generalization capability, a Self-Organizing Map (SOM) clustering was employed. In addition to the backpropagation algorithm, the Particle Swarm Optimization (PSO) algorithm was also employed to optimize the network weights and biases. Furthermore, to enhance the model's generalization power, SOM clustering was used. The use of evolutionary algorithms such as PSO in training neural networks is an effective approach to improve the accuracy of intelligent models, especially in simulating river suspended sediment and applications related to water resources and watershed management structures.
Results and discussion
Using SOM clustering and the Davies-Bouldin index, the optimal number of clusters was determined as 12 for Koozeh Toupraqi station and 15 for Hir Chai station. Statistical analysis and the Kolmogorov-Smirnov (KS) test showed that data distributions across training, validation, and testing sets were similar, which enhances the generalization capability of the models. Training the neural network models with PSO yielded better performance and lower prediction errors compared to backpropagation. The ANN-PSO-Sig and ANN-PSO-Tan models achieved the best results at Koozeh Toupraqi and Hir Chai stations, respectively. Bias analysis further confirmed that PSO-trained models had lower errors in total sediment load estimation. Overall, results showed that PSO-based training outperforms pure backpropagation training. At Koozeh Toupraqi station, the hybrid ANN-PSO model with sigmoid activation function (ANN-PSO-Sig), and at Hir-Hirchai Topraghi station, the hybrid model with hyperbolic tangent activation function (ANN-PSO-Tan) were selected as optimal models, showing biases of +5.25% and -19.2% and RMSE values of 86.28 and 89.2 tons per day, respectively. These findings demonstrate the improvement in suspended sediment load prediction accuracy by using PSO in neural network training.
Conclusion
The use of the PSO metaheuristic algorithm in training neural network models improved their performance in simulating suspended sediment load. This method outperformed gradient-based error algorithms and provided more accurate weight optimization. The improved bias accuracy in PSO-trained models is crucial for designing hydraulic structures and water resource management. Furthermore, SOM clustering helped select homogeneous and representative datasets for model training, enhancing model generalizability. Overall, considering the complexities and uncertainties in hydrological systems, employing intelligent models combined with evolutionary optimization algorithms like PSO is an effective approach for simulating and monitoring suspended sediment loads. The obtained results can be applied in planning and implementing watershed engineering measures and water resource management.
Mojtaba Soleimani-sardo; Esmaeil Silakhori
Abstract
Today, land use change is considered as a challenge of environmental issues and known as an ecological problem. Land use changing is one of the most important parameters in planning over time. The purpose of this study is to detect land use changes in the Jiroft Basin in the years 1997, 2008, and 2018 ...
Read More
Today, land use change is considered as a challenge of environmental issues and known as an ecological problem. Land use changing is one of the most important parameters in planning over time. The purpose of this study is to detect land use changes in the Jiroft Basin in the years 1997, 2008, and 2018 and it’s predicting in 2040. For this, Landsat images were collected and the preprocessing steps, including atmospheric and radiometric corrections, were done by ENVI software. A false-color combination, as well as an NDVI vegetation index map, were prepared for these years. Land use maps were prepared by supervised classification using maximum likelihood algorithm. The land use changes evaluated by Land Change Modeler (LCM) in these periods. Finally, land use map for 2040 was predicted by the Markov chain and IDRISI software. According to the Kappa index, the exported maps showed an acceptable accuracy (>0.76). Land use changes between 2008 and 2018 showed that the urban areas, agricultural lands, gardens, salty lands, and barren area were increased, but rangelands and forests were decreased. In the coming years, it is expected that with the current management method, the urban areas, agriculture and barren area will increase, while forest, gardens, and rangeland areas will decrease. To reduce the land use change effects, it is recommended to act according to sustainable development by notice to the ecological potential of the land.
Bahram Choubin; Karim Solaimani; Mahmoud Habibnejad Roshan; Arash Malekian
Abstract
Integrated watershed management and regeneralization of available information to ungauged basin needs to recognize homogeneous watersheds. The hydrologic similarity of watersheds is caused by the hydroclimate and physical behaviors. In present study, hydroclimate and physical indices were used for indicating ...
Read More
Integrated watershed management and regeneralization of available information to ungauged basin needs to recognize homogeneous watersheds. The hydrologic similarity of watersheds is caused by the hydroclimate and physical behaviors. In present study, hydroclimate and physical indices were used for indicating the homogeneous sub-watersheds in Karkheh Watershed and then results were compared. Factor analysis to reduce in the dimension of variables was conducted, separately for climatic, hydrological and physical parameters. Finally, using Fuzzy c-means (FCM) and hierarchical clustering analysis (HCA) homogeneous sub- watersheds were indicated by hydro-climate and physical parameters. Factor analysis results showed that indices of CSDI (cold spell duration index), GSL (growing season length), RX5day (monthly maximum consecutive 5-day precipitation), TX90p (percentage of days when daily maximum temperature is greater than 90th percentile) and TMAXmean (mean of maximum temperature) of climate indices, and indices of percent of hydrologica group D and flood potential index of hydrologic indices were selected. Also indices of basin area, basin elongation, average length of drainage and total topography between the physical parameters were selected. Comparing the results of the FCM and HCA indicated that the optimal number of clusters is same, but the results of watershed classification are not same in each cluster of two ways. Classification by hydroclimate and physical indices highlights that 25 and 27 basins were classified similar, respectively in two methods of clustering. Clustering by hydroclimate parameters produced different results compared with physical parameters, so that the 17 and 19 sub-basins are in the same classes in the FCM and HCA, respectively. However, there is no preference to accept watershed classification by hydroclimate or physical parameters, thus a combination of hydroclimate and physical parameters were used for classification. Watershed classification by the combination of hydroclimate and physical parameters indicated that 33 sub-basins were classified similar in both FCM and HCA methods. Classification in Karkheh basins based on the combination of physical and hydroclimate parameters revealed that the northern areas are in group 3, central regions (from east to west) are in group 2 and southern areas are in group 1. Inherently, these basins are similar in each group and demand the same protection operations in view of watershed management.
Somaiye Moghimi; Yahya Parvizi; Mohammad Hossein Mahdian; Mohammad Hassan Masihabadi
Abstract
Soil organic carbon is one of the most important soil characteristics, and any changes in its content and composition, affects soil physical, chemical, and biological characteristics. Enhancing soil organic carbon improves soil structure, increases water and nutrients in soils, reduces soil erosion and ...
Read More
Soil organic carbon is one of the most important soil characteristics, and any changes in its content and composition, affects soil physical, chemical, and biological characteristics. Enhancing soil organic carbon improves soil structure, increases water and nutrients in soils, reduces soil erosion and degradation and thus greater productivity of plants and water quality are expected in watersheds and ultimately soil and ecosystem reclamation happens. Climatic, topographic and managerial factors affect soil organic carbon content. In local scale, climatic factors have not high efficiency on soil organic carbon and topographic factors play more important role compared to climate on soil organic carbon variability. The objective of this study was to predict and evaluate the effects of topographic factors such as elevation, slope percent, aspect, hill shade, and curvature on the soil organic carbon content of a rangeland in Mereg watershed, Kermanshah, Iran. Stepwise Multi Linear Regression (MLR) and Artificial Neural Network (ANN) were employed to develop models to predict soil organic carbon. AMulti-Layer Perceptrons (MLP) ANN withback-propagationerror algorithm was applied to this research.Theresult showed that themulti linear regression and ANN models explained53and 77percent of the total variability of soil organiccarbon, respectively. The calculated RMSE and MBE were 0.40 and 0 for the MLR and 0.16 and 0.003 for MLP models. Results indicated that designated ANN model with 5-9-1 arrange was more feasible than multi linear regression for predicting soil organic carbon. Elevation with 0.79, hill shade with 0.64 and slope percent with 0.24, were identified as the important factors that explained the variability of soil organic carbon.
Somayeh Karimiasl; Behzad Hessari; Kamran Zeinalzadeh; Mahdi Erfanian
Abstract
Introduction
Salmas Plain represents one of the most critical areas in the country experiencing subsidence. In general, various factors cause land subsidence, but in many areas, the excessive extraction of ground water from aquifers causes land subsidence. The increasing use of ground water, especially ...
Read More
Introduction
Salmas Plain represents one of the most critical areas in the country experiencing subsidence. In general, various factors cause land subsidence, but in many areas, the excessive extraction of ground water from aquifers causes land subsidence. The increasing use of ground water, especially in the sites that are accumulated with alluvial deposits, shallow sea or unconsolidated lake, leads to subsidence or collapse of the land. With the excessive extraction of ground water, the water level of the aquifer decreases and the hydrostatic pressure decreases, which makes it possible for the land to subside gradually. Subsidence in plains mostly occurs due to this factor, namely excessive groundwater extraction and compaction of clay and silt layers between aquifers. In this case, even if the water table level rises again, the land cannot return to its original level.
Materials and methods
In this study, the susceptibility of land subsidence in Salmas Plain was investigated using layers of influential factors in subsidence with ArcGIS software and fuzzy logic. In the first stage, statistical information on some factors causing subsidence, including groundwater level decline, well extraction rate, aquifer storage coefficient, transmissivity coefficient, precipitation, DEM map, soil texture, and bedrock depth, was collected and raster maps of each of these factors at the aquifer level were prepared. In the next stage, fuzzy layering was performed using fuzzy membership functions based on the impact of decreasing or increasing each of these factors on land subsidence. Subsequently, the maps were combined using fuzzy operators (Gamma OR, AND, SUM, PRODUCT) to obtain a unified map of aquifer subsidence susceptibility. Finally, to select the best combination of operators, the results were compared and evaluated with field observation data and the ROC curve performance index.
Results and discussion
The results showed that the OR operator had the lowest conformity with observed subsidence in the area with an AUC of 0.693. Gamma operators with an AUC above 70% had the highest overlap or conformity with observed subsidence in the plain. In this study, the Gamma 0.9 operator was selected as the best fuzzy operator with an AUC of 0.805. The results indicate that the eastern part of the aquifer is critical in terms of subsidence. Approximately 25% of the total area of Salmas Plain, equivalent to 93 square kilometers, has subsidence with very high susceptibility.
Conclusion
Based on the results obtained, it can be said that although the AUC value of the fuzzy operator sum is higher, the Gamma operator with a value of 0.9 has the highest conformity with the ground reality on the fuzzy map, even though it has a lower AUC value. It is essential to mention that the minimum operator AND and Product create a region with low susceptibility, while the maximum operator OR and SUM maximize the susceptible area. They cannot achieve satisfactory performance in preparing a subsidence susceptibility map. Here, they have only been used to demonstrate the inefficiency of fuzzy operators in maximizing or minimizing subsidence susceptibility.
Farhad Misaghi; Parisa Asgari; Maryam Nouri
Abstract
IntroductionThe availability of water for agriculture is of great importance, and despite the water crisis that is becoming more severe every year, both quantitatively and qualitatively, this issue should be seriously considered. Water resources include surface and groundwater, which are qualitatively ...
Read More
IntroductionThe availability of water for agriculture is of great importance, and despite the water crisis that is becoming more severe every year, both quantitatively and qualitatively, this issue should be seriously considered. Water resources include surface and groundwater, which are qualitatively more at risk, therefore, in order to preserve them, the sources of pollution must be known and appropriate solutions must be provided to prevent or eliminate these pollutions. Materials and methodsIn this research, phosphate transfer cycle in Zanjanrood Watershed has been simulated using SWAT model. For calibration and validation, SWAT-CUP software and measured values of average monthly current intensity at Sarcham hydrometric station between (1996-2013) were used and 26 sensitive parameters were selected for sensitivity analysis. There are three options for irrigation method, three options for fertilizer application and two combined options. In order to analyze the uncertainty of the indicators p-factor and r-factor and to analyze the quality of the model results, two indices of coefficient of determination (R2) and nash-sutcliffe coefficient (NS) have been used. Results and discussionIn the monthly runoff calibration stage, at the output of the field, the coefficients of r-factor, p-factor, R2, NS were 0.27, 0.11, 0.83 and 0.53, respectively, and in the validation stage were 0.60, 0.18, 0.73 and 0.53, respectively. The results showed that with increasing the level of pressurized irrigation, the amount of phosphate contamination at the outlet of the basin did not change significantly. Regarding the amount of fertilizer, the 50% reduction in the consumption of phosphate fertilizers has reduced the amount of phosphate entering the Zanjanrud River by 19.2%. On the other hand, a 50% increase in the use of fertilizers has increased the input phosphate by 17.7%. ConclusionThe results showed the proper performance of the SWAT model and its ability in the mentioned simulation. Also, by changing the surface irrigation method to subsurface and increasing the irrigation efficiency, there is no significant change in the average amount of phosphate output from the basin. On the other hand, by reducing the amount of fertilizer and preventing improper fertilization by farmers, pollution of surface and groundwater resources can be greatly prevented.
Seyed Ali Ayyoubzadeh; Mahdi Habibi; Mohammad Rostami; Mojtaba Sanei; Mohammad Faramarz
Abstract
Side weirs are widely used to divert water from rivers. In movable bed rivers, deposition of sediment particles along the side weir may cause some problems in diverting water. This research is done in a laboratory flume of 0.9 meter wide and 10 meter long with a longitudinal slope of 0.001. Three value ...
Read More
Side weirs are widely used to divert water from rivers. In movable bed rivers, deposition of sediment particles along the side weir may cause some problems in diverting water. This research is done in a laboratory flume of 0.9 meter wide and 10 meter long with a longitudinal slope of 0.001. Three value of weir length i.e. 0.6, 0.4 and 0.2 with a single weir height of 0.08 meter were used in the experiments. The variations of water surface profiles along the side weir were measured for various upstream Froude Numbers. The obtained results from experiments on movable bed condition were compared with those from rigid bed condition and also with the results from analytical solution. The results showed that bed form made by flow regime in the vicinity of the side weir does effect on the water surface profile over the weir and thus changes the diverted flow discharge. Water surface and discharges over the side weir were found in good agreement with the results obtained from the analytical solution in compare with the results obtained from channel with movable bed. The computed relative error for flow discharge in channels with movable and rigid bed is 6.35% and 24.18% respectively. This amount for variations of water surface profiles along the side weir is 8.03% and 9.88% respectively.
Ghazaale Madadi; Saeed Hamzeh; Aliakbar Noroozi
Abstract
Most of drought assessment systems are largely based on rainfall data. Although the short period of data, poor quality of rainfall measurement network and low-dense distribution of stations reduce the ability of detecting drought spatial patterns. Therefore, it is obligatory to detect climate data sources, ...
Read More
Most of drought assessment systems are largely based on rainfall data. Although the short period of data, poor quality of rainfall measurement network and low-dense distribution of stations reduce the ability of detecting drought spatial patterns. Therefore, it is obligatory to detect climate data sources, which would get rid of this problem, then to be used as an alternative option. Accordingly, in this study for monitoring drought in West Frontier Basin (including the Ilam, Kermanshah, Kurdistan and Lorestan provinces), using meteorological data (including 30 climatology and synoptic stations), to assess monthly data satellite TRMM (3B43). Drought indicators using SPI index for time scales of three, six, nine and 12 months in the period of 12 years (2000-2012) were calculated. After evaluating the accuracy and validating of monthly data from satellite images, estimation value of the drought on the determined time scales was done by use of TRMM dataset. The estimated value of the drought (SPI) across the study area using TRMM satellite images and maps of rainfall of ground-stations was calculated in MATLAB software after that for all the pixels continuously SPI value was calculated. The results indicate that, the SPI index from satellite images and ground stations are closely related. According to the statistics of weather and precipitation, year 2008 was introduced as the low rainfall year, besides the results of the study showed that the SPI value of the basin, in 2008 was lowest that determined it as the dry year.
Behnam Farid Gigloo; Ebrahim Omidvar
Abstract
Ephemeral Gully (EG) erosion is one of the most destructive types of water erosion, which contributes significantly to land degradation. EG erosion prediction is necessary to assess the magnitude of soil loss and to implement the appropriate conservation measures. The aim of current study was to ...
Read More
Ephemeral Gully (EG) erosion is one of the most destructive types of water erosion, which contributes significantly to land degradation. EG erosion prediction is necessary to assess the magnitude of soil loss and to implement the appropriate conservation measures. The aim of current study was to evaluate the efficiency of EGEM model for EG erosion prediction in Ghoorichay Watershed, Ardabil Province, Iran. For this purpose, a number of 17 EG erosion was identified and monitored between the years 2014 to 2016. The morphological characteristics and erosion rate of EGs were measured and recorded after seven effective rainfall events. In order to calculate the EG erosion, EGEM model requires four major categories of input data, including identification information, watershed data, soil data, and rainfall data. The model has two major components: hydrology and erosion. The runoff induced by a rainfall event in each gully catchment was determined by the Natural Recourses Conservation service (NRCS) Curve Number (CN). The result of EGEM model performance evaluation showed that the eroded soil volume and cross-section were predicted with a determination coefficient of 0.96 and 0.89, respectively. Sensitivity analysis revealed that the curve number was the most sensitive parameter, so that, with a 10% increasing and decreasing in CN, the volume of soil loss varied 22.98 and -18.92%, respectively. It can be concluded that EGEM model was suitable for event-based EG erosion prediction in Ghoorichay Watershed and it can be recommended for studying and planning on EGs in similar watersheds.
Seyed Hamidreza Sadeghi; Aliakbar Davudirad; Amir Sadoddin; Shahla Paimozd
Abstract
Today, land degradation is inevitable due to growing population and corresponding demands, and also economic development, unscientific and illogical utilization of resources. Monitoring and identification of factors affecting is therefore essential for controlling and management of land degradation in ...
Read More
Today, land degradation is inevitable due to growing population and corresponding demands, and also economic development, unscientific and illogical utilization of resources. Monitoring and identification of factors affecting is therefore essential for controlling and management of land degradation in an area. However, such important issues have been less considered by experts and managers. To this end, the present study aimed to analyze the trend and identifying the important affecting factors on land degradation in the Shazand Watershed, Iran, based on the Environmental Sensitive Area Index (ESAI) for significant changes due to a variety of uses, management and industrial development from 1986 to 2014. According to the ESAI maps in five year nodes of 1986, 1998, 2008 and 2014, some 16.56, 33.39, 42.32 and 49.52 percent of the study area were in critical condition of land degradation, respectively. Based on the results, the process of land degradation in the region was increasing and land degradation was considerable in the periods leading up to 1998 and 2014. The sensitivity analysis on factors influencing land degradation in the study area also revealed that the role of vegetation, anthropogenic and managerial factors on ESAI changes were more than other factors and therefore could moderate or intensify the land degradation.
Hamzeh Noor; Ali Dastranj; Saeed Sadeghi
Abstract
Flood control projects, artificial recharge of ground water aquifers, and optimizing the efficiency of water and soil resources are the most important benefits that have been achieved as a result of the construction of flood spreading stations in the country. The aim of this research is assessment ...
Read More
Flood control projects, artificial recharge of ground water aquifers, and optimizing the efficiency of water and soil resources are the most important benefits that have been achieved as a result of the construction of flood spreading stations in the country. The aim of this research is assessment and determination of effectiveness of Jajarm flood spreading project. For this purpose was the economic evaluation of flood spreading project using Net Present Value (NPV) and Benefit/Cost/ ratio studies in Jajarm Station. The social impacts of the Jajarm flood plan were also assessed through a popular questionnaire. Results showed that NPV was 262258 million Rials with discount rate according to the Central Bank. This shows that the Jajarm flood project is economically justified on the basis of economic evaluation and that investment is economical. The evaluation of the impacts of the floodplain project from the view point of the users of the project margin, also indicates that the people of the region are relatively satisfied with the project. Particularly people's satisfaction with the role of the flood spreading project in reducing flood damage to residential, land and communication areas in the region is significant.
Nazli Zenozi Alamdari; Behrouz Sobhani; Mehdi Eshahi,; Masihallah Mohammadi
Abstract
Introduction
Climate is a complex system that is changing primarily due to the increase in greenhouse gases. To study the effects of climate change on agricultural, hydrological, and environmental systems, general circulation models (GCMs) are used to simulate climate variables. These models, based ...
Read More
Introduction
Climate is a complex system that is changing primarily due to the increase in greenhouse gases. To study the effects of climate change on agricultural, hydrological, and environmental systems, general circulation models (GCMs) are used to simulate climate variables. These models, based on approved Intergovernmental Panel on Climate Change (IPCC) scenarios, enable the modeling of climate parameters over extended periods. Globally, various centers and models simulate future climatic conditions using different emission scenarios, physical structures, and computational approaches. The simulations from CMIP6 GCMs form the foundation for many IPCC conclusions regarding future climate changes. These data are utilized directly or after downscaling to evaluate local and regional climate changes (IPCC, 2021). This study analyzes and predicts trends in precipitation and minimum and maximum temperatures in East Azerbaijan Province under climate change conditions from 2021 to 2100.
Materials and methods
This study aims to investigate precipitation and minimum and maximum temperatures and their trends from 2021 to 2100 across stations in Tabriz, Ahar, Jolfa, Maragheh, and Miyaneh. Data from 12 CMIP6 models (ACCESS-CM2, BCC-CSM2-MR, CESM2, CNRM-CM6-1, CanESM5, MIROC6, MRI-ESM2-0, IPSL-CM6A-LR, GISS-E2-1-G, HadGEM3-GC31-LL, NESM3, and NorESM2-MM) were used under three Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5). The Kling-Gupta Efficiency (KGE) method was applied to identify the best models for simulating precipitation and temperature by comparing historical model data (1989–2018) with observed data from selected stations. Bias correction of model outputs was then used to forecast climate variables under the SSP scenarios. Finally, the mean time series of precipitation and minimum and maximum temperatures for the future period were compared with historical data to quantify changes over the 80-year horizon (2021–2100) for East Azerbaijan Province.
Results and discussion
The performance of 12 CMIP6 climate models was evaluated for generating past and present climate data (1989–2018). Based on uncertainty analysis, the BCC-CSM2-MR and MIROC6 models were identified as the best for simulating precipitation and temperature. These models were used, with bias correction, to predict precipitation and minimum and maximum temperatures for the future period (2021–2100) under optimistic, moderate, and pessimistic scenarios for East Azerbaijan Province. The results revealed that in all scenarios, annual temperatures are projected to increase while annual precipitation will decrease. Annual maximum temperatures across the selected stations are expected to increase by 0.57–6.41°C, while annual minimum temperatures will rise by 0.46–4.89°C. Precipitation is projected to decrease by 2.3% to 9.18%. The highest temperature increase and precipitation decrease are expected at Jolfa and Tabriz stations, respectively.
Conclusions
This study demonstrates that CMIP6 models effectively simulate future climate parameters and align well with historical climate data for East Azerbaijan Province. The high accuracy of these simulations makes them suitable for forecasting future climatic conditions and facilitating macro-level management strategies. Such strategies can enhance resource productivity, particularly in water resource management, to address the challenges posed by climate change.
Seyed Hamidreza Sadeghi; Mohsen Zabihi
Abstract
Rainfall erosivity factor is the first noticeable point in soil erosion issues that plays very important role in detachment of soil particle from the origin bed. Hence, investigation of rainfall erosivity factor trend is necessary in decision-making and planning in order to manage soil and water resources. ...
Read More
Rainfall erosivity factor is the first noticeable point in soil erosion issues that plays very important role in detachment of soil particle from the origin bed. Hence, investigation of rainfall erosivity factor trend is necessary in decision-making and planning in order to manage soil and water resources. However, studies on various aspects of erosivity like trend and in interaction with precipitation and SPI index have not been attended well. The present study therefore aimed to investigate the rainfall erosivity factor trend based on the Fournier index in 28 stations throughout North-Khorasan Province during the period of 1987 to 2006 by using the Mann-Kendall test. In addition, the SPI and precipitation trend were comprehensively investigated for better characterization of erosivity trend analysis. Results showed that Noushirvan, Faruj, Ayerqayeh and Gholaman stations had decreasing trend and other study stations (71.85%) had increasing trend in the modified Fournier erosivity index. The SPI and precipitation in the study area indicated that most of the stations (89.28%) excluding Khartot, Noushirvan, Faruj and Ayerqayeh had increasing trend. The maximum and the minimum values of modified Fournier erosivity index with 70.97 and 33.44 mm were also assigned to Darkesh and Abiary Bojnourd stations, respectively.
yasin salehi; Alireza vaezi
Abstract
IntroductionSoil erosion is the most important aspect of land degradation and one of the most important environmental, agricultural and food production problems in the world. More than half of the agricultural lands in semi-arid regions are under rainfed cultivation, and the tensions caused by erosion ...
Read More
IntroductionSoil erosion is the most important aspect of land degradation and one of the most important environmental, agricultural and food production problems in the world. More than half of the agricultural lands in semi-arid regions are under rainfed cultivation, and the tensions caused by erosion and destruction of land are important in terms of the effects within the field of erosion, such as soil fertility, and the effects outside the field, such as soil pollution. Information about the size distribution of eroded particles is a substantial step for managing the loss of nutrients and the transfer of pollutants from the soil. For this purpose, this study was conducted to investigate the particle size distribution of sediments resulting from interrill erosion under the influences of slope gradient and soil texture in some soils of the semi-arid region of Zanjan Province. Materials and methodsToward this, four hillslopes having different soil textures (sandy loam, silty loam, sandy clay loam and clay loam) in four north-south slope percent (five, 10, 15 and 20%) were investigated using a simulated rainfall with an intensity of 60 mmh-1 for 60 minutes. In order to monitor the runoff and sediment samples from the beginning of the runoff until reaching a stable state, were taken at 5-min intervals from the initiation of runoff. The particles size distribution of sediment was determined by the method of particle separation using a series of sieves with diameters of 75, two, one, 0.5, 0.25, 0.1 and 0.05 mm. Also, the percentage of finer particles (silt and clay) was calculated by hydrometer method. Then the sediment particles are divided into eight categories: gravel (1-75 mm), very coarse sand (1-2 mm), coarse sand (0.5-1 mm), medium sand (0.25-0.5 mm), fine sand (0.1-0.25 mm), very fine sand (0.05-0.1 mm), silt (0.002-0.05 mm) and clay (<0.002 mm) were categorized. Results and discussionThe results showed that, with the increase in the slope of the land surface, the size distribution of sediment particles changed in all soils. So that, the transport of particles larger than 0.1 mm (including very coarse sand, coarse sand, medium sand and fine sand) increased with increasing slope. While the percentage of silt particles (0.002-0.05 mm) decreased in all textures. Also, particles with the size class of medium sand and fine sand formed between 40 and 50% of the sediment particles for each texture and did not change significantly with the increase of the slope. The highest ratio of particles in the sediment to the main soil was related to silt particles and in silty loam texture (4.33 times) and the lowest was related to clay particles and in silty loam texture (0.26 times). Sand and silt particles in different textures, had high transmission ratios. Silt particles in three textures of sandy loam, clay loam and silty loam had a ratio of more than one and clay particles less than one. Except in clay loam soil, sand particles changed in the range of 0.83 to 1.24 times compared to the main soil and the overall average ratio of its availability in sediment to original soil was 0.98 times. ConclusionIn general, this research showed that with increasing slope, the selectivity of fine particles decreases and the share of coarse particles increases. The effects of these changes are more visible in fine-textured soils. Due to the increase in the destruction of aggregates and flow rate with the increase of the surface slope, it is very important to prevent the removal of vegetation and observe the principles of tillage in order to reduce the direct impact of raindrops on the soil surface and reduce the transportability of particles by the flow. Also, the results show that the ratio of particles in the soil texture and the characteristics of soil structure (abundance and stability of aggregates) are the determining factors of particle transport and it is necessary to consider these characteristics in choosing soil conservation methods.
