Mehdi Teimouri; Omid Asadi Nalivan
Abstract
With the increase in population, the importance of groundwater resources as one of the most important sources of drinking water in the arid regions becomes apparent. In this research, in order to determine the areas with groundwater potential in the city of Torbate Jam and prioritizing the effective ...
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With the increase in population, the importance of groundwater resources as one of the most important sources of drinking water in the arid regions becomes apparent. In this research, in order to determine the areas with groundwater potential in the city of Torbate Jam and prioritizing the effective factors, hierarchical analysis methods and maximum entropy method using MaxEnt model and the factors of distance from fault and fault density, lithology, slope, slope direction, distance from the waterway and drainage density, elevation, land use, slope curvature, topographic humidity index and topographic position indicator was used. Also, for assessing these two methods, the Receiver Operating Characteristic (ROC) was used. From 220 sources, 30% were randomly assigned as validation data and 70% were categorized as test data in maximum entropy method. Results showed that 29.6% of the watershed had high groundwater potential according to the maximum entropy method. Based on Jack-Knife Diagram, DEM, slope, distance from fault and lithology were the most important factors affecting groundwater potential, respectively. The Area Under the Curve (AUC) in the maximum entropy method indicated a precision of 91% (excellent) at the training period and 80% (very good) in the validation period to determine areas with potential for groundwater. Based on AHP method, 34.4% of the area has groundwater potential, and the slope layers, lithology, elevation and distance from the faults were the most important factors, respectively and accuracy of this method was 73%. The results showed that applying AHP and maximum entropy methods, while saving time and cost, have a good ability to predict the potential of groundwater and the maximum entropy method has more superiority than the hierarchical analysis method.
Mahmoudreza Tabatabaei; Amin Salehpour Jam
Abstract
Relationships between river water quality parameters and physical, geochemical and biological processes carried between basin resources (soil, vegetation, geology, land use, etc.), meteorological variables (temperature, precipitation, snowmelt, etc.), River hydrological variables (flow discharge), as ...
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Relationships between river water quality parameters and physical, geochemical and biological processes carried between basin resources (soil, vegetation, geology, land use, etc.), meteorological variables (temperature, precipitation, snowmelt, etc.), River hydrological variables (flow discharge), as well as human interventions are often very complex, nonlinear and non–deterministic in a way that makes their complete understanding impossible. In this situation, the use of computational intelligence (such as artificial neural networks) is a useful tool in simulating and estimating river water quality variables such as suspended sediment load. In the present study, by combining open source GIS libraries and neural network models (with and without supervisor), an intelligent GIS system has been designed and coded that can estimate daily suspended sediment load under univariate or multivariate conditions. The results of applying this system to Mazaljan River Watershed at Razin hydrometric station showed that this system is able to simulate suspended sediment load with proper performance and validation (with root mean square error of 1033 tonday-1, mean absolute error of 455 tonday-1 and Nash-Sutcliffe efficiency of 0.89 for the test data set). In general, this system can be used as a national infrastructure in the simulation and management of suspended sediment in all hydrometric stations in the country by relevant organizations.
mojtaba rafyi; Khalil Rezaei; KOUROSH SHIRANI; MOHAMADI NASRIN
Abstract
Identification of areas that prone to subsidence and estimation of its rate plays an important role in the control management of this phenomenon. Differential interferometry radar technique (D-InSAR) with very high accuracy is one of the most suitable ways for identify and measure the rate of subsidence. ...
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Identification of areas that prone to subsidence and estimation of its rate plays an important role in the control management of this phenomenon. Differential interferometry radar technique (D-InSAR) with very high accuracy is one of the most suitable ways for identify and measure the rate of subsidence. In this study, to identify and measure the subsidence in Mahyar Plain differential radar interferometry techniques have been used in the period of 2004 to 2010. For this purpose, eight pair images of time series were used from ASAR sensor in C-band radar in ascending passage. The method used in this study is based on laboratory-field surveys. For validation of technique, survey data such land use and geology maps and data of observation wells in the region were used. As a result, maximum rate of annual subsidence in the area was 6.4 cm yr-1. Also, results showed that the highest amount of subsidence occurred in areas under cultivation and due to excess extraction of groundwater and subsidence of aquifer surface. The rate of subsidence was obtained 0.384 cm for each two cm drop of water table according to the relationship between subsidence and the changes of piezometric wells surface.
nasim arman; Ali Shahbazi; mohammad faraji; somaieh dehdari
Abstract
Water harvesting and surface runoff control systems are the important components of urban planning and development and ignoring these issues is likely to raise crisis. In order to decrease the urban flood damages, the urban runoff is needed to be evaluated correctly. Today some of models are developed ...
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Water harvesting and surface runoff control systems are the important components of urban planning and development and ignoring these issues is likely to raise crisis. In order to decrease the urban flood damages, the urban runoff is needed to be evaluated correctly. Today some of models are developed for urban runoff simulation. One of the most important models in evaluating and management of urban runoff is SWMM. The aim of this study is to evaluate SWMM efficiency on urban runoff simulation in Izeh urban basin. To define design rain, concentration time was computed while considering the duration of the cloudburst as equal to this time. Also three performance indexes of Nash-Sutklif, errors sum of squares and Bias were used in order to model calibration and validation. Moreover, areas of high susceptibility were determined for two, five, 10, 20 and 50 years of return periods. Later, it was found that the principle reason of inundation is the lack of sufficient capacity of water ways. In some points, even with sufficient capacity, inundation occurs, confirmed by model. In these cases the causes stem from the improper design and construction of bridges which has lessen the size of water ways and caused junk clogging. Three rainfall events were recorded on March 13, 2017, March 28, 2017 and April 6, 2017 which were considered in order to calibrate and evaluate the model performance. Along with that, the discharge, depth and velocity of water at the outlet were considered as well. The results of the SWMM application gave indication of a good matchup between discharge, depth and the velocity of runoff for observed and estimated data. In this case, this model could be utilized to well predict the inundation hazard, design and the estimation of the cost and volume of drainage systems, management of watershed and prioritization of region to address flooding issues.
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 ...
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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.
Marzieh Hajimohammadi; Abolfazl Azizian; Bagher Ghermezcheshmeh
Abstract
Knowledge of climate variabilities and their behavior in future periods and their effects in various fields has great importance especially in strategic and macro planning in water resources. This study aims to evaluate the effect of climate change on hydrological condition of the Kan Watershed. For ...
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Knowledge of climate variabilities and their behavior in future periods and their effects in various fields has great importance especially in strategic and macro planning in water resources. This study aims to evaluate the effect of climate change on hydrological condition of the Kan Watershed. For this purpose the HadCM3model under the A2 emission scenario and also statistical downscaling model (SDSM) were applied for temperature and rain variables simulation. Then, SWAT model was used for monthly runoff simulation and SUFI-2 algorithm was used in SWAT-CUP software pack for calibrating and uncertainly analyzing. The performance of SDSM model was evaluated base on MBE and NRMSE parameters, the result indicated that temperature variable was simulated more accurate than of precipitation. The result of the predicting temperature in period (2011-2040) compare with the base period (1961-2001) showed the maximum and minimum temperature will increase by 1.3 and 0.8 °C, respectively. Also, the rainfall will decrease by 3-4 percent for all of selected stations. The most rainfall reduction will be for spring. While in some months of winter an increase of precipitation was predicted. The result of calibration and validation of SWAT model agreed well with the observed data, so that Nash-Sutcliff efficiency coefficient, as objective function, was 0.82 and 0.71, in calibration period (1983-1991) and validation period (1992-1996) respectively. Finally, results of runoff prediction showed an increase in winter and a decrease in other seasons based on climate scenarios. Overall, according to obtained results runoff will decrease by seven percent for future period.
Ahmad Sharafati
Abstract
Rainfall runoff models are used mostly in simulation of flood events. Also, calibration of rainfall runoff model parameters is an important and challenging issue in flood simulation. Due to random characteristic of these parameters, the deterministic optimization is not a suitable approach for calibration ...
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Rainfall runoff models are used mostly in simulation of flood events. Also, calibration of rainfall runoff model parameters is an important and challenging issue in flood simulation. Due to random characteristic of these parameters, the deterministic optimization is not a suitable approach for calibration of rainfall runoff model. So, in this study, the SUFI (Sequential Uncertainty Fitting) algorithm is used as a stochastic approach and the optimized range of parameters were extracted. The obtain results shown, in calibration step, the correlation coefficient between observed hydrographs (three events) and the best generated hydrographs were more than 0.9 and also, the average difference between observed hydrographs and the best generated hydrographs were less than 5 percent. Furthermore, in validation step, the correlation coefficient between observed hydrograph and the best generated hydrograph was 0.99 and also, the average difference between observed hydrograph and the best generated hydrograph was 11 percent. So, the SUFI algorithm is a suitable approach in stochastic calibration of HEC-1 model.
Akbar Hassani; Hosseinali Bahrami; Aliakbar Noroozi; Shahin Oustan
Abstract
Reflectance spectroscopy can be used to study agricultural and environmental aspect of soil that are sensitive to soil organic and inorganic compounds. Despite the extensive studies in the field of visible-near infrared reflectance spectroscopy, there are rare researches in gypseous and calcareous soils. ...
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Reflectance spectroscopy can be used to study agricultural and environmental aspect of soil that are sensitive to soil organic and inorganic compounds. Despite the extensive studies in the field of visible-near infrared reflectance spectroscopy, there are rare researches in gypseous and calcareous soils. The objective of this study was to obtain a model that can predict chemical properties of gypseous soils via reflectance spectroscopy methods. Soil samples were collected from 102 locations in five different provinces in 0-30 cm of depth. Some chemical properties of soils, such amount of gypsum, equivalent calcite, cation exchange capacity, pH, EC, exchangeable calcium, magnesium, sodium and potassium and amount of silt, clay and sand were measured by standard methods in the laboratory. Air-dried soil samples were scanned at one nm resolution from 350 to 2500 nm, and calibrations between properties and reflectance spectra were developed using cross-validation under Partial Least Squares Regression (PLSR) and Boosted Regression Trees (BRT). Raw reflectance and first derivative reflectance data were used separately and combined for all samples in the data set. Data were additionally divided into two random subsets of 70 and 30 percent of the full data, which were each used for calibration and validation. Strongest correlations were obtained with gypsum, equivalent calcium carbonate, cation exchange capacity, exchangeable Ca and Mg, organic matter, sand and clay contents. Overall, BRT provided better predictions when under cross-validation. However, PLSR and BRT results were comparable in terms of prediction accuracy when using separate data sets for calibration and validation. In conclusion, VNIR spectroscopy was variably successful in estimating soil properties and showed its potential for substituting laboratory analyses or providing inexpensive co-variable data in environmental studies.
Majid Hosseini
Abstract
In this study, a simulation has been performed using the Soil and Water Assessment Tool (SWAT) model with the data of the Ghare-sou watershed. The main objective of the study was testing the performance of SWAT and its feasibility to simulate the water balance in this watershed. Required data such as ...
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In this study, a simulation has been performed using the Soil and Water Assessment Tool (SWAT) model with the data of the Ghare-sou watershed. The main objective of the study was testing the performance of SWAT and its feasibility to simulate the water balance in this watershed. Required data such as soil properties, land use and topographic maps were collected from the Natural Resource Office of Kermanshah province, and the weather data, including daily rainfall, temperature, relative humidity and discharge were collected from Meteorology Agency and regional water company of the province. Before calibration, a sensitivity analysis has been performed for all parameters, using OAT (One parameter At a Time) method to evaluate and demonstrate the influences of the model parameters on four major components of water budget including surface runoff, lateral flow, groundwater and evapotranspiration. Calibration and validation of the model were performed using the SUFI2 algorithm. River discharge data from 1982 to 2000 were used for the calibration and those of 2001 to 2005 for the validation. Different criteria were used to evaluate the performance of the simulation. During calibration, the simulated flow matched the observed values with a Nash-Sutcliffe coefficient of 0.56 and a coefficient of determination (R2) of 0.6. These values were 0.6 and 0.65 during the validation. The calibrated SWAT model is suggested to be used in simulation of the monthly flow of the Ghare-Sou watershed, in order to assess the impacts of different management practices and environment changes on the flow.
Azade Jabary; Majid Hosseini; Amir Khosrojerdi
Abstract
The present research is looking for determining and evaluation of water balance in Sanjabi Watershed located in Kermanshah Province due to a variety of problems raised by the population increase. For this purpose, the SWAT model parameters have been calibrated by applying required information layers ...
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The present research is looking for determining and evaluation of water balance in Sanjabi Watershed located in Kermanshah Province due to a variety of problems raised by the population increase. For this purpose, the SWAT model parameters have been calibrated by applying required information layers in a period extending from 1995 to 2004 and their sensitivity were analyzed by SUFI2 program. The flow parameters’ sensitivity was computed by P-Value and t-State in SUFI2. The most sensitive parameters were calibrated and thereafter model was validated for a period extending from 2005 to 2007. The model evaluation results showed that the value of NS (Nash Sutcliff), R2 (Coefficient of determination), Mean Absolute Relative Error (MARE) and Percent Difference (D) for calibration period were 0.78, 0.78, 0.2 and -0.2, respectively and for validation period were 0.74, 0.86, 0.3 and 0.01, respectively. Results showed the desired accuracy of SWAT for runoff simulation. Discharges for calibration and validation periods were generally under and overestimated, respectively. The water balance values are calculated as the amount of water available in the soil. So that the water balance resulted as negative in years 2005 (normal year), 2006 (wet year) and 2007 (dry year). Nevertheless, in these three years, autumn and winter monthly water balances were positive while in spring and summer were negative. The results also showed that most water losses were due to evapotranspiration in this watershed.
Hiwa Osmani; Baharak Motamedvaziri; Abolfazl Moeni
Abstract
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 Tehran’s Latyan Dam upstream area. In order to test the efficiency ...
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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 Tehran’s Latyan Dam upstream area. In order to test the efficiency of this model in simulating output discharge, by comparing Roodak hydrometric station simulation values situated at the exit of the area during an 11-year period (1997-2007), it was specified that the model did not perform well in simulating Bik discharges. Further on, at first, 21 effective flow parameters were entered into the SWAT-Cup software, which after analyzing sensitivity, 14 parameters were used for calibration and validation. Calibration was carried out for years 1997 to 2003, and validation was conducted for years 2007 to 2007. Different assessment indexes were employed to measure performance of the model in SWAT-Cup software and the SUFI2 algorithm, which indexes R2, NS, P-Factor, and R-Factor for the calibration period were 0.91, 0.88, 0.96, 1.79, and values for the validation period 0.92, 0.92, 0.9, and 1.54, respectively. Moreover, the Alpha coefficient for underground water, surface water delay coefficient, and soil outward density were recognized as the most sensitive parameters in output discharge.
Hossein Saadati; Shaban Ali Gholami; Foroud Sharifi
Volume 1, Issue 2 , July 2009, , Pages 87-98
Abstract
Lack of hydrometric data is the main issue for research and executive plans. In the present study in order to solve this issue, the capability of SWAT model has been studied in terms of daily discharge simulation in un-gauged watersheds. This model can simulate six hydrological and biological processes ...
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Lack of hydrometric data is the main issue for research and executive plans. In the present study in order to solve this issue, the capability of SWAT model has been studied in terms of daily discharge simulation in un-gauged watersheds. This model can simulate six hydrological and biological processes such as daily discharge, daily sediment, yearly and monthly water balance, water quality, agricultural products and estimation of vegetative cover for different animal grazing management systems. Simulation has been done for both gauged and un-gauged basins in Kasilian catchment for two time periods as calibration and validation of model. Calibration has been done using data derived from 4 years recording data (1987-1981) while validation has been done using 6 years data (1981-1986). Results show that, ABF, CN2 and REVAPC parameters are most sensitive and also Z and T-Laps parameters are low sensitive among other parameters. The model simulated runoff reasonable with r2=0.69, PBIAS=-2.5, and NS=0.72, whereas, the validation of model for the same data showed that r2=0.57, PBIAS=4.3, and NS=-0.54, which indicates that the performance this model is not quite valid for low stream flows because of sensitivity of hydrological parameters. The new version of SWAT model, modified during 2000 to 2005, has a capability in using GIS, thus it can be used in the same study area.
