Ali Bakhtiarizadeh; Mohammad Najafzadeh; Sedigheh Mohamadi
Abstract
Introduction
The groundwater aquifer is one of the most vital resources, being considered more important in the countries (e.g., Iran) located in hot and dry areas. One of the ways to prevent contamination of groundwater resources is to focus on their vulnerability. So, a trustworthy assessment of groundwater ...
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Introduction
The groundwater aquifer is one of the most vital resources, being considered more important in the countries (e.g., Iran) located in hot and dry areas. One of the ways to prevent contamination of groundwater resources is to focus on their vulnerability. So, a trustworthy assessment of groundwater vulnerability is useful to determine the contamination points of the aquifer for effective protection and management of groundwater resources.
Materials and methods
In this research, DRASTIC index was applied to evaluate groundwater susceptibility while considering effects of land use and nitrate pollution for Kerman-Baghein Plain located in Kerman Province. In this regard, seven parameters including the depth of the water table, net feeding of aquifer, aquifer texture, surface soil texture, topography, impact of the vadose zone, and hydraulic conductivity were employed to calculate the DRASTIC index. It should be noted that this index has previously been applied by researchers for assessment of the vulnerability of the aquifer against groundwater pollution in different regions. However, despite the complexities in the underground water system and the opinions of experts in assigning the rank and weight of the parameters in this index and the difference in the conditions prevailing in the studied areas, it has always prompted researchers to take practical steps to improve this index. This improvement has been carried out in a number of studies by adding other parameters (e.g., land use and the effect of nitrate) to the parameters of the DRASTIC index. Therefore, in the present research, the parameters of land use and potential risk associated with land use have been used to compute the Composite DRASTIC index (CD) and Nitrate Vulnerability Index (NVI) in the Arc/GIS software environment, respectively. In this way, the CD index was obtained by adding the land use parameter to the DRASTIC index and the NVI index by multiplying the raster map of the potential risk rating related to the land use in the DRASTIC index. It should be noted that according to the land use map evaluation, this plain includes 54% of low-density pastures, 24% of irrigated agriculture, 10% of hand-planted forests, 6% of bare and desert lands, 5% of residential areas, and 1% of claypans. After the evaluation of three vulnerability criteria using all three indices DRASTIC, CD and NVI, their correlation with Ggroundwater Contamination Risk (GCR) was also investigated.
Results and discussion
The results revealed that the correlation of the DRASTIC index with the risk of underground water pollution is 8%, the CD index is 30% and the NVI index is 54%, with a probability of 99%, they show a significant correlation. The results indicated that the addition of the land use parameter caused to increase the correlation of vulnerability with the risk of groundwater pollution, and multiplying the potential risk associated with land use led to further increase of the correlation. As a result, the NVI index was selected as the superior index compared to the other two indices.
Conclusion
The results of the NVI index of Kerman-Baghin Plain indicated that this plain is divided into two categories including very low vulnerability with an area of 1528.07 km2 (75.52 %) having an NVI value of less than 70 and low vulnerability with an area of 495.33 km2 (24.48 %) having NVI value from 70 to 110. Taken together, in order to properly manage the groundwater resources and prevent the pollution of these resources, it is recommended to prohibit the establishment of industries and the cultivation of agricultural sector causing the pollution in areas with low vulnerability.
Rahim Kazemi
Abstract
During the last two decades, there has been a lot of research on the base flow issue in the country, but so far, no comprehensive and specific article review of base flow research has been conducted, untill the various aspects of this issue be identified and the cases ignored, be introduced and addressed. ...
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During the last two decades, there has been a lot of research on the base flow issue in the country, but so far, no comprehensive and specific article review of base flow research has been conducted, untill the various aspects of this issue be identified and the cases ignored, be introduced and addressed. In this research, first, by literature review at the global and national level, the progress of studies in different fields of this issue were investigated and then dissertations, articles and reports published in international journals and related conferences have been classified and discussed for the past two decades. The main purpose of this research was to identify issues of research at base flow and to identify lesser and overlooked issues in country research. The articles reviewed in this research were analyzed based on spatial domain, research method, theory, data analysis techniques and topic. Results showed that research orientation in base flow in Iran can be divided into four general categories; 28.21% of studies related to applied orientation; 37.18% to comparison and introduction of proper baseflow separation method; 19.23% to investigation of factors affecting base flow and 15.38% to general use and description of hydrological conditions of the study area. The overall conclusion, indicates limited studies, lack of innovative, and focus on the use of conventional and repetitive methods and also lack of attention to this issue by scientific and research centers of the country.
Saeideh Ansariyan; Mahnoosh Moghaddasi; Mojaba Moradi
Abstract
The success of the artificial recharge projects of aquifers need to recognition the appropriate points. The aim of this investigation is finding appropriate points for artificial recharge in “Kavir Meighan” basin in Markazi province. Because of that the Geographical Information System (GIS) ...
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The success of the artificial recharge projects of aquifers need to recognition the appropriate points. The aim of this investigation is finding appropriate points for artificial recharge in “Kavir Meighan” basin in Markazi province. Because of that the Geographical Information System (GIS) is used. In this investigation. the method“Analytic Hierarchy Process (AHP)” is used to find suitable points. By using the opinion of the experts, the necessary criterion to choose suitable points are: Water Quality, Water Depth, Slope, Land use, Geology, Soil texture and the position of wells, springs and Qanats. In AHP methods the raster layer of used criterion was prepared. Then by using double comparison and Expert choice software, the weight of the any layers was made. In this method the maps were put together by overlap methods. After that, inappropriate points those are too close to wells, springs and qanats, were showed. Finally, the potential map of artificial recharge zone was prepared. In AHP method the potential map contents 29 zones, the total area of them is 14,770,183 square meters.
Payam Amouzegari; Mostafa Panahi; mir khalagh mirnia
Abstract
Groundwater resources are the most important source of fresh water in the world. In Iran which is located in the arid and semi-arid region, mismatch of consumption needs with rainfall time along with climate change has increased the demand for groundwater. Excessive extraction of groundwater in the Alashtar ...
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Groundwater resources are the most important source of fresh water in the world. In Iran which is located in the arid and semi-arid region, mismatch of consumption needs with rainfall time along with climate change has increased the demand for groundwater. Excessive extraction of groundwater in the Alashtar Watershed reduced the water level in the aquifer of the plain and water resources of this area have faced a negative balance. Due to the inherent limitations of the country's water resources and increasing the split between supply and demand, the use of economic instruments and the establishment of the water market for optimal allocation of groundwater is a necessity. Accordingly, this study in order to determine the market price of groundwater with the aim of accurately identifying the local markets for groundwater and also measure the views of local water market operators about some of the strategies for advance the water market designed and implemented. The statistical population in this research was all rural exploiters are the main reservoirs of groundwater in the basin who contribute to the buy and sale of these resources. Regarding market prices in the study area, the average price of groundwater was 1,749 Rials per cubic meter, and the total value of groundwater was estimated as 555,307.5 Milion Rials. The results showed that in 103 villages there is a market for the buy and sale of groundwater. Those villages that have a local groundwater market, 76% of the villages have been established by creating popular organizations and the water regulatory council and 43% of the villages by create a bulletin board agreed to facilitate the buy and sale of groundwater resources.
Reza Chamani; Mahmood Azari; Sven Kralisch
Abstract
The hydrological effects of climate change are a great challenge for water resources management. Determining climate change impacts on hydrological processes is a prerequisite for adaptation strategies to climate change; which in turn is necessary for water scarcity crisis in future. The purpose of this ...
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The hydrological effects of climate change are a great challenge for water resources management. Determining climate change impacts on hydrological processes is a prerequisite for adaptation strategies to climate change; which in turn is necessary for water scarcity crisis in future. The purpose of this research is to determine climate change impacts on hydrological regime of the Chehelchay watershed in Golestan province. J2000 distributed process based model was used for simulation of the hydrological process. Output results of seven climate models including CanESM2, CCSM, BBC-CSM1.1, CESM1-BG, CESM1-CAM5, ICHEC- EC-EART and MPI-M-MPI-ESM-LR for two Representative Concentration Pathways scenarios (RCP 4.5 and RCP 8.5) for 2071-2100 were used for climate change impact analysis. Study results revealed that the maximum temperature for RCP 4.5 and RCP 8.5 in 2071-2100 will increase by 2.6 and 4.7 °C and the minimum temperature will increase by 2.4 and 4.5 °C respectively by the end of the 21st century. In addition, precipitation for RCP 4.5 will increase by 0.6 percent and for RCP 8.5 will decrease by 0.6 percent. Modeling results show these will lead to significant changes in the hydrological regime. In particular, evapotranspiration will increase by 9.6 and 16.7 percent and stream flow will decrease by 4.2 and 3.2 percent. The results of the hydrological changes will cause a decrease in stream flow in April –June and for RCP 8.5 will be continued till October.
hassan torabipodeh; ahmad godarzi; reza dehghani
Abstract
Simulation and evaluation of river sediment is one of the important issues in water resources management. Measuring the amount of sediment in conventional methods generally involves a lot of time and cost and sometimes does not have sufficient accuracy. In this study, a wavelet neural network was used ...
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Simulation and evaluation of river sediment is one of the important issues in water resources management. Measuring the amount of sediment in conventional methods generally involves a lot of time and cost and sometimes does not have sufficient accuracy. In this study, a wavelet neural network was used to estimate the sediments of the Kashkan River in Lorestan Province, and its results were compared with conventional smart methods such as artificial neural network. Parameters of discharge, temperature, water soluble solids content and precipitation as input and sediment discharge were selected as output during the monthly statistical period (1984-2013). Correlation coefficient, root mean squared error, and Nash Sutcliff coefficient were used to evaluate and compare the performance of the models. Results showed that the combined structure has been able to provide acceptable results in estimating sediment yield using two intelligent methods. However, in terms of accuracy, the wavelet neural network model with the highest correlation coefficient (0.850), the lowest root mean square error (0.151 tonday-1), and the Nash-Sutcliff criterion (0.758) were prioritized in the validation stage. Results also showed that the wavelet neural network model has a high ability to estimate the minimum and maximum values.
Rahim Kazemi; Jahangir Porhemmat; Forood Sharifi
Abstract
The Flow Duration Curve (FDC) is a classical method used to graphically represent the relationship between the frequency and magnitude of stream flow and is required as a prerequisite for water resources management projects. In this study, by analyzing daily data of hydrodynamic stations, 47 stations ...
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The Flow Duration Curve (FDC) is a classical method used to graphically represent the relationship between the frequency and magnitude of stream flow and is required as a prerequisite for water resources management projects. In this study, by analyzing daily data of hydrodynamic stations, 47 stations with the appropriate statistics and the common period between 1976 and 2011 was selected in a semi-arid region of the country. Using a topographic map with a scale of 1: 50000 and determining the position of the stations, the study area was determined and 11 physiographic parameters influencing the flow duration curve including: average height, basin area, gravilillus coefficient, basin slope, main river length and hydrological parameters including annual rainfall, Base flow index, hydrograph recession constant, curve number, permeability and the number of rainy days were extracted for each basin. The flow duration curve indices were then extracted using daily flow data. Then factor analysis was performed and independent factors influencing the flow duration curve were determined. Finally, homogeneity was performed based on independent main factors and the regression relations of the curve indices were extracted in each homogeneous region.In order to investigate the validity and accuracy of the models in homogeneous regions, error-independent test methods, normal distribution of errors and control stations were used. The results showed that the selected factors for factor analysis in semi-arid climatic zone (75.875 percent) of the variance of data were explained. The six parameters of precipitation, curve number, slope, rainy days, permeability and area were known as the most effective parameters. The results of the accuracy assessment of the models using the control stations showed that the relative error of the relations presented in the homogeneous region was 0.17, 2.17, 2.73, 1.53 and 1.94, respectively. The normal distribution of errors, the coefficient of determination of more than 0.90 and the Durbin Watson coefficient between 1.5 to 2.5 also Nash-Sutcliff near "one" indicate the reliability of the regression relations presented for estimating the flow duration curve indices in the ungagged catchments in semi-arid areas of the country.
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 ...
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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.
Gholamreza Chamanpira; Gholamreza Zehtabian; Hassan Ahmadi; Arash Malekian
Abstract
Utilization of water resources, using a combination of simulation and optimization, are a useful and powerful set for specifying decision-making and management strategies. In this regard, MODFLOW mathematical model, as an efficient and cost-effective tool to evaluate different management options was ...
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Utilization of water resources, using a combination of simulation and optimization, are a useful and powerful set for specifying decision-making and management strategies. In this regard, MODFLOW mathematical model, as an efficient and cost-effective tool to evaluate different management options was used. After providing a conceptual model of the aquifer, requirement data were defined in different versions of the V. MODFLOW (V. 5.33) software. Then, the model was calibrated by the manual method that has higher accuracy than software techniques and validation operations were also carried out. In the simulation process, with the goal of water resource management, the results of modeling and calibration model were used to optimize the groundwater table level. In this study, a linear programming model was used for optimizing the management. Lingo software was used to implement this model and achieve the optimal management. The information needed to solve the problem, was based on the output of a simulation model and optimization options. Due to linearity of objective function, a multi-objective linear programming model was selected to solve the problem. General multi-objective optimization problem with n decision variables, m constraints and p objectives is presented in optimizing relationships. The objectives of the optimization problem were maximizing the profits of agricultural products and minimizing the use of aquifer water. Results indicated that the amount of yield and water use were different before and after optimization. . The amount of annual water consumption before optimization was 92.22 million m3 while after optimization was 75.51 million m3. In other words, the rate of water consumption was reduced by 18 prevent. Results also showed that annual water consumption in agriculture was 31.79 million m3 that shows 65.5 percent reduction compared to the present situation. The amount of benefits before optimization was 47, 798 million Rials, while after optimization it was 63,689 million Rials. In other words, the amount of total profit increased by 33.25 percent. Based on the scenario of a national document (pure water requirement), total profits increased by 15 percent.
Majid Khazaei; Mohammad Reza Mirzaei
Abstract
Prediction in hydrology is as estimation of hydrological and meteorological conditions in a specific interval time. In this regard, understanding the relationship between precipitation and runoff is necessary for water resources optimal management. The purpose of this study was to compare different models ...
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Prediction in hydrology is as estimation of hydrological and meteorological conditions in a specific interval time. In this regard, understanding the relationship between precipitation and runoff is necessary for water resources optimal management. The purpose of this study was to compare different models of artificial neural networks (two type of ANNs: RBF and MLP) and time series models (ARMA) to discharge estimation in a part of the Taleghan watershed, using monthly flow discharge data for a period of 30 years between 1977 and 2007. Among the different ARMA models, a model with a lowest error and akaike (AIC) criterion was selected as an optimal model. Using trial and error method, ANNs were designed by specifying the number of hidden layers and neurons in each layer, sigmoidal transfer function, training function, weight/bias learning function and performance function. Using trend analysis, Halt-Winters and Box-Jenkins (ARMA) methods, time series analysis showed that ARMA (2, 2) (R= 0.77) and Halt-Winters (R=0.72) presented more accurate results. In general, it could be concluded that ANNs models produced more accurate predictions of flow discharge than time series approaches. Also, the results revealed that the MLP model (average R=0.83) produced more accurate predictions of flow discharge than RBF model (average R=0.81). Assessment of accuracy of all models based on RMSE and R showed that the model 1 (with RMSE= 6.45 and R= 0.86) obtained with a network architecture of 4-20-1 configuration. Model 1 used the input vector consisting of antecedent monthly discharge with one to four time lag.
