پژوهشی
Ali Shahidi; Fahime Khadempour
Abstract
1-Introduction Increasing water consumption due to population growth has led to a reduction in the quality and quantity of extracted water. Given this situation, quantitative and qualitative knowledge of suitable sources for drinking and farming is necessary and inevitable. Meanwhile, ground water ...
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1-Introduction Increasing water consumption due to population growth has led to a reduction in the quality and quantity of extracted water. Given this situation, quantitative and qualitative knowledge of suitable sources for drinking and farming is necessary and inevitable. Meanwhile, ground water is considered a safe source for water supply. Today, due to the excessive use of groundwater resources in many plains, water levels have fluctuated and groundwater levels have fallen, and these plains have been hit by decreasing water quality. Therefore, water resources control and optimal use of them are of high priority. Since, groundwater resources are considered as important sources of water supply for various uses. In order to better understand the qualitative status of water resources, water quality indicators are used. To do this, by conducting experiments on water samples and using mathematical relationships defined for each index, a value is obtained that can be used to describe the qualitative state of water based on it and refer to the relevant tables. 2-Methodology Based on international standards for drinking and agriculture uses, some of the parameters examined are lower and others are more than global standards. Basically, these differences indicate the presence of pollution in various water sources. The water quality index is, in fact, simply a numerical value that reduces the large amounts of data, including physical, chemical, and biological parameters, and generally indicates the overall quality of water for various uses, especially for drinking. Typically, heavy metals are included in the water quality index to assess overall water contamination. In this study, the quality of groundwater in the Jangal plain in Khorasan Razavi province has been investigated. 10 wells in this plain were analyzed for concentrations of Ca2+, Mg2+, Na2+, HCO3-, SO42-, Cl-, pH and TDS with GWQI and AWQI indices in the period 2007-2016. Also, plain zoning was performed using the GWQI index and Arc GIS 10.2 software. In cases where the AWQI value is zero, it means that there is no pollutant in water, and if this value reaches 100, that is, all pollutants have reached their maximum permissible limit. The high level indicates the high level of contamination and the passage of this value from 100 indicates serious contamination. 3-Results The results showed that most of the Jangal plain wells pollution are less than the contamination level during the statistical period. Fayez Abad, Kheirabad Ali Akbar Rahmani and Bandazik Salehi Wells have passed through the limit of contamination over the years and have serious pollution and are not suitable for drinking and farming. Based on the zoning, the indicator status in all wells (except wells of Fayez Abad (well No. 2), Kheirabad Ali Akbar Rahmani (well No. 9), and Badazaki Salehi Forest (well No. 10) have inappropriate water (red)) and in the whole area of the Jangal zone is poor (orange color), so the pollution of these wells is not serious and is suitable for drinking and farming. The total amount of all parameters except total dissolved solids (TDS) in all wells is standard. The reason for this is the lack of industrial activities and human communities near these wells. The highest mean total dissolved solids is 5378.49 mg/l. In this study, the least amount of GWQI and AWQI indices for Janet Abad Khordemalkin well were 69.66 and 56.49 (highest quality in 2008) and the highest of these two indicators were 239.12 and 189.48, respectively. 4- Conclusion According to the results of this study, the GWQI index in the region ranges from 69.66 to 239.12 and the AWQI index is between 56.49 and 189.48, that is, the quality of groundwater in the Jangal area is weak and inappropriate. The cause it is also the high solids content of the total solution of water. In fact, in this region, all of the measured quality parameters, except the total dissolved solid, are at the standard level. According to the results of this study, although the amount of calcium and magnesium is in the standard range but at lower levels, and given the body's need for these micronutrients, it is necessary to plan the provision of these elements through other sources or add them to the water in the refinery.
پژوهشی
Morteza Samadian; Behzad Hessari; MirAli Mohammadi; Mohammad Taghi Alami
Abstract
1-Introduction River training, flood control projects and every changing of river geometry will change the morphology conditions of the river and hydraulic characteristics of the flow in the river. In fact, the goal of river training plans can be found on the basis of the initial energy equilibrium of ...
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1-Introduction River training, flood control projects and every changing of river geometry will change the morphology conditions of the river and hydraulic characteristics of the flow in the river. In fact, the goal of river training plans can be found on the basis of the initial energy equilibrium of the river. In this study, the impact of river training on the hydrodynamic conditions of Zarrineh River in conjunction with Shahindezh city in different scenarios were investigated. Zarrineh River training project modeling, as a general objective, is the use of hydraulic simulations to create a river water surface based on new physical, civil, and hydrological properties of a given reach. The motivations for conducting such simulations are flood plain extent mapping based on current and new scenarios and the determination of water level along the study river reach. The objective of this project is to create maps before and after a new river training plan, all within the GIS and Autocad environment with georefrenced origin. Study of Zarrineh river project requires a thorough evaluation of the possible impacts that it may have, both upstream and downstream from the Vahdat Bridge on Zarineh River. Prediction of the operation, maintenance, and repair or replacement of the bridge, requirements of existing and proposed projects are other roles that river hydraulics simulations play in the planning and design processes. Zarineh River is a very wild river and every civil project highly needed to be evaluated from different aspects especially new geomorphological conditions. New liberalized areas beside the river for each scenario should be determined and evaluated for new land use utilizing particularly for Eco-Tourism usages. Sharifi and Pernoun (2017 p. 59) emphasized that the dynamical power of the river in the upstream and flow forces reduction in the downstream have a significant effect in the geometry formation of the rivers. Niranjan et al., (2010) showed that the MIKE11HD model has been able to accurately estimate and simulate water level in Berahmani river. The simulated river surface profile from MIKE11HD was used to simulate protective structures behavior in the river. The performance of the MIKE11 model in the simulation of hydrologic-hydrodynamic processes of rivers were confirmed in other studies such as Guang et al. (2017), Uleke et al. (2017), Tran et al. (2018) and Kha et al. (2018). 2- Methodology MIKE11 was selected to simulate current and selected new river training scenarios that iteratively solves a one-dimensional energy balance to produce water elevations based on river geometry, channel roughness, flow rate and boundary conditions. MIKE11, developed by DHI, is a software package for simulating flows in rivers. The river geometry is provided in the form of channel cross-sections at regular intervals along the direction of flow. The number of cross sections that are taken varies with study requirements and stream characteristics. About 1 km reach of the upstream and downstream of existing Vahdat bridge with 14 cross sections under current situation (without bridges and without training), the bridge with 120 meters without training, the bridge with 120 m, 200 m and 300 m with bed and banks training. For the current and scenarios it is needed to predict stage, discharge, and velocity as functions of time anywhere on a river in different return periods such as 25 yr. To measure cross-sectional coordinates, previous topographic maps generated from field surveys performed with land surveying instruments were used. All information to set up the Mike model, including input data files, simulation period, time step and the name of result files and also initial and boundary conditions have been determined and defined. Flow hydrographs for the project at the bridge location for all scenarios, extracted from hydraulically simulations from Mike11. For Hydrograph prediction the Saint-Venant approach with Finite Element method and Six-Point Algorithm of Abbott used to discretized temporal and spatial elements. 3- Results and discussion Zarrineh river project consists of Vahdat Bridge that should be modelled and finally it should be cover reliability of new area liberalization without any impact to users of Shahindezh such as Municipality, regional water authority, Environmental protection agency and Ministry of Roads and City affairs. In river training scenario with widening bridge to 300 m, in addition of a liberalization of 90 ha areas on both sides of river banks, water level will be decreased about 65 cm and maximum flow capacity will be increased to 115000 m3. The calibration results indicate that the estimated error rate of flow volume (REV) and the relative error in the peak (REQP) for training scenario are 0.197 and 1.792% respectively that corresponding to current condition about 0.068 and 2.82 percent .This figures shows good agreement between modeled and observed values. Vahdat Bridge with 120 lengths with 1200 m3/sec (25 yr return flow) will overflow to adjacent areas. The modelling results show the high potential of river training on the flood transmitting and flood routing and also, the accuracy of the simulation of unsteady flow is one dimensional for the desired range by the MIKE11 mathematical model. 4- Conclusion The river training projects should be modelled, controlled, evaluated for overflow problem from sidewalls and also river bed and banks should be controlled that is not affected by water score problem. For secure hydrograph transmitting in the reach of Zarineh River and Shahindezh city conjunction, the 300-meter bridge widening scenario is selected and the executive maps and detailed plans for the river training, bridge with a width of 300 meters, sidewalls and end sill structure (river bed stabilizing structure for preventing score) were provided.
پژوهشی
leila Biabani; Arash Malekian; Behrooz Akbarpoor
Abstract
The management of groundwater resources is a major for identifying areas with high potentials for groundwater. In this study, we tried to identify areas with the potentials for groundwater in Sufi chay Watershed by using frequency ratio model. Conditioning Factors used in this study include: elevation, ...
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The management of groundwater resources is a major for identifying areas with high potentials for groundwater. In this study, we tried to identify areas with the potentials for groundwater in Sufi chay Watershed by using frequency ratio model. Conditioning Factors used in this study include: elevation, slope, drainage density, landuse, Lithology, Soil, Faults and Topography. In the frequency ratio, at first wells with a discharge rate of above 11 liter per second were extracted in the region; then, 70 percent Training wells (6981 pcs) and 30% of the wells for validation (2992 pcs) were randomly selected. Based on the frequency ratio, necessary analyses were conducted in classes and maps and maps were overlapped. Finally, the groundwater resources map for model were produced. ROC curve method was used to evaluate the performance of model. Based on this, the percentage of the area achieved in the Frequency model ratio are as follows 63% of the areas were low; 18% Average; 12% high, and 7% Very high.
پژوهشی
Mehdi Asadi; Khalil Valizadeh Kamran; Mohammad Baaghideh; Hamed Adab
Abstract
Monitoring evapotranspiration has important implications for global climate modeling. Therefore, the evapotranspiration rate of different land uses in the northern half of Ardebil province based on object-based classification with Kappa coefficient of 0.945 and overall accuracy of 0.956, using Landsat ...
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Monitoring evapotranspiration has important implications for global climate modeling. Therefore, the evapotranspiration rate of different land uses in the northern half of Ardebil province based on object-based classification with Kappa coefficient of 0.945 and overall accuracy of 0.956, using Landsat 8 images related to the date of 2018/7/1, using SEBAL and mountain SEBAL Estimated and compared with Penman-Monteith method. Based on the obtained results, the water levels with the amount of 9.61 and 9.5 mm / day have the highest evapotranspiration and urban and Bayer lands with mean values of 2.845 and 2.08 mm / day, respectively, in the methods of SEBAL and SEBAL Mountains have the lowest 24-hour evapotranspiration. Also, the amount of water requirement for pea crop was estimated to be 7.14 and 6.70 mm / day, respectively, for SEBAL and mountain SEBAL and was compared with the Penman-Monteith method at a value of 6.32 mm / day which has a mean absolute difference (MAD) of 0.60. In the following, the area of each land was extracted, which had the lowest amount of cultivated pea land with the area of 1202.62 hectares and the area (1147.25 hectares) declared by the Agricultural Jihad in Ardebil province was about 4.6 percent, which seems to be acceptable.
پژوهشی
Mirali Mohammadi; Farnaz Mohammadi; Ahmad Fakherifard; Sajad Bijanvand
Abstract
1- Introduction Mainly the flood is caused by the surface runoff resulted from the properties of precipitation and river basin. The reduction of flooding by the effect of vegetation and soil in a small basin is less than a basin with a large area. Hence, to have a flood zoning map, the first step is ...
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1- Introduction Mainly the flood is caused by the surface runoff resulted from the properties of precipitation and river basin. The reduction of flooding by the effect of vegetation and soil in a small basin is less than a basin with a large area. Hence, to have a flood zoning map, the first step is studying economic flood management and flood control projects. This paper focuses on Baranduz-chay River as a case study, located in the Urmia lake basin. The river reach having 3 km long, was studied between two hydrology stations namely Bibakran at the upstream and Dizaj at the downstream. The annual peak discharge data of Baranduz-chay has surveyed during the years from 1974 to 2013, where the appropriate Manning roughness coefficient, n, by averaging 0.0325 as an upstream coefficient and 0.0301 as a downstream coefficient were both implemented in the HEC-RAS software and its result including floodplain zones elevation extraction by the Muskingum-Cunge method, based on the floods with different return periods obtained. After converting these zones to their corresponding risk for each return period time, it has been delineated in Arc-Map software through HEC-geo-RAS extension, floodplain zones were then defined. The maximum inundated area is 97.34 Hectares and belongs to 1000 years return period which has the most risk as 63.58% within 3 years of useful periods. The Rule Curve is obtained by inundated areas with both different return and useful periods from the risk formula in which the general Area-Period-Risk formula was extracted. Basically, the magnitude of the floods and their repetition over time is subject to rainfall intensity, permeability, and topographic conditions in the area. The occurrence of floods as one of the natural disasters that cause many financial losses in many parts of the world. The first step in economic studies of flood management or flood control is flood zoning. Flood zoning means the extent to which the flood covers the area. Today, via modern science and technology, human beings are trying to optimize designs and to reduce these costs. Therefore, it seems that flood zoning study in the permanent and seasonal rivers path appears to be of great importance by conducting case studies in vulnerable areas. ShahiriParsa et al. (2016: 55-62) used the integration of the HEC-RAS one-dimensional model and the two-dimensional CCHE2D model on the Sungai Maka river in the state of Kelanten, Malaysia. They concluded that in this case, some important factors are: Manning’s flow resistance coefficient, n, the geometric profile of the river section and the choice of the most suitable flood return period. The mentioned parameters have a major role in providing flood zoning outcome, which has caused the most changes in the geometric shape of the river section. Their results showed that the greatest difference between the models was 6% in the location of the meandering rivers. The results of both models were also consistent in most of the transverse sections, and, due to the difference in the shape of the rivers, the greatest difference was the difference between the two models. Sung et al. (2011: 1-12) used the Maskingum method to process unqualified basins by analyzing the HEC-HMS hydrologic model and the HEC-geo-HMS geo-hydrologic model, the extraction of sub-basins and characteristics of the basin was extracted. The results showed that the percentage of flood events proportional to the maximum discharge errors of a moment of less than 20% and a runoff volume of less than 10% to reaches 100%. 2- Methodology Baranduz-chay river as the main river and permanent water catchment area of the study area. It originates from the highlands of Iran and Turkey border. The catchment area of this riverside in Saatlu is about 666 square kilometers and in Babarood is 1012 square kilometers. This research was associated with a similar risk due to the risk relationship with different return periods for the restricted areas around the river, based on different return periods. To determine risk areas or certain return periods, peak discharges were fitted with the best statistical distribution and through that, peak discharges were then calculated with different return periods and each of them was determined along the river and its expansion area. 3- Results and discussionFig. 3, shows the risk versus area (A, RISK), the risk with a downward trend, which means that the area risk is decreasing with the area covered by the risk area. By fitting a variety of exponential, linear, logarithmic, polynomial and power statistical functions, among those functions as shown in Fig. 3, risks with different useful lives are plotted simultaneously and from among functions, the power function was selected as a suitable fit function in order to obtain the general probabilistic distribution function and its parameters based on different useful life. Fig. (3) Risk diagram versus area (Rule Curve) with a different useful life 4- Conclusions For the Manning roughness coefficient, n, in the hydraulic model, the Manning’s n for the upstream and downstream stations were computed. The roughness coefficients, n, were then obtained for the upstream and downstream stations as 0.0325 and 0.0301, respectively. In order to obtain the corresponding risks for the areas covered by a flood of 3 km long from the Baranduz-chay between the upstream Bibakaran station and the lower reaches of the Hoerl's model, which is a type of power function. The risk-space-period curve for the specified periods is 2, 3, 5, 10, 25, 35 and 75 years (for more details, see Mohammadi, 2016).
پژوهشی
Gholam hassan jafari; Zinab Barati
Abstract
1- Introduction The public opinion is that in the landform-topographic study, the drainage system, and the drainage pattern, by using geomorphic indicators one could assess the performance of active tectonics (Maghsoudi et al., 2011). This is true if we do not consider the primary structure of the earth, ...
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1- Introduction The public opinion is that in the landform-topographic study, the drainage system, and the drainage pattern, by using geomorphic indicators one could assess the performance of active tectonics (Maghsoudi et al., 2011). This is true if we do not consider the primary structure of the earth, rock type, and local factors determining the microclimate (Abedini et al., 2015; Jafari and Barati, 2018). Considering these factors, the results question the geomorphic indicators. In this paper, the researchers study the role of various factors in the drainage asymmetric index of 117 sub-basins in the Alvand mountainous of Hamadan. A subject not considered in the drainage asymmetry index of areas such as the Alvand mass of Hamadan is the shape of the magma lies between the sedimentary layers at the time of cooling. In relation to the drainage symmetry index, this paper tries to study the physical properties and the effect of local factors in the watersheds of the Alvand Hamedan Batholith. Although the drainage networks asymmetry of is analyzed with morpho-tectonic indices, the basic land structure, lithological and erosion properties can also affect the asymmetry of the basin. 2- Methodology For this purpose, parameters of the dominant slope, average slope, average height, the area of the right and left of the river, main river length, river airy length total length of the rivers, distance of the source of the dividing line, and rock types in different parts of sub-basins were determined. These parameters were used in calculation and analyses of Gravelius coefficients (compactness coefficient), elongation ratio, drainage density and asymmetry index. For the phenomenological investigation of the drainage network index status, with the help of topographical maps 1: 50000, the outlet point of the Alvand Batholith sub-basin was identified in the mountainous area. Accordingly, 13 sub-basins were classified in the Alvand Batholith. Class B subclasses are located inside the subclasses of class A and subclasses of class C are located inside class B subclasses. To separate sub-basins in each of the 13 sub-basins, the longest river was considered as the main river. All the streams connected to it are separated as subclasses of Class B. In the next step, the main river basin in the sub-basins of class B was also determined and the rivers entering it were designated as the sub-class C. Accordingly, a total of 117 sub-basins was identified. 3-Result and discussion In order to investigate the factors affecting the asymmetry index (tectonics, lithology, microclimate and physiography's characteristics of sub-basins); at first the status of sub-basin rock was studied. The largest area lies in the cordierite-Gabbro Stone (15.4%), and the smallest area lies in the Granite- Schist- Gabbro and cordierite-Gabbro (0.69%) groups. Investigating the elongation coefficient the sub-basins in which the dominant stone is granite shows a very low elongation ratio of these sub-basins. They lie in a group that is less elongated than the rest of the sub-basins in other rocks. In terms of the Gravelius coefficient, it can be said that the more symmetrical the basins tend to be circular in shape, as the mean Gravelius coefficient of the stable sub-basins for the asymmetric index is 3.35 vs. 2.64 in the relatively stable sub-basins, which fully confirms this point. The ratio of bifurcation of unstable sub-basins is very high, and according to the rocky area, the drainage density in the unstable sub-basins is inversely related to the slope of the basin. 4-Conclusion In general, sub-basins of the northeast slopes are more asymmetrical than sub-basins in the southwest slopes, which it can be due to the zhizman form of the Alvand Batholith, the differences in the physiographic properties, and finally the dominant sub-basin rocks. In the wider sub-basins of the slope and the varying direction of slope, are vectors that can have a significant effect on the drainage network asymmetry. The further elongation ratio of drainage of the basin with low drainage density, in granite rock, affects the drainage network asymmetry of the basin. Investigating the conditions of slope values in different classes of the asymmetric index in sub-basins other than granite rocks indicates that the difference between the value of the left and right slopes of rivers is not a significant effect in the basin asymmetry. By decreasing the sub-basins area, the effect of direction and slope value, elongation ratio and bifurcation coefficient on asymmetric basins decreases. The study of the Gravelius coefficient indicates that the shape of the more stable sub-basins is closer to the circular shape. The bifurcation ratio of most unstable sub-basins is very high. The drainage densities of unstable sub-basins have an inverse relationship to the basin slope. The difference between the rock types on the left and right and the river's position on the boundary between the two rocks have an important role in the basins asymmetry.
پژوهشی
Mansor Parvin
Abstract
1-Introduction In recent decades, the demand for water has intensively increased in arid and semi-arid regions of Middle East and North Africa (Souissi et al., 2019:1, 2). Nowadays extensive use of underground water resources has been converted to a challenge in arid and semi-arid regions (Gaur 2 et ...
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1-Introduction In recent decades, the demand for water has intensively increased in arid and semi-arid regions of Middle East and North Africa (Souissi et al., 2019:1, 2). Nowadays extensive use of underground water resources has been converted to a challenge in arid and semi-arid regions (Gaur 2 et al., 2011). Excessive use of underground water resources may cause problems such as the reduction of water level, the reduction of quality and pollution of underground water, which can cause water tension (Souissi et al., 2019, 2). To cope with this hydrologic crisis, optimal programming and management of underground water resources seems essential (Singh et al., 2017, 1440:3). Mahi Dasht plain is one the most important plains of agriculture in Kermanshah and the country and had a significant share in the production of various rainfed and irrigated agricultural products. Underground water resources of Mahi Dasht as the main source of providing the required main water of human societies of Mahi Dasht catchment area has faced the reduction of water level due to improper harvesting and the occurrence of droupht. Zoning and identifying regions in need of being recharged by underground water of Mahi Dasht plain has had an important role in the management and recovery of the balance of these resources and the conduction of this study was a necessity. The purpose of this study was zoning and identifying those regions who are in need of being recharged by underground water of Mahi Dasht using potential recharge index method. 2- MethodologyIn this study, eight parameters of lineaments, drainage density, land use, topography slope, soil, annual rain and geomorphology in potential recharge index method for zoning regions in need of being recharged by underground water were utilized. Each of these eight parameters can be divided into low, moderate, high and very high classes based on their nature and the amount of effect in feeding underground water (Table 1). Based on the categorization of Shaban et al., (2006), each of the classes allocated the following scores to themselves: low class (score 1 to 2 ), moderate class (score 2 to 4), high class (score 4 to 6) and very high class (score 6 to 8). Each of these eigth parameters had their specific weights and lithology parameter of 33% as well as soil parameter of 3% had the most and the least weights (Table 1). Finally, the eigth parameters were scored based on Table 1 and according to the WLC method, they were integrated using the following equation and the RP was provided. Pr=(RFw*RFr)+(LGw*LGr)+(GGw*GGr)+(SGw*SGr)+(LDw*LDr)+(DDw*DDr)+(LCw*LCr)+(SCw +SCr) 3- Results and discussion In the catchment basin of Mahi Dasht, almost 80% of the area had very high, high and moderate potential recharge. The reason behind this issue can be attributed to the appropriateness of geographical conditions and geology of the basin. According to lithology, almost 80% of the area of the studied basin was made up of quaternary deposits and carbonate makers; this issue had an utmost role in recharging underground water resources. In Mahi Dasht basin, Mareg River follows the fault path of Mahi Dasht and mountain areas of the basin specially carbonate regions of that, are extremely tectonic, which leads to the more penetration and high recharging of the underground water resources. Geomorphologic conditions of Mahi Dasht plain is appropriate for being recharged with underground water, since 43% of the area of the basin is made up of torrential-alluvial plain landforms and alluvial fans. Agricultural, garden and jungle uses have included 78% of the area of the studied basin; this issue has an important role in recharging underground water resources of the basin. Almost 58% of the area of Mahi Dasht basin has soils with A and B hydrologic groups, which created appropriate potential recharge for the underground water of this basin. Almost 80% of the area of the studied basin of the constructional plain level of Mahi Dasht has a slope of less than 10 degrees which contrives the appropriate condition for being recharged with underground water in the basin. The studied basin had a mean rain of 590 mm, which stated the appropriate raining condition of the basin for being recharged with underground water resources. Wide parts of Mahi Dasht basin especially in the foothills had a high drainage density, which had an utmost effect in the recharging of underground water resources. 4-Conclusion The level of Mahi Dasht plain has been located in an area having very high recharge potential due to the appropriateness of lithological, tectonic, geomorphologic-topographic, land use, soil and climate conditions. The area having very high recharge potential coincided on rough country regions and geomorphologic, slope and lithological conditions had the highest limitations. Moderate potential area coincided on north mountain basin. Bed outcrop of penetrative carbonate makers, the high lineaments` density and high rains caused moderate recharge potential in these regions. Most of the areas of south heights of the basin were located in the area having low recharge potential due to the bed outcrops of impenetrable makers of Kashkan, Amiran, Gorpi and Ladiolarite. Finally, it could be stated that Mahi Dasht basin wouldn’t face limitations in terms of appropriate areas for underground water resource recharging. The bed and margin of Mareg River and the level of Mahi Dasht plain and its surrounding areas were appropriate for underground water recourses` recharging.
پژوهشی
reza dehghani; hassan torabi; hojatolah younesi; babak shahinejad
Abstract
River flow prediction is one of the most important key issues in the management and planning of water resources, in particular the adoption of proper decisions in the event of floods and the occurrence of droughts. In order to predict the flow rate of rivers, various approaches have been introduced in ...
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River flow prediction is one of the most important key issues in the management and planning of water resources, in particular the adoption of proper decisions in the event of floods and the occurrence of droughts. In order to predict the flow rate of rivers, various approaches have been introduced in hydrology, in which intelligent models are the most important ones. In this study the application of hybrid wavelet vector hybrid model to estimate the discharge of Kharkhe basin rivers on daily discharge statistics of hydrometric stations located upstream of dam during the statistical period (2008-2018) has been evaluated and its performance with vector machine model The backup was compared. The correlation coefficients, root mean square error, mean absolute error was used for evaluation and also comparison of the performance of models in this research. The results showed that the hybrid structures presented acceptable results in the modeling of river discharge. Comparison of models also showed that the hybrid model of support-wavelet vector machine has better performance in flow forecasting. .Overall, the results showed that using a hybrid backup vector machine model can be useful in predicting daily discharge.
پژوهشی
Ebrahim Asgari; abazar esmali; Raoof Mostafazadeh; Gholamreza Ahmadzadeh
Abstract
1- Introduction The comparison of different geological formations in term of sediment yield is one of the most important issues in many soil and water conservation studies. Moreover, the measurement of runoff production rate and sediment production is the prerequisite of watershed management. The potential ...
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1- Introduction The comparison of different geological formations in term of sediment yield is one of the most important issues in many soil and water conservation studies. Moreover, the measurement of runoff production rate and sediment production is the prerequisite of watershed management. The potential of a watershed toward erosion is the result of erosivity, erodibility of geological formations, slope gradient and land use types in the watershed. Accordingly, runoff is one of the important factors in the water erosion issues. Different geological formations depending on the rock composition, erosion and slope gradient, have a potential to produce sediment and play an important role in the amount of soil losses. The behavior of rocks and quaternary deposits against weathering and erosion depend on the nature of the rock and environmental affecting factors. Therefore, the main aim of the present study was investigating and comparing the geological formations regarding the runoff and sediment yield along with runoff threshold in Gharehshiran watershed of Ardabil province using a rainfall simulator measurement. 2- MethodologyBased on the geologic map of the studied area, the boundaries of different geological formations were defined and then according to the objectives of the present study, a field rainfall simulator (100 × 100 cm) with a height of one meter was used for field experiments. Theoretically, the use of rainfall simulator systems saves time and cost, which can be used for monitoring the amount of runoff and sediment along with all processes involved in erosion and sediment production. However, it should be noted that the use of rainfall simulators is also subject to limitations that can never fully create natural conditions. The plot scale measurements have been conducted through 45 samples in predefined geological formations of the studied area. The runoff threshold initiation time and the amount of runoff and sediment were recorded through field experiments. The runoff and sediment samples were collected in individually stored containers and were then, transferred to the laboratory. The values of runoff were measured and the samples were oven-dried for 24 hours at 105 °C and then the deposited amount of sediments were obtained. The amount of sediment in each sample was determined using a producer of precise weighting. Then, the normality of the data was analyzed using Kolmogorov-Smirnov test. The comparison of the geological formations was examined with respect to sediment amount, runoff, and initiation time threshold using One-way ANOVA method through SPSS software. Furthermore, the significant different in mean values of studied variables between geological formations were compared with Duncan's test. Then, the correlation between the studied variables in various geological formations was evaluated using Pearson correlation analysis in SPSS software. 3- Results and Discussion The results of one-way ANOVA test showed that there was no significant differences between different geological formations considering runoff and sediment yield (p < 0.05). While, there was a significant difference between geological formations with respect to the runoff threshold initiation time (p < 0.05). Comparison of the mean values of runoff threshold time using Duncan test indicated that the highest and lowest thresholds time of runoff production were observed in Qt2 (alluvial terraces) and Qb (basaltic lava) formations with the values of 8.28 and 2.28 minute, respectively. According to the results, there was an inverse relationship between runoff and sediment variables in different formations. Also, the correlation between the runoff threshold time and the amount of runoff was negative with -0.318 correlation coefficient (p < 0.05), while, correlation between the runoff threshold time and sediment yield values was positive (r=0.327) at 5% confidence level. 4- Conclusion Many of the geological formations in this area were related to Quaternary and Tertiary periods. Young alluvial terraces and upland terraces, along with marl, sand, conglomerate, and clay formations were related to the Quaternary period, which were the results of erosion from rock units of past periods. It is suggested that the effects of other effective factors on erosion and sediment production processes should be considered in future researches to make a better and comprehensive conclusion. In conclusion, it can be said that studied geological formations were assigned to the Quaternary era and had a similar behavior in term of runoff and sediment production, while the difference in composition and mineralogy of different formations led to differences in runoff threshold.
پژوهشی
Sayed Meysam Davoudi; Reza Ghazavi
Abstract
1- Introduction The strategic management and planning is the highest level of management that has a long-term attitude in resource allocation and decision making. Relying on a combination of perspectives, policies, structures, and effective systems in this field, the strategic approach in water resources ...
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1- Introduction The strategic management and planning is the highest level of management that has a long-term attitude in resource allocation and decision making. Relying on a combination of perspectives, policies, structures, and effective systems in this field, the strategic approach in water resources management prevents sudden future events and crises that will lead to the sustainable development of water resources (Pour Fallah et al., 2009). Determination and development of water resources are one of the important steps in sustainable use of water resources. There are several methods and models for this purpose, each of which contains its own concept and insight and follows specific techniques and instructions. Among the various models, the SWOT matrix, which assesses the system strengths, weaknesses, opportunities, and threats, is more common and well-known (Hill and Vetbrook, 1997). Extraction of a strategy based on the strengths and weaknesses of the internal environment and the opportunities and threats outside the management field provides realistic solutions to the decision maker, and the closeness or distance of the solutions from the sustainable development model - planning (Azarnivand et al., 2013). Although the common use of this model is mainly related to the strategic planning of production and service organizations, its unique features make it possible to use it in the analysis of various issues such as watershed management at extra- organizational levels. More recently, the use of SWOT analysis for water resources management has been proposed in previous research (Petusi et al., 2017; Negar, 2015). 2 -Methodology This study was performed in four main stages, namely identification of internal and external factors, weighting of factors, creation of matrix for the evaluation of internal and external factors, and finally selection of appropriate strategies (Ghazavi, 2019). The formation of SWAT matrix leads to the presentation of four management strategies as follows. • Competitive/Aggressive Strategy (SO): By implementing this strategy, an effort is made to take advantage of external opportunities. • Review/Conservative Strategy (WO): The goal is to take advantage of opportunities in the external environment to improve internal weaknesses. • Diversity Strategy (ST): Reduce the impact of external threats using strengths. • Defensive Strategy (WT): Defensive mode that aims to reduce internal weaknesses and avoid external threats (Sarai and Shamshiri, 2013) 3- Results and discussionAccording to the results of the present study, the total final score of internal factors was 2.98 in the evaluation matrix, which can mean the strength of internal factors. The total final score of external factors was 2.89 in the evaluation matrix, which means that Natanz city has been able to take advantage of the factors that create opportunities or situations, or avoid some of the factors that threaten the city. Based on the results, the best strategic position for Natanz urban watershed is in the offensive range, which focuses on internal strengths and external opportunities. Besides the existing capabilities and potentials in Natanz should be used in managing runoff management. 4- Conclusion In order to provide appropriate strategies and strategies for strategic management of Natanz urban watershed, strengths, weaknesses, opportunities, and threats were studied using the SWOT method. The findings show that Natanz city, despite a low level of the urban basin for various reasons, was not able to make optimal and desirable use of this natural facilities for its development and progress. The existence of impenetrable levels, digging numerous wells to supply water to factories and industries, and the lack of municipal wastewater treatment plants are some of the threats to the region. According to the results, aggressive strategy is the best structural strategy for the Natanz urban watershed.
