نشریه منابع آب و توسعه
سال دوم شماره 5 (پیاپی 8، زمستان 1393)

Talog Dam located in Khuzestan province plays an important role in power generation and water supply of the region. Some studies are performed on this dam. These studies produce Artificial Time Series and accurate estimates of inflow to the dam which will have an important role in water resources planning in the future. In this study, using the statistics estimated Talog river at the dam site Talog, stochastic modeling was performed for both of them. Various stochastic models such as Autoregressive Model (AR), Moving Average (MA), and Autoregressive Moving Average (ARMA) were fitted to the data. According to the Akaike and Schwarz information criteria, the results of Modeling showed that ARMA model (2,3) was the best model in comparison with the other models. Therefore, according to the selected Model, five artificial time series and forecasting future time series for the model were performed the results of which are presented in the present study.

Geographical Information System (GIS) is an important instrument in hydrogeology and is of great use in evaluation, supervision and protection of groundwater. This study was an attempt to investigate the application of GIS and Analytical Hierarchical Process (AHP), using Expert choice software, to determine locations suitable to construct underground dam in aquifer of Jaru basin, northeast of Khuzestan, in the least time and with the lowest cost. In this research, different parameters in thematic layers; thickness and width of aquifer, cross resistant of aquifer (RT), thickness of unsaturated zone, ground slope, hydraulic gradient, drainage density and distance from high solubility formations were provided and were converted to raster data, using ArcGIS10.1 software. Then, a raster map was prepared for different layers using AHP. General plan of the area was provided using weightedsum method. Based on the potential to construct underground dam, the area was divided into the following 5 subareas: Very Good, Good, Average, Bad and Very Bad. Finally, a part of the northwest of Jaru basin was determined as a suitable part for constructing an underground dam. It is expected that the method of locating underground dams would be developed to provide new water resources in dry areas.

Erosion and sediment transport process in rivers is one of the most important and complex subjects in river engineering. Due to the fact that rivers have always been under erosion and sediment transport, the investigation of sediment transport capacity and mechanism of sediment transport is very important in river hydraulic and morphology. In this research, an attempt was made to evaluate the efficiency of Artificial Neural Networks in prediction of suspended sediment. Using Multi-layer perceptron model (MLP) of Neural Network method, the suspended sediment of Gorgor hydrometric station in Jarahi river of Khozestan was predicted, and the results were compared to those of the sediment rating curve method. According to the results, The ANN model presented acceptable predictions in simulation of Gorgor station suspended sediment load in comparison to the sediment rating curve method. The results also showed that the Artificial Neural Networks estimate the suspended sediment load more accurately (R2=0.952, RMSE=0.0185, r2=0.93) than the available methods such as the rating curve method. However, it must be mentioned that ANN is not able to predict the peak values correctly, which can be a weakness of this model.

The availability of suitable water is one of the developmental factors. The quantity of water as well as its quality are of paramount importance, considering the effect they have on human health and agricultural development. Ignorance of the optimum use of water resources has led to a change in the quality of water resources and consequently their uselessness for various consumptions. Jamash catchment is the main source of Ghaleh Ghazi plain recharge that is located at the end of this catchment. This plain is an important agricultural center of the province and the catchment is the major agricultural water resource in the region. Field studies have shown that the main reason for surface runoff contamination is geological formations of the basin. The contact between the surface and underground water with these formations results in an increase in watersoluble minerals and electrical conductivity. During low flood and base flow this problem is more manifest. It is more observed in the middle part of the basin and its outlet. In this research, the reasons behind the changes in water quality and their relation with geological formation are investigated through chemical analysis of hydrometric stations and springs samples.

Infiltration is one of the most important parameters of hydrologic cycle. To prevent soil erosion and to utilize water resources, soil infiltration characteristics should be determined. The present study aimed to determine the effect of land-use changes on infiltration and then to choose the best infiltration model of each land-use. Field experiments were conducted in 3 various landuses including pasture, agriculture and garden land-use. Then, agriculture and garden land use engender from pasture land-use, in 5 various tensions (0, 3, 6, 10, 18 cm-H2O) and 3 replication. Infiltration models of Kostiakov, Lewis Kostiakov, Horton, Green- Ampt, Philip and SCS were evaluated. Simulation cumulative infiltration and infiltration rate were compared with the observation data using relative error (RE) and root mean square error (RMSE) parameters. The results indicated that land-use changing from pasture to agriculture or garden leads to an increase in infiltration rate and cumulative infiltration. The comparison of infiltration models indicated that in pasture and agriculture land-use, Kostiakov and Philip models have higher accuracy than other models, but in garden land-use, Horton and Kostiakov models were better than the other ones.

Flood zoning maps are extensively used in flood management studies. Today, these maps are considered one of the basic and most important sources of information in the studies of civil projects in the world and in the agenda of related organizations before taking any action and making any investment. The main purpose of this study is to investigate the applications of floodmaking situations of border Rivers using GIS, generally mathematical models, environmental issues and land use. The field data was analyzed using ArcView which is a powerful software in modeling the water projects. After the initial analysis, these data and the hydraulic data of the river such as river discharge were analyzed using Hec-Ras software. Then, the data and the results obtained from the software were introduced to ArcView. Next, the final implementation of the project and determination of the flood-making zones of the river were investigated. Finally, the effects in terms of environmental and land use issues were taken into consideration.

Increasing the flexibility of water distribution and delivery and reducing water loss by downstream control systems plays a crucial role in improving the network performance. With respect to this issue، the use of performance indicators for evaluating irrigation systems is indispensible. In this paper، the original design of Varamin irrigation network was evaluated and compared with the 7-day irrigation period and off night operation with specific conditions. Furthermore، the effect of off night operation in the sensitivity of control structures (duck bill) in downstream of the network was evaluated. The result revealed that off night operation had a better performance compared to the 7- day irrigation period. Thus، there is more water available for downstream farmers in the off night scenario rather than 7- day irrigation period scenario. Besides، they can gain as much water as upstream farmers gain.

The procedure that is to be selected for a sustainable maintenance of open channels in agriculture largely depends on the type of supervising process and the availability of its appropriate device. In this paper, social acceptance and technical problems related to the contractor, farmer, taskmaster and supervisor were taken into consideration. The study was carried out in conveyance channels of agricultural regions in Lorestan province (Delfan Palin), which is 19 km long, from 2007 to 2010. The layouts of structures were performed with 6 to 8 cm thickness and trapezoidal section by gravel, sand and concrete mix. The main problem and influencing factor for desirable utilization are the wrong change in predetermined section scheme and technical failure to perform, respectively. After the classification and assessment of the problems, some solutions which have more positive effects on the next stages of channel construction were suggested.

Considering the limitation of surface streams in recent years in Isfahan, usage of surface resources by artificial recharge is a way to surmount this problem. Sets of accurate data which confirm the use of assistant tools such as Geographical Information System (GIS) were required. In this study, Najafabaad aquifer was modeled in site selection for artificial recharge of ground water tables. For this purpose, parameters such as slope, land use, distance from streams, soil texture, lithology and depth of water table were investigated. Using GIS technique, a database for further studies was established. Layers related to the parameters were obtained from information and DEM Sheets. Then, layers were weighted via Weighted Sum Method. Finally, the suitable points in site selection for artificial recharge sites were determined by overlaying layers.

In this study, it was tried to identify the most important aquifer in Kurdan plain, karaj area, using hydrostratigraphic, hydrogeologic and sedimentological data. To this end, in the first place, Kurdan alluvial fan as the most important aquifer in the area was investigated using geological investigations and translate the geological sections to the hydrostratigraphic units. Geophysical maps such as iso-resistivity, iso-thickness and iso-depth maps were utilized to identify the aquifer geometry. Next, alluvial fan grain-size analysis and assessment to the hydrogeological properties of aquifer were studied by sediment samples analysis. The results showed that as we move away from the origin of the sediment, although the thickness increases, the discharge and the water quality decrease. Higher uniformity coefficient of grain size distribution curves in median zone of the alluvial fan indicates that hydrogeological properties of this zone are appropriate for groundwater extraction. Finally, using some parameters such as resistivity, bed rock depth and uniformity coefficient and via expert weighting and analytical hierarchically process, potential of water extraction map was prepared. The results showed that the median zone of alluvial fan has an acceptable water extraction potential.

In the present study, an attempt was made to explore chaghlalvandi alluvial aquifer, using resistivity method. The study area is located in chaghlalvandi, northeast of Khoramabad, Lorestan. This study aimed to investigate aquifer geometry and groundwater characterization, in order to manage aquifers in a better way. This study was carried out using vertical electrical sounding with Schlumberger array, and 150 VES were surveyed along 11 profiles in this aquifer. The obtained data was processed and interpreted. Then, real resistivity sections were prepared along each of the profiles. Geological layers were identified according to the resistivity of them. Resistivity maps, iso- thickness map of alluvial and RT map of the aquifer were prepared. According to the obtained results, the aquifer includes some layers covering a wide range of alluvia from coarse-grained calcareous to fine alluvial clay. The thickness of the alluvium increases from the aquifer margin to the middle. The maps would be used to select appropriate position, maximum depth and optimization of distance for drilling water wells and management of the aquifers.

Air temperature is a key parameter in environment and earth sciences studies. Determining the air temperature using TVX method and remote sensing technique by surmounting the restrictions of sparse network of meteorological stations is of paramount importance. The main objective of this study is to investigate the efficiency of TVX method in estimating the air temperature emphasizing the precise estimation of land surface temperature. In this regard, Sobrino and Price algorithms were used for land surface temperature estimation. A comparison of RMSE values related to the land surface temperature and air temperature was indicative of a 7% and 18% decrease of errors, respectively. Moreover, TVX method is sensitive to the vegetation cover. Therefore, increasing the efficiency of TVX method should be done in terms of two components, land surface temperature and NDVI index. Using this method can affect the results of investigating hydrological cycle such as change of evaporation from lakes, change of volume and duration runoff and consequently water resources management planning.

Measuring the amounts of pollutants in the treated wastewater represents the level of performance and efficiency of the Wastewater Treatment Plant (WWTP). In this cross-sectional study, an attempt was made to monitor the performance of partialmix aerated lagoons in Miandoab WWTP for a period of 9 months in the summer, fall and winter of 2012. The sample was selected from both the input and output of WWTP during daylight hours once a week. The results showed that the performance of the treatment is influenced by weather conditions and the efficiency of the system will decrease if the weather is cold which will lead to a slowdown in the biological activities. The analysis of the system's performance indicated that the elimination efficiency of the pollutants from wastewater is higher in summer in comparison with other months. The Removing Percentage of BOD5, COD, TSS in summer was 5.9, 6.4 and 6.6 percent higher than those values in winter. The comparison of the concentration of the effluent of WWTP with the standards of Iran's Environmental Protection Agency showed that the output of the plant can be used for agricultural irrigation.

In this paper, an attempt was made to investigate the diffusion of oil and water in underground reservoirs. Underground water is often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells. Mathematical modeling of this phenomenon was presented as a nonlinear diffusion problem. Variational iteration method was utilized for this purpose. Among the main features of the method are its flexibility and ability to solve nonlinear equations. This technique does not require any discretization, linearization or small perturbations and therefore reduces the numerical computations to a great extent. Numerical examples were examined to show the efficiency of the technique.

Climate change has recently received much attention at local, national and international level. To this end, an attempt was made to investigate the trend of total precipitation, maximum precipitation and temperature in Iran at annual scale. The data was obtained from 36 hydrometric stations from 1969 to 2009. In this study, the slope of the linear trend in the data was investigated using TSA, TFPW, PW and VCA methods. The effect of coefficient of autocorrelation of data was eliminated, and discharge time series were prewhittened, then the changing trend of total precipitation, maximum precipitation and temperature of original and prewhittened time series were analyzed using MK test. Ultimately, the ability of TFPW, PW and VCA methods in delimiting autocorrelation coefficient were investigated. The results showed that TFPW method is the best one for delimiting autocorrelation coefficient. The results of the investigation were presented based on MK_TFPW at the annual scale. Moreover, the results were indicative of a significant negative trend for the total precipitation in most parts of the country, a significant positive trend for the temperature in northwest of Iran and almost no trend in most parts of the country (no negative or Positive trend) for maximum precipitation.

The study area is located in northern Dezful City, adjacent to Dez dam, in southwest of Iran and has variable groundwater potentials. Correct understanding of groundwater potential is essential for water resources management and sustainable use. Groundwater potential mainly depends on the amount of recharge. Lithology, slope, topography, weathering, porosity and vegetation are among the factors which influence recharge. Due to the large number of influencing factors on recharge and capabilities of Geographic Information System (GIS) in managing large amounts of spatiotemporal data from various sources, this tool was employed for preliminary studies. In order to increase judgment accuracy and flexibility in finding the highest natural recharge potential of the area, GIS was integrated with Fuzzy AHP. In the first place, factors influencing groundwater recharge were identified and weighted based on existing standards. The resulting zonation map was then used to identify areas with the highest penetration rate. Results showed that central and western parts of the area have the highest penetration rates, while areas adjacent to the northern parts have the lowest effect on groundwater recharge. It was also concluded that lithological variations caused by sedimentation conditions and fault activities, control groundwater potential among different geological formations and within each formation.

Chahardoli basin with an area of 340 square meters is located in the southeast of Kordestan province. In order to analyze the water quality, 66 samples were taken from wells, springs and qanats by Kordestan Regional Water Co. The concentration of major ions, electric conductivity (EC) and pH of the samples were measured. In This study, GIS was used to classify and map groundwater quality suitable zones for agriculture and domestic purposes. Water quality was classified for agricultural purposes by using USSL diagram and residual sodium carbonate (RSC) and it was classified for domestic purposes according to WHO (1984) standard. Finally, the water quality map for domestic purposes was prepared in four classes by combining the four weighted layer maps including incrustation, magnesium concentration, total dissolved solids (TDS), and total hardness,. The dual purpose map for both agricultural and domestic uses was prepared by combining the three weighted layer maps including EC, sodium absorption ratio (SAR) and RSC, the water quality map for agricultural purposes was prepared in three classes. After combining the two different quality maps. The results showed that GIS is a good instrument for identifying suitable quality groundwater zones for different purposes.

One of the most important conditions in time series analysis is that time series have to be stationary. A time series is stationary in its statistical parameters when its expected value is time independent. Most time series are non-stationary. Thus it is necessary to recognize the factors causing non-stationariness and eliminate them from the time series. One of the important factors causing non-stationariness is the time series trend. In this research, the annual precipitation data set of 31 synoptic stations in the captials of the provinces in Iran during the period of 1961 to 2010 were used to investigate possible trends. The results of this study indicated that among 31 stations in the country, approximately 32 percent of the stations had a non-significant upward trend at the level of 5 percent, 9 percent of the stations had a non-significant downward trend at the 1 percent level and almost 48 percent of the stations in the country had a non-significant downward trend at the 5 percent level in the recent half-century.

The phenomenon of transport in aquifers, as heterogeneous porous media, has been the subject of research over the past two decades. Characterizing the role of dispersivity in mass transport in such media is essential to any effort in predicting the movement of contaminant in water resources. In this study, to presume heterogeneity of porous media, three types of spatiallyvaried dispersion coefficients were used. These coefficients including linear, power and exponential functions were inserted separately in the mass transport equation in porous media. Then, these models were solved analytically using boundary conditions of the first- (Dirichlet) and third-kind (Cauchy). To illustrate concentration profiles, data of continuous injection of sodium chloride ions in a laboratory soil column were used. The values of concentration in column at various times were estimated by CXTFIT2.1 code. Concentration profiles of both boundary conditions showed that at early times after the injection, dispersion coefficient of the linear model was more compatible with the experimental data and with elapsing time, results of the power model were better than those of the other two models. Moreover, the results showed that Cauchy and Dirichlet conditions were more appropriate for solving linear and exponential models, respectively.

In this study, environmental risk assessment (ERA) was utilized to identify and assess the risks of Anzali wetland on the southern coast of the Caspian Sea in northern Iran. Fault tree analysis (FTA) was used to identify environmental risk factors and environmental failure mode; and effect analysis (EFMEA) was used to assess the risks. Based on the results of ERA, rural and urban wastewater and agricultural wastewater with the RPN 125, non-native species and soil erosion and sediment transport in rivers with RPN 100 and industrial wastewater with RPN 80 are the most important risk factors. According to the conducted ranking, 20% of the risk factors have low level risk while 53.3% placed on the moderate level risk and 26.7% belonged to the highrisk level group. At the end, management strategies to control and manage the environmental risks for Anzali wetland were proposed. This study shows the effectiveness of the FTA method in identification of the environmental risk factors and EFMEA method in risk quantity estimation.