مجله تحقیقات منابع آب ایران
سال نهم شماره 3 (پیاپی 28، زمستان 1392)

The Great Karun River Basin plays a vital role in the Iran's food and Hydro-energy productions (78% and 13% in hydropower and food production, respectively). These put a high pressure on water recourses in this basin resulting in development projects on agricultural, industrial, and service sectors. In this situation, unsustainable development leads to increase in the basin vulnerability to external hazards. The present paper aims to demonstrate that in the real world we are not dealing with the vulnerability of a system to a hazard, but we need to address viability of a system focusing on three major domains of the system vision and mission; states; and processes or flows. In recent years one of the weakest rings in the Karoon River Basin water chain has been the issue of water quality that raised itself as a big issue for the managers and experts, as it seriously influences the water allocation. The aim of this research was to assess the trends and reasons of vulnerability of the Great Karun Water System to hazards with an especial focus on water quality as the main attribute of concern in the basin. System dynamics approach and the Vensim software have been adopted to simulate the water system in this research. The results showed that exterior hazards and scenarios have lower influence on water quality in comparison with policies of the industrial, agricultural, and service sectors. This indicated that to reduce the vulnerability in the Great Karun water system it is essential to change the policies in food and energy production.

Trend investigation is one of the key characteristics of time series. However, all common trend tests (e,g. Kendall and Mann-Kendall) are based on stationary time series and with this assumption that there is no long-memory in the time series. Based on both classical Kendall and Mann-Kendall tests, it was shown in this study that there was a significant (p-value<0.001) increase in annual Mashhad temperature (with a record length of 127 years spanning 1885-2011). However, considering the time series as a long-memory process (fractional Gaussian normal with Hurst exponent of 0.92), standard deviation of the test statistics were increased by a factor of greater than 6. As a result, the increasing trend in temperature was not accepted at common significant levels of 0.01 and 0.05. Some regression equations were developed for correction of standard deviations of Kendall and Mann-Kendall trend tests as a function of record length and Hurst exponent, for the first time. The results remained identical for incomplete time series. A stochastic method, based on frequency factor of Chow, was proposed for data filling and showed that the results are stable.

One of the methods for estimation of flood quantiles in ungauged watersheds or watersheds with short data records is using the regional frequency analysis method. In regional studies, the clustering methods are used to achieve homogeneous regions. Self-Organization Feature Map (SOFM) is recently used in several researches for clustering the watersheds. However the interpretation of the SOFMs output units is one of the SOFMs problems. Consequently, the trained SOFM units are used as input to the other clustering algorithms. In this study, SOFM method is used to form a two- dimension feature map, and then output nodes are fed to fuzzy c-mean clustering to form the required regions for flood frequency analysis. The optimum number of the clusters is determined by Xie-Beni and Kwon indices. The results showed that this approach has a good performance to determine homogeneous regions in Mazandaran province, northern Iran.

This study investigated the karst development in Poyon anticline, Southwest of Iran. For this propose, the parameters of karst development including lithology, slope, vegetation density, faults, distance from faults, lineament density, distance from lineaments, precipitation, and temperature were investigated. Using Analytical Hierarchy Process (AHP) the weight of each layer on karst development was estimated. Final map of karst development was extracted by combination of effective layers. The results showed that 59 percent of Poyon anticline area had high karstification potential, 5.3 percent had moderate potential, and 35.7 percent had either very low potential or no karstification potential. Areas with high potential of karst development are located in north of karst aquifer (Ilam - Sarvak Formation). Springs with high discharge were noted mainly in karst areas with high potential. The result can be adapted for aquifer development management.

Limited surface water resources and enormous population growth in recent decades have resulted in groundwater overexploitation and damage to natural resources in Iran. Optimum groundwater resources management should be considered as the key issue and a basis in short and long term planning in order to stop further damages. Though the simulation-optimization approach has been widely used in groundwater resources management researches, there is still no comprehensive software to address all the aspects. In this research, a graphical interface, Graphical Ground Water Management (GGWM), was developed based on MODFLOW-2000 and GWM softwares. The developed model was applied in a case study for Shahr-e-kord plain aquifer. Considering the progressive water table drop in the area, the main goal of the model was to find a sustainable solution. The model were verified in the real case and the results showed that by withdrawal management in agricultural wells, it is possible to improve the water table drawdown by 10% compared to the current condition.

This papers aims at developing a new methodology for Waste Load Allocation (WLA) to the effluent dischargers in Zarjub river basin in Gilan Province, Iran. In waste load allocation problems, besides maintaining the river water quality, minimizing the effluent treatment costs should also be taken into account. The concept of Nash Bargaining Equilibrium and Borda scoring social choice Method are utilized for finding the best solution among a number of alternatives. Each alternative is a combination of treatment scenarios for the dischargers. These alternatives form a compromise set which are obtained using the Fallback Bargaining Procedure. The methodology introduced in this paper can be considered as a substitute for the methodology developed in Mahjouri and Bijani-Manzar (2013). To investigate the impact of each alternative on river water quality, the concentration of Dissolved Oxygen in a control point is determined using Transfer Coefficients which are derived from a water quality simulation model. A penalty function is used to calculate the amount of penalty cost assigned to the violations from the standards in the control point. In this research compromise sets were primarily selected among alternatives, using the Borda scoring social choice method. Then, all alternatives in the compromise set were investigated to find out whether they are Nash Equilibriums. If the number of Nash Equilibrium alternatives was more than unity, the Nash Bargaining Function was used for finding the best solution among them. The results of the two mentioned procedures were then compared to select the final alternative based on the allocated costs to the total dischargers and the amount of violation from the river water quality standards resulted from the selected alternative. In the final step, the Extended Trading Ratio System (ETRS) is utilized for exchanging the allocated amount of discharges to the dischargers which decreased the total allocated cost to dischargers. On the whole, the proposed methodology can find a final solution among a set of alternatives which in addition to maintaining the river water quality condition, can lessen the total treatment costs.

The optimizartion of photocatalytic process by Taguchi method and the prediction of removal efficnecy by artificial neural network were investigated in this research. Immobilized photocatalytic reactor was irradiated with TiO2 by UV-A lamps to produce hydroxyl radicals for degradation of phenolic synthetic wastesater. Taguchi method and L16 orthogonal array for experimental planning was used for determination of optimum conditions including initial phenol concentration (50-500 mg/L), UV lamps power (8-60 W), pH (4-12), TiO2 concentration (20-80 g/m2), and UV lamp distance from concrete surface (5-20 cm). The results showed that influent phenol concentration and solution pH had the highest effect on the removal efficiency. The optimum conditions were obtained for influent phenol concentration of 50 mg/L, pH of 12, UV lamp of 60 W, titania amount of 80 g/m2, and UV lamp distance to concrete surface of 10 cm. Prediction of photocatalytic process performance by artificial neural network showed that the best result was obtained at the structure of (5-6-4-1). Transfer functions for this model were Gaussian, Hyperbolic Tangent, and Sigmoid for hidden layer 1 and 2 and output layer, respectively. The difference between measured and predicted values of output nodes was less than 5%.

The conventional methods for estimating the suspended load in rivers are using the sample of debit-sediment and fit them into exponential patterns, power model, neural networks, or frequency distribution table. In high flood flows these models cannot be extrapolated and their estimations are unrealistic. This is due to the bounded water power to carry suspended load (physical properties). Multivariate Adaptive Regression Spline (MARS) model are proposed in this paper to pass this limitation. MARS is a piecewise linear spline model that has better performance in extrapolations. The MARS exponential and power models were fitted on debit-sediment data of 23 stations khorasan razavi province in this article. The results were compared in two modes of interpolation and extrapolation and base on statistical and physical criteria. Statistical criteria models included the R2adj, sum of squares error (SSE), generalized cross validation (GCV), and diagnostic residual. The physical criteria included realistic estimation of the sediment in two modes of interpolation and extrapolation. The results showed the superiority of MARS model to other practices.

When dealing with the quality of water resources for different uses, collecting samples from all parts of a study area is not economically possible. In this regard zoning methods are powerful tools in the providing the data based on spatial variation. This research aimed in groundwater quality zoning for agricultural uses in the Varamin plain, southern Tehran, using Interpolation methods with Geographic Information System (GIS) and the weightings in the Analytical Hierarchy Process (AHP). Qualitative data from 74 tube wells in the plain of Varamin from 1388 to 1387 is used. Firstly, raster maps were prepared using Inverse Distance Weighted (IDW) method for the study area. These maps prepared for the Sodium Absorption Ratio (SAR), Permeability Index (PI), the Kelley Ratio (KR), Magnesium Adsorption Ratio (MAR), Residual Sodium Carbonate (RSC), Dissolved Sodium Percentage (SSP), Electrical Conductivity (EC), and Total Hardness (TH) Then the final weights of parameters in water quality potential were determined using AHP and the pair wise matrix. Finally, with overlaying maps and applying final weights of the parameters in GIS, the map of qualitative potential of the groundwater resources in the area for agricultural purposes was prepared. The results showed that in the northwestern, southwestern, and western parts, the status of groundwater for agriculture are poor and in the central, northern, and northeastern parts there are the quality of water is suitable for agriculture purposes.

The Bahar great plain is located in north of the Hamedan city. Bahar, Lalejin, and Famenin cities are also situated in this plain. In the vicinities of these cities especially in the eastern parts of the plain, lots of water wells are dugout with very bad taste and smell in waters. Greate amount of HCO3-, CO2, SO2 gases are exhalative from these wells. Acids formed from reaction of these gases and water, erode well instruments. Gases are stated to have hydrothermal origin according to several studies. The result of this research does not support this hypothesis.