مجله تحقیقات منابع آب ایران
سال دوازدهم شماره 2 (پیاپی 36، تابستان 1395)

Over the past few decades¡ due to human activities¡ aquatic ecosystems have experienced severe damages; Lake Zrêbar¡ located at 3 Km West of Marivan in-Iran¡ is not exempt from this issue. Approximately nine villages as well as the city of Marivan is located in periphery of the lake. The stakeholder analysis methodology was used in this study to assess the socio-economic and political sub-systems of the Lake Zrêbar basin. This analysis showed that over the last few years¡ for various reasons¡ including economic growth¡ demographic dynamics¡ and sediment inflow¡ the lake has faced with environmental and social problems. The wide variety of stakeholders in the lake as well as the complexity of issues has made the case of Lake Zrêbar as a complex problem. The results showed that the stakeholders¡ who are directly active in the region¡ have been ignored. Therefore¡ it is suggested that the ground-based participation of all stakeholders to be carried out. It is also important to take care that the economic benefits of the local communities to get balanced with the pressures loaded on the lake ecosystem. The whole stakeholders should be herad to come up with a comprehensive narration of the lake issues. That process is expected to be effective to attract the stakeholders’ support to the process of sustainable restoration of the lake.

Risk analysis, because of employing mathematical models for evaluating confronted hazards and also pertinent vulnerability, introduces errors in results. The source of mentioned errors could be input data (components) and/or model structure which will impose meaningful uncertainty upon the model output. Present research investigates the effect of uncertainty of discharge-probability function on flood temporal and spatial risk assessment. The Monte Carlo method was engaged for uncertainty analysis and the Azaroud watershed in southern part of the Caspian Sea was selected as the case study. The study was based on temporal and physical loss functions of rice, while HEC-RAS provided the required hydraulic information. Combining loss functions and flood hydraulics in a GIS framework led to Agricultural Expected Annual Damage (AGEAD). Finally the uncertainty of discharge-probability function was introduced to AGEAD which caused it to increase from %1.8 to %1.9. Based on the achieved results, the contribution of probability-discharge function uncertainty in rising up the agricultural expected annual damage was 5.5 %.

Improper wells location and excessive groundwater extraction can cause severe damage to aquifers and lead to numerous economic consequences. The purpose of this study is to develop a simulation-optimization model for determination of optimal well's placement and pumping rates, while satisfying the requirement of quantitative and qualitative considerations. The proposed model integrates the groundwater flow simulation model MODFLOW and the Particle Swarm Optimization algorithm. The coupled PSO-MODFLOW model has been applied to the Sarakhs aquifer in the north-east of Iran to minimize the total cost of drilling, transfering and water treatment for supplying the drinking demand of the Sarakhs city. Discharges as well as locations of the pumping wells were taken as the decision variables. Also, the maximum pumping rate and maximum water-table drawdown were incorporated as the problem's constraints. The results show that the proposed approach not only satisfies the constraints but also reduces the total cost of water withdrawal by 5% from 598 million Tomans in the present plan to 572 million Tomans in the optimum plan. Sensitivity analyses indicates that results are not significantly sensitive to changes in aquifer’s hydraulic conductivity, while the maximum pumping rate directly affects the number of required wells and can therefore make a considerable change in the final cost.

In this paper, climate change impacts on annual meteorological variables and river-flow of the Sirvan Basin are assessed. Future scenarios of CGCM3 (including annual precipitation, mean daily maximum and minimum temperatures) for A1B, A2, and B1 scenarios are downscaled using Change Factors method for the Sirvan Basin. Climate change impacts on these variables and on the potential evapotranspiration of the basin are assessed. For hydrologic simulation of the river-flow of the basin, 20 annual hydrologic models are tested and finally the two best models (namely M8 and ICARLike) are employed. Then annual river-flow of the Sirvan Basin for current and future climate conditions is simulated; and climate change impacts on hydrologic variables of the basin are assessed. It is projected that the temperature and potential evapotranspiration will be increased and precipitation and river-flow will be decreased in the Sirvan Basin in the future. Despite importance of uncertainties related to the emission scenarios and hydrologic models, under all of investigated future scenarios, it is expected that the stream-flow of the basin will be reduced in the future.

Trends invesigation of climatic variables in a catchment can lead to more realistic approaches for water resources planning and management. In this paper, monthly, seasonal and annual trends of inflow, precipitation, evaporation and temperature are studied for Sefidroud dam. Therefore, a parametric test (Regression) and a nonparametric tset (Mann-Kendall) under three different scenarios of independence, short term persistence, and long term persistence are used. The assumption of dataset independency is one of the limitations of the Mann -Kendall test. Therefore, if hydro-climatic time series are characterized with short or long term persistence, this assumption is unacceptable and leads to unreliable results. Since, serial correlation and Hurst phenomenon are seen in most hydro-climatic time series, it is necessary to modify Mann-Kendall test for considering these effects. For comparison of trend analysis results, the homogeneity of hydro-climatic variables is studied by cumulative deviation test, Worsley Likelihood test, and the Bayesian procedure. Comparison of results indicates remarkable significant decreasing trends for inflow using different methods and assumptions. Furthermore, decreasing trends for precipitation and minimum temperature and increasing trends for maximum temperature indicate that hydro-climatology of the study area might be impacted by possible climate change. Obtained results also show that most time series with significant deacrising or increasing trends are also characterized with significant non-homogeneity. Therefore, simultaneous use of homogeneity and trend analysis tests for studying Hydro-climatic variables lead to more reliable results.

Unsustainable use of groundwater resources caused drop in the water table and then has had widespread socio-ecological effects throughout the country. Different approaches have been studied by researchers to control the crisis. Most of those studies focus on engineering aspects, while in the principles of the integrated water resources management; it is emphasized on interdisciplinary approaches. Dealing with the problem of decrease of water table in Rafsanjan, thie paper examines the effects of the institutional context in the formation of such problems. Therefore, using the causal loop diagrams, the paper aims to analyze the factors related to the institutional context of groundwater resources in the regional and national scales. At the regional scale, with a focus on groundwater resources of Rafsanjan, dynamic structures were identified. In the national scale, the role of "formal rules" in reinforcing the growth dynamics was evaluated. The results suggest an overshoot and collapse mechanism dominate in the regional scale where the institutional context has not been capable of controlling the growth dynamics, but reinforced the growth dynamics through the mechanisms of "Shifting the burden ", "Eroding goals ", and "Fixes that fail ".

Precipitation forecast in monthly to seasonal time scales is one of the challenges facing the Iran meteorological organization. It is also one of the fundamental needs of water resources management in agriculture, industry and drinking water sectors. Development of numerical prediction in monthly time scale is much less than numerical short term prediction in Iran; in this regard, despite to short term weather prediction, there is no operational numerical monthly to seasonal forecast model in Iran. Lack of a reliable operational seasonal forecast system cause huge damages to water resources, agriculture and natural resources sectors in all country regions. MRI-CGCM3 is the operational dynamical seasonal forecast model which is being used in Japan Meteorological Administration (JMA). In this paper output of MRI-CGCM3 was post processed using three different techniques of multiple regressions (MR), moving average (MA) and artificial neural network (ANN) over three sites of Mashad, Sabzevar and Torbat-e-heydarieh. Post processed monthly precipitation obtained from three different methods were compared with Direct Model Output (DMO).Performance of monthly forecast has been increased by 6% up to 20% when applying post processing techniques to direct model output. Result confirmed that multiple regressions (MR) techniques have the highest performance in improvement of monthly forecast skill over selected stations among all three post processing techniques.

Global Warning has caused the characteristics of extreme rainfall changed out of range of the internal variability of climate. In this research, an analysis is presented from how variation in intensity, Duration-and Frequency (IDF) of rainfall under 10 climate scenarios derived climate models and A1B emission scenario for 2021-2040 periods in Khorasan-Razavi province. The IDF values for 23 raingage have projected under future climate scenarios in 3 risk levels (25%, 50% and 75%) by a proposed combined approach include: (1) Develop a nonparametric downscaling model to projection of future daily rainfall in arid and semi-arid regions, (2) Establishing frequency-quantile relationships between the t-hour and daily rainfall based annual maximum for estimating the IDF values. Under risk level 2, the results show a wide range of between -23% to .3% in rainfall intensity than baseline (1993-2012). The short-duration rainfalls change in more positive range then long-durations; and for return periods of more than 10-year, the range of changes will be wide in this area. Generally, central and southern regions will be received slight increase than northern regions. Also, the high rainfall regions will be ahead a more severe flooding, while the low rainfall regions will be suffered a more severe decrease. Also, in low risk level, rainfall intensity will be increased in the future period; it can be warning to design hydraulic infrastructures with high emphasis.

Due to some factors such as limitations in water resources, increasing needs in these resources in all aspects and also the impact of climate changes on these resources, the optimal management of water resources and efficient use of them is an essential task. To achieve this optimal management, appropriate optimization techniques can be utilized. In this paper, a multi objective model is developed for conjunctive use of ground water and transitive water in Yazd-Ardakan basin. To attain this, optimization approaches including Genetic algorithm (GA) based on penalty function and non-dominated sorting genetic algorithm (NSGA II), were used. Three objective functions were developed including, maximizing economic income obtained from water resources considering qualitative aspects the aquifer sustainability, minimizing failure in water supply and balancing aquifer storage. 3-D analysis Mod flow model served to simulate ground water aquifer. The monthly water budget was extracted using 3-D analysis Mod flow model. The findings indicated that NSGA II is prior to GA in optimizing water allocation model. On the other hand, using annual renewable ground water storage, considered in water allocation, instead of using monthly renewable ground water storage resulted in better allocation model performance.

The present study has reviewed the characteristics of some 170 inter-basin water transfer projects in various parts of the world with different ecological conditions. The minute reviewing of existing experiences indicated that the apogee of implementing inter-basin water transfer projects had been made in the 19th century. According to the results, 43.75, 18.75, 12.5 and 25 percent of the projects have been implemented for drinking, agricultural and energy production, environmental and multi-purpose water supply purposes, respectively. However, in many developed countries more than 80 percent of the inter-basin water transfer projects were implemented for providing drinking water. According to the data, in the world more than 27 percent of the water withdrawal capacity is transferred with inter-basin water transfer projects. In Iran, based on available data, the capacity of inter-basin water transfer project is 6.35 km3 per annum mainly transferred for agricultural purposes through constructing long tunnels. Since, inter-basin water transfer projects directly affected the management of origin and destination basins, the socioeconomic and environmental conditions were often weakened in source or destination in the long term. Consequently, inter-basin water transfer projects would be applied only in emergency conditions, the lack of any other alternative solution and emergency drinking water supply. It will be also possible to imply with integrated recognition of study regions conditions and its potentials, having comprehensive and systematic management approach and ultimately with consideration of environmental, economical, social and political dimensions of study regions.

Water resources conservation and protect them from the pollution, has a high importance in natural cycle of our life. Nitrate, as one of the important resources of water pollution, is a serious threat to aquatic ecosystems, and due to its high solubility, extraction of it from the water is a costly process. Providing a reliable, low cost and fast method is necessary to eliminate pollution. The study has tried to determine the refining potential and capacity of Eichhornia crassipes in order to remove nitrate from the water. Factors such as initial concentration of nitrate, contact time, absorbent mass, pH and the presence of other competing ions such as sulfate on nitrate absorption have been studied. The results showed that the best efficiency of nitrate removal, more than 99%, in the optimum condition (the retention time of 30 hours, absorbent dose 3 plants (15 stem) and pH=6.4) was occurred. In addition, the efficiency of nitrate removal by the presence of sulfate ions does not reduced. By increasing the initial nitrate concentration, from 30 to 150 mg/L, there is no any significant change in removal efficiency. Actually, by increasing absorbent mass, removal time was increased from 67.96% to 100%. The process of nitrate absorption followed by Langmuir isotherm (R2=1). However, the results showed that Eichhornia crassipes, a promising plant with great functionally, can be used as a refiner for removing nitrate as simple, efficient and low cost method.

Groundwater is frequently utilized as a water resource for drinking, irrigation, and industry purposes in Iran due to limited and unreliable surface water reservoirs. The main aim of this study is to develop systematic approach in GIS inference fuzzy system management to analysis and mapping groundwater quality of Shahr-e-Babak plain located in northwest of Kerman Province. The analysis show that 21.4 and 40.5 percent of Shahr-e-Babak plain groundwater have suitable quality for drinking in east and southeast and for irrigation in north and northeast, respectively. Grouping analysis also showed four types of irrigation water such as C3S1, C3S4, C4S1 and C4S2. C4S1 type of high salinity to low sodium hazard was the most dominant in the study area. Based on the results it’s declared that using spatial fuzzy and grouping analysis in GIS can obviously clarify controlling factor of ground water quality of aquifers. So, protecting groundwater from pollution is crucial for water resources planning and management.

The hexavalent chromium is one of the heavy metals that toxic and soluble in water, that amount is exceeded in drinking water in Birjand. On the other hand 80% of the pine trees of green space Birjand. This study to remove of hexavalent chromium from aqueous solution by pine fruit powder has been done. The adsorbent prepared in laboratory scale and pulverized by standard ASTM sieve (100 meshes). In this research, the effect of pH, contact time, adsorbent dose, initial Cr (VI) concentration and Temperature and also Langmuir and Freundlich isotherm models was studied. The results showed that increasing the pH and initial chromium concentration led to reducing of the removal efficiency and increasing contact time, adsorbent dose and Temperature led to increasing of removal efficiency. The chromium ions adsorption by pine fruit powder is follows Langmuir isotherm model and also pine fruit powder is suitable natural adsorbent for the removal of chromium (VI).

Considering the surface water resource as one of the main potable water supplies and the application of chlorine as one of the main disinfectant drinking water has increased the rate of Disinfection by products (DBPS) formationthat One of the main group of DBPS are THMS compounds that are carcinogen compounds. Objective of this survey the determination of THMS concentration in Sanandaj water treatment and ralation between THMS formation with free residual chlorine and organic matter. Sampling was done on ten steps, at various stages of Sanandaj water treatment during the year, and 50 samples were analyzed and results.THMS were measured with gas chromatography. The THMS concentration in input raw water (less than15μg/l) and output (20μg/l) that was lower than the international standard .This study showed that a positive relation is between THMS formation with free residual chlorine and organic matter. After coagulation, flocculation unit is the lowest THMS. Which represents the performance of this unit focuses on eliminating THMS. THMS is the highest level of the final chlorination..

Gaining the Customer satisfaction is becoming the main target of companies. Feeling satisfaction shall cause increasing in threshold of customers’ tolerance to pay more for their required product. Use of modern water meter reading methods (including the method of remote meter reading and Pre-paid meters) have been able to result in increasing the customers’ satisfaction in many developed countries. So, this research studies the relationship between the use of modern methods of meter reading and customer satisfaction of water and waste-water Company of Qom Province. The data in this research are illative and have been analyzed by use of descriptive and illative statistical indicators of the existing methods rely on illative statistics such as comparing two samples. The main tool for data collection in this research is questionnaire and structured interviews. Sampling method of this research is simple random. The results show that the highest satisfaction is related to the method of remote meter reading, and Face reading and pre-paid meters are on the next steps.