IRAN-WATER RESOURCES RESEARCH
Year:2016 | Volume:12 | Issue:2|Papers Count:16

Over the past few decades, due to human activities, aquatic ecosystems have experienced severe damages. Lake Zrebar, located 3 Km West of Marivan city in Western 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 Zrebar 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 Zrebar 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 wells' 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, transferring, 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 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 5980 million Rials in the present plan to 5720 million Rials in the optimum plan. Sensitivity analyses indicates that results are not significantly sensitive to changes in aquifer 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 the climate change impacts on annual meteorological variables and river-flow of the Sirvan Basin in western Iran 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 the investigated future scenarios it is expected that the stream-flow of the basin will be reduced in the future.

Investigating trends of the 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 test (Mann-Kendall) are used under three different scenarios of independence, short term persistence, and long term persistence. The assumption of dataset independency is one of the limitations of the Mann-Kendall test. This assumption is unacceptable and leads to unreliable results if hydro-climatic time series are characterized with short or long term persistence. 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 decreasing 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 aquifers water table and accordingly has had widespread socio-ecological effects throughout the country. Different approaches have been studied by researchers to control the crisis. Most of these studies focused 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. In Iran the numerical prediction in monthly time scale is much less practiced than the numerical short term prediction. Despite the need to the short term weather predictions, there is no operational numerical monthly to seasonal forecast model in Iran. Each year the lack of a reliable operational seasonal forecast system causes huge damages to water resources, agriculture and natural resources sectors all over the country. 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 in north eastern Iran. Post processed monthly precipitations were then compared with Direct Model Output (DMO). It is shown that the performance of monthly forecast has been increased by 6% up to 20% by applying post processing techniques to direct model output. Result confirmed that multiple regressions (MR) techniques have the highest performance in improving the monthly forecast skill over selected stations.

Global warning has caused the characteristics of extreme rainfall to be changed out of the internal variability range of climate. In this research an analysis is presented for the variation of rainfall intensity, duration, and frequency (IDF) in Khorasan-Razavi province under 10 climate scenarios derived from the global climate models and A1B emission scenario for 2021-2040 period. The IDF values for 23 rain gages is projected under future climate scenarios in 3 risk levels (%25, %50 and %75) by a proposed combined approach consisted of: (1) developing a nonparametric downscaling model to project the future daily rainfall in arid and semi-arid regions, and (2) establishing frequency-quantile relationships between the t-hour and daily rainfall based on the annual maximum for estimating the IDF values. Under the risk level of %50 the results show a wide range of variation in rainfall intensity between -23% to +7.3% relative to baseline (1993-2012). Short duration rainfalls change in more positive range than long-durations and for return periods of more than 10-year the range of changes will be wider in this area. Generally, central and southern regions will be received slighter increase compared to the northern regions. Also, the high rainfall regions will face a more severe flooding while the low rainfall regions will suffer from a more severe decrease. Furthermore, in low risk level the rainfall intensity will be increased in the future period which can be alerting for design of hydraulic infrastructures of high importance.

Due to limitations in water resources, increasing needs in these resources in all aspects as well as 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 should be utilized. In this paper, a multi objective model is developed for Yazd-Ardakan basin for conjunctive use of ground water and water transferred from outside of the 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 of the aquifer sustainability, minimizing failure in water supply, and balancing aquifer storage. 3-D analysis MODFLOW model served to simulate ground water aquifer. The monthly water budget was extracted using 3-D analysis MODFLOW model. The findings indicated that NSGA II is superior to GA in optimizing water allocation model. On the other hand, using annual renewable ground water storage instead of monthly data 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 has been met in the 19th century. According to the results, 43.75, 18.75, 12.5 and 25 percent of the projects have been respectively implemented for drinking and agricultural water supply, energy production, environmental objectives, and multi-purpose water supply purposes. 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, more than 27 percent of the global water withdrawal capacity is transferred with inter-basin water transfer projects. In Iran, based on available data, the capacity of inter-basin water transfer 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 one of the basins in the long term. Consequently, inter-basin water transfer projects should be applied only in emergency conditions when no other alternative solution is practicable and when emergency drinking water supply is emerged. This should also satisfy the integrated recognition of study region conditions and its potentials, having comprehensive and systematic management approach and ultimately with consideration of environmental, economic, social and political dimensions.

Conserving water resources and protecting them from pollution are of 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 it is a costly process to extract it from water. Providing a reliable, low cost, and fast method is necessary for eliminating pollution. This study tried to determine the refining potential and capacity of Eichhornia crassipes for removing nitrate from water. Factors affecting the nitrate absorption including initial concentration of nitrate, contact time, absorbent mass, pH, and the presence of other competing ions such as sulfate have been studied. The results showed that the best efficiency of nitrate removal of more than 99% occured in the optimum condition; the retention time of 30 hours, absorbent dose of 3 plants (15 stem) and pH of 6.4. In addition, the efficiency of nitrate removal in the presence of sulfate ions was not reduced. By increasing the initial nitrate concentration, from 30 to 150 mg/L, there was no significant change in the removal efficiency. By increasing absorbent mass the removal time decreased and the efficiency increased from 67.96% to 100%. The process of nitrate absorption followed Langmuir isotherm (R2=1). Finally the results showed that Eichhornia crassipes is a promising plant with great functionally which can be used as a refiner for removing nitrate with a simple, efficient and low cost method.

In Iran the groundwater is frequently being utilized as a water resource for drinking, irrigation, and industrial purposes due to limited and unreliable surface water resources. The main aim of this study is to develop systematic approach in GIS inference fuzzy system management to analyze and map the groundwater quality of Shahr-e-Babak plain located in northwest of Kerman Province. The analysis showed 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 i.e. C3S1, C3S4, C4S1 and C4S2. High salinity low sodium hazard type of C4S1 was the most dominant in the study area. The results declared that the use of spatial fuzzy and grouping analysis in GIS can obviously clarify controlling factors of aquifer water quality.

The hexavalent chromium is one of the heavy metals that is toxic and soluble in water. This study is done to remove the hexavalent chromium from aqueous solution by pine fruit powder. The adsorbent prepared in laboratory scale and pulverized by standard ASTM sieve (100 mesh). In this research, the effect of pH, contact time, adsorbent dose, initial Cr (VI) concentration, and Temperature as well as the Langmuir and Freundlich isotherm models was studied. The results showed that increasing the pH and initial chromium concentration led to decrease in the removal efficiency and increasing contact time, adsorbent dose, and temperature increased the removal efficiency. The chromium ion adsorption by pine fruit powder followed the Langmuir isotherm model. Pine fruit powder is a suitable natural adsorbent for the removal of chromium (VI).

Exploiting surface water resource as the main potable water supplies and the application of chlorine as the main disinfectant for drinking water have increased the rate of Disinfection by-products (DBPS) formation. One main group of DBPS are Trihalomethane compounds (THMS) which are carcinogen. Objective of this survey is the determination of THMS concentration in Sanandaj water treatment plant units and the relation between THMS formation with free residual chlorine and organic matter. Sampling was done ten times in one year and at various stages of water treatment. 50 samples were tested and the results were analyzed. THMS were measured using gas chromatography. The THMS concentration in input raw water (less than15mg/l) and the output flow (20mg/l) was lower than the international standard. This study showed that THMS formation has a direct relation with free residual chlorine and organic matter. The lowest amount of THMS are observed after the coagulation-flocculation unit which represents the performance of this unit in eliminating THMS. THMS are in the highest level after the final chlorination.

Gaining the customer satisfaction is being dominant as the main target of companies. Feeling satisfaction shall cause increase in tolerance threshold of customers to pay more for their required product. Use of modern water meter reading methods (including remote meter reading and Pre-paid meters) fulfilled the increase in customers’ satisfaction in many developed countries. Accordingly, this research studies the relationship between the use of modern methods of meter reading and customer satisfaction in water and wastewater Company of Qom Province in central Iran. The data in this research are illative and have been analyzed using descriptive and illative statistical indicators such as comparing two samples. The main tools for data collection in this research were questionnaire and structured interviews and the sampling method was simple random. The results show that the highest satisfaction is related to the method of remote meter reading. Face reading and pre-paid meters are on the next ranks.