نشریه منابع آب و توسعه
سال دوم شماره 1 (پیاپی 4، فروردین 1393)

In this paper the results of investigation on the combination and conjunctive use of Detention dams and Storage reservoirs are presented. Detention dams are basically In-Stream structures while Storage reservoirs canbe built beside streams. Experiments have shown that in areas where water scarcity is a major problem، ground water should not be considered as the only source for water supply. High frequency floods are not commonly recognized as a reliable water supply. This paper intends to reveal the fact that using such an unfamiliar source of water is essential and vital to resolve water scarcity problem in arid and semi arid regions. Combining flood control and water harvesting tasks، may justify Hydro projects from economic point of view. In the case study، it was illustrated that detention dams could effectively capture high frequency floods which leads to local flood control cost reduction. This provides the required investment for constructing off-Stream reservoirs to supply fresh water for different purposes especially for municipal consumption.

The most important management tools of the optimized allocation of water specially in desert lands is the investigation of production elasticity and demand elasticity of water. Therefore, new cultures such as greenhouse cultures have an important role in optimum use of water resources. The purpose of this article is to estimate production elasticity and demand elasticity in greenhouse cultures with the goal of optimum use of water resources. So, elasticity of water-derived demand has been estimated due to the production function of greenhouse cultures. In this study, 95 beneficiariesfrom a population of 153 farmers were chosen in Yazd province using Cochran approach. Production elasticity of water was estimated to be 0.278. It is showed water used in second region of production that is economic region. According to the water estimated elasticity, with increasing water price by one percent, production will increase by 0.278 percent. Regarding the water consumption of greenhouse in the second economic region, supporting greenhouse productions can lead to optimum use of water input and help agriculture sector in desert lands.

Agricultural waste water is considered as an unconventional sources of water. Reusing these resources can decrease the pressure on fresh water resources and reduce the expenditure of irrigation. Indiscriminate use of pesticides in agriculture has become a serious threat for surface water and groundwater. Biodegradation is one of the most effective ways to destroy pesticides in the environment. Regarding the advantages of bioremediation techniques, such as low cost, high efficiency and environmentally friendly features, researchers are interested in using these methods to reduce or remove pollutants from the environment. The aim of this study is to evaluate the potential of T.asperelum fungi to remove Confidor from contaminated agricultural sewage, under the influence of pH, Confidor concentration, time and the presence of surfactant. The results show that T.asperellum is capable to remove 41.49% of Confidor from contaminated water. The results of initial concentration and pH effect on Confidor removal indicate that with increasing toxic concentration and decreasing pH, the Confidor removal will increase. Tween 20 as a surfactant enhances remo val efficiency of Confidor from polluted wastewater.

The main aim of this paper is to investigate the spatial dependency between per capita income and per capita water pollution in MENA countries over the period of 1990-2012. In order to achieve this objective, the empirical model has been estimated by applying mixed spatial auto regressive (MSAR) approach for these groups of countries. The main empirical findings indicated that, per capita GDP (Gross Domestic Product) has a positive and square of per capita GDP has a negative and significant effect on per capita water pollution in MENA countries. Moreover, dependency effect has a positive and significant impact on per capita water pollution.

Many of the impacts of climate change will materialize through changes in extreme events which were rarely addressed in Iran. This paper presents an investigation of the impacts of climate change on a selection of extreme events for the upper Gorganrood river basin. LARS-WG5 was used to downscale the IPCM4 and GFCM21 predictions of the A2 scenarios for the projected periods of 1985 -2030 and 2080-2099. To depict spatial and temporal patterns of drought, SPI index was used. The results revealed that precipitation is projected to decrease in all seasons except in winter. Inaddition, minimum temperature shows increasing trends compared to maximum temperature and specifically change will occur in spring and summer seasons as compared to the current climate. Generally, there is an increase in the number of hot and dry days and a decrease in the number of humid and frost days during two periods in different weather stations. Moreover, with increasing drought severity during the projected periods, in particular, the 2080-2099 period in the weather stations located in the north of the watershed, it was necessary to carry out a long-term planning for future watershed conditions management.

Climate change in recent years has led to significant changes in meteorological elements, thereby resulting in a sharp drop in surface and underground water resources supply, particularly in arid and semi-arid areas. In this paper, using limit indices of precipitation- temperature, SPI index and the sum of Drought Magnitude (DM), first the long-term drought conditions, then the effects of climate change on groundwater resource's status of Ramhormoz plain. Water supply in different parts of the region is highly dependent on groundwater resources. To evaluate the effects of climate change, the output of general circulation climate models (GCM) were used until temperature and precipitation data were converted to micro-scales by LARS-WG model to determine the values of aquifer recharge in time periods in the furure. To evaluate changes in groundwater levels at different time periods, the dynamic model of neural network was developed in MATLAB software environment. Assuming the preserved status quo of the study area development, the results indicate a declining trend of the aquifer volume due to climate changes and its effects on resources and uses of the study area. Moreover, the Drought Magnitude (DM) was detected as a better benchmark to show the drought situation in the region.

Songun copper processing plant’s feed is 61% grade porphyry which changes to 30% grade copper concentrate after flotation. 2100 m3/h water is required for concentrating process in this plant. During the concentrating process, 1204 m3/h tailing with a solidity of 50% are produced and transferred to the tailing dam. The high volume of the waste water, which contains chemical additives and discharges to the environment, may lead to numerous environmental issues. In this study, through the investigating the factors which affect deposition, the optimum deposition conditions of the tailing slurry was determined using Taguchi experiment design method. Then, by designing and making a pilot scale deep cone thickener along with applying the optimum deposition conditions in continuous feeding, an underflow with a solidity of 61% was gained. Thus, the average percentage of Songun coppers’ tailing thickener underflow solidity is 48% which will be improved by the proposed method that leads to 170 m3/h increase in the amount of reclaimed water from tail thickener and also a decrease in raw water and chemical drugs consumption in the concentrating process and thus, a reduce in the number of environmental impacts of effluents discharging to the dam.

Today, according to the limitation of water resources and direct effect of precipitation on the amount of obtainable water, developing cloud seeding projects is one of the strategies in management of water resources. Therefore, the optimum use of water resources, including atmospheric water resources (clouds and humidity of atmosphere) plays an important role in reducing the effects of this crisis. The aim of this study is to investigate increasing runoff due to cloud seeding in two sub-basins, namely Kuhdasht and Rumishgan. Thus, after investigating the Isorain maps and the study area’s topography and considering the precipitation systems, the target areas of cloud seeding were determined in two ways, i.e., ground-based generators and airborne generators. Then, determining the potential cloud seeding months, it was attempted to determine the volume of the target area’s rainfall in the potential cloud seeding months. Finally, assuming a 10% increase in precipitation, the runoff volume and the cost of each cubic meter water obtained by cloud seeding in two sub-basins Kuhdasht and Rumishgan were determined. The cost evaluation of the increasein the runoff caused by cloud seeding was performed by using mixed cloud seeding cost.

Drought phenomenon as a natural and inevitable disaster has frequently occurred in different countries, especially in hot and arid regions. In this study, monthly rainfall data measured at Bam synoptic station in the period of 1957 through 2010 (54 years) were used for modeling. According to the Akaike criteria (AICC), PARMA (1, 0) model was selected for modeling and forecasting the next 18-years of Bam rainfall series. Correlation coefficient between the modeled and actual data (0.867) confirmed the selected model. Then, a 72-years of rainfall series was studied using PN, DI, CZI, SPI, MCZI and ZSI drought indices. The results showed that seven severe, eight moderate and eight weak drought periods occurred from 1957 to 2010. Moreover, a severe drought period will happen in 2014. Two moderate ones in 2015 and 2023 and a weak one in 2022.

The application of BioDisk wastewater purification systems technology (RBC) has significantly improved economic aspects of purification and pollution control. Oxygen is needed to enable the aerobic activities inside the biological film, and since the aeration is done by rotation of discs at low speeds, energy expenses drop significantly. The major advantage of using RBC systems is that it is quite resistant to shocks of organic loading and toxic materials. The main goal of this paper is to study the mixing of sanitary wastewater with clean drain (passed through sand filters and drain boilers) at Neyshabour Power Plant and its use as the flow input into the RBC system, and also to study the effects of such a mixing process on the reduction of organic loading and improvement of COD and BOD5 reduction in RBC system by choosing total discharge rates of 45, 60 and 70 l/m. The results of the study indicated that the optimal discharge rate at which maximum BO 5 and COD reduction rates were achieved was the 70 l/m rate, including 45 l/m sanitary wastewater and 25 l/m clean drain.

Water resources projects need environmental impact assessment studies for ensuring that the programs and activities of the project accord with the policies and objectives and are in line with regulations, standards, environmental laws and regulations. Environmental impact assessment of the Grein dam of Nahavand was defined using Rapid Impact Assessment Matrix (RIAM)scores. In this method, a variety of terms change into quantitative criteria in the evaluation process. Appeals are easy to evaluate and compare. Using this method in environmental impact assessment of the Grien Dam of Nahavand, positive and negative environmental effects of dam operations, both construction and operation phases, were analyzed. The results showed that the effects of both the construction phase and operation of dams were significantly negative and the effects of positive versus negative effects were minimal.

Nowadays,the increasing gap between supply and demand draws attention to optimal water management. On this account, WEAP model was utilizedd for planning and managing water supply and demand in Zarajabad basin, Ardabil province. In order to implement water allocation plans in the study area by the aforementioned modeling, several scenarios were applied until 2022. The results showed that due to the low population density of the region, population growth rate did not have a significant impact on supply and demand in the basin area. Creating a reservoir dam will lead to storing surplus water during high water season in the area and provideing water in low water season.The results showed that provision of rural drinking water supply with permissible level of BOD in the summer when temperatures rises is not problematic. The results also indicated that in order to meet environment needs, ecological and environmental issues should be taken into consideration.

Drought is a climate phenomenon which might occur in any climate condition and all regions on the earth. Effective drought management depends on the application of appropriate drought indices. Drought indices are variables which are used to detect and characterize drought conditions. In this study, it was tried to predict drought occurrence,based on the standard precipitation index (SPI), using k-nearest neighbor modeling. The model was tested by using data of precipitation stations in Bam, Kerman Province. The results showed that the model gives reasonable predictions of drought situation in the region. Finally, the efficiency and precision of the model was quantified by some statistical coefficients. Appropriate values of the correlation coefficient, mean absolute error, root mean square error, efficiency of model and coefficient of residual mass indicated that the present model is suitable and efficient.

Water consumption rate in the plains of Iran is very alarming. In most provinces, during the past few years, low rainfall, lack of appropriate nutrition for aquifers and continuous pumping are the causes of a significant decrease in groundwater level of the plain. Among the most important and manifest consequences of groundwater level dropping are land subsidence, increase of the cost of drilling deeper wells and water pumping, decrease of the level of water of wells and their quality, and drying of springs. In this research, the areas that suffered the most damage due to water crisis in terms of the indiscriminate withdrawal and excessive drop over the past few years are specified and evaluated through accurate field observations. The obtained results from the investigation of indiscriminate withdrawal of the wells, rainfall decrease and sharp fall in ground water level, especially in the past few years are indicative of a 6-year drought period in Fars province and a 4-year one in Charmahal-Bakhtyari province. The results showed that if the current trends continue, without implementing serious actions to reduce excessive withdrawal in Fars and ChaharMahal-Bakhtiari provinces, we will encounter severe environmental consequences and economic and social problems in near future.

Due to water crisis, it is essential to find new ways to increase water use efficiency forachieving the economic benefits. Thus, for determining the optimal cropping pattern, considering water cost should be taken into consideration. In this study, the optimal cropping pattern has been compared to the current cropping pattern in the irrigated fields of Golpayegan network. Considering the main crops and their related area, the cost of agricultural inputs and final price of crops was consequently calculated in 2011- 2012 (the farming year). The final price of water (m3) in irrigation and drainage network was extracted from the data represented by Ministry of Power. Then, the cropping pattern was optimized by Lingo 11 and Excel software. Considering both economic value of water in agriculture sector and users’ power for purchasing water,the results of this study indicated that the receiving price of 1500 Rails per cubic meter is suitable in 2012.

Drought is one of the periodic dormant natural disasters. Drought occurs when the total annual precipitation is less than the long term average. Although it is erroneously considered a rare and random e vent, it occurs in virtually all climatic zones in arid and semi-arid regions. Its characteristics vary from one region to another. Continuous drought has negative effects on water resources, agriculture and local economy. Since there are no permanent rivers in the study area, water resources and regional economies are dependent on springs, wells, canals and basins that are highly affected by precipitation changes. The aim of this study was to investigate the impact of drought on the net and gross income of rural households. Thus, after determining the drought period using the SPI index, its relation with net and gross income was investigated. The total net income earned through agricultural activities, gardening, livestock, beekeeping and poultry in the early dry period was more than 29/7 billion, while in 1385, at the end of the decade it declined to less than 14/2 billion. The changes which led to economic losses of more than 15/5 billion were investigated.

Despite having hot and dry weather, Sistan (Zabol) is of the areas in which natural flood and drought usually occur and its residents suffer huge losses.The purpose of this study was to investigate the relationship between drought,dehydration and emigration of the residents of this area during 1997-2012. It alsoaimed to investigate the factors affecting the emigration of the residents using field researches, written reports and interviews with officials of the relevant agencies. Statistical center of Iran reported a decreasing trend of the population of Sistan during 2006-2012 and one of its reasons is migration.The main cause of migration of residents of Sistan is reduction of rainfall and dryness of the available wells in the area. Dryness of Hamoon lake during the recent years has played an important role in the increasing trend of migration.Some suggestions are presented for resolving this crisis including simplifying the process of adaptation to drought through training residents, following the water rights of Sistan and Hamoon lake and encouraging the immigrants to use the appropriate capacities for employment.

With respect to the importance of social impact assessment in watershed management projects, this research has assessed the social impacts of dam construction project in Tutang village located in Hormozgan province. We focused on the impacts of dam projects on the social relations of local people. Network Analysis method was used to perform the research and required data were collected through a questionnaire. Grouping and centrality concepts and Visone software were used to analyze the data. Results revealed that dam construction intention has led to the conflicts and grouping among local people. Individuals with high cooperation to solve the water shortage problem gained the highest social authority as they can be helpful to solve the conflicts among local people and so to increase the probability of success of watershed management projects.