جستجوی مقالات مرتبط با کلیدواژه « بهره برداری » در نشریات گروه « آب و خاک »

Taleghan Dam is the main suplier of water required by the agricultural sector of Qazvin plain. Reducing the amount of water allocated to the Qazvin plain irrigation network and uncertainty about the welfare provided by farmers due to the interruption of the time between the production of the crop and its supply to the market, have caused farmers to seek welfare by reducing fallow and draining groundwater resources. In this study, with the aim of preserving groundwater resources and providing livelihood to farmers, the groundwater level in the irrigation network of Qazvin plain is simulated under six scenarios: 1) Continuation of current harvest without increasing cultivated area 2) Increasing cultivated area by reducing fallow 3) Simultaneous optimization of Cultivation pattern and distribution water with price forecasting 4) Simultaneous optimization of water Cultivation pattern and distribution water with price forecasting and reduction of functional vacuum 5) Simultaneous optimization of Cultivation pattern and distribution water with price forecasting and increasing efficiency Irrigation 6) Simultaneous optimization of Cultivation pattern and distribution water with price forecasting, increasing irrigation efficiency and reducing the yield gap using the system dynamics during the years 2002-2037 in Qazvin plain irrigation network. The results showed that the drop in groundwater level under scenario one and two will be on average 1.2 and 2.4 meters per year. Simultaneous optimization of the cultivation pattern and water distribution with price forecasting in scenario three, four and five droped groundwater level to 1.6, 1.4, 1.3 and 1.2 meters annually, while the welfare of farmers is compensated, too.

The use of modern irrigation systems due to the increase in efficiency and productivity of water consumption is a basic solution compatible with water shortage conditions. The use of proper irrigation methods to maintain food safety and reduce water requirements is a global issue. The most important goals of the implementation of these systems are quantitative and qualitative protection of water and soil resources and sustainability of agricultural production.

In this study, technical and hydraulic evaluation of seven new irrigation systems (integrated irrigation, Movable Sprinkler Solid-Set Irrigation Systems and Trickle Irrigation) implemented in Shahrekord, Bon and Saman cities in Chaharmahal and Bakhtiari province was performed. To evaluate integrated and Movable Sprinkler Solid-Set Irrigation Systems, Christiansen uniformity coefficient (CU), distribution uniformity (DU), potential application efficiency of low quarter (PELQ), application efficiency of low quarter (AELQ) in two block scales were experimented and the whole system were calculated. To evaluate drip irrigation systems, uniformity indices of water emission throughout the system (EU), potential application efficiency of low quarter (PELQ), application efficiency of low quarter (AELQ) were calculated.

The results showed that the values of CU, DU, PELQ, AELQ indices for the tested block in integrated and Movable Sprinkler Solid-Set Irrigation Systems were equal to 68.6, 59.38, 46.85 and 58.56 and and for the system, 67.01, 58.48, 45.2 and 56.5. Was calculated. Also, EU, PELQ and AELQ index values for drip irrigation system were 55.62, 51.91 and 53.83. The results showed that the above systems have a good infrastructure and most of the problems of these systems are related to the phase of operation and maintenance of these systems by users.

The main problems of these systems that have led to a decrease in performance evaluation criteria are the deficit irrigation, lack of knowledge of users and lack of training on how to use the system properly (pressure regulation, periodic visits to the system, interest Correct and principled removal, etc.), changes in high pressure and uneven distribution in the system, changing the irrigation cycle, using more sprinklers and non-compliance with the proposed cultivation pattern in accordance with the design booklet and the use of drippers are inappropriate. Therefore, according to the comprehensive review, it is suggested that training courses should be given to farmers by changing the type of system from traditional to modern methods, and farms that are optimal in terms of exploitation should be identified and visited by others.

Water stored in the reservoir is one of the main sources of water supply in arid regions. Therefore, optimal operation of it is of utmost importance, especially in drought duration. In this study, optimal operation of Voshmgir dam using continues hedging policy optimized by linear programming (LP) and Partial swarm optimization Algorithm (PSO) that located in Golestan province north of Iran was investigated. The objective function is minimization of the Shortage index. In order to examine the effects of used hedging policy, 3 continuous drought years was considered. To evaluate the results of the models, evaluation criteria such as the percentage of water supply, reliability, vulnerability and stability indicators was used. The threshold volume changes per month was extracted and the base hedging rule curve for reservoir was presented. Evaluating the results of two models showed stability index in linear programming with 41.78 model was much higher than particle swarm algorithm with 6.416. Which indicates the higher performance of this model in the optimization of hedging policy in Voshmgir reservoir.

What has been identified as the relationship between natural resources and conflict? In what ways are natural resources used to trigger conflict and instability? Who are the main players and actors in resource conflicts? To address these questions, this article critically reviews the main theoretical and empirical works on natural resources conflict. This area was studied as the target population due to the rich forest and rangelands resources and considering the existing conflicts in the Ardabil province. The conflict of interest between exploiters and natural resource experts is one of the problems that may have remained from the period of nationalization of forests and rangeland (1962) and has become more critical gradually. In this regard, the inapplicability of the laws, the numerous transfers that have taken place over the years, and the lack of transparency of the border between national lands and exceptions, have led to many problems. This study seeks to investigate the reasons and causes of the conflict between the key natural resources key stakeholders including beneficiaries people who use the rangelands or forest and the local authority or national actors (government) over natural resources in the study area.

legal, managerial, exploitation, and social components were examined from the perspectives of both experts and stakeholders. A number of 205 questionnaires were completed by the officials of natural resources of Ardabil and Garmi cities and its stakeholders with the Snowball Method. The validity of the main variables was more than 0.7, which is an acceptable number. Divergent validity index, among all features, was less than 0.9, which indicated that there is no dependence between the variables of each feature. Since the scale of measuring the views of experts and stakeholders is the rating, the non-parametric Mann-Whitney U-test was used to compare the views of two groups on the causes of conflict in natural resources.

The results showed that the natural resources conflict in the whole region, there isn’t a significant difference between the factors affecting the conflict between the local community and government experts in terms of perspective. The most important components for increasing the conflict in this region from the perspective of beneficiaries are lack of expertise of the resolution council, lack of government support for ranches, financial poverty, conflict with rangeland encroachers, low level of awareness of stakeholders, and according to the experts, lack of government support for ranches, lack of law, lack of rangeland cooperative, insufficient water in rangeland, financial poverty, lack of cooperation among the people and migration. Land grabbing, coaling, wood smuggling, and understory tillage aren’t the most challenging issues. From the managerial point of view, both groups have declared that the most effective way to reduce the conflict is the confinement of forests and pastures, but the participatory management issues were not acceptable according to the two groups’ viewpoints. Effective presence of experts in the field, recognizing the livelihood potentials of the region and encouraging and educating people to know alternative jobs are suitable ways to reduce the conflicts.

It seems that the plans of stopping the exploitation of natural resources are more accepted in this region. Participatory management is one of the solutions to reduce the conflict which necessity of its implementation was not acceptable according to the two groups’ viewpoints.

The poor performance of irrigation districts led to the unreliable distribution of surface water among farmers. Therefore, it is necessary to improve the water distribution in the irrigation district. For this purpose, there are two practical solutions, improve operational method and adjustment of estimation of agricultural water demand, each of which has been researched separately. In this study, for the first time, the effect of improving the adjustment of estimation of water demand was investigated by developing and combining AquaCrop model and ICSS hydrodynamic model for Roodasht irrigation district under a water shortage scenario in the status quo. For this purpose, the daily agricultural water demand was estimated for each of the secondary irrigated units based on the cultivation pattern by using the AquaCrop model. After calculating the average daily flow rate to each off-take (the output of the water distribution simulator model in the main canal) the adequacy index was calculated for two conditions, 1) with considering the amount of requirements specified by the network administrator  (available condition) and 2) adjustment of water demand. The results showed that the performance evaluation indicator improved from 3% to 16% for all off-takes by adjustment of agricultural water demand. This improvement has been achieved by reducing the amount of water right in the upstream and middle of the main canal and increasing the amount of water right for downstream. Also, the equity of water distribution has improved among water users by adjustment of agricultural water demand.

a significant portion of water is wasted during the conveyance and distribution process due to seepage and operational losses. To deal with the limitation of water resources, it is necessary to provide methods for reducing losses from canals. Therefore, the current study aimed to represent a method for estimating the minimum seepage and operational losses in earthen canals in order to improve water efficiency in agricultural water distribution systems using ant colony optimization algorithm.

In this research, the innovation and aim are to optimize seepage and operational losses in water distribution system using the ant colony optimization and the results of the algorithm are used to manage water resources, especially in agricultural water distribution systems. To achieve this goal, initially, basic information was collected from the Moghan plain canal and for the purpose of hydraulic flow simulation in the canal a simplified mathematical integrator-delay model was used. Then, in order to minimize seepage losses, a formula extracted from research history was applied. In addition, the seepage formula was calibrated and validated based on the measured seepage amount at each segment over the 23 km of the canal. Also, to optimize the purpose of this study, two single objectives, which they were minimizing seepage and water shortage delivered to each offtake in the main canal distribution process, respectively, were defined and adjusted in ant colony optimization algorithm model. Then, by linking the hydraulic simulator model, the estimation seepage formula and the Ant colony optimization model, it was possible to optimize the mentioned objective functions.

According to the results, optimizing the first objective function, in order to minimize seepage losses caused the reduction of total seepage amount during the 23 Km of selected research area, from 0.199 Cubic meter per second (seepage in the present condition of the studied canal) to 0.187 Cubic meter per second. Therefore, the reduction in seepage losses for the first objective function was 6 percent. However, the application of the first objective function has led to an increase in the amount of operational losses from 39.91%, which is the amount of current operational losses in the canal, to 45.55%. In other words, the operational losses from the first objective function compared to the current operational losses, increased by 5.64%. Accordingly, the total reduction of losses in the first objective function compared to the current losses in the canal was 0.39 percent. By applying the second objective function, the results show a reduction in operational losses from 39.91% to 27.91%, which indicates a 12% reduction in operational losses compared to the current situation of this type of losses. Also, seepage losses have increased from 0.199 cubic meter per second to 0.2168 cubic meter per second, which indicates an 8.9% increase in seepage losses compared to the current situation. Overall, the total losses reduction in the second objective function compared to the current situation is equal to 3.1 percent.

single objective functions of seepage and operational losses reduction results showed that optimization with the purpose of reducing seepage losses did not lead to a significant reduction in total losses in irrigation canals. On the other hand, in order to reduce operational losses, Ant colony optimization algorithm model by choosing optimum water depths could reduce the amount of operational losses to a considerable amount. According to the results, it can be generally acknowledged that modernization, renovation and rehabilitation projects of irrigation networks with the target of reducing losses and improving water use efficiency, if more focused on improving the operating process, more reduction of losses would result in agricultural water distribution system.

The water shortage and the recent droughts have revealed the necessity of paying attention on increasing the water productivity, more than done in the past. In this regard, using pressurized irrigation systems is recommended as alternatives for surface irrigation systems. So this study, in order to assess the system performance and water productivity in such systems, nine and ten of the existing sprinkler irrigation systems (constant classic and wheel move) were evaluated in Isfahan and Hamedan Provinces, respectively. The Potential and the actual application efficiency of the low quarter, the distribution uniformity and the Christiansen's coefficient of uniformity were determined. The Averages of PELQ, AELQ, CU and DU in Isfahan province were 61.5%, 58%, 66.8% and 75.8%, respectively and those of Hamedan province were 53.9%, 44.8%, 71.1% and 81.1%, respectively. By determining the average of water consumption and the crop yield, the averages of water productivity in Hamadan and Isfahan provinces were found 6.6kg.m-3 and 6.3kg.m-3, respectively. The averages of water consumption in the irrigated potato fields in Hamadan and Isfahan were 6745 m3/ha and 6298 m3/ha, respectively. The results of this study showed that in most of the studied fields, deficit irrigation has been happened. From the results of these assessments, it can be deduced that the main problems in the implementation of these systems are: inaccuracy of design, the mismatch of design criteria with the implementation phase, incorrect performance, insufficient users' knowledge and the lack of accordance between the amount of water used and the crop water requirement.

Despite the many studies that have been done in reservoir exploitation, due to the willingness of researchers to reduce errors in calculations, this issue is still a matter of interest and is of interest to water researchers. In this regard, the use of the capability of Fractional Algorithms Which are generally derived from nature and used in complex problems and optimization problems. In recent years, it has been highly regarded. Therefore, in the present study, the optimal allocation of water resources in the semi-Sistan reservoir reservoirs has been investigated under management scenarios using the Fuzzy Firefighting Technique. The results of the research show that the best value of the target function was 2309/66 million cubic meters. Also, in the early years, the optimal release of firefighting algorithm was obtained at 29.1376 million cubic meters, with a demand of 98.3121 million cubic meters, of which 69.1745 million cubic meters were lacking. The results of the evaluation of various management scenarios showed that if these projects were implemented, the amount of water allocated to the agricultural sector would be significantly reduced. Therefore, it is suggested that with the spread of Iran's legitimate rights from Afghanistan, it will be possible to overcome the dangers and droughts of the last few decades.

In this research, by considering the variable-speed pump, the effect of speed on pump performance, network hydraulics and energy consumption in a water distribution network in both single-objective and multi-objective models was investigated by using the new G-JPSO algorithm. The objective function in the single-objective problem is to minimize the amount of energy consumption throughout the day, and the decision variables are the amount of pump rounds in different hours of the day and night. In the multiobjective optimization problem, the first goal was to minimize the cost of consuming energy and the second goal was to maximize the hydraulic reliability. In order to determine optimal pump operation program, an optimization-simulation model based on G-JPSO optimization algorithm was developed. In this model, the algorithm was integrated into the MATLAB environment with the hydraulic part of the EPANET model as the reference of the commands and information. The proposed model was used in the Vanzyl distribution network and the optimal exploitation instructions were extracted and the results were compared with the JPSO algorithm and the ACO. The results of the paper showed that in the single-objective problem, the G-JPSO algorithm's results are 3.28 and 0.38 percent better than JPSO and ACO, respectively. In general, the energy consumption of variable-speed pumps was lowers the constant- speed pumps. In a multi-objective problem, in all optimization scenarios, the G-JPSO algorithm was able to achieve points in comparison with the ACO algorithm, which, in addition to cost reduction, has higher reliability.

Inefficient operational methods, in distribution of water within irrigation canals, call for applying more efficient ways such as using automation systems. This study assesses capabilities of the automatic operational systems, including centralized Model Predictive Control (MPC) and decentralized Proportional-Integral (PI) controller in enhancing the fairly water delivery throughout the Roodasht main irrigation canal. Existing canal’s operational condition was compared with operational status employing PI and MPC control systems. Comparison was conducted using water level error-based performance indicators of MAE and IAE, and equity indicator. Two operational scenarios including normal and severe inflow fluctuation were assigned. According to results of first scenario, upstream PI system resulting to better indicators of MAE and IAE values rather than other systems. MPC controller leading to better performance in comparison with upstream and downstream PI configurations. Application of MPC system resulted to 12% improvement in equity indicator. In the second scenario with sever inflow fluctuations at the headgate, the maximum IAE and MAE indices for MPC controller were 3.53% and 1.45%, respectively, while these indicators for decentralized systems exceeded 100%, demonstrating the inability of the decentralized systems to control the flow rate in severe water shortage conditions. Finally, calculated equity indicator in second scenario, for current operation, upstream and downstream PI and MPC, were 39.23%, 18.71%, 15.95%, and 4.33%, respectively. Results reveal that the application of centralized MPC controller has significantly improved the equity indicator by 35%.

Due to lack of available water resources and the continuous increase in the water demands, construction of new dams seems inevitable. Dams are such infrastructures for water storage and supply, especially in drought periods. If the operation of the reservoir is optimized, the purposes of dam construction is efficiently supplied. Since the optimum operation of large water resource systems are time consuming, complex and sometimes unattainable, the use of alternative methods of optimization models seems a good solution which are accurately acceptable and give near-optimum answer. Nohob Dam is one of these dams which are implementing at Khar-Rud River at the Qazvin province. The main aim of the operation of the dam is to store Khar-Rud river flows and adjust to meet water rights for agricultural lands downstream and artificial recharge of Qazvin plain. The aim of this study was to investigate the water allocation to agriculture and environmental uses and artificial recharge of aquifers in drought conditions using MODSIM model. The operation of the dam was simulated using the MODSIM model for a long period of 50-year and during the periods of 1965 to 2015, as well as a 17-year hydrological drought period during the periods of 1998 to 2015, which is determined on the basis of average changes in river discharge relative to the long-term average. Simulation was conducted monthly for four options of “before the sedimentation”, “20-year sedimentation”, “50-year sedimentation”, and “no-reservoir conditions”. Water allocation priorities are as follows: 1- environmental requirements, 2- agricultural water rights, and 3- artificial recharge. Reducing Khar-Rud water volume at the dam site from the years 1998 to 2015, has caused the loss of Nohob dam performance for various reasons, including drought and water withdraw from upstream, so that the needs of any sections is not supplied. By comparing the results of sedimentation options, it is identified that in 20-year sedimentation conditions, the reservoir has the best performance, which is due to the low dead volume compared to the useful volume of the reservoir in these conditions. By comparing reservoir performance with no-reservoir conditions with the other sedimentation options, it can be concluded that the dam construction will not have much effect on improving the water distribution conditions and the amount of supply in these conditions will not be significantly improved. In order to evaluate the simulation results of the operation of the reservoir, various parameters, such as, supply percentages, reliability, resilience and vulnerability were used. Also, the simulation results showed that in long-term simulation (50-year) and drought conditions, the dam construction would slightly change the increase in the volume and temporal water supply and demand in the region, so that the percentage of provision of the total demands of water in 20-year and 50-year sedimentation conditions are reduced from 77.4 to 37.6% and 73.7 to 35.8%, respectively, and for no-reservoir conditions, it is decreased from to 58.8 to 34.1%. By continuing the drought conditions and increasing water supply up to 1-2% as compared to the no-reservoir conditions, the dam construction and the continuation of its implementation is completely unjustified. In general, it can be concluded that in the drought conditions, the dam construction to improve the water distribution conditions is not justifiable, and perhaps its application is only to control the sudden flooding and prevent the damage caused by the flood at downstream of the dam.

Optimal operation of dam reservoirs is important due to their role in runoff control and water supply for different sectors. In this study, the Firefly Algorithm (FA) is investigated to solve the problem of optimal operation of Haraz dam reservoir to provide water for agriculture, drinking, industry and environmental of downstream for a period of 27 years (since 1984 to 2011). The objective function was defined as minimizing the sum of squared monthly relative deficiencies during operation. The efficiency of these algorithms was compared and evaluated by determination of reservoir performance indices, the value of objective function, annual deficit, monthly average deficit and release. FA method with reliability of 88.3 percent is supplied the downstream demands better than GA and SOP with reliability of 82.4 and 66.7 percent. The Vulnerability index of models is obtained 0.20, 0.23 and 0.99, respectively. The results showed the better performance of FA algorithm compared to the other two methods in solving the problem of the reservoir operation.

In this research, pressurized irrigation systems including 7 center pivot, 3 linear, and 8 solid-set with portable sprinklers systems in the provinces of Tehran, Qazvin, Alborz, and Qom were assessed using by uniformity coefficient, distribution uniformity, Potential Application Efficiency of Low Quarter, Application Efficiency of Low Quarter, and of Irrigation Adequacy indices. In order to compare the assessed systems, weighted averages of all used indexes were calculated. The results showed that the weighted average of mentioned indices are 78, 63, 69, 69 and 49 for center pivot, 75, 68, 64, 55 and 62 for Linear, and 77, 66, 60, 60 and 61% for solid-set with portable sprinkler respectively. By analyzing indices and comparison with field and pumping stations observations, it was found that the incorrect design, mismatch between design, performance and management, and incorrect operation are the main causes of low performance.

Geomembranes is a kind of geosynthetics that is used to control water losses in water storage ponds. and conveyance irrigation canals with a a fast growing rate. This lining material, in addition to the ease and speed of execution, can control water seepage losses completely. In this research, the role of execution and operation issues in control of water seepage losses in geomembrane linings was investigated. For this purpose, in 5 provinces of Alborz, Isfahan, Khouzestan, Semnan and Hamedan, 15 cases (ponds) were selected. All of these ponds were lined with HDPE geomembrane sheets with a thickness of 1.5 mm , made in Iran, with a lifetime of 8 years and ponds depth was 3 meters. Total water losses in these ponds were determined in three stages of one crop year. . Based on the results, the amount of water seepage losses from geomembrane lining is between 0.1 to 37.6 and on an average 13.9 liters/m2/day, which is about 125 times lower than the seepage losses in concrete lining. The lowest seepage losses were in Hamadan and Khuzestan provinces with 0.3 and 0.2 liters/m2/day ,respectively, and the highest value belonged to Alborz, Isfahan and Semnan provinces with 23.1, 16.2 And 29.6 liters/m2/day, respectively. Due to the uniformity of the geomembrane sheets and the geometric conditions of the ponds, the difference in the amount of seepage losses was found to be related to the quality of the execution and operation issues of geomembrane lining in the ponds. The most important issues in the ponds with high value of water seepage losses were the lack of attention to the slopes of the bed in design and execution, sediment accumulation and the need for dredging during operation, inadequate bed prepration and compaction, the presence of rocks and sharp objects under the lining, the formation of wave, the cuts due to the absence of under lining in the weld sides and the corners of the pond and human destruction during the lining.

In the present study, the state of pressurized irrigation systems in Qom province was investigated. Regarding the fact that by 2016, 81% of pressurized irrigation systems in this province are local and 19% are sprinkler, therefore, 11 local and 3 sprinkler irrigation systems (including solid-set with portable sprinklers, wheel move, and center pivot) were selected for investigation. First, the water and soil characteristics of the fields were studied then coefficient of uniformity (CU), distribution uniformity (DU), the yield of potential application efficiency of low quarter (PELQ), the yield of application efficiency of low quarter (AELQ) and adequacy of irrigation (ADirr) indexes were calculated. Obtained results showed that the mentioned indexes were 74.6, 60.8, 62.6, 62.6, 62% for solid-set with portable sprinkler, 57.6, 44.7, 76.1, 71.3, 86% for wheel move, and 81, 63, 85, 85, 71% for center pivot, respectively, and the weighted average of DU, PELQ and AELQ for local irrigation were 53.9, 45.3 and 53.9 %, respectively. Finally, the observed problems of system operation were analyzed and it was found that the main reasons of low performance were due to the management and some were due to the design and performance phases.

Considering the critical conditions that have occurred in recent decades for water resources of the country, agricultural managers are considering developing micro-irrigation systems in agricultural lands, so for their sustainable development and utilization, the evaluation of these systems is necessary. In this regard, the technical and hydraulic performance of 9 irrigation systems in Isfahan province was evaluated. In this experiment, some field measurements were taken to obtain the required parameters for system evaluation. Assessments were made based on the SCS guidelines. The results obtained from the calculation of the evaluation parameters show that amounts of coefficient of emitter discharge variation (qvar) was less than 10% for 33% of the projects, ranging from 10 to 20% for 44 percent of the projects, and over 20% for the rest of the projects, qualified as favorable, acceptable and unacceptable, respectively. The amounts of distribution uniformity (DU), in 22% of projects was more than 90%, 55% between 80 to 90% and the rest between 70 to 80%, qualified as excellent, good, and fairly good. The potential application efficiency of low quarter (PELQ) and application efficiency of low quarter (ALEQ) were between 42.4 to 78.1 % and between 47 to 81.5 percent, respectively, which is moderate. Inappropriate pressure in blocks, deficient skills of the operators, dripper clogging, and lack of proper maintenance for filters, reduce PELQ and AELQ in some projects.

Improving management of existing irrigation canals is indispensable in order to save more water. In this study, a set of four nonstructural solutions introduced in order to improve the operational performance of a main irrigation canals suffering from fluctuations of inflow water. To this end the existing operation of the Roodasht main irrigation canal was simulated applying a mathematical model and assessed by the operational performance evolution indices. Then the abovementioned solutions were investigated. The four solutions consist of operation with known disturbances; unknown disturbances; rotational water delivery out of the intakes alongside of the main canal and increasing discharge inflow. The results indicated that operational level were improved by the solutions, for example by employing the third and the forth operational solution, average value of the maximum error in water delivery was decreased by 25% and adequacy of water delivery activity was improved by18% respectively. Also, the results showed that under severe decrease of inflow to the canal, the mentioned solutions improved water delivery and distribution between upstream and downstream 17 percent.

Improving agricultural water productivity is one of the important objectives in irrigation canal networks. Accordingly, localizing and implementation of the modern operational technologies is essential. In order to deal with operation of main irrigation canal under inflow fluctuations, in the present study, the application of decentralized automatic control system, as the first step towards the canal automation is investigated. The Inflow fluctuations happen due to water scarcity in those irrigation networks located in the southern part of the watersheds. To this end, a decentralized PI Controller is designed to be applied for operation of mathematical model of the of Roodasht main irrigation canal. The deigned controller was tested by two normal and harsh unpredictable inflow fluctuation scenarios. The results of the simulation are evaluated by the operational performance evolution indices. The results indicate that the canal operational condition under the normal inflow fluctuations is reasonably controlled by the designed PI system. But in the case of harsh inflow fluctuations, the PI controller is not capable to handle the condition and the middle and downstream canal reaches are suffering from inappropriate water taking. Therefore it can be concluded that, application of the modern centralized controller would be recommended as a reliable options for operation of the main canal.

A critical groundwater (GW) shortage in the Mahvalat Plain (MP) is alarming. As GW is the sole source of freshwater in the area, the objectives of this study are to survey and asses its current status, and to set a strategy for balancing the recharge and withdrawals to achieve the sustainable management of the most precious resource. The mean annual withdrawal and recharge of 48 production wells and 3 strings of aqueducts (Qanats) during the 1665-2008 period were 254 million m3 (Mm3) and 157 Mm3, respectively. This 97 Mm3 annual deficit resulted in the mean annual decline of the water table by 1.35 m during the same period. Chemical analyses of water samples from 48 wells and 3 strings of aqueducts indicate that the electrical conductivity (EC) increased from 0.17 s/m to more than1.5 s/m form the northeastern part of the MP towards its margins. Moreover, salinity, SAR and Sodium percentage of most samples made them unsuitable for irrigation. To achieve a sustainable management of the most precious resource, i.e., water, the solutions include: Restriction of the pumping hours according to the directives of the local water authorities to decrease the mean annual of 121Mm3, Reduction of the irrigated fields by 2/3 of the current practice, Installation of sprinkler and drip irrigation systems, Practicing advanced surface irrigation methods, Amortization of the wells with an EC of more than 0.75s/m of their water by the Government and closing them completely, and installation of smart water meters on the remaining productions wells and their continuous monitoring.

According to the low efficiency of irrigation and drainage networks and water distribution in Iran، simulating water flow and sensitivity structures and networks is considered as a new approach to evaluate the performance hydroelectric projects in the country. In this study، because of reduced water supply and distribution، especially in downstream irrigation and drainage networks Varamin to evaluate the sensitivity network in off takes structures. The sensitivity of the survey data by examining Water original data and compared them with the amount of water needed to grow the network. Network simulation and analysis using hydrodynamic model Sobek presented for sensitivity and relationships off take structures is done. Studies and sensitivity analysis for hydraulic structures Varamin irrigation system showed that baffle modules sensitivity are considerable. The study of equations، the sensitivity baffle modules occurred more than the depth upstream and valve patency rate in terminal structures. For optimal operation of the irrigation system in Varamin best way to provide for downstream water depth of each channel. In these conditions، the water supply and wastewater in all modules in the patency rate does not change.