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

To Estimate Parameters and Evaluation of Cropsyst Model to Predict the Growth and Yield of Two Wheat Cultivars in Northeast Khuzestan, an field experiment was conducted in the form of randomized complete block design in a research farm in Ramhormoz with three replications. Factors were included irrigation regime at two levels (full irrigation and stop irrigation after flowering), cultivation date (six dates including: October 30, November 15, November 30, December 15, December 30, and January 15) and two varieties of wheat. (Chamran 2 and Sirvan). Based on the results, the critical day length, the ceiling day length, the number of basic vernalization days, the minimum growth rate in the absence of vernalization, and the saturation point of vernalization for Chamran 2 variety are equal to 14, 8, zero, and 0.9, respectively. and 24, and for the number of Sirvan, it was 13.8, 7.8, zero, 0.93 and 25, respectively. The results obtained from the simulation of flowering and physiological ripening stages based on RMSE, d, CRM and EF statistics showed that the Cropsyst model simulated the mentioned stages with good accuracy for different figures. The simulation results of dry matter of aerial organs for different figures showed that this model was able to simulate 95 to 98 percent of this parameter in different treatments of planting date and irrigation. The error value of the model based on the RMSE statistic for the dry matter of aerial organs in Chamran 2 and Sirvan cultivars was 627 and 351 kg per hectare, respectively.

Machine learning is a new artificial intelligence method that seeks to write a program with the best performance by using learning experience. Machine learning models with different algorithms can be predictive or descriptive or have both properties and be used in different fields. On the other hand, for better management of flood risk reduction, it is necessary to know the effective factors in each region and flood sensitivity analysis. Since so far, few researchers have analyzed the threshold of influence of variables affecting the occurrence of floods using machine learning methods, the current research is new in this respect. Based on this, the current research has been conducted to identify the threshold of variables affecting the zoning of flooded areas using machine learning and remote sensing data in the Karun Basin area. The results can be put on the agenda of the relevant managers in identifying the influence limits of different variables on the occurrence of floods and the management of flood-sensitive areas by relying on the effective limits of the variables in the study area.

Landsat OLI 8 images on April 8, 2019 were used to identify flooded areas. In this regard, to identify groundwater, the corresponding image of the previous year of the region was used to separate and identify groundwater zones. Then, the remaining pixels of the study area as whole samples and flooded areas were entered into the modelling process as target samples. Therefore, flooded areas with a code of one and other areas with a code of zero entered the modelling process as dependent variables. Also, the variables that were entered as independent variables in the machine learning process include actual evaporation and transpiration, land use, soil density mass, soil clay percentage, soil water deficit, DEM, NDVI, land cover index, Palmer drought severity index, potential evaporation and transpiration, precipitation. cumulative, soil sand percentage, soil texture, soil moisture, minimum and maximum temperature. Next, by entering these variables and performing the machine learning process, the models were evaluated and TreeNet was selected as the best model. Then the threshold of each of the studied components on flood zones was obtained from machine learning. Also, in the present study, learning and test data were used in a ratio of 70% to 30% and completely randomly. It is worth noting that the number of 200 trees with at least six nodes was set for modelling.

Different components have certain thresholds at the beginning of land flooding so regarding vegetation as the most important effective factor in flood zoning, it shows that the lack of vegetation causes flooding, and the higher the level of vegetation, the more it prevents flooding. Also, the cumulative precipitation threshold for flooding the studied area was 15 mm of rainfall, and less than that, the incoming rainfall did not pose a risk of flooding the studied lands. The amount of 15.5 mm of rainfall was the turning point and the threshold of the beginning of the flooding in the study area. Regarding the soil moisture deficiency index, it shows that the threshold of flooding based on this index was 144, in other words when the soil moisture profile is more than the mentioned value, the incoming precipitation must compensate for the soil moisture deficiency, and as a result, floods will be prevented. On the other hand, most flooding conditions have existed at a height of 16 m, and as the height increases, the risk of flooding the studied area decreases, so that there is a failure at a height of 19 m, and when the height reaches 22.5 m, the risk Flooding disappears, and at a height higher than 26 m, flooding is restrained and will reach a steady state. The reason for this can be the plainness of the studied area and the widening of the flood zone in the plain.

The results showed that the components of the vegetation cover index, cumulative precipitation, soil water deficit, Palmer drought index, height, and surface soil moisture respectively had the greatest effect on the flooding of the studied area. Also, in the studied area, the effect of soil sand percentage, soil clay percentage, soil density, potential evaporation and transpiration, slope direction, maximum daily temperature, and soil texture on flood zoning was insignificant. The evaluation of the efficiency of the model with the indicators of ROC, specificity, sensitivity, and overall accuracy is 0.95, 91.2, 90.43, and 91.12, respectively, which indicates accuracy. The results of flood zoning with the ground reality indicated R2 and MAE equal to 72.8% and 0.27%, which confirms the accuracy of the zoning results with the ground reality relatively well. The analysis of the results shows that there will be an increased risk of flooding in the wetland and swamp areas due to the high humidity and water level. The results of the present research can be used by planners and managers of natural hazards to reduce floods.

It is necessary to evaluate irrigation systems in order to determine their optimal performance, modify and manage them. In this research, five drip irrigation systems in Salas Babajani city located in Kermanshah province were selected and evaluated based on the instructions of the American Soil Conservation Service (SCS) and Merriam and Keller methods. The results of investigations showed that the wetted area ranged between 14.89 and 33.49 percent of the total area. The minimum and maximum values of water distribution uniformity in the investigated systems (EUs) were determined as 29.49 and 62.56 percent, respectively. The values of lower quartile application potential efficiency (PELQs) and lower quartile application efficiency (AELQs) of the systems fluctuated between 26.83 to 53.3 and 29.48 to 62.56 percent, respectively, which indicate the poor performance of the systems in all fields. According to Langiller Saturation Index (LSI) values obtained from water sources in the fields under study, in two fields, there was a tendency for calcium carbonate precipitation, but in other fields, there was no risk of precipitation. In general, the poor performance of the systems were due to various reasons, such as: not installing a central control station or a suitable filtration system, insufficient wetted area, inappropriate type and number of droppers, clogging of the droppers, pressure difference in the systems, inappropriate pressure and its uneven distribution, inappropriate distance and duration of irrigation and finally the poor management of exploitation.

As a result of droughts and human interventions, the Urmia Lake basin has faced increasing unallowable withdrawal of water resources and environmental requirements share. Over the past two decades, a series of natural and human factors have gradually changed the water balance of Lake Urmia. In addition, decreases in precipitation have been the main reason for the gap between water resources and increasing water consumption in the basin, especially in the agricultural sector. In order to deal with the Urmia Lake catastrophe, a working group was formed for the Urmia Lake restoration. The working group planned and proposed solutions to reach the ecological level of the lake in three stages within 10 years through in-basin water supply and inter-basin water transfer programs. The present research, while investigating the solutions for providing the environmental water requirement of Lake Urmia using the Analytic Hierarchy Process (AHP) method, changes in the water volume of Lake Urmia in the scenarios of water transfer from the surface flow of each entering river in the lake in the years of high intensity severe to mild drought, the implementation of the approvals of the national working group to restore Urmia Lake, including a 40% reduction in agricultural consumption from the sources of dams and other rivers without dams, releasing water from dams in non-agricultural seasons, transferring water from urban wastewater and finally transferring water between the Zab basin has quantitatively been evaluated using the MODSIM simulation model. This research will help to predict the amount of transferable water in drought, normal, and drought conditions and to plan the water accounting of the Urmia catchment. 

The watershed of Lake Urmia, located in the northwest of Iran, with an area of 51,876 square kilometers, is one of the six main watersheds of the country, which is located between the provinces of West Azerbaijan, East Azerbaijan, and Kurdistan. In terms of its territorial location, the catchment area of the Zab Kochak river is in the western part of the international border with Iraq and in the catchment area of the Western Border River basin. A significant part of the Zab watershed (source of water transfer) is located outside the country and in Iraq. The route of water transfer between the basins of the Zab basin is from the place of two dams, Silweh and Kaniseeb, which after entering the Godarchai river will eventually enter the Urmia lake water body. The different solutions from the working group’s approval have been selected for developing six scenarios. Then, the Scenarios have been evaluated by the MODSIM model and AHP analysis method. The scenarios are including reducing agricultural expenses from dams in operation, saving by reducing agricultural expenses from other rivers, transferring water between basins, transferring effluent to Lake Urmia, releasing water from dams in operation to Lake Urmia. A hierarchical structure was developed with the aim of evaluating solutions to save Lake Urmia through internal sources and transfer water sources. In this structure, there are four criteria of climate, consumption, economic-social, and environmental status. Sub-criteria of drought, surface water extraction from rivers, extraction from dam sources, extraction from groundwater resources, development of agricultural lands, and ensuring the sustainability of river flow. and providing solutions for inter-basin water transfer, a 40% reduction of agricultural water consumption from surface water sources of rivers and dams, wastewater transfer, and a 40% reduction of agricultural water consumption from underground water sources in Expert Choice software, were analyzed. 

In order to evaluate the effectiveness of the defined scenarios, the simulation model was implemented for future conditions during the next 10 or 15 water years for different scenarios. The results show that the implementation of scenarios 4 and 6, will bring the largest increase in the volume of lake water, of course, with the occurrence of precipitation and proper input. Regarding the results of scenario 1 and the sameness of its results in two periods of 10 and 15 years, it can be stated because in the definition of the scenario, it is a dry year and the amount of evaporation of the lake water is more than the amount of input into the lake. There has been no increase in the lake's water volume for several consecutive years. Also, the results show that in wet and dry years, if the maximum transfer flow scenario is implemented, we will not have a flow from the Zab river to the downstream side, and it will not be accepted from the hydrodiplomacy point of view for the neighboring country in terms of influencing the use of the Dukan dam. Therefore, water diplomacy solutions are needed to reduce environmental threats. Therefore, the issue of transferring water from the Zab basin to Lake Urmia cannot be considered guaranteed in the long term due to the impossibility of reducing the outflow of water from the country to zero. 

In conclusion, in order to evaluate all scenarios to satisfy the environmental needs of Lake Urmia shows that the protection of the lake requires correcting the mistakes of the path traveled in the current and past years, and preferably with a 40% reduction in agricultural consumption from dams and other rivers, groundwater in the basin is the main supplier of Urmia Lake. Inter-basin water transfer is the next priority because the source catchment is able to transfer water in the face of droughts due to the reduction of runoff and related challenges as well as its negative economic and social effects. It will not be as much as predicted and included in the program (600 million cubic meters per year). In addition to that, water diplomacy is necessary in terms of impacting downstream transboundary uses and reducing environmental threats. The results of this research and the high costs of water supply requirements, in parallel with the investigation of controversial options and costs of inter-basin water transfer projects, macro-management of water resources towards demand and consumption management and water saving programs and the modification of water consumption patterns and the legality of the behavior of water users from within the catchment area of Lake Urmia should be low-cost, sustainable and reliable solutions.

protection of water and soil is the fundamental work for development natural resources in any country. Lake of available data of soil erosion is a limitation for land managers to apply soil and water conservation in the watershed scale. Over the past decades several erosion models have been invented under different environmental conditions, but, very limited numbers can be used under watershed scale that are enable to considering soil conservation measures. Among the existing methods, WEPP model, has been known as a process oriented model that can be used in different spatial scale namely: hillslope, watershed and large basin. The WEPP model requires a large amount of input data and the model efficiency is highly related into the input data. The main aim of the present investigation was the assessment of WEPP model and spatial extension of the GeoWEPP for estimating of soil erosion and sediment yield in the paired watershed.

The study area is located into the Taleghan watershed and the pair catchments of Zaidasht with area of 198.4 ha. All environmental data including: soil attributes, vegetation, climate data were extracted by field and laboratory data analysis for the five erosion plots and whole of the watershed. Model calibration was conducted based on the both infiltration and erodibility parameter through Nash- Sttcliff and R2 as well as RMSE coefficients.

After optimizing the base value of hydraulic conductivity to about 50% for runoff, the efficiency of the model using the Nash-Sutcliffe coefficient was 0.64, which means that the estimated runoff of each plot is close to the observed values. For the amount of sediment, using the basic values of the model relationships, the model did not provide the right result and the best results were obtained with an increase of 100% for rill erodibility and 150% for interrill erosion, and a decrease of 9% for shear stress and 12% for conductivity. has obtained hydraulics and the efficiency of the model using the Nash-Sutcliffe coefficient was 0.51%, the estimated values are close to the observed values of the plots. Also The results showed that in 2016 , the sediment on the submontane level was 0.2 and 0.1 ton/ha/yr for the control and the sample, respectively and In the watershed, 1.1 and 0.3 ton/ha/yr were obtained for control and sample, respectively.Therefore, the WEEP model in the study area will be effective when the parameters of erodibility and hydraulic conductivity are measured with high accuracy. On the other hand, the results of GeoWEPP were obtained in the control and sample basins, respectively, 3.3 and 2.5 ton/ha/yr.

Based on the field observations and forms of erosion, GeoWEPP spatial extension was able to present a realistic picture of the erosion situation at the basin level Considering that this extension can remove the limitation of the model implementation in terms of area, therefore it is recommended to estimate the sediment in the scale of the watershed and in a distributed manner.

Water quality indicators are a standard for classifying surface water based on the use of standard parameters and is a mathematical tool that converts a large amount of data used to describe water properties into a number and obtains a water quality level. The aim of this study was to assess and compare the sensitivity of NSFWQI and IRWQISC water quality indicators to quality parameters using variance-based methods on Haraz River with monthly sampling in 2022 in 7 selected stations in the range of Panjab to Haraz reservoir Dam in the province Mazandaran. The results of the present study have shown that the water quality in S1 (upstream) and S2-1 stations are relatively good at best, and bad at worst. Water quality in stations of S2, S3, S4, S5-1 and S5 (downstream), in the best case is moderate and in the worst case in September have poor quality. SRC method was used to analyze the uncertainty and sensitivity of the NSFWQI index and FAST and SOBOL methodologies were used for the IRWQISC index. The results of sensitivity analysis based on Factor Prioritization approach showed that in NSFWQI index, DO, BOD, CF, T and P parameters respectively and in IRWQISC index after DO parameter, BOD, P and N parameters had the most impact on output. In the uncertainty analysis, the results of applying SOBOL methodology for different stations of Haraz River were consistent with FAST method, but the results of sensitivity analysis obtained from these two methods were different from each other. Considering the obtained results and despite the similarity of the results of the two methods, it can be said that SOBOL methodology has been more successful than FAST methodology in this study due to unconditional convergence.

Due to the importance of determining the behavior of plants in water shortage conditions, it is necessary to determine the coefficients of plant sensitivity to water at different stages of plant growth. Water shortage in the Sistan plain is a serious and important issue, so that the lack of water supply to the Helmand border river, which is the only source of water supply in the region, leads to the destruction of agriculture. The low possibility of increasing new water resources and the need to increase agricultural production from limited water resources in this region requires the use of appropriate scientific and technical methods to increase the productivity of agricultural water consumption. Also, changing the pattern of cultivation and replacement of high-income crops in recent years in arid areas has received much attention from farmers. The purpose of this study is to investigate the effects of water stress on the behavior of garlic in dehydrated conditions to calibrate the production function of this plant to obtain yield response coefficients in conditions of water shortage.

In this study, garlic plant was implemented in the form of a randomized complete block design with three replications in 1398 and 1399 in Sistan and Baluchistan province. Treatments were applied based on stress levels compared to control 30, 35, 40, 45, 50, 60 and 70% of water requirement. This station is located 20 km southeast of Zabol city at latitude 61 degrees and 41 minutes and latitude 30 degrees and 54 minutes in Sistan region. The altitude of the station is 483 meters above sea level, the average annual rainfall is 55 mm and the annual evaporation rate is 4500 to 5000 mm. This region has a very dry climate with very hot summers and mild winters. The area of ​​the experimental plot was equal to 750 square meters was selected for planting garlic of Chinese cultivar before planting the bed was reinforced with animal manure and after growing based on soil fertilizer test, 300 kg of potassium phosphate, 200 kg of triple phosphate and 100 kg. One kilogram of urea was added to the soil. Then plow and disc and finally leveled. On the 24th of October, grooves were planted with a shovel at a distance of 20 cm and a depth of 5 cm to plant garlic of Chinese cultivar, and garlic tubers were planted at a distance of 8 cm on the rows. Then, based on the obtained information, the two functions of Tafteh and Raes production were investigated and yield response factors were determined during the growing period.

Comparing the two methods used the highest yield of garlic in the study was 8240 kg / ha, for the production of which 833 mm of water was used. The data of the first year were used to calibrate the yield response factors of garlic and after calibrating the two production functions of Raes and Tafteh, the values ​​of the yield response factors of garlic were presented. This coefficient was different in the range of 0.5 to 1.2 in different periods of garlic plant growth, the change curve was presented. Evaluation of Rice method in the second year with root mean square error of 1302 kg / ha and normalized value was about 23%.

In the method of Tafteh the mean root mean square error was 485 kg / ha and the normalized value was about 11%. Therefore, the method of Tafteh is recommended in determining the yield of garlic under water stress conditions.

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.

Social conflicts around the water axis, salinization of water resources, declining groundwater levels, etc. indicate the existence of major shortcomings in the country's water management system. Some of these consequences are due to natural factors such as drought, climate change, etc. Another part is affected by water governance policies. Governance and management are similar in general, but in fact management in the form of executive and governance activities is the existing structural framework for the implementation of those activities. Water governance is a range of political, social, economic, and administrative systems that exist for the development and management of water resources and the provision of water services at various levels of society and is a direct mechanism for people's livelihood. Another reason for the importance of governance is the relationship with some macro indicators of society. The indicators of good governance vary according to the circumstances of each society. In the process of evaluating good governance, any kind of judgment and evaluation should be based on certain criteria and indicators. Localization of indicators in any society will accelerate the achievement of stability in the desired area. In this article, with the aim of being aware of the global knowledge in order to implement good water governance in the country, the various stages of changes in world water management were examined and its effects on domestic water policy and management were pointed out. Then, a comparative study of local water resources management and indigenous knowledge with indicators and principles of good governance was conducted. Finally, by explaining the context and structure of the principles of governance in the country, it became clear that good governance will be possible through accountability, the right to comment, and social justice, which are of great importance.

Groundwater in arid regions such as Iran plays a very large role in drinking water supply and agriculture. One of the threats to the future of groundwater exploitation, could be the contamination of these resources by harmful substances. At present, about 60% of the water consumption of Varamin plain region and the total volume of water consumption in the drinking sector is provided from groundwater sources. One of the best ways to prevent groundwater pollution is to identify vulnerable aquifer areas. The SINTACS model has been used to assess the vulnerability of the Varamin plain aquifer. This method consists of seven parameters that after combining the parameters, the vulnerability index map is obtained. The index of this method varies between 92 and 168.Results show that the north of the plain is very vulnerable and vulnerability is low in the south-eastern parts of Jalilabad village and downstream areas of the plain, while the rest of the plain has moderate vulnerability. A three-dimensional numerical model was used to evaluate the results of the model and the model was validated for a period of one year. The accuracy of the constructed model was evaluated as appropriate. In this model, nitrate contaminant was considered as an aquifer contaminant. In order to validate the inherent and special vulnerability of the SINTACS model, the nitrate output of the model was used, The correlation square of the results was about 65%, which shows a good agreement between the two models even thogh the numerical model is considered as micro- model compared to SINTACS one. Considering the role of the aquifer of Varamin plain in supplying the required water of the region, the quantitative and qualitative protection of this aquifer is a necessary and strongly recommonded. Also, in order to reduce the nitrate ion concentration in the study area, long-term solutions such as improving the agricultural structure and cultivation pattern of the area and constructing a collection network and wastewater treatment plant are proposed.

Vegetation is an important factor affecting runoff, quantity and quality of water in a watershed. This study investigates the effects of vegetation reduction in the eastern watershed of Lake Urmia on two parameters of runoff and the potential for water pollution .The WWPSS model was used to simultaneously assess the three parameters. Vegetation shows a fraction of the types of grass, tree and land without vegetation that were obtained from MODIS VCF satellite images. Runoff was calculated as accumulated water budget downstream. This model also provides an indicator to determine the potential level of water pollution. The results showed that rangeland cover decreased by an average of about 32%. Also, the average runoff production increased by 2.6, 3.16, 2.9 and 3.25 percent, respectively, in the existing conditions in 4 sub-basins of Aji Chai, Qaleh Chai, Marduq Chai and Sufi Chai compared to the situation before the reduction of vegetation coverage. According to the results, the difference in water pollution potential between the baseline and existing conditions in different parts of the watershed has fluctuated in the range between -9 to15% and an average of 0.6%. This change has increased the pollution load in some places and decreased it in others; but in general, it has led to incremental changes in water pollution potential with an average of about 2.5% in the total watershed. The method used can be used to quantify and map ecosystem water changes and its application in environmental assessment and management.

With the increase of population and pressure on water and soil resources, the important of agriculture and influential parameters in this field have increased more than before. One of these parameters is the evapotranspiration of the reference plant for irrigation planning, which is accurate estimation of that can play an important role in increasing water productivity. There are different methods for estimating the evapotranspiration of the reference plant that in this study, experimental methods in three general categories based on temperature, radiation and mass transfer and five different models of Valiantzas method by comparison with the FAO-Penman-Mantith method as reference method have evaluated. For this purpose, meteorological data of 10 synoptic stations of Mazandaran province in a 15-year period (2004-2018) were used. The results showed that between experimental methods based on temperature, Hargreaves-Samani method in six stations, Trajkovic method in two stations and Blaney-Kridel method in one station perform the best performance. Among the experimental methods based on radiation, Jensen-Hayes method in seven stations and Abtiv method in three stations have the best performance. The results indicated under-estimate for the estimation of the reference plant evapotranspiration by all three experimental methods based on mass transfer compared to the FAO-Penman-Monteith reference method. In all of the 10 stations investigated, the Trabert method was more accurate than the WMO and Maheringer methods and was closer to the FAO-Penman-Monteith reference method. All 5 different models of the Valiantzas method have under-estimates compared to the FAO-Penman-Monteith reference method. Valiantzas 4 model in six stations, Valiantzas 5 and 2 models each in two stations provided the best performance.

The durability of concrete is defined as its ability to resist weathering action, chemical attack, abrasion, or any other deterioration process to retain its original form, quality, and serviceability when exposed to harsh environment. To a large extent, it is commonly accepted that concrete durability is governed by concrete’s resistance to penetration of aggressive media. This media may be present in a liquid or gaseous state and that may be transported by various mechanisms such as permeation, diffusion, absorption, capillary suction, and combinations of the items just mentioned (Azarsa and Gupta, 2017).Over the last few decades, a great deal of attention has been paid to research and development of electrical resistivity measurement techniques as a nondestructive technique (NDT) to evaluate the durability of concrete structures. Irrigation canals are water structures that transport water supplied from supply sources, such as diversion dams, to the point of consumption for drinking or agricultural purposes. To prevent water seepage losses, the canals beds are lined with various materials such as concrete, stone and sandstone mortar, asphalt, etc. The use of concrete lining in irrigation canals has been more common in Iran and other countries than other materials. Concrete used in irrigation canals is non-reinforced with a thickness of 5 to 10 cm. The basic requirements for good concrete-lined in hardened state are satisfactory compressive strength and sufficient durability. After the implementation of any construction structure, in order to know the desired performance and quality of implementation, it is necessary to evaluate that project. To prevent water seepage in irrigation canals, most of them are lined with concrete materials. Destructive method of core sampling is often used to evaluate the quality of concrete lining in irrigation canals. This is a very costly and time consuming process and requires a great deal of specialized manpower and equipment, while the effects of core damage are not easily remedied. To evaluate executed concrete projects, they are often used using destructive methods and various laboratories are run on them in the laboratory. Although this method achieves relatively real and direct results from the desired parameters, it also has side effects that are sometimes difficult to compensate for. These include project damage, high costs, the need for extensive equipment and equipment, and time consuming, which can sometimes lead to downtime. To prevent these complications, non-destructive testing methods, which are much simpler, faster, and less expensive, can be used if there is evidence of correlation. These include electrical resistance testing, ultrasonic and Schmidt hammers. Today, non-destructive concrete experiments have a good and practical effect on the repair of concrete structures. Non-destructive concrete experiments, by providing various data on existing structures, allow experts and specialists to judge and decide on the performance, needs and methods of repair and reconstruction of concrete structures.

The criterion for evaluating the quality of concrete cover of irrigation canals in different environmental conditions, in practice, is the same as in non-water structures and concrete cover of irrigation canals in the country, the basis of which is the amount of compressive strength and technical criteria, respectively. It is published in 108 (Anon., 2014). In this publication, durable concrete is introduced as concrete that has a relatively high compressive strength and is executed correctly. In this study, in order to establish a relationship between non-destructive electrical resistance tests on site with the parameters of water absorption and compressive strength, which requires destructive testing for their achievement, 13 section from 7 main canals in different study basins were selected in Hamedan province. The electrical resistivity of concrete lining these sections was carried out by using of 4-point Wenner method. The Wenner probe technique was first introduced for the geologist’s field in order to determine soil strata by Wenner at the National Bureau of Standards in the 1910s and then modified through time for concrete application. In this technique, four equally spaced linear electrodes are used to measure the surface electrical resistivity of concrete (Figures 1 and 2). The two exterior electrodes apply an AC current to the concrete surface while the electrical potential is measured from the interior probes. It should be noted that DC current is not desirable as it may result in inaccurate readings because of polarization effect. About 12 cores from each canal and totally 156 cores were prepared. In the laboratory, the compressive strength, initial, boiling and capillary water absorption was measured and the relationships between the non-destructive electrical resistivity tests with each of the parameters of laboratory experiments on the cores were investigated.

Based on the results, it was found that only 3 of the concrete-lined canals were durable in the cold region and the remainder lacked durability. According to the results of the electrical resistivity values with the compressive strength, the correlation direct correlation of 87% is established, so that due to the non-destructive nature of the electrical resistivity test, it can be used to determine other durability and resistance parameters. The results also indicate that the other parameters of durability of the concrete lining in the studied irrigation canals include initial, boiled and capillary water absorption with a correlation coefficient of 87%, 89% and 85%, respectively, and an indirect exponential relationship with electrical resistance values.

Based on results of this paper, without destructive testing, all of these parameters can be estimated accurately by non-destructive 4-point electrical resistance testing and projects can be evaluated.

Surface Solar Radiation (SSR) as the largest source of land-surface energy is an important parameter in meteorological and climatological studies. Limitations in ground-based measurements have encouraged the users to approach low cost and reliable methods to estimate radiation components, for the regions where the ground-based radiation data are sparse. Different methods have been developed for estimating SSR including empirical models, radiative transfer models, semi-empirical models, and models based on satellite and reanalysis products. In most studies in Iran, empirical methods have been investigated. Despite the simplicity of these models, they do not accurately represent SSR variations because of not considering all the parameters affecting radiation variations, at large spatial scales with different climates. The Global Land Data Assimilation System (GLDAS) is a combination of measured and satellite data that uses advanced land surface modeling and data assimilation methods. One of the strengths of this model that makes GLDAS unique is that it has global coverage, high spatial-temporal resolution and is available for free. GLDAS is a terrestrial modeling system uncoupled to the atmosphere. This work was aimed to evaluate SSR derived from GLDAS using ground measurements over Iran from 2012 to 2015 on a daily basis.

In this study, measured SSR in 24 radiometer stations of Iran from 2012 to 2015 was extracted. Since the measured data are associated with some errors, the quality of the data must be checked and screened before use. In this study, Moradi's proposed method was used to control data quality. The studied areas were classified into three zones of coastal, arid and semi-arid climates based on Digital Elevation Model (DEM) and UNESCO climate classification approach. The GLDAS SSR outputs were extracted with a spatial and temporal resolution of 0.25° grid cell and 3-hourly from 2012 to 2015. The GLDAS is one of the LDAS projects and has been extended jointly by the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) and the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP). The purpose of GLDAS is to produce high quality temporal and spatial land surface data. GLDAS drives three land surface models: Mosaic, Noah, and CLM. GLDAS assessments SSR at the land surface using a method and cloud and snow products from the Air Force Weather Agency's (AFWA) Agricultural Meteorology modeling system (AGRMET). Since the GLDAS data are created using the gridded Binary format, the nearest neighborhood interpolation method was used to match these data with ground-based data and GLDAS datasets were generated for station points using CDO software. In this study, GLDAS datasets were compared against measured SSR datasets by four validation metrics. The metrics used are determination coefficient (R2), the mean bias error (MBD), the mean absolute error (MABD), relative mean absolute error (RMABD) and root mean squared error (RMSE).

Statistical analysis showed that the performance of GLDAS in SSR evaluation is reasonable in Iran with a high-efficiency coefficient of 0.88. Also, it was shown that the GLDAS has a higher ability to estimate SSR under clear sky (warm seasons) conditions than cloudy conditions (cold seasons). Similar to the obtained results, Träger-Chatterjee et al. (2010); Jia et al. (2013); Boilley and Wild (2015) and Heidary Beni and Yazdanpanah (2017) also showed that the ERA- Interim, NCEP-DOE, RegCM4 and angstrom model are also more capable of estimating SSR in warm seasons. Seasonal bias variations at three studied areas showed that the most changes occurred in summer and least changes in winter. The highest overestimation was also observed in the coastal areas in summer and the lowest overestimation in the semi-arid regions in spring. The evaluation of the GLDAS performance against the site measured SSR data suggests that the GLDAS tends to underestimate in 71% of the studied stations. Moreover, the stations located in the arid region provided a better estimation of SSR as compared with semi-arid and coastal locations. These results were compared with those of Boilley and Wald (2015) that showed ERA-Interim and MERRA reanalysis models have high uncertainty in areas with tropical humid climates, and in regions with arid climates, models perform better in SSR estimation. Our findings were also in good agreement with their results.

GLDAS SSR outputs can be used for agricultural studies. This is due to the facts that arid and semi-arid climates are dominant in Iran and the growing season is mostly in the warm season.

Evaluation of watershed operation performance is always done by comparing watershed responses before and after operations. This process causes the effect of the operation to spread over time and not to see its true effect and consequently, the weakness of that series of operations will remain unknown over time. Therefore, considering the importance of check dams in watershed management programs in Iran, the goal of this study is determination of real-time impact or life span of check dams in controlling discharge and sediment load and evaluating of their impacts in Kand’s watershed in Tehran province. .

At the first, life span of check dams has obtained based on Double-Mass curve, and field surveys . Then, the study period (1999-2015) is divided into three periods: before the construction of the check dams (first period), the life span of the check dams (second period) and the end of the life span of the check dams (third period) and the discharge and sediment load changes at the outlet of watershed are investigated and compared with the common approach. Sedimentation rate curve methods were also used to estimate the sediment load in each period.

The time points of occurrence of slope fractures in double mass curves as well as field observations indicate that the duration of impact (life span) of check dams in the Kond’s watershed was on average four years (from 1999 to early 2003). The results of the evaluation of the impacts of the check dams in the case study indicate that despite the constant precipitation conditions, the outflow discharge and the maximum, minimum and average characteristic discharges in the second period, compared to the first period, has decreased by 43, 49.66, 53.28 and 100, respectively. The amount of sediment load reduction in the second period is much more noticeable than the first period and is 92.47%. However, at the end of the life span of check dams (third period), the amount of discharge and sediment load has increased, returning to the level of the first. Comparison of the results of this evaluation approach (determine the life span) with the common approach (before and after project implementation) also shows that in the common approach, due to the distribution of the effects of operations over time, the performance of check dams will be measured at half their actual performance.

The results of this study show that considering the life span in the evaluation process will provide more realistic results. Actually the efficiency of check dams in Kond’s watershed is considerable during their life span, but their shorter life span is a significant weakness of this type of watershed operation. Actually relying on check dams to stabilize watersheds has not been a successful solution and only prevent to exit sediment production from the watershed and, for this reason, in the third period, the watershed response has returned to the pre-operation conditions (temporary effect). Therefore, the benefits of watershed management operations in the Kond’s watershed were off-site impacts and the on-site impacts were limited to reducing the slope of the main stream.In fact, in order to increase the life span of check dams, watershed management operations with on-site impacts should be prioritized, which this in itself requires erosion control at the source, ie the slopes

Uniformity of water distribution is one of the most important factors in the evaluation of irrigation systems. The aim of this study was to investigate the uniformity of distribution (CU) and distribution uniformity coefficient (DU) in center pivot irrigation system with different distances of cans in radial direction and to obtain the relationship between these two coefficients. In this regard, three scenarios in the layout arrangement of cans were considered for evaluating the center pivot irrigation system in the Qazvin Megsal Cultivation-Industry. In the first scenario, the distance of 60 cans in a radial direction of 5 meters, in the second scenario, the area under irrigation of the system was divided into 60 equal concentric circles, and the location of each can placed middle of distance of circles, and in the third scenario, 15 cans were spaced 10 meters, 20 second cans The distance of 5 meters and 25 cans was spaced 2 meters in a radial direction. In the first case, all sprinklers were healthy and in the second case, 30 sprinklers was blocked to examine the effect of cans arrangement on CU and DU coefficients. The results showed that in the first case, the CU and DU coefficients for the first scenario were 84.4 and 79 for the second scenario, 83.9 and 74.8 and for the third scenario it was 80.9 and 73.5, respectively, and in the second case The CU and DU coefficients for the first scenario were 75.1 and 65.3, respectively, for the second scenario, 77.8 and 64.8, respectively, for the second scenario 82.8 and 73.7, respectively. It is not possible to use the formulas of the classical sprinkler irrigation method because the cans are weighed. In this study, using the measurements of CU and DU in the center pivot system and as well as the findings of other researchers, a linear regression relationship with a coefficient of 0.89 between CU and DU in irrigation was obtained. . Using this relationship, we can reduce the volume of Du calculations in irrigation.

Approximately 94% of the total renewable sources of water is allocated to agricultural. Total irrigation efficiency in this section is estimated to of less than 43%. By using of new Irrigation methods, water consume efficiency can be increased. Correct selection of irrigation system is an important section in optimal operation of water resources. The necessity to pay attention to the characteristics and limitations of irrigation systems, the physical and chemical properties of water and soil, the environmental, economical and social Consequences, cause the selection of irrigation system become a relatively complex problem. One of the pressurized irrigation methods is semi-portable sprinkler irrigation systems. These systems have not been evaluated in some areas of Markazi province. Also, in some areas such as Arak plain that had been previously evaluated, due to the long time span and also increasing of area under cultivation, re-examination is needed. So, the performance of 10 semi-portable sprinkler irrigation systems was investigated in Arak, Shazand, Khondab and Kamijan areas.

This research includes collecting basal information, field measurements and software calculations. To determine the wind speed and direction during the test, anemometer was used. To determine the soil moisture, chemical and physical properties, samples was taken and sent to laboratory before experiment. All field testing were carried out during irrigation and also windless or low wind speed days. In each test, hydraulic variables of system, such as pressure of sprinklers, were measured at the time of performance. a pressure gauge was installed on next raiser and pressure was measured instantaneously to Increase Accuracy. The flow rate of the sprinklers was also measured by volumetric method using two hoses, a 20 Liter gallon and a chronometer. For more Accuracy, the flow rate of each sprinkler was determined from the catalog data of each sprinkler. It has been attempted to select the location of the sprinklers in points where pressure is moderate. The water collecting cans, all 15 cm in height and 15 cm in width, were placed in a 3 * 3 meter mesh. Then after an hour of operation, system was shut down and the water inside cans was measured using a calibrated measuring cylinder and was written in a form. After field operations and collecting of required data, computational operations were performed to determine the technical evaluation parameters of the system. The evaluation parameters in this study include Coefficient of Uniformity (CU), Distribution Uniformity (DU), Application Efficiency of Low Quarter (AELQ) and Potential Efficiency of Low Quarter (PELQ), that calculated for both testing block and Total system.

The results of evaluation in 10 systems indicate that due to inappropriate design and implementation, all of the evaluation parameters are less than allowed range (81% ≥ 81% CU and 81% ≥ 67%), but also Mismanagement is effective. In all of these systems, due to lack of precipitation and depletion of groundwater surface, farmers use deficit- irrigation, which Equality of application and Potential efficiency prove this. On the other hand, exception of KF system, in all systems, the number of simultaneous sprinklers in operation is increasing compared to those in the approved design, which is one of mismanagement that leads to decrease of pressure and Spray radius can't be estimated that caused in lack of distribution uniformity and resulting in inadequate irrigation in some areas and deep penetration losses in other areas. Increasing the number of simultaneous water sprayer in operation is a significant Objection. The actual efficiency of 37.9% in KHH2 to 63.8% in the KHN system was calculated. Changes in pressure varied from 13% in the KHH2 to 43% in the KM system. The average discharge varied from 1.7 L/s in KHF to 2.88 L/s in KF system and spray losses were estimated from 5.5% in the KHN to 32% in the KHF system. Distribution uniformity in the test block varied from 47% in the KF to 71% in KHN and Coefficient of Uniformity varied from 58% in KHH1 to 83% in AG system. Distribution Uniformity in all system varied from 44/3% in KF to 68/5% in SHJ system. The Potential Efficiency of Low Quarter of the test block varied from 39.5% in KHH2 to 67.3% in the KHN system and in whole system varied from 37.9% in the KHH2 to 63.8% in KHN system. The Application Efficiency of Low Quarter of the test block varied from 39.5% in KHH2 to 67.3% in KHN system and in whole system varied from 37.9% to 63.8%. In conclusion, according to the results of this study, semi-portable sprinkler irrigation systems in plains of the Markazi province are not in good condition and have various design and implementation problems.

The performance of the existence emitters in micro-irrigation systems is on the basis of pressure dissipation and the inefficiencies of these systems in the pressure and discharge uniformity regulations have been reported by researchers. In this research, in order to improve emitters' efficiency in micro-irrigation systems, a new emitter named water volume control emitters was designed and evaluated. One hundred emitters were installed in the field condition on a micro-irrigation system and the applied water volume was measured until cutoff time. The experiments in pressures of 0.5, 1, 1.5, 2 and 2.5bar with three repetitions were conducted. In each repetition, the cutoff time of the emitter located in five positions at the first, third, mid, two-thirds and end parts of the lateral pipe were measured. Finally, the obtained results were evaluated on the basis of ASAE standards. In the field experiments, the maximum value of variation coefficient was obtained 3.3% in the pressure of 0.5bar (minimum pressure). Therefore, the system performance was evaluated in the excellent category in the all applied pressures. Also, the minimum coefficients of distribution uniformity (97.6%) and emission uniformity (91%) were obtained in the minimum pressure of 0.5bar so that these values were very favorable. In all of the pressure-discharge equations, the discharge exponent values were approximately estimated 0.55. The type of flow in emitters was turbulent. The appropriate performance of the mentioned emitters in creating a favorable water distribution uniformity showed that the change of view about emitters' operational mechanism and the developing new emitters with efficient mechanism can improve the efficiency of micro irrigation systems.

Water resources management depends on the precise assessment of water storage and access in each region, as well as environmental interactions of these resources. The man objective of this study was to delineate the potential zones of groundwater storage using FAHP. Mapping and assessment of it required maps of geomorphology, drainage, density, lineament density, slope and vegetation, which were initially prepared as the input layers in FAHP; the appropriate weights were attributed to them based on FAHP. Potential zones of ground water were classified into five classes of poor, average, good, very good and excellent. The number and density of available wells and springs in the study area dealt with the potential of the region for groundwater storage. So, ROC was used to assess the validation of results, considering spring points as signs of water resources. According to the results, classes of very good, good, average, weak, and very weak were ranked as the first to the last in terms of privilege order with an area of 37.7, 55, 40, 107, and 98.4 square kilometers, respectively.

Conveyance and Water distribution irrigation canals are hydraulic structures that transport water supplied from sources such as diversion dams for drinking, agricultural, industry or other purposes. These canals are usually lined by materials such as: concrete, stone with sand cement mortar, asphalt, to prevent water seepage losses along the flow path. Concrete lining that is used in irrigation canals is an unreinforced concrete with a thickness of 5 to 10 cm. Basic requirements of good hardened concrete are: satisfactory compressive strength and sufficient durability (Aba, 2005). After the implementation of each engineering structure, it is necessary to evaluate the project to determine the optimal performance and quality of implementation. Evaluation of the quality of irrigation canal linings is often carried out by the destructive and costly method of coring and carried out various experiments in the laboratory. Although destructive method yields relatively exact and straightforward results from the desired parameters, it also has some side problems that are sometimes difficult to recover. The problems of destructive test (DT) method with coring and destructive method are associated with damage of project, high cost, need the expert group and equipment, time-consuming and sometimes stoppage of project operation. Non-destructive testing (NDT) methods can be used to prevent these complications. Electrical, ultrasonic and Schmidt hammer tests are among non-destructive testing. Nowadays, non-destructive testing of concrete has an effective and practical function in the repair of concrete structures. Non-destructive testing of concrete by providing data on various existing structures allows experts to judge and decide on the performance, needs and methods of repair and restoration of concrete structures. The indicator of evaluation of the quality of concrete lining in irrigation canals in different environmental conditions is the same as the other structures based on the amount of compressive strength (Anon., 2014). The failure of hardened concrete due to repeated cycles of thawing- freezing in cold air in hydraulic structures (such as irrigation canals that can absorb water and saturated) is more probable than other concrete structures (Ramazanianpour and Shahnazari, 1988).

In this study, in order to establish a relationship between non-destructive testing (NDT) of Schmidt's Hammer number with destructive testing (DT) of compressive strength and water absorption parameters, 13 sections from 3 main conveyance canals were studied in Nahre Shaban irrigation network in Nahavand City. At all sections, non-destructive testing of Schmidt's Hammer accomplished for determining the rebound number, then from the same points, 12 and totally 156 cores were provided from 3 canals. Next relationship between rebound numbers (RN) with each of the parameters of laboratory experiments on the linings was investigated. The study area in this study was 6 km from the main canal of the irrigation network of Nahre Shaban in 3 sections of Ghaleqabad, Shaban and Jahanabad in Nahavand City. This canal is divided by diversion dam of Sha'ban with height of 3.5 m which was constructed in a section with coordinates of (X = 262862, Y= 3775625) during 1985 and 2001. Table 1 presents the characteristics of the main canal at the location of the Ghaleh Ghobad river section on the Shaban network. The coordinates of each section of the canal intended for coring were determined using GPS; these coordinates are presented for the 13 points in the selected canals in Table 2.