mehdi zakerinia

In recent decades, with the trend of warmer weather and heavy rains caused by climate change, events such as floods or droughts have clearly increased in many parts of the world. Therefore, it seems necessary to predict climate change by models to know the future conditions and manage water resources in line with adaptation.

The aim of the current research was investigation and evaluation of climate change forecasting on Hashemabad Gorgan synoptic station which located in the Qarasu basin of Golestan province. Precipitation data, maximum temperature and minimum daily temperature of the studied station were obtained from the Meteorological Department of Golestan province and the data of 1990-2014 were considered as the base period. The homogeneity of the observational data checked by using four tests of Standardized Normality Homogeneity (SNH), Bishand Range (BHR), Pettit (PET), Van-Neumann Ratio (VON) provided in the trend package in RStudio environment. Further, by examining the statistical tests of correlation coefficient (R), Root Mean Square Error (RMSE), Mean Absolute Error (MAE) and Kling Gupta (KGE) among the three models MIROC-ES2L, EC-Earth3-Veg-LR and EC- Earth3-CC From the set of CMIP6 models, the EC-Earth3-CC model was selected as the best model at this station. Straw scaling was performed using the linear scaling method (LS) by Climate Model data for Hydrologic modeling (CMHyd) software. Projection was made for three statistical periods of the near future (2026-2050), medium (2051-2075) and long-term (2076-2100) according to two intermediate (SSP2-4.5) and very pessimistic (SSP5-8.5) scenarios. Also, the trend of observational data and future periods was determined by the non-parametric Mann-Kendall test and age slope.

The results of the statistics parameter’s error showed that the models do not have a good ability to estimate precipitation and have high uncertainty, but they will have good results for temperature. The results of the investigation of the average monthly changes of the precipitation variable in all three future periods, except for the SSP2-4.5 scenario in the middle future, have a decreasing trend compared to the observation period, and this decrease in the SSP2-4.5 scenario is more in the near future than in the SSP5-8.5 scenario and less in the distant future. The average changes of the maximum temperature and the minimum temperature in all three future periods have an increase compared to the observation period, and this increase is more evident in the two middle and far future periods in the SSP5-8.5 scenario than in the SSP2-4.5 scenario. It can also be said that the increase in the maximum temperature variable for both scenarios will be higher than the minimum temperature in all three future periods. The highest increase in maximum temperature according to the SSP2-4.5 scenario compared to the observation period in all three future periods in July and the lowest increase respectively in the near, middle and far future period in Jan, Dec and Jan and according to the SSP5-8.5 scenario the highest increase respectively in The months of March, July and August and the lowest increase in all three periods was observed in January. The highest minimum temperature increase according to the SSP2-4.5 scenario compared to the observation period in the near, middle and far future respectively in July, Feb and Aug and the lowest increase respectively in April, Dec and Jan and according to the SSP5-8.5 scenario the highest and lowest increase. The close period is observed in Feb and Jan, and in the other two periods in August, and the highest and lowest increases of both middle and far periods are observed in August and April, respectively. The results of examining the situation of SSP2-4.5 scenario, the monthly values of precipitation in all the months of the future period except April, the monthly values of the maximum temperature of all the months of the three future periods and the minimum temperature of all the months of the three future periods except of May and June of the near period and The distant future Jan has no significant trend at the 95% and 99% confidence levels. The significant trend status of the climatic parameters of the SSP5-8.5 scenario has increased in all three future periods compared to the SSP2-4.5 scenario.

Finally, the results of this research showed that the air temperature in the desired station is getting warmer and it can affect the quality and quantity of water resources, so it is suggested to investigate the effect of climate change on runoff in future researches.

Soil desalination in drained fields is very important because soil salinity harms on crop yield. Therefore, for the optimal management of water and soil, and the sustainability of agricultural lands, salinity monitoring in soil is essential. In this study, 44 soil samples from the depth of 0-30 and 30-60 cm were prepared from drained lands, during one cropping year. Then, soil salinity and acidity map was produced by GPI, LPL, IDW, Ok, RBF methods. Evaluation of salinity at 0-30 cm showed that stable kriging in the first and third months, exponential kriging in the second month, RBF inverse multi-quadrant model in the fourth and fifth months, were the best models. The results 30-60 cm showed that stable kriging in the first and third month, Gaussian kriging in the second month, Exponential kriging in the fourth month, and RBF inverse multi-quadrant model in the fifth month were selected as the best model. Also, evaluation of pH at the depth of 0-30 cm showed that Spherical kriging in the first month, GPI with the first power in the second and fifth months, IDW with the second power in the third month and Exponential kriging in the fourth month had the lowest RMSE. Evaluation of pH at 30- 60 cm showed that stable kriging method in the first, third, and fourth months and GPI with the first power in the second and fifth months had the lowest RMSE. The problem of salinity and alkalinity was observed in most of the surveyed region, and the level of salinity in the surface layer of the soil was higher than in the deep layer. The comparison of the salinity map in different months shows that the salinity has been decreasing during the 5 months of monitoring and the general trend of pH changes is similar to EC.

Traditional water distribution with Mirab is effective to a certain extent in the fair distribution of water, but it has limitations in terms of efficiency and productivity. While in modern networks, it is possible to try to optimize the allocation and distribution of water by using advanced technology and infrastructure. Of course, the implementation of a modern irrigation network, despite the high cost of its implementation, does not necessarily mean that it will be successful in the assigned operation, and its performance should be evaluated and analyzed by experts in this matter. water consumption efficiency in two villages of Shahkooh Sofla with traditional irrigation network and Mohammad Abad with renovated irrigation network and integrated lands has been done. The required data in this section included a questionnaire and field measurements of water flow in the network, and finally with the help of these data, the water productivity in the fields was calculated. performance per water volume unit (CPD), and economic productivity indicators, including gross profit per water volume unit (BPD) and net profit per water volume unit (NBPD) were calculated average CPD index in terms of fresh weight, BPD and NPBD in the Shahkooh, 7.54 (kilogram of wet matter per cubic meter), 12425, 10427 (tomans per cubic meter) and in the Mohammad Abad, respectively 0.41 (kilogram of dry matter per cubic meter), 1510 , 918 (tomans per cubic meter) has been obtained. Therefore, in Shahkooh , despite the traditional network of water distribution management, more economic productivity has been achieved

In order to evaluating effects of irrigation with saline-sodic water, we conducted three infiltration experiments in clay-loam soil in end-close furrow. We were using 5cm water depth every week, which had EC=12 ds/m and SAR=32. Experiments were done with volume-index method in end-close furrow in third, sixth and tenth irrigation. Therefore infiltration speed and cumulative infiltrations curves were fitted in different times with Kostiakov and Philip models. Results showed that great decrease in infiltration rate was happened since irrigation with saline-sodic water in experiment. Therefore infiltration rate decreased 40.6 and 68 percent from third irrigation to sixth and sixth to tenth irrigation, respectively. So using saline-sodic water can decreased infiltration rate up to 81 percent in 50 days. Evaluation of the simulation results of test data again Kostiakov &loese and Philip model data with RMSE and MBE parameters showed that these models could simulate soil infiltration rate changes good under the effect of irrigation with saline-sodic water. Also simulation accuracy was increased at the end of experience time than initial and mead time infiltration tests

Heavy metal pollution is one of the most important environmental hazards found in all human societies. One of the most important of these pollutions is pollution by cadmium, which because of to its effects on the environment, it is necessary to purify it from soil and water. Among these risks, we can mention the increase in the concentration of heavy metals in the environment, the contamination of the human food chain, and the increase in cancer cases. There are various methods for purifying polluted water, among them using the ability of plants, i.e. phytoremediation is a suitable solution for purifying heavy metals from the environment due to its greater compatibility with the environment. Pollution by heavy metals such as lead, nickel, and especially cadmium has been reported in the industrial areas and towns of Golestan province, and even the use of these wastewaters is widespread without performing pollution reduction processes.

in this research, in order to evaluate, prevent and correct the damages of using cadmium-contaminated water, an experiment with 6 treatments and 3 repetitions was conducted in the form of a randomized block design with and without phytoremediation process with the aim of providing irrigation water to rapeseed plants. Reed and vetiver plants were used for herbal treatment. The drip irrigation system was selected. A retention time of 10 days was chosen for the treatment of water contaminated with cadmium, and the irrigation cycle was considered accordingly. During the experiment and after harvesting the rapeseed crop, the amount of changes in the concentration of cadmium in water samples, plant components and soil were measured and analyzed using SAS software.

The results showed that the amount of cadmium accumulated in the seeds of the rapeseed plant and in its aerial parts, in the treatments irrigated with contaminated water after the phytoremediation process by reed and vetiver grass, had a significant decrease of 1% compared to the treatments without phytoremediation. At the end of the growing season, the concentration of cadmium in the soil that was irrigated with water treated with reed and vetivergrass was 1% lower than the concentration of cadmium in the soil irrigated without treatment. Of course, the investigation of the mutual effects of plant treatment on the yield parameters characteristics of rapeseed including height, pod number, stalk diameter, root depth and weight of 1000 seeds indicated that water pollution with cadmium had no significant effect on the mentioned yield parameters.

The Center pivot system is one of the most advanced sprinkler irrigation systems that recently has been used in Iran. According to this research on the compatibility of the system with the cultural, economic, climate and optimization performance of the system is essential. The importance of this matter on one side and the lack of information on the other hand, it highlights the need for an investigation. In this regard, the evaluation of the Center pivot system in two speeds 10 and 60 percent took a radial and vertical. The uniformity coefficient (CU) in the radial arrangement of cans and in two speeds 10 and 60 % was 80.3 and 76.4%, respectively and the uniformity of water distribution (DU) was 72.6 and 65.5 respectively. Also the uniformity coefficient (CU) in the vertical arrangement of cans and in the same speed was 61.1 and 59.3 % respectively. Uniform distribution of moisture in the soil after irrigation with rate of 60% was 86.37 percent. So the amount of Uniform distribution of moisture in the soil was higher than the uniformity coefficient in the Surface Soil (CU). The main reason is the horizontal flow and water transfer in the soil and its influencing factors (Mass flow, Diffusion and Hydrodynamic dispersion). According to this and given the lack of available water resources in arid and semi-arid area, maybe there is no need to increase water of irrigation in order to increase the uniformity of water distribution to more than 70 percent

The entry of pollutants from agricultural land into water bodies is one of the most environmental issues connected to the tile drainage systems. Also leaching of drain water may cause the required nutrients for crop growth becomes out of reach. Thus, applying Best Management practies (BMPs) to relief the side effects of agricultural tile drainage systems is crucial. Over the past few decades, several BMPs have been introduced and studied with the aim of manage and control the volume and pollutants amount of tile drain water in agricultural lands, of which Controlled Tile Drainage (CTD) is one of them. Due to difficulty and costly nature of long-term monitoring programs, which is often used to assess impacts of applying BMPs on non-point source pollution, the AnnAGNPS model developed by USDA is a reliable alternative to simulate an effect of applying CTD at the watershed scale. AnnAGNPS, a comprehensive computational model that evolved from AGNPS, was designed for evaluating non-point pollutant loadings in agricultural watersheds and river basins. Briefly, AnnAGNPS is a distributed parameter simulation model that subdivides a watershed into small, homogeneous subwatersheds called “cells.” Cells are interconnected by stream channels called “reaches” In this study, an impact assessment of applying CTD on Total Suspended Sediment (TSS), Total Nitrogen (N total), Dissolved Nitrogen (N dissolved) and Surface Runoff were evaluated by AnnAGNPS at the Qharesu Watershed.

Qharesu watershed with an area of about 1670 square kilometers is one of the watersheds of Golestan province, which is surrounded by the Gorganrud watershed area from the north and east, Nekarud watershed in the south and the Gorgan Bay from the west. Finally, it is discharged into this bay. An average meteorological data of 5 statistical years of 2016 to 2020, used as a model input data in order to further adapt to the climatic conditions of the region in future, when tile drainage system is operated. The surface runoff data and suspended sediment load were also obtained from the Siah-Ab hydrometric station (outlet point of Qharesu watershed). Calibration and validation of the model performed by runoff and TSS observation data, in which the degree of confirmity between observation data and model output data performed by using three indices of Nash-Sutcliffe, RSR, and PBIAS.Two tile drain depth scenarios were examined in detail to mimic tile drainage control: The depth of 0.2m (CTD0.2) as an extensive controlled drainage and the depth of 0.6m (CTD0.6) as the recommended depth in the growing season for controlled drainage. The depth of the drainage base considered 1.1m as a reference condition as well.

The results showed that the model is reliable for simulating the studied parameters. The indices of E, RSR and PBIAS for runoff were 0.85, 0.48 and -2.6 for the calibration period and 0.76, 0.44 and -10.9 for the validation period respectively. These numbers were 0.73, 0.43 and -31.7 (calibration) and 0.66, 0.54 and -29.1 (validation) for sediment data.The AnnAGNPS model predicted a slight decrease in runoff and total nitrogen and a moderate decrease in dissolved nitrogen at the outlet of the Qharaesu River under the CTD0.6 scenario (during the growing season). Also, the increase in sediment load due to CTD0.6 was almost negligible. Based on the model results, Controlled drainage to a depth of approximately 0.6m below ground level is a suitable equilibrium point for reducing nitrogen and sediment loads at the watershed scale. Considering the importance of the outlet point of Gharesu, which is discharged to Gorgan bay, and since a significant part of tile drainage system in this watershed has not been impelemented yet, applying controlled tile drainage system is possible at a lower cost and more comfortable. Therefore, the possibility of applying CTD0.6 scenario should be on the agenda of authorities.

Water is one of the sources that play an essential role in crop production and, if not properly managed, creates a severe limitation on drinking water consumption and agriculture. Water scarcity has become a crisis in recent years. It has challenged rice production in the country, so there is no choice but to increase productivity and optimize low-quality water. The use of effluent in supplying part or all of the water and nutrient needs of the crop, in addition to reducing the pressure on available water resources, also lowers production costs. It also avoids the problems of disposal of natural resources and environmental issues. Wastewater application can increase the amount of water available to the plant by changing the physical properties of the soil. Therefore, overall, these factors contribute to the sustainable use of water and soil resources in agriculture (Nikbakht & Rezaei, 2016). Direct and unmanaged use of this type of water, referred to as abnormal water, causes soil damage and reduces crop production in irrigation operations. Due to the importance of water and its scarcity in the country, proper use of water resources and irrigation water is one of the most critical goals in the agricultural sector. Therefore, a method that can increase the plant's yield under normal conditions by using a certain amount of water and the use of irrigation water in such a way that no problems occur for the plant can be used as a solution. It is essential to manage irrigation water use. In this regard, one of the approaches used in irrigation operations in recent years to use unusual waters is to pass irrigation water through a magnetic field. Water is a magnetic magnet that passes through a device with a magnetic core (Bodnarenko & Gac, 1984). Special measures, including unconventional water, are required to provide irrigation water for strategic products such as rice, which needs much water. Despite the beneficial aspects of urban wastewater, using these waters without proper management in agriculture leads to irreparable damage in a long time. To reduce its effects and the use of wastewater treatment systems, the magnetization method is considered. In the present study, the effect of magnetization of Gorgan urban wastewater effluent on hulls yield, biological yield, harvest index, water use efficiency, physical efficiency of water, and economic efficiency of water have been investigated.

For the cultivation of high-yielding rice crops, the use of irrigation systems and low-quality water are ways to reduce water use and overcome the crisis of dehydration. To improve the quality of water, there are different methods such as using magnetic fields. The purpose of this study was to investigate the magnetization effect of wastewater treatment plant in agricultural campus of Gorgan University of Agricultural Sciences and Natural Resources in a factorial randomized complete block design with three replications on some rice growth indices in 2018. Experimental treatments include irrigation (underground (S) and surface irrigation (B)), type of irrigation water (ordinary water (C) and Gorgan urban wastewater treatment plant (W)) and magnetization (M) and non-magnetization water treatment method. (O)). The treatment composition was surface irrigation with conventional non-magnetic water treatment. During the experiment, plant height, 1000-grain weight, biological yield, harvest index and water use efficiency were measured. Results showed that application of non-magnetic wastewater increased plant height, 1000-grain weight, biological yield, harvest index and water use efficiency. The results showed that using non-magnetic surface treatment (OWB) and combination non-magnetic wastewater (OWS) increased plant height, 1000-grain weight, biological yield, harvest index and water use efficiency. The combination of (OWB) in plant height was at the same treatment level and increased in other traits compared to treatment, however, the composition (OWS) of harvest index increased with %26.7 and water use efficiency with 0.47 kgr/ha compared to other treatments and especially control. Underground irrigation method in addition to reducing water use compared to surface irrigation, improved harvest index and water use efficiency. According to the results of this study, irrigation of rice does not need to create a water layer on the soil surface and in order to increase production and increase water use efficiency while preserving the quantitative and qualitative characteristics of the plant, the use of abnormal water must be such that the environmental and health risks are minimized?

Rice is the second most important edible grain after wheat in Iran. The most important factor for sustainable production in rice production lands, is water. Almost 75 percent of the world's rice is produced from paddy fields and rice is the largest consumer of water among all crops. Its growth is significantly affected by climate change and water scarcity. This research was carried out to compare the direct cultivation and transplanting of rice under different irrigation methods from the point of view of water productivity. The current work was designed as split plot based on randomized complete block design with 6 treatments and three replications in 18 plots with 6 m wide and 12 m length (72 m 2) in area of approximately 1500 m2 at the Agricultural Research Station of Golestan province in spring and the summer of 2018. Treatments including three levels of basin irrigation, sprinkler and drip (tape) irrigation were considered as main factors and two methods of direct cultivation and transplanting were considered as sub-factors. The results of analysis of variance showed that the effect of irrigation and sowing method on the yield of rice were significant at 0.01 level probability. The highest amount of biological yield in transplanting was obtained by basin irrigation (8177 kg/ha) and in direct seeding in basin irrigation and taper irrigation (7375 and 6836 kg/ha, respectively). The highest 1000-grain weight in transplanting method was obtained in basin irrigation and direct seeding method in traditional irrigation and tape irrigation. The highest number of filled grains in the panicle was observed in the basin irrigation treatment in transplanting, with significant difference compared to the amount observed in direct seeding. Traditional irrigation between planting methods had not significant effect on the number of hollow grains; while in sprinkler and tape irrigation (with an average of 51 and 56 for sprinkler and tape irrigation, respectively), the number of hollow grains had a higher rate in direct seeding (with an average of 41 and 45 for sprinkler and tape irrigation). The results showed that basin irrigation with 8177 kg/ha grain yield in transplanting method and basin and tape irrigations with 7375 and 6836 kg/ha in direct seeding method had the highest grain yield. Sprinkler irrigation had the lowest paddy yields in transplanting (4188 kg/ha) and direct seeding (5712 kg/ha). Tape irrigation with 7390 and 6840 m3 of consumed water, resulted in lower water consumption compared to traditional irrigation (10700 and 1693 m3), respectively. The highest amount of water use efficiency was obtained in direct and tape irrigation (0.99 kg/m3) and in traditional and tape irrigation (0.76 and 0.66 kg/m3, respectively). Adjusting water consumption both through lower water consumption and reduced water wastage can lead higher water productivity of rice production systems creating sustainable rice production systems. In transplanting method, tape irrigation and traditional irrigation had higher water use efficiency than sprinkler irrigation, although a significant water use reduction in tape irrigation rather than basin irrigation should be analyzed economically at real water prices. Overall, in this study, the tape irrigation method, by reducing water consumption, was able to increase water productivity and maintain the yield of rice in direct cultivation. Sprinkler irrigation had the lowest yield of rice in transplanting and direct cultivation. Problems such as lack of uniformity of spraying and waste water through the wind as well as poor quality of sprinklers are the main reasons for the decrease of the efficiency of sprinkler irrigation.

Due to the increasing deterioration of river life systems because of human intervention, droughts and climate change, the recognition of the environmental flow in planning water resources development studies to maintain the health of it is necessary. The main objective of in this research is to implementation and assessment the methods of Tennant, Flow Duration Curve, Eco deficit, Aquatic Base Flow, Flow Duration Curve shifting (FDC Shifting) and Desktop Reserve Model (DRM) in estimating the environmental flow of Gharasoo River in different months of the year in the range of studies of Siahab hydrometry station to entrance to Gorgan Gulf in order to conservation and restoring of the above river. In the present study by comparing the results of suggested values of environmental flow in Gharasoo River were determined to be estimate Tennant method 0.57 m3/s for April to September and 0.19 m3/s for October to March, Flow Duration Curve method in conditions of relatively suitable (Q90) and suitable (Q75) was respectively 0.17 and 0.393  m3/s, Aquatic Base Flow method 0.57 m3/s, FDC Shifting method in relatively modest conditions with an annual average of 0.94 m3/s, Eco deficit method 0.88 m3/s and in class B DRM model 0.69 m3/s. Accordingly, by providing the ecological regime of the Gharasoo River, it is possible to maintain proper conditions for maintaining the ecosystem health using FDC Shifting method in C management class (48.5 percent of natural stream of the river).

To cope with the current water resources issues in Iran which are going to pose a real threat on a national scale, taking into consideration all determining factors causing these formidable water resources challenges, is of paramount importance. Computer modelling has been increasingly developed over the last few decades for water resources management and planning. In the present study, climate variables include precipitation, relative humidity and temperature were predicted for the period of 2020-2049 using SDSM model. Then, impacts of climate change on hydrological conditions were evaluated via Soil and Water Assessment Tool (SWAT) in the Talvar river watershed located in the Kurdistan province.

The Talvar river watershed with an area of 2490 km2 is situated between longitudes of 47° 06' 09" E and 47° 45' 58" E and latitudes 35° 03' 26" N and 35° 35' 26" N, located in the Kurdistan province. Land use in this basin is mostly cropland and pasture. Cropland accounts for approximately 85% of the total area, among which paddy fields account for 10% and dry land farming accounts for 75%. Pasture cover 14% of the study area. All other land use types (rural area, urban area, water) make up only 1% of the study area. Mean elevation of the watershed is 1927 m above mean sea level. The SWAT model requires input on topography, soils, land use and meteorological data. Recently available GIS maps for topography, land use, and soils of the study area were used. The Talvar river watershed was discretized into 50 sub-basins and also, based on the land use, slope and soil classes the watershed was subdivided into 1151 HRUs. The climatic data were derived from 7 meteorological stations located in and out of the basin under study. Climatic data refer to daily precipitation, maximum and minimum temperature, relative humidity data. The calibration of the SWAT model was done manually based on physical catchment understanding and sensitive parameters and calibration techniques from the SWAT user manual. Sensitivity analysis has been performed using OAT (One Factor at a Time) method to evaluate and demonstrate the influences of the model parameters on water budget components including surface runoff, lateral flow, groundwater and evapotranspiration. Data from Qorveh synoptic station (1990-1999) were used for calibration of SDSM model. Climate variable include precipitation, relative humidity and temperature were predicted for the period of 2020-2049 using SDSM model in RCP26, RCP45 and RCP85 scenarios and simulated values were compared with baseline period (1990-2005). The performance of the SWAT model was evaluated via coefficient of determination (R2) and Nash–Sutcliffe efficiency (ENS) and the performance of the SDSM model was evaluated via coefficient of determination (R2), Nash–Sutcliffe efficiency (ENS), Mean Absolute Error (MAE) and Percent Bias (PBIAS).

Based on the results of sensitivity analysis, the parameters of initial SCS runoff curve number for moisture condition Π (CN2), soil available water capacity (SOL_AWC), soil bulk density (SOL_BD), saturated hydraulic conductivity (SOL_K), maximum canopy storage (CANMX), soil evaporation compensation factor (ESCO), minimum melt rate for snow during the year (SMFMN), maximum melt rate for snow during the year (SMFMX), snowfall temperature (SFTMP) and snow melt base temperature (SMTMP) have the greatest influence on water budget components including surface runoff, lateral flow, groundwater and evapotranspiration. According to the results, a satisfactory agreement was observed between monthly simulated and measurement discharge (R2 and ENS were 0.65 and 0.44 for calibration and 0.77 and 0.59 for validation periods). The results of the SDSM model showed that the monthly mean of minimum and maximum temperatures will increase compared to the baseline period except for September, October, November and December months. Also monthly average of precipitation will decrease in winter and spring seasons but it will increase in the summer and autumn seasons. The results of runoff simulation showed that monthly average of runoff will increase in January, February and December months compared to the baseline period. The weakness of the model to simulate flow for some months was probably due to poor characterization of snowmelt processes in basin under study.

In studies realted to hydrology, water conservation and management, accurate information of the water capacity in different soils for measuring water infiltration, drainage and erosion control is essential in order to launch irrigation projects in watersheds. The purpose of this study is to evaluate the effect of clay layers in the transfer of water through loamy sand.

Soil columns with a height of 150 cm and a diameter of 15 cm, were filled with clay layers to depths of 13 and 20 cm. Then the same volume of water with different salt concentrations was added to all columns. Also water sampling was carried out on a daily basis.

Results showed that the layer clay could reduce the volume of water passing through the columns and by increasing the thickness of the clay layer, the ratio of passed water decreased. The results showed that by increasing the depth of the clay layer in the control treatment to a depth of 20, the amount of water at a concentration of 13 mEq and 20 mEq decreased by 16 and 35 percent.

Different performances were due to the thickness of clay layer. Because of the small clay texture and high compressibility, the movement of water in the soil can be delayed. This feature can be used to prevent the movement of leachate and pollution into the soil and contaminate groundwater. It seems that by changing the depth of the clay layer, the conductivity can be controlled in sensitive areas.

The beneficial use of unconventional water resources for sustainable agriculture, taking into account the environmental impacts and economic returns, is a multi-criteria decision-making process based on the value of each criterion. In this research, after collecting resources and extracting decision making criteria regarding the use of wastewater in agriculture, a hierarchical structure based on two technical-economical and environmental factors is prepared and using a hierarchical analysis in the GIS software environment, the feasibility of using wastewater for cultivation of 10 common crops was carried out in Golestan province. The irrigation water fairness, the techno-economical distance from the outlet of the treatment plant and the suitability of the land for cultivating are from the technical-economical sub-criteria And the quality of irrigation water, soil, plant and aquifer vulnerability are the environmental criteria of this structure. Also, some parameters such as slope, topography, land use, depth of soil and technical permissible distance were considered as limiting factors. The results of this feasibility study, which was carried out using data from Kurdokoy wastewater treatment plant, Despite the low utilization rate of all plants due to lack of utility parameters such as nitrate, microbial contamination and aquifer vulnerability, which had the highest sensitivity and relative weight, cotton and canola have the highest desirable yield of 10 common crops In the area covered by the wastewater plant.

Cotton is a plant that responds to the amount of irrigation water and irrigation time, and due to lack of water in Golestan province, the need for optimal use of water unit is more than ever before. This will not be achieved except through modern methods of surface irrigation or irrigation under pressure and appropriate management of irrigation and increasing water use efficiency.

This experiment was conducted as a split plot design in a factorial design with three replications at Hashem Abad Cotton Research Station. Physical and chemical parameters of soil such as soil texture, bulk density, moisture content of crop capacity and wilting point, soil salinity and soil acidity before cultivation were measured by sampling from two depths of 0.25 to 25 cm and 25 to 50 cm. Farm fertilizer requirement was calculated according to the results of the experiments. The distance of cotton cultivation during the studied surface was considered the same. Before irrigation was done due to soil moisture content. Planting two cotton cultivars was done randomly. During the growing season and before the first irrigation, a single-hinged rainwater system was implemented. During irrigation period, irrigation was carried out based on the water requirement of Plot i5 and irrigation continued on the basis of the water requirement of this plot to reach the farm capacity. During the growth period, the symptoms and the indicators of yield components included plant growth measurements, first flowering time, time of the first product, etc., and finally the yield was recorded. Different amounts of irrigation water treatments including rain irrigation, irrigation over water requirement as main plots and treatments of different amounts of nitrogen fertilizer including 0, 33, 66 and 100 percent fertilizer recommendation as well as cotton cultivars were considered as subplots.

The results showed that the highest yield (4362 kg / ha) was related to 4I treatment and the lowest yield was obtained from rain fed (without irrigation) with 3379 kg / ha. The yield of I2, I3, I4, I5 and I6 treatments was 2,2, 16,7, 29,1, 8,1 and 15/7 percent, respectively, than rain fed (I1). Among fertilizer treatments, the highest yield was related to unfermented fertilizer application, which was significantly different with treatments of 66% and 100% fertilizer requirement. The lowest yield was 66% fertilizer requirement. In a research year (2012) due to suitable rainfall in the growing season, cotton plants were well-grown, and any excess water or nitrogen fertilizer accelerated vegetative growth which ultimately led to a decrease in reproductive growth and Subsequently, performance declined. In terms of precocious percentage, rain and I4 treatments were the earliest and the shortest treatments. Different amounts of nitrogen fertilizer had no effect on premature percentage. The highest number of bolls per plant was related to I5 and I6 treatments, which difference was significant with I1 and I2 treatments, but not significant with I3 and I4 treatments. The amount of nitrogen fertilizer application from 0% to 100% of fertilizer requirement did not have a significant effect on the number of bolls per plant.

The yield of Golestan cultivar was 17.9% higher than that of B-557. Water use efficiency in rainfed and irrigation treatments was 1.51 and 0.81 kg / m 3 / ha, respectively. B was 557 earlier than Golestan cultivar. Two cotton cultivars called Golestan and 557 B were identical in number of bolls per plant. It is recommended to select Golestan cultivar as a basic cultivar pattern. In rainfed overwrought years, an irrigation can be done or watering is done in supplementary form.

This study was carried out to evaluate the economic and technical effects of climate change on the agricultural sector of Ghareso basin in Golestan province. In the first part, using the IHACRES rainfall-runoff model and rainfall, temperature, and monthly runoff data during the base period (1994-2010), the Ghareso river flow was simulated during the period of 2011-2040. Then, the probabilistic status of water resources allocation and provision of agricultural sector was evaluated by WEAP model. In the second part, in order to reduce the negative effects of climate change on the agricultural sector, using the goal programming economic model, optimal cultivation with the goals of minimum water consumption and maximum future profits was determined. The results of the first part showed that runoff decreases in the upcoming periods by 31.34% compared to the base period. In addition, the results of the WEAP model indicate an increase in the unmet need of the agricultural sector in the region under study. This result suggests that with the continuation of climate change in the future to reduce the negative effects in agriculture, the region's cultivation pattern should be changed to remove cotton and increase barley and rice. These changes were identified in the results of the second part of the model through the Goal Programming Model. In the optimal cultivation pattern, the gross profit of farmers in the studied area in the period of 2011-2040 increased from 1386 billion Rials to 1991 billion Rials compared to the base year.

Ecosystems management of river and water flow necessary for continuity of life and ecological sustainability of river based systems, requires recognition of environmental flows in the politics and intentions of water resource development projects and inclusion it in watershed management programs. In order to, in this research were analysis application of hydrological methods (Tennant, Tessman, Flow Duration Curve, Smakhtin, Arkansas, FDC-Shifting and DRM) and ecohydraulic habitat suitability simulation model (SEFA) in the environmental flows assessment of Qarasoo River in Golestan Province in interval of hydrometry stations Ghazmahalleh and Siahab, respectively with mean annual flow of 0.26 and 1.92 m3/s for restoration habitat, natural resurrection and conservation of biodiversity. The investigating provision of optimal flow ecosystem with field studies and measurements hydraulic and qualitative characteristics of the river in order to identify the favorable conditions of Capoeta capoeta gracilis hierarchical habitat showed would have the maximum and minimum flow regime required to preservation the Qarasoo river ecosystem according to ecological needs in months of april and september is estimated to order equivalent 3.11 and 0.48 m3/s, with average annual 1.6 m3/s (equivalent 83 percent of natural stream of the river). The results of study show environmental menaces will follow using the values obtained from simple hydrological methods Tennant, Smakhtin and Flow Duration Curve in water resource planning of this river , by contrast ecohydraulic model of SEFA can provide a general croquis of habitat suitability in intervals different of river relative to regime changes natural flow and attainment to optimal

Water resources management in the basin area is increasingly associated with the allocation of environmental flows as a tool for improving the quality of ecosystem habitats in river conservation and restortion projects. In order to facilitate the estimation of the environmental flow of the Gharasoo River in Golestan province, based on the research framework after the hydrological analysis and field studies and observations, the Habitat Suitability model of the C.Capoeta gracilis species was developed and in the next step, of the flow was performed hydrodynamic modeling of the hydraulic parameters, and Finally habitat simulation and modeling with the integration of ecological and hydrodynamic studies of the flow and extracted the ecological flow regime. Based on the results of this study, C.Capoeta gracilis species in various stages of life has shown a response to changes in hydraulic parameters (depth and velocity) and flow rate, and to conservation of the ecosystem of the Gharasoo river using River2D model and variables of Habitat physics and Habitat Suitability Index of based Weighted Usable Area, Minimum and Maximum Environmental Flows are proposed to be 0.47 m3/s for the month of September and 3.03 m3/s for month of May. Results of this study showed the use of a two-dimensional hydrodynamic model for modeling the habitat desirability of the target species can recommended a tool for improving the performance of modeling in habitat simulation and implementation of the ecological river regime in river engineering projects conservation and restoration.

Scarcity of water resources in the entire country is more serious in the northern provinces like Golestan. Therefore, farmers have to use saline water or waste waters. One way to adapt to this condition is to use unconventional water such as Caspian Sea water, with lower salinity as compared with water from free seas, for common crops like soybean. Thus feasibility of using Caspian Sea water that has integrated with narrow common water and the calibration of Aquacrop model under the effect of salinity and water stress for soybean crop in Golestan province are more important. The Aquacrop model assumes a linear relationship between the biomass yield (BY) and crop transpiration one one hand and water productivity (WP) value on the other (Steduto and Albrizio, 2005). This model, as compared to other crop models, requires minimal input data and its new version 4.0 (June, 2012) has a salinity module which was used in this research to simulate the grain yield  (GY) and WP of soybean under deficit and saline water irrigation. Furthermore, the AquaCrop model has not often been tested to simulate the yield of soybean under saline conditions in the semi-arid climate of Golestan province. This study aims at evaluating the efficiency of AquaCrop model in soybean yield simulation. The results are to be used for optimizing water consumption under water and saline stress. To this end, an experiment was carried out at the research farm of Gorgan University of Agricultural Sciences and Natural Resources.

Population growth, agricultural and industrial development, degradation of surface water resources, groundwater levels drop are among the major factor causing water scarcity. The integrated management of groundwater and surface waters could serves as a solution to solve these challenges. In other words, sustainable water resources can be achieved through Integrated Water Resources Management, which is the comprehensive approach to all the components that affect and influences the status of water resources. With this approach, the importance of management tools such as integrated water resource simulation models to help planners and managers of this sector is increasingly evident. Connecting the WEAP model to MODFLOW allows the values calculated by WEAP to be sent to the MODFLOW for input on groundwater influxes, river levels, groundwater withdrawals (pumping) and surface runoffs. After it, the groundwater level, sub-streams between the aquifers and the flow between surface and underground water are sent to the WEAP as input of the next step of the calculation. The purpose of this research was to investigate the effects of scenarios related to demand and available water resources, integrated water management in the urban sector and sewage system application in Bojnourd region. In this study, with using a water resources simulation model (WEAP) and its connection to groundwater simulation model (MODFLOW), water consumptions for Bojnourd basin was evaluated. Calibration and validation of both models has done under taken data based on 6 (from 2005-06 to 2010-11) and 2 years (from 2011-12 to 2012-13) respectively. Then different management scenarios, including current state water resources scenario, dam's drinking water supply for Bojnord city via transferring water from Shirin Dareh dam, developing sewage systems and finally combination of 2 last scenarios were considered. Under these scenarios, projections for a period of 28 years (from 2013-14 to 2040-41) and its effects on water resources of Bojnord basin were studied.The hydrometric station data of Babaaman at the outlet of the Bojnourd basin, which is the only hydrometric station representing this basin, was used to calibrate the WEAP model. Also, data from four rain-sensing stations, one evaporation station and one synoptic station were obtained from the year 1380 to 1390.Demographic data and Urban water demand and rural demand, population and consumption per person was assessed. Industry sector Water demand is estimated monthly. According to geological studies, the Bojnourd basin has two types of alluvial and limestone aquifers, both of which are defined in the model. Then, sensitive and effective parameters were determined by calculating the sensitivity percentage of the mode. Finally, the results of calibration and validation of the model were done from three indicators of Nash-Sutcliff (Ef), Coefficient of determination (R2) and Root Mean Square Error (RMSE), respectively, and the reliability index were used to evaluate the scenarios. The results showed that Simultaneous applying multiple water management strategies seems to be better than any of its individual states, reducing water withdrawing on various resources. Reliability of water supply in the whole complex scenario, for urban drinking water, rural and industry purposes were estimated around 100, 100 and 65.3 percent respectively. As a result of this scenario, the annual recharge of the aquifer with 5.39 million cubic meters per year can be relative balance between harvesting and recharge. it can be concluded that reliable results will be obtained from simultaneous simulation of drinking and industry water management. Keywords: aquifer, Bojnourd, simulation, water resources management

changing the flow regime of aquatic ecosystems and providing a minimum flow of protection aquatic species. The purpose of this research is to provide the essentials to be prepared tools for the assessment and design of restoration and regeneration projects for Zarrin-Gol river habitats using ecohydraulic and hydromorphological indices based on the habitat suitability simulation. In this regard based on the research framework, after the field studies and the development of the habitat suitability model for the target species, the hydrodynamic simulation of the flow was carried out and eventually the ecological flow regime was extracted. The results showed that River2D model by connecting the flow requirement characteristics of C.Capoeta gracilis and using hydraulic and hydrological relations, would have the maximum and minimum flow regime required to maintain the Zarrin-Gol river ecosystem according to ecological needs in the months of april and october is estimated to order equivalent to 5.09 and 0.89 m3/s, with average 1.79 m3/s (equivalent 84 percent of natural stream of the river). Based on the results of this study, in environmental studies of water resources and river engineering, the two-dimensional hydrodynamic River2D model is able to simulate flow, modeling habitat suitability of target species and predict the dynamics of habitats to protect the proper habitat of fish in river ecosystems. The calculation of the environmental flow can be an appropriate estimate for the ecological response of the river to the morphological changes caused by hydrological processes.

Irrigation is known as one of the most important factors in the production of grains in dry climate. The present irrigation method used for wheat and alfalfa production is mainly surface irrigation (Basin, Border, and furrow) and this method consumes more water and has less water efficiency than innovative irrigation methods. Using pressurized irrigation systems can both save water and increase water use efficiency. The purpose of this study is to investigate the feasibility of using strip drip irrigation in winter wheat. In order to determine the most suitable distance between irrigation tapes and find out the effect of Alternate Partial Root Drying (APRD) on water use efficiency, yield and components of wheat yield , a factorial experiment with 6 treatments and three replications was conducted in Pelband plain-Khorasan Razavi province- in 2016-2017. Then, water consumed, yield and its component yield were compared in traditional flooding method - conventional flooding. The treatments applied in this research consisted of drip-tape irrigation with distance of 50 cm (I1) and 60 cm (I2) and 70 cm (I3) and three intermittent drip-tape irrigation with spacing of 50 cm (I4) and 60 cm (I5) And 70 cm (I6) and all of them with three repetitions. The results of mean square variance analysis showed significant difference in tape irrigation distance and wheat component on, yield and water use efficiency was significant at 1% level, and irrigation interval on number of pancakes, number of seeds in the cluster, stem height, Yield and water use efficiency were significant at 1% level and significant differences were observed on 1000 grain weight at 5% level. And the interaction effects on 1000 grain weight and grain number per cluster was not significant, but there was a significant difference between the number of pancakes and the level of 1%. Also, stem height and yield and water use efficiency at 5% level were statistically significant Had The highest yield and water use efficiency related to the irrigation bar spacing 50 and fixed irrigation type were 4958 kg / ha and 1. 57 kg / m3, respectively, and the least irrigation bar spacing were 50 with alternating irrigation it is equal to 3005 kg / ha and 95 / kg / m3 respectively. The performance and efficiency of water use in irrigation were measured at 5030 kg / ha and 1.05 kg / m3 respectively. The results of this study showed that irrigation intervals of 50, 60 and 70 cm with irrigation method were recommended for wheat cultivation in the study area. the irrigation bar spacing 50 with fixed type is more better than furrow irrigation in drought years, because of saving water around 1620 cubic meters and less than 500 kilograms decrease performance .

Regional analysis is used as one of the low flow estimation methods for the study of drought in areas without sufficient data. In this study, drought analysis is done based on no rainfall periods data from 67 synoptic stations with an appropriate data time and uniform distribution in the country of Iran. After sorting out the daily precipitation, periods without precipitation is assessed in each station. First the homogeneous regions identified and then the most suitable criteria statistical distribution function was determined in those areas. In order to analyze the frequency the FREQ program in MATLAB saftware was used. The minimum and maximum daily rainfall was 17 years for Semnan station and 56 years for Tabriz station and several other stations respectively. Based on regional analysis, the whole country of Iran classified in 8 Classification homogeneous regions. Spatial maps of maximum periods without rain during dry periods showed that from north to south and from West to East in the country were longer and in general in the country there are three separate locations in the distribution of dry periods. In northern Iran, periods without rain spells reduction and increased wet periods, this indicates that low sensitivity of this area to dry condition. Southern regions (particularly the provinces of the Persian Gulf and Sea of Oman) and central regions as the most sensitive areas in terms of reduction of days of rain and increase in precipitation at different return periods were found.

Water quality river is important from the economic, social and environmental aspects, and its importance is felt in the planning of water resources management and health assessment of watersheds. The present study aimed to investigate the water quality of Qarasoo River in Golestan province by descriptive cross-sectional method using qualitative variables and biological parameters of water in hydrometric stations located on Qarasoo River during the period from 1380 to 1393. An overview of the relationship and sources of physicochemical variables provides. Based on the results of chemical analysis and plotting the Schoeller, Wilcox and Piper diagrams, the water quality of the river is not suitable due to the high concentrations of sulfate, sodium and chlorine ions according to the drug Schoeller diagram, and is agricultural according to the Wilcox In the C3S1 classification, which represents a moderate quality. Also, according to the Piper diagram, which shows the hydrothermal type of water, the qualitative water type is introduced as Calcium-Magnesium-Chloride type. For improving the quality of river water and its efficient, by creating suitable environmental conditions and improving the ecological conditions in the river, point and non-point pollutants entry into the river water especially urban sewage and industrial wastewater and agricultural pollutants should be prevented with long-term plans.

Since the importance of water in the durability and survival of life is clear to everyone, water issue has always been the focus of researchers and experts. Iran, having its own geographical and climatic location, has a small share of rainfall. Therefore, having an average annual rainfall of about 240 millimeters, one-third of the global average (860 millimeters), it is part of the dry and semi-arid climate (Alizadeh, 1997). Due to the lack of statistics, complexity of hydrological ecosystems and the impossibility of full recognition of the conditions in many catchment areas of the country, the use of methods that measure the amount of runoff from rainfall in non-statistical basins or those with incomplete statistics are of prime importance. One of these methods is the use of the capabilities of hydrological models in the simulation of hydrological processes which is one of the initial stages of water resources management and planning, and also the study of the hydrological effects of land use change and the way of exploitation of natural resources in a basin, where it is possible to simulate the hydrological processes, such as runoff, in the basins with complete statistics with the lowest cost and minimum time, and then use the information to estimate runoff in similar basins with no statistical data or incomplete statistics (Namdorost, 2002). LARS-WG5 is one of the generators of meteorological accidental data that is used to generate daily rainfall data, daily irradiance and maximum and minimum daily temperatures in a station under present and future climate conditions (Semenov and .Brooks., 1998). Zarghami et al (2001) reported a 2.3 degree increase in temperature and a 3 percent reduction in rainfall over the years 2020-2090 for East Azarbaijan province with the LRS-WG Exponential Meteorological Scale under the A1B, A2 and B1 scenarios using HADCM3 output.