0 2476-3594 Isfahan University of Technology 4046 Ggeneral Experimental and Numerical Simulation of Water Hammer in Water Conveyance Pipeline and Effect of Surge Tower Pipe in Controlling this Phenomenon Ghanbari H. b mamizadeh J. c Valizadeh M. d b Ilam University c Ilam University d Ilam University 1 12 2021 25 3 1 12 06 07 2020 12 10 2020 Water hammer is one of the unsteady flows in urban water distribution networks, which has been of great importance due to the damage caused to the pipeline and has always been of interest to researchers. In this study, the phenomenon of water hammer due to the sudden closure of the valve in the downstream end has been investigated in a laboratory and using a numerical model. In the laboratory section of the study, the effect of flow changes with control equipment and without control equipment on the maximum and minimum height of pressure wave head was investigated. The results showed that the proper performance of the surge tower pipe in reducing the maximum pressure wave as well as improving the negative pressures in the system. In a maximum discharge of 35.75 liters per minute, surge tower pipe reduced pressure wave head by a maximum of 70.40%. In a minimum discharge of 7.70 liters per minute, the surge tower pipe reduced the height of maximum pressure by 34.82%. Also, in minimum discharge, surge tower pipe has improved the minimum pressure wave head by more than 78%. AFT Impulse numerical model was used to analyze the water hammer. The results of the numerical model were examined in a benchmark problem using a characteristic method and its validity was confirmed. Simulation of laboratory model with numerical software showed that this software only predicts the first wave properly when water hammer produces negative pressures, but in the next cycles it does not show the depreciation rate of the pressure wave, properly.
4052 Ggeneral Regional Analysis of Hydrological Drought in Ajichai Basin Using RDI Index ahmadzadeh H. e Fakheri Fard A. f ghorbani M.A g tajrishy M. h e Tabriz University f Tabriz University g Tabriz University h sharif university 1 12 2021 25 3 13 30 19 07 2020 05 11 2020 In drought risk management, the regional analysis of drought is significant. In this paper, this important issue is investigated by presenting the new hydrological regional drought index (RDI). For this purpose, the Ajichai basin was selected as the study area. First, the time series of the streamflow drought index (SDI) was calculated for each of the hydrometric stations in the basin f regional analysis of hydrological drought. Then, to determine the homogeneous regions in terms of hydrological drought, the k-means method was used for clustering analysis. Based on the clustering results, 6 Homogeneous regions were identified in the basin. For each of these regions, the time series of the RDI index was calculated from 1365 to 1393. The results showed that during the study period in each of the regions 1, 2, 3, 4, 5, and 6, mild Wet and mild drought has occurred at 82.1, 80.1, 78.9, 83.3, and 84.3 percent of regions, respectively. Also, the total percentage of drought events (moderate and high) is higher than the total percentage of wet events (moderate and high) in all regions. So, during the study period, the total percentage of drought events (moderate and high) is more than twice the total percentage of wet events (moderate and high) in regions 2 and 3. 3034 Ggeneral Effects of Climate Change on the Probability of Occurrence of the First Fall Frost and the Last Spring Frost (Case Study: Isfahan) Abedi-Koupai J. i Rahimi S. j Eslamian S. k i Isfahan University of Technology j Isfahan University of Technology k Isfahan University of Technology 1 12 2021 25 3 31 44 03 07 2015 04 04 2016 Changing the date of the first fall frost and the last spring frost is an important phenomenon in agriculture that can be one of the consequences of global warming. Using general circulation models (GCMs) is a way to study future climate. In this study, observations of temperature and precipitation were weighted by using Mean Observed Temperature-Precipitation (MOTP) method. This method considers the ability of each model in simulating the difference between the mean simulated temperature and mean precipitation in each month in the baseline period and the corresponding observed values. The model that had more weight, selected as the optimum model because it is expected that the model will be valid for the future. But, these models are not indicative of stationary climate change due to their low spatial resolution. Therefore, in this research, the outputs of GCM models are based on the three emission scenarios A2 and B1 and A1B, downscaled by LARS-WG for Isfahan station. The data were analyzed by SPSS software at a 95% confidence level (P<0.05). The results indicated that in the Isfahan in the future period 2020-2049 based on the three scenarios, as compared with baseline period 1971-2000, the first fall frost will occur later and the last spring frost will occur earlier. The first fall frost will occur later for 2 days (based on the A1B emission scenario) to 5 days (based on the A2 emission scenario) and the last spring frost will occur earlier for 2 days (based on the and B1 emission scenario) to 4 days (based on the A2 emission scenario). Finally, the best distribution functions for the first fall frost and the last spring frost for the baseline period and under climate change were selected and compared using the EasyFit software. 4048 Ggeneral Analysis of Groundwater Balance of Samalqan Plain Aquifer Using SWAT and MODFLOW Models Nasiri Sh. l Ansari H. m Ziaei A.N. n l Ferdowsi university of Mashhad m Ferdowsi university of Mashhad n Ferdowsi university of Mashhad 1 12 2021 25 3 45 57 10 07 2020 01 12 2020 Reducing surface water resources and successive droughts and consequently excessive use of groundwater resources, especially for agricultural purposes, have caused irreparable damage to the natural resources of the country. In the meantime, knowing the status of the water balance of the plain can help to effective management of water resources in the region. Samalqan plain is located in a semi-arid climate in North Khorasan Province. Since the surface water resources for water supply are not very reliable, so, the main source of water supply in the region is well. Due to the existence of rivers in the plain, the low thickness of the alluvium, groundwater level fluctuations, and the high uncertainty in the calculation of hydrodynamic coefficients, the need for careful hydrogeological studies and determining the role of each parameter affecting groundwater is necessary. This study was conducted to simulate the Samalqan aquifer and analysis of water balance for the years 2003 to 2013 using the MODFLOW model. To identify the groundwater recharge rate, this component was estimated by the SWAT model. Calibration and validation of the model with an error of 1.1% and 1.2%, respectively, indicated that an appropriate estimation between the simulated and observed heads. Assessment of the groundwater hydrograph in the observation wells showed that the groundwater level in most places has many monthly and seasonal fluctuations. After drawing the potential lines of the plain, the inputs and outputs were identified, and using the reserve volume changes, the water balance was determined. The results showed that the water balance of the plain was negative and the reservoir deficit was estimated at 9.14 million cubic meters. Therefore, this model can be used to predict the future situation of aquifer and the management of water resources in the region. 4035 Ggeneral Effects of Climate Change on Quantity and Quality of Urban Runoff in a Part of Karaj Watershed Based on RCP Scenarios Noori Khaje Balagh H. o Mousavi F. p o Semnan University p Semnan University 1 12 2021 25 3 59 78 13 06 2020 01 12 2020 In the present study, CanESM2 climate change model and stormwater management model (SWMM) were employed to investigate the climate change effects on the quantity and quality of urban runoff in a part of Karaj watershed, Alborz Province. The base period (1985-2005) and future period (2020-2040) are considered for this purpose. Based on the existing main and lateral drainage system and to be more accurate, the watershed was divided into 37 sub-watersheds by ArcGIS software. To simulate rainfall-runoff, the intensity-duration-frequency (IDF) curve has been prepared for a 2-hour duration and 10-year return period, for the base period and RCP2.6 and RCP8.5 climate change scenarios based on the obtained precipitation data from Karaj synoptic station. Results showed that mean 24-hour precipitation values in RCP2.6 and RCP8.5 scenarios will increase by 21% and 11%, respectively, and maximum 24-hour precipitation values will decrease by 17% and 23%, respectively, as compared to the observed values in the base period. Also, based on the results of quantitative and qualitative runoff modeling in the study watershed, and according to the outflow hydrograph in the RCP2.6 and RCP8.5 scenarios, the outlet runoff discharge will decrease by 5.8% and 7.1%, respectively. Also, the flooded areas in the watershed will decrease by 13% and 15.28%, respectively. The concentration of pollutants in the RCP2.6 and RCP8.5 scenarios, compared to the base period, including total suspended solids (TSS), will increase by 7.48% and 9.24%, total nitrogen (TN) will increase by 6.93% and 8.48%, and lead (Pb) will increase by 7.32% and 8.91%, respectively. 4086 Ggeneral Evaluation of the Efficiency of the CA-Markov Model in Predicting Spat-Temporal Changes of Land Use in Dust Source of South and Southeast Ahwaz Norouzi A. Ansari M.R. Agricultural Sciences and Natural Resources University of Khuzestan, 1 12 2021 25 3 79 94 14 10 2020 08 12 2020 At present, the occurrence of dust storms is one of the most important environmental problems in Khuzestan Province, and the south and southeast regions of Ahwaz have been recognized as one of the interior dust sources and are the priority of corrective operations. Given that land use change is one of the desertification factors in the mentioned region, therefore, modeling its changes is necessary and provides useful information for planners to control and revive the degraded lands. The objective of this study was to evaluate the efficiency of the CA-Markov model in predicting land use changes in the dust source of south and southeast of Ahwaz based on two long-term and short-term approaches. In the long-term approach, land use maps of 1986 and 2002 years and in the short-term approach, land use maps of 2002 and 2007 years have been used to predict land use for the year 2016 and then the simulation results were validated. The results showed that the values ​​of allocation error, quantity error, and kappa coefficient for the long-term approach were 42.55%, 13.95%, and 0.08 respectively, and for the short-term approach were 12.56%, 10.42%, and 0.22 respectively, which indicates the weak ability of the CA-Markov model to evaluate the desertification trend in the dust Source of south and southeast Ahwaz. Use of uniform transition rule throughout the simulation period without considering the factors and processes affecting land use change, the non-same trend of land use change during study periods, changes due to human activities, drought, and long forecast period can be the reasons for the poor performance of the CA-Markov model to predict the desertification trend the dust Source of south and southeast Ahwaz. 4069 Ggeneral Optimization and Management of Water Consumption in SugarCane Using the AquaCrop Simulation Model (Case Study: Amirkabir Industrial Cultivation, Khuzestan) Abedinzadeh M. Bakhshandeh A. Andarziyan B. Jafari S. Moradi telavat M Ramin Khuzestan University of Agriculture Open in Google Translate Ramin Khuzestan University Agricultural Research and Training Center and Natural Resources of Khuzestan Province, Agricultural Research, Education and Extension Organization, Ahvaz, Iran. Ramin Khuzestan University of Agriculture Open in Google Translate Ramin Khuzestan University of Agriculture Open in Google Translate 1 12 2021 25 3 95 114 07 09 2020 19 12 2020 Iran is located in the dry belt of the earth and is predicted to face water stress in the next half-century. Currently, the area of sugarcane cultivation in Khuzestan is over 85,000 hectares and due to the high water needs of sugarcane and drought conditions, optimization of water consumption and irrigation management is necessary to continue production. Therefore, in this study, the values of soil moisture, canopy cover, biomass yield in five treatments and irrigation levels (start of irrigation at 40%, 50%, 60%, 70%, and 80% soil moisture discharge) during 2 planting dates in the crop year 2015-2016 on sugarcane cultivar CP69-1062 in Amirkabir sugarcane cultivation and industry located in the south of Khuzestan was simulated by AquaCrop model. The measured data on the first culture date (D1) and the second culture date (D2) were used to calibrate and validate the model.  The results of NRMSE statistics in canopy cover simulation in calibration and validation sets with values of 2.1 to 15.6% and 3.8 to 18.3%, respectively, and in biomass simulation with values of 6.2 to 15.2%, and 9.5 to 12.6%, respectively and coefficient of determination (R2), range 0.98 to 0.99 indicated that the high ability of the AquaCrop model in simulation canopy cover and biomass yield. whereas, the values of NRMSE of soil depth moisture in the calibration and validation sets ranged from 11.6 to 23.8, and 12.2 to 22.7, respectively, with a coefficient of determination (R2), 0.73 to 0.96 (calibration) 0.8 to 0.93 (validation) showed less accuracy of the model in the simulation. The best scenario is related to the third proposal that water consumption, water use efficiency, and yield are 1710 mm, 1.53, and 42.27 tons per hectare, respectively, which shows a reduction in water consumption of 360 mm. 4034 Ggeneral Estimation of Snow Cover Level in Ardebil and Sarein Cities Using Sensor Data Sentinel2 MSI Satellite Asghari saraskanrood S. Modirzadeh R. Mohaghegh Ardabili University Mohaghegh Ardabili University 1 12 2021 25 3 115 130 07 06 2020 19 12 2020 Snow cover is one of the important climatic elements based on which climate change may have a special effect. In general, climate change may be reflected in different climatic elements. Therefore, it is very important to study and measure changes in snow level as one of the important sources of water supply. Ardebil and Sarein cities are located at 48° 18׳ east longitude and 38° 15׳ north latitude. In this study, Sentinel-2 optical satellite was used to monitor the snow cover surface in 2018, and NDVI, S3, NWDI, NDSI, Cloud mask indices were applied to detect snow-covered surfaces using ArcGIS and Snap software. Next, to validate the snow maps extracted from the images, it was compared with the snow data in terrestrial stations using linear regression in MATLAB software and to evaluate the accuracy of the model statistical indices including RMSE, MSE, BIAS, CORR were used. The present study showed that according to Ardabil city climatic conditions, maximum-snow covered area in January with an area of 356.52 km2 and minimum snow-covered area in March with an area of 96.10 km2. The highest snow cover is observed in the high slope areas in the western slopes (Sabalan Mountain Heights) and the lowest snow cover is observed in the lower eastern slopes. The results of linear regression with generalization coefficient are 85% and the results of statistical indices of error are equal to MSE: 0.086, BASAS: 0.165, CORR: 0.924, and RMSE: 0.03. Correlation relationships between terrestrial data and estimated snow maps showed a high degree of correlation. This result is statistically significant at the 99% level. The use of optical images in estimating snow levels is very cost-effective due to the size of the areas and the high cost of installing snowmobiles. The results obtained in the present study indicated that traditional radar images with high spatial resolution and good correlation with terrestrial data can be a good alternative to snowmobiling ground stations at high altitudes or in passable areas. 4036 Ggeneral Variability of Sediment Components with Application of Vermicompost and Nano-manure and Various Moisture Levels Gholami L. Khaledi Darvisan A. Karimi N. Sari Agricultural Sciences and Natural Resources University Tarbiat Modares University Sari Agricultural Sciences and Natural Resources University 1 12 2021 25 3 131 143 14 06 2020 21 12 2020 Soil loss can cause many intra-regional and extra-regional problems, on the other hand, the effect of soil moisture on processes of soil loss and sediment yield for the identification and simulation of soil hydrological response is necessary. Therefore, the application of soil conditioners is essential for soil and water conservation. The present study was conducted to investigate the effect of soil conditioners of vermicompost and nano-manure on variables of soil loss and sediment concentration at moistures of air-dried, 15 and 30%, and rainfall intensities of 50 and 90 mm h-1. The obtained results in addition to confirmation of the significant effect of each conservation treatment at the level of 99 percent on the intended components showed that the conservation treatment of vermicompost compared to nano-manure treatment had more effect on measured variables. Also, the conservation treatment of vermicompost could decrease the soil loss at soil moisture air-dried, 15, and 30 percent with rates of 72.15, 66.63, and 78.76 percent (50 mm h-1), respectively, and 45.01, 35.57, and 10.45 percent (of 90 mm h-1), respectively. The effect of conservation treatments, soil moistures, and rainfall intensity and the interaction effects of conservation treatments × rainfall intensity and rainfall intensity × soil moisture on changes of soil loss and sediment concentration were significant at the level of 99 percent. The application of vermicompost and nano-manure had acceptable results on studied parameters but the vermicompost effect was more than nano-manure. Therefore, due to the widespread use of different types of conditioners, nowadays, it is needed to move the application feasibility of conditioners such as vermicompost and nano-manure that these have not the adverse effects of environmental. 4066 Ggeneral Identification of Dust Sources and Storms in the South of Kerman Province Using Remote Sensing Data Jafari R. Sanati H. Isfahan University of Technology Isfahan University of Technology 1 12 2021 25 3 145 158 26 08 2020 21 12 2020 The southern regions of Kerman Province have repeatedly encountered dust storms. Therefore, the objective of this study was to identify dust sources using effective parameters such as vegetation cover, land surface temperature, soil moisture, soil texture, and slope as well as to detect dust storms originating from these regions based on 31 MODIS images in 2016 and SRTM data. After normalizing parameters, the dust source map was prepared by fuzzy logic and assessed with an error matrix and available dust source map. Results showed that 30.5% of the study area was classified as a low source of dust, 39.55% as moderate, and 29.85% as severe-very severe. The overall accuracy of the produced map was about 70% and the producer and user accuracy of the severe-very severe class was more than 87%. The detection of dust storms originated from the identified dust sources also confirmed a crisis situation in the region. Due to the repeatability and continuity of obtained dust source map at pixel scale, it can be used to update available dust source maps and manage dust crisis in the region, properly. 4083 Ggeneral Digital Mapping of Surface Soil Salinity in Khuzestan Province, Using Regression Kriging Savari Z. Hojati S. Taghizadeh Mehrjerdi R. Shahid Chamran University of Ahvaz Shahid Chamran University of Ahvaz Ardakan University 1 12 2021 25 3 159 175 05 10 2020 13 01 2021 Soil salinity and its development are the main problems that should be prevented by correct management methods. Recognition of saline districts and the preparation of salinity maps are the first steps in this way. Nowadays, the application of auxiliary data in digital soil mapping is increasing due to the current associated problems in the preparation of traditional maps. The objectives of this study were to map soil salinity by the Regression Kriging (RK) method,  to identify areas with high salinity, and to investigate the relationship between soil salinity and soil-forming factors in Khuzestan Province. For this purpose, 291 surface soil samples (0-10 cm) were randomly collected in April 2014. Auxiliary variables or soil-forming factors were included in the land parameters such as slope, watershed and wetness index, OLI and TIRS images of Landsat 8, and the category maps (soil, land use, and geological maps). Also, kriging approaches were used to compare the precision of different mapping methods. The results indicated that the Regression Kriging method has a higher precision compared with other methods so that the coefficient of determination, Mean Absolute Error (MAE), and Root Mean Square Error (RMSE) were estimated as 0.84, 0.41, and 6.21, respectively. The Decision Tree Regression method could also create a good relationship between soil salinity and auxiliary variables. The results showed that some auxiliary variables were more effective on the prediction of soil salinity including 2, 4, 5, and 7 bands of Landsat 8, Brightness Index, Wetness Index, Multiresolution index of Valley Bottom Flatness (MrVBF), Channel Network Base Level (CNBL), NDVI, SAVI and soil map. A Digital map of soil salinity was prepared by the obtained rules, and then it was assimilated with the map of error of variance to prepare the final soil salinity map. Accordingly, soil salinity was found to have an increasing trend from north to south in Khuzestan Province which indicates a salinity problem in the south of the Province. The main reasons for the high salinity in the south and southwestern parts of the area could be attributed to the high water table levels, differences in topography, capillary movement of salt to the soil surface, the difference in the type of land uses, and also groundwater quality and irrigation water which is altered by the frequent application of wastewaters and animal manures. 4067 Ggeneral Two-Objective Simulation-Optimization Model for Cropping Pattern and Water Allocation in Semnan Plain Ghodspour M. Sarai Tabrizi M. Saremi A. Kardan Moghadam H. Akbari M. Islamic Azad University, Tehran scince and Research Branch, Tehran, Iran Islamic Azad University, Tehran scince and Research Branch, Tehran, Iran Islamic Azad University, Tehran scince and Research Branch, Tehran, Iran Ministry of Energy Water Research Institute Arak University 1 12 2021 25 3 177 189 01 09 2020 13 01 2021 The application of simulation-optimization models is a valuable tool for selecting the appropriate cropping pattern. The main objective of this research is to develop a two-objective simulation-optimization model to determine the pattern of cultivation and water allocation. The model performs the optimization with the multi-objective metamorphic algorithm (MOALO) after simulating different states of the cultivation pattern. The decision variables including land and water allocated to ten-day periods of plant growth were designed in a way that the minimum utilization of water resources and economic maximization were identified as target functions. The developed model was used to simulate and optimize the cultivation pattern with an area of ​​5500 hectares and water allocation of Semnan plain with renewable water at the rate of 60.8 million cubic meters. Harvesting scenarios of 80 (GW80) and 100 (GW100) percent of renewable groundwater and scenarios of change in existing cropping pattern of 30 (AC30) and 60 (AC60) percent were considered and each scenario was simulated with the MOALO algorithm. Optimization using the proposed model in four scenarios improved the water and economic objective functions compared to the initial simulation performance. The results showed that the four proposed scenarios were obtained by minimizing the water objective function and maximizing the economic objective function relative to the current situation (simulation). In general, the proposed model had a good performance despite its simplicity, which is a specialized tool to optimize the crop pattern with water allocation. 4019 Ggeneral Comparison of the Efficiency of Soil Taxonomy (2014) and WRB (2015) Systems in the Study of Soil Variations in Different Landform Positions Khosravani P. Baghernejad M. Abtahi A. Ghasemi R. Shiraz University Shiraz University Shiraz University Shiraz University 1 12 2021 25 3 191 207 23 04 2020 13 01 2021 Soil classification in a standard system is usually defined based on information obtained from properties and their variations in different map units. The aim of this study was to compare soil genesis and morphological characteristics in different landforms with WRB and Soil Taxonomy (ST) Systems. From nine studied profiles, six profiles were selected as representative profiles and dug in Colluvial fans, Piedmont plain, and Alluvial plain physiographic units, respectively. Then, the soils were classified according to the pattern of the two systems. Also, variation analysis of variance (ANOVA) and comparing means were used to quantify interested soil properties. The results of soil physio-chemical properties at different landform positions were significant based on analysis of variance of the effect of physiographic units and soil depth at the level of 1 %. Soil classification results based on WRB indicated that WRB were recognized four reference soil groups (RSG) included Regosols, Cambisols, Calcisols, and Gleysols at the first level of WRB classification in comparison of ST with recognizing two order Entisols and Inceptisols could separate more soils. The soils were located on the alluvial plain with a high groundwater level in the WRB due to the creation of restrictive conditions for root development in contrast to the ST called “Aquepts” in the suborder level but in a WRB is classified as the “Gleysols” RSG. On the other hand, ST, unlike WRB, used the Shallow criteria at the family level to describe the shallowness of soils and the limitations of root development. Generally, the efficiency of each system varies despite the differences in their structure and depending on the purpose of using them. 3928 Ggeneral Experimental Study of Discharge Coefficient at the Dentate Trapezoidal Labyrinth Weir Meshkavati toroujeni J. dehghani A.A. ٍEmadi A. Masoudian M. Sari Agricultural Sciences and Natural Resources University Gorgan Agricultur and natural resource university Sari Agricultur and natural resource university Sari Agricultur and natural resource university 1 12 2021 25 3 209 224 02 09 2019 20 01 2021 One of the crucial problems that exist in the irrigation networks is the fluctuation of the water surface flow in the main channel and changes in the flow rate of the intake structure. One of the effective methods to decrease these fluctuations is increasing the weir crest length at the given width of the channel with the use of the labyrinth weirs can be achieved for this purpose. The labyrinth weir is the same linear weir that is seen as broken in the plan view. In this study, a labyrinth weir with a length of 3.72 m, three different heights of 15, 17, and 20 cm, three different shapes of dentate (rectangular, triangular, and trapezoidal), and a linear weir were used in a recirculating flume with 15 m length and 1 m width. The result showed that for a given length and height of weir, with the increasing of the upstream water head to the weir height ratio (), the discharge coefficient decreases. The results showed that by increasing weir height, the discharge coefficient decreases for a given length of the weir. Linear weir and labyrinth weir without dentate create more water depth at the upstream by 3.3 and 1.2 fold compared with dentate labyrinth weir. 4062 Ggeneral Predicting the Future of Desertification in Tehran Province Affected by Climate Change and Human Activities Sayadi M. Khosravi H. Zareh S. Ahmadali Kh. Bagheri S. University of Tehran University of Tehran University of Tehran University of Tehran University of Tehran 1 12 2021 25 3 225 244 14 08 2020 31 01 2021 Desertification is a phenomenon that has more destructive effects in arid, semi-arid, and semi-humid regions than in other regions. This paper tries to provide a map of the future of desertification in Tehran Province, for futurism in the face of land degradation and desertification. The IMDPA model was used to evaluate land degradation and desertification. To use this model and evaluate desertification, three criteria of groundwater including groundwater depletion, electrical conductivity, and sodium adsorption ratio indices, climate criterion including precipitation, aridity, and drought indices, and land use criteria were selected as key criteria effected on desertification according to regional conditions. Land use index map with IGBP standard and zoning map of other indicators were prepared by IDW method for 2011 and 2016. The maps of land use index and other indices were predicted using the CA-Markov model in TerrSet software, and using the RBF method in artificial neural network toolbox, respectively. Scoring based on the IMDPA model, the maps of indices and criteria maps were prepared for 2011, 2016, and 2021. Finally, the desertification intensity map was calculated by geometric averaging for all three criteria for all three time periods. The results showed that 59.78% and 40.22% of the area of Tehran Province were in the low and medium classes, respectively. However, in 2016, the area of the medium class has increased to a 44.8%, and it is predicted that this increase will continue until 2021 so that 47.65% of the area of Tehran Province will be in the medium class. In addition, in this year, about 1% of the area of Tehran Province will be allocated to the high class in the western regions, which did not exist in the previous two periods. In general, due to human activities, the intensity of desertification in the western and southern parts of the province is higher than in the eastern and northern regions. 4055 Ggeneral Estimation of Seasonal Capillary Rise and its Relationship with Evapotranspiration and Soil Salinization in Khuzestan Region Rahimian M.H. Abedi Koupaei J. National Salinity Research Center (NSRC), Isfahan University of Technology 1 12 2021 25 3 245 260 26 07 2020 06 02 2021 Soil salinization is a phenomenon that threatens agricultural lands and natural areas, leading to reduced productivity, declinations of soil resources and vegetation covers, and finally, the abandonment of these areas. This study has quantified the groundwater Capillary Rise (CR) and actual Evapotranspiration (ETa) and their relationship with the soil salinity of Azadegan plain, west of Khuzestan Province. The study area has an arid climate, characterized by shallow and saline water table and a high potential evaporation rate. For this purpose, field samplings were carried out in four consecutive seasons of the year to measure salinity, soil moisture, and texture, groundwater table, and salinity at 27 scattered representative points of the study area. The CR values were estimated in different seasons of the year using UPFLOW model. Moreover, four representative Landsat satellite images were acquired to map seasonal changes of ETa through the SEBAL algorithm. Then, the effects of ETa on CR and consequent soil salinity build up were quantified in a seasonal time scale. The results showed that the average daily ETa of Azadegan plain varied from 1.55 to 7.96 mm day-1 in different seasons which caused a capillary rise of around 1.2 to 1.5 mm.day-1. This has led to the upward movement of 12 to 18.8 ton ha-1  month-1 of salts from shallow groundwater to the soil surface, which has caused surface soil salinization. Also, there was a close relationship between ETa, CR, and soil salinity parameters, which can provide insight into modeling of spatial and temporal changes of soil salinity and provision of solutions to reduce the accumulation of solutes in the soils of the study area. 4027 Ggeneral Evaluation of Efficiency of Sediment Transfer Functions in GSTARS Numerical Model Asadi F.Z. Fazloula R. Emadi A. Sari Agricultural Sciences and Natural Resources University Sari Agricultural Sciences and Natural Resources University Sari Agricultural Sciences and Natural Resources University 1 12 2021 25 3 261 273 16 05 2020 13 02 2021 Investigating and understanding river change issues is one of the important factors in sediment hydraulic sciences and river engineering. These studies can be done with the help of physical, mathematical models, or both, but due to financial and time constraints, mathematical models are more general and often used. In this study, the GSTARS model was used to investigate erosion and sedimentation and select the most appropriate function in 12.5 km in length from the Talar river in Mazandaran Province. Simulation using the 55 sections taken in 2006, the daily flow data of the hydrometric station of the Shirgah, located at the beginning of the rich and characteristics of the river sediment, was done. The calibration and validation of the model with cross sections taken in 2012 showed that Yang's sediment transport equation has the highest correlation with reality and can be used to predict river change. The amount of sediment depleted from the case study using the Yang equation is estimated at 8590 tons per year. Also, the study of longitudinal profiles of the river with different sediment transfer functions showed that the study reach at the end range has an erosion trend and is not capable of sand and gravel mining. 4057 Ggeneral Assessing the Trend of Spatial Land Use Changes of Karun 3 Dam in the Period 1991 to 2018 Pajouhesh M. Shekohideh H. Heydari Z. Shahrekord University Shahrekord University Shahrekord University 1 12 2021 25 3 275 288 04 08 2020 27 02 2021 Land use changes identifying to assess and monitor sensitive areas for sustainable planning and land management is essential. Remote sensing and the use of GIS technology as some of the most common methods in the world in monitoring land changes, especially, in the study of large areas. In this study, the trend of spatial land use changes in the area of Karun 3 dam was investigated. in the before and after the construction periods and dam intake using remote sensing and GIS over 27 years. In this study, the satellite imagery of Landsat 5 TM sensors from 1991 and 2008 and Landsat 8 OLI sensors in 2018 were analyzed and processed. Using object-oriented classification with land use maps for the three periods 1991, 2008, and 2018 with the overall accuracy of the Kappa index of 0.93 and 0.89 percent for 1991, 0.94, and 0.88 percent in 2008 and 0.93, respectively, and 0.86% in 2018 was prepared. The results showed that the water use of the region with an area of 37.68 square kilometers is increasing and agricultural lands and residential areas with an area of 1349.04 and 226.56, respectively, forest lands with an area of 1041.49 remained as the dominant cover of the region and rangelands by going through a decreasing trend of increase in both periods after forest use, with an area of 878.87, they had the largest area. According to the obtained results, it can be said that the construction of the Karun 3 dam has caused the flooding of agricultural lands and their conversion to another use, as a result of which the villagers were forced to migrate due to losing their jobs and abandoned residential areas become other uses. 3958 Ggeneral Rain Water Use Efficiency of Rainfed Wheat (Triticum aestivum L.) as Affected by Tillage Direction in Slope Vaezi A. Zarrinabadi E. Salehi Y. University of Zanjan University of Zanjan University of Zanjan 1 12 2021 25 3 289 304 01 12 2019 27 02 2021 The effective use of rainwater is a key issue in agricultural development in arid and semi-arid regions. The tillage system as an important soil management measure can affect the rainwater retention, soil moisture content, and in consequence crop yield in rainfed lands. This study was conducted to evaluate the effects of slope gradient and tillage direction on rainwater use efficiency (RWUE) in rainfed lands in Zanjan Province. The field experiment was performed in five slope gradients (12.6, 15.3, 17, 19.4, and 22%) and two tillage directions (along slope and on contour tillage) at two replications. Mass soil water content was determined at 5-day intervals and runoff was measured after rainfalls. Wheat grain yield was determined for each plot and RWUE was computed using the proportion of wheat grain yield and precipitation. Base on the results, runoff, soil moisture, wheat grain yield, and RWUE were affected by tillage directions, so that runoff in contour line tillage decreased about 6.4 times compared to along slope tillage and in consequence increased soil moisture, wheat grain yield, and RWUE about 8.7, 24.8, and 24.8%, respectively. Increasing runoff production in contour line tillage at steeper slopes was associated with a lower capacity of cultivated furrows that strongly declined soil water retention and negatively affected wheat grain yield and RWUE in the lands. This study revealed that the efficiency of the contour tillage in water retention and RWUE decreases in steeper slopes in rainfed lands. 4082 Ggeneral Analysis of Earth Dam Body Behavior under Rapid Drawdown Conditions in Reservoir Water Level by Laboratory and Numerical Methods Pakmanesh M. Mousavi Jahromi H. Khosrojerdi A. Hassanpour Darvishi H. Babazadeh Hossein Islamic Azad university, Tehran, Iran Islamic Azad university, Tehran, Iran Islamic Azad university, Tehran, Iran Islamic Azad university, Tehran, Iran Water Engineering Departments Islamic Azad university, Science and research Branch, Tehran, Iran 1 12 2021 25 3 305 318 04 10 2020 28 02 2021 The present study is investigated the earth dam stability during drawdown based on both numerical and experimental aspects. To validate the numerical model, a model was performed experimentally. Some soil mechanic tests were carried out through the hydraulic experiments to attain the usage factors of the numerical investigation. To investigate the effect of hydraulic conductivity on the rapid drop of water level and the use of hydraulic parameters of materials, seepage flow in the model was modeled by seep/w software. The input information to the software including hydraulic conductivity and water volume were measured by performing a constant load test and using a disc penetration meter, respectively. After validation of hydraulic conductivity with the experimental model, the results were compared with observed data. Comparison between numerical and laboratory discharge illustrated that the numerical model with laboratory model is well confirmed. In addition, saturated and unsaturated simulations demonstrated that the unsaturated model is highly consistent with the experimental model. It is assumed that due to the drawdown conditions, unsaturated models can achieve high accuracy for simulating the flow through a homogeneous earth dam.