JWSS - Journal of Water and Soil Science

In this research, a regression model was introduced to study the mechanisms of the formation of gullies in the Quri Chay watershed, northern Ardebil province (Moghan Plain); this was done through investigating the effective factors of geo-environment and soil characteristics on the gully erosion. For this purpose, 17 gullies were randomly assigned through field surveys. Mapping and recording the morphometric of the selected gullies were performed by GPS positioning after seven rainfall events. The catchment-upper area of each gully was determined and its related physical parameters were calculated in order to investigate the effect of the physical characteristics of the catchment. Soil sampling was also done at the head of each gully at two different depths (30-30 and 60-30 cm) in order to determine the physical and chemical characteristics of the soil. According to measurement of the morphometric characteristics of the gully and soil characteristics through multivariate analysis of the data, a suitable regression model was developed for the longitudinal development of erosion after determining and calculating environmental factors related to the upper catchment of the gullies. The results of the correlation matrix between the longitudinal extension of the gully and the factors investigated indicated that the factors related to the physical characteristics of the beside watershed (area, perimeter, main stream length and average width of the catchment, main stream slope), gully morphometric characteristics (mean of gully cross section, the gully expansion area, and the gully average width) and soil characteristics (geometric mean of the aggregates diameter, lime, organic matter percentage) affected  the formation and expansion of gully erosion in the Quri chay catchment. The results of regression analysis showed that the longitudinal expansion of the gully was mostly influenced by the area around each gully and the percentage of organic matter, which resulted in pressure on the rangeland and the loss of vegetation, which increased runoff and accelerated the lengthwise expansion of the gully. Also, the  increase in the area of the beside catchment the gullies is known as one of the factors influencing the length of the gully, due to the high volume of runoff entering the head cut section; so it is necessary to manage  runoff in the gully with the large beside catchment.

The aim of this study was to evaluate the effect of increasing DEM spatial resolution on the assessment of the morphometric characteristics of waterways, as well as analysis and modeling of it by using RS and GIS techniques. In this study, which was carried out in the south of Darab city DEM 90 m (as one of the most usable data in waterway modeling), increase spatial resolution of DEM attraction algorithm in neighboring pixels with two models including: touching and quadrant neighboring models to estimate the value of sub-pixels. After manufacturing output images for sub pixels in 2, 3 and 4 scales with different neighborhoods, the best scale with the most appropriate type of neighborhood was determined using ground control points (270 points); then, the values of RMSE were calculated for them. The results showed that with using the Attraction model, the accuracy of the output of images was improved and the spatial resolution of them was increased. Among scales with different neighborhoods, 3 scales and quadrant neighboring model exhibited the most accuracy by the lowest value of RMSE for the DEM 90 meter. Evaluation of waterways morphometric features showed that DEM extracted from attraction algorithm had more ability and accuracy in waterways extraction, Extraction of morphometric complications, and information in the study area.

Subsurface drip irrigation systems, compared to other irrigation systems (basin and furrow), enhance the delivery of water and nutrients directly into the root zone. The purposes of this study were to determine wetting front advancement in a subsurface drip irrigation and to compare the results with the HYDRUS 2D model simulation. In this study, the irrigation using T-Tape was carried out on a sandy-loam soil by two emitters at different irrigation times. The Wet moisture meter device was used to determine the soil water content. Evaluation of the simulated and measured soil water content was performed by using the adjusted determination coefficient (R²), relative error (RE), and the normalized root mean square error (NRMSE). Based on the results, the NRMSE of soil water content prediction for the emitters at the depths of 20 and 40 cm was calculated to be in the range of 10 to 19 and 10 to 13 percent, respectively. Also, RE for the emitters at depths of 20 and 40 cm was in the range of -16 to -5 and 8 to 11 percent, respectively. The average R² for the emitters at depths of 20 and 40 cm was calculated to be 0.87 and 0.98, respectively. Also, five scenarios (F1, F2, T1, T2 and S1) were evaluated to assess the amount of water stored in the soil profile and water mass balance. The results indicated that the model could be used to predict the soil water content subsurface drip irrigation.

Preferential flow is of great importance in the environment and the human health. So, rapid water transportation and consequently, pollutants and pesticides leak out and get into the groundwater, making it very difficult to measure and quantify. To quantify and describe the preferential flow, two gravity-driven models were used: 1) kinematic wave model (KW) introduced by Germann in 1985), and 2) kinematic dispersive wave (KDW) model developed by applying a second-order correction to the Germann’s model by Di Pietro et al. in 2003. So, the experimental data was obtained using the laboratory mini-rainfall-simulator over cylindrical soil samples at the laboratory. Their parameters were obtained using Solver add-ins in the Excel software. Then, the results were compared using the root-mean-square error (RMSE). The results showed that the KDW model could better predict the preferential flow (with lower RMSE). Also, the regression results showed 1) there was no significant relation between the preferential flow and the total porosity, and 2) there is a significant relation between the preferential flow and the macrospores.

Quantitative description of the spatial variability of soil hydraulic characteristics is crucial for planning, management and the optimum application. Field measurement of infiltration is very expensive, time-consuming and laborious. Soil structure also important effects on water infiltration in the soil. The objectives of this study were to determine the spatial variability of water infiltration, to select the most appropriate infiltration model, to calculate the parameters of relevant models, and to quantify the soil structure by using the fractal geometry. Infiltration parameters were estimated by using some physical soil properties, as well as fractal parameters, in this research. To achieve these purposes, 161 sites were selected and their infiltration was measured by using the constant head double-ring infiltrometers method in a systematic array of 500*500 m. The observed infiltration data from all examined sites were fitted to three selected infiltration models. Soil bulk density (BD), soil water content, soil particle size distribution, soil aggregate size distribution (ASD), organic carbon content (OC), saturation percentage (SP), soil pH and electrical conductivity (EC) were also measured in all 161 sites. For the quantitative assessment of soil structure, the aggregate size distribution, fractal parameters of the Rieu and Sposito model as well as the mean weight diameters (MWD) and geometric mean diameter (GMD) were also obtained. The obtained results indicated that the infiltration rates of the studied areas had generally low basic infiltration rates (1.1-31.1 cm hr^-1) for most sites with the average of 6.69 cm hr^-1. According to all obtained results and based on the least-square method, the Philip model was selected as the best performing model to account for infiltration. The aggregate size distribution demonstrated a fractal behavior, and the infiltration parameters could be significantly correlated with the fractal parameters and other soil physical properties.

In the vast majority parts of the Earth, a prospect now visible is the mostly synthetic thinking and fabrication by the human hand. Collision and impact of humans on the natural environment in the short and long-term courses for obvious geographical features have changed a variety of spaces. One of the consequences of human impact on the natural environment during the current period is the phenomenon of climate change. One of the climatic parameters that plays an important role in agriculture, energy, urban, tourism and road transport is the minimum temperature. In this study, an attempt was made using the minimum temperature data from 5 meteorological stations in the West Mazandaran province, as well as HADCM3 model data, to show how to change this parameter in the future periods based on simulation by the SDSM model. Accordingly, after selection of the suitable climate variables and model calibration, the accuracy of the created model in the base period was evaluated; after ensuring the sufficient accuracy of the model according to A2 and B2 scenario, data minimum temperature in 2100 was simulated. Based on the simulation results showed that the values of minimum temperature in the region over the coming years would increase. This parameter was such that the average seasonal periods 2016 to 2039, 2040 to 2069 and 2070 to 2099, as compared to the baseline period would increase, on average, by 1.8, 3.5 and 6 percent. The largest increases in the minimum temperature in the western and southern parts of the region could occur. It was also found that unlike other months of the year, the minimum temperature in January would be a decreasing trend.

Water is a vital source for both human and biological living. Today, water management and conservation, not only both in developing countries but also in and the developed countries ones, has is of great importance. In the traditional economy, water is not considered as a productive factor in the national accounts; however, but in reality, water is the primary factor in many direct and indirect goods and services. To evaluate the effect of growth in the added value of agriculture, industry and electricity sectors on the added value of water sector in the Mazandaran province, coefficients of ARDL model were estimated using the Micro fit software. The extended Dickey-Fuller unit root test was used for the statistical test of variables. The static test of variables showed that all variables were significant at the 95% confidence level and were also consistent with the theory. A 1% increase (decrease) in the added value of industry and electricity resulted in the increase of 0.54 % and 0.39 %, respectively, increase (decrease) in the added value of the water sector, respectively. Also, 1% increase (decrease) in the added value of the agricultural sector caused in a 0.54% increase (decrease) in the added value of the water sector. Industry and electricity sectors affected the added value of water sector more than agriculture. In the long-term, the growth of the added value of the industry sector had the greatest impact on the growth of the added value of water sector. Based on the results, controlling water use in agriculture, industry and electricity sectors increases increased the effects of the added value of these sectors on the added value of the water sector.

Due to the growing population, crop production is one of the essential needs of the society. Since soil and water salinity can have a great impact on the crop yield loss; so, the appropriate irrigation method can be applied to reduce these effects. In this study, the system dynamics model was developed using VENSIM. The model simulated the effect of salinity and water stress on the crop yield, moisture and salinity of the root zone. In order to calibrate and validate the model results, 9 treatments data were collected from the Right Abshar Irrigation Network, on the Zayandehrud basin. After statistical analysis and calculation of RMSE index and the standard error, the fit between the measured and simulated crop yield, the moisture and salinity of root zone was calculated. The average of these indexes for all treatments was 2776.98 kg/ha and 0.07 for crop yield, 0.026 and 0.09 for soil moisture and final, 0.54 dS/m and 0.08 for the salinity of root zone, respectively. The results showed that the model could be calibrated accurately and completely in estimating the crop yield with the reasonable accuracy.

Sugar beet is one of the most important agricultural crops and its yield depends on irrigation water. Due to the impossibility of assessing the effect of all water amount strategies on sugar beet yield, it is necessary to use crop models such as WOFOST, AquaCrop and Cropsyst. In order to achieve this goal, a set of data collected from Shahrekord’s Agricultural Research Station were used. Treatments consisted of irrigation water amount (in five levels: E0: 100%, E1: 85%, E2: 70%, E3: 55%, and E4: 30%) based on crop evapotranspiration in different growth stages (T1: initial, T2: T2: mid-season, and T3: late season). The values of RMSE statistical criteria for the results of AquaCrop, WOFOST and CropSyst simulation were equal to 0.57, 0.68, and 0.26 ton.ha^-1, respectively. NRMSE results were also obtained to be 0.11, 0.13, and 0.05 ton.ha^-1 for the mentioned crop mpdels, respectively. The results of the EF criteria revealed that CropSyst (0.91) had better efficiency, as compared to AquaCrop (0.62) and WOFOST (0.47). Regarding the results, it is suggested to use CropSyst to simulate sugar beet yield in similar conditions.

Increasing the productivity and conservation of limited water resources in the agricultural sector, especially in the agricultural sub-sectors, is closely related to the revision of the traditional approaches of production system in the agricultural sector of developing countries. The aim of this study was to develop the optimal combination of crop production in Varamin Agricultural and Animal Husbandry Complex as one of the leading agricultural units in the agricultural sector of Varamin County with the emphasis on increasing water use efficiency. For this purpose, the statistical data and information of the 2015-2016 crop year of the complex were used in the framework of the multi-criteria decision making model. The results showed that in the optimum crop pattern in this unit, the priorities of maximizing net energy production and the annual profit as the economic goals would be significantly aggregated with the goal of increasing water use efficiency. Accordingly, in the optimum condition, net energy production was increased by 10%, gross profit was improved by 4%, and water use efficiency was promoted by 15%. Therefore, according to the results, it is suggested that, in order to achieve the economic aspirations and increase water use efficiency in Varamin Agricultural and Animal Husbandry Complex, wheat, alfalfa, silage and maize corn, based on the values calculated in this study, constitute the main combination of the crop production pattern.

Today, supplying water to meet the sustainable development goals is one of the most important concerns and challenges in most countries. Therefore, identification of the areas with groundwater potential is an important tool for conservation, management and exploitation of water resources. The purpose of this research was to prepare the potential groundwater map in Nahavand, Hamedan Province, using the weight of evidence model and combining it with logistic regression. For this purpose,  the information layers of slope angle, slope aspect, slope length, altitude, plan curvature, profile curvature, TWI, SPI, distance from fault, fault density, distance from river, drainage density, lithology and land use were identified as the  factors affecting groundwater potential and digitized in the ArcGIS software. After designing the groundwater potential map with these three methods, ROCs were used to evaluate the results. Of 273 springs identified in this study, 191 (70%) were used to prepare the groundwater potential map and 82 springs (30%) were used to evaluate the model. The area under curve (AUC) obtained from the ROC curve showed an accuracy of 80.4% for the weight of evidence model and 82.5% for the weight of the evidence- regression combined model

Fruits and citrus wastes are generated in the food industry in large quantities. Their management in Iran, as one of the major hubs of fruits and citrus production, is of great importance. In this study, the biochar samples were prepared from pomegranate, orange and lemon peel waste produced in a juice factory using the pyrolysis process in the range of 400-500 °C; then their efficiency for zinc adsorption from an aqueous solution was investigated. The kinetic and isotherm data of zinc adsorption were fitted by the linear and nonlinear forms of the Langmuir and Frendlich isotherm models and the first-order and second-order pseudo-kinetics models. The results showed that under the experimental conditions applied, the maximum amount of zinc absorption by biochars derived from pomegranate, orange and lemon peel was 2.42, 1.83 and 3.17 mg/g, respectively. The results of adsorption isotherm models also showed that the use of the linear form could lead to a completely different interpretation, as compared to the original form of the model. Based on the linear forms, the Langmuir isotherm was the best; meanwhile, according to the non-linear forms, the Freundlich isotherm was the best model to describe the adsorption data. In addition, the reaction kinetics indicated that both original and linear models had the same results, and the data were better fitted by the pseudo-second order model.

In this study, the effect of some soil parameters on the life forms and total aboveground net primary production (ANPP) in meadow rangelands in Fandoghlou region of Namin county in Ardabil Province were investigated. ANPP in 180 plots of 12 by harvesting and weighting method were measured. Eighteen soil samples were collected along transects. Some physical and chemical attributes of the soil were measured by standard methods. The relationship between these parameters and ANPP was performed using multivariate regression (enter) method. To determine the effects of important soil parameters on ANPP variation, principal component analysis (PCA) was used. The results of regression analysis showed that electrical conductivity (EC), magnesium (Mg), spreadable clay (WDC), volumetric moisture content (VM), organic carbon (OC), soluble potassium (KS), exchangeable potassium (Kexch), sodium (Na) and phosphorus (P) were the effective parameters on the life forms and total ANPP (p<0.01). The accuracy of obtained equations for grasses, forbs and total ANPP were calculated 79, 76 and 70%, respectively. Moreover, results of PCA showed that soil parameters justify 84.52 percent of total ANPP variation and in comparison, with regression results with 28% it provides better results.

Seepage losses and poor operational activities are the two main source of water losses throughout the agricultural water conveyance and distribution systems in irrigation districts. This study aims to investigate the performances of two strategies of “canal lining” and employing the “Canal Automation” in order to reduce the losses mentioned above. The investigation was carried out on a couple of main canal reaches of Moghan Irrigation Districts. Two numerical models were simulated by Seep/w software to compare the seepage rate between the canal with and without concrete lining. The results reveal that the ability of concrete lining to reduce seepage losses along the canal is about 10%. Performance assessment of the “Canal Automation” strategy to minimize operational losses within the main canal was carried out employing Model Predictive Control (MPC). The results of the latter strategy indicate that employing the MPC not only reduces the operational losses along the canal by 15% but also improves the operation of the main canal so that the minimum efficiency and adequacy performance indicator was obtained 100% and 83% respectively. Therefore; due to Executive considerations and financial constraints in the same cases, the potential of each of the two strategies can be considered to reduce the conveyance and distribution losses and ultimately choose the most suitable option.

In this study, the discharge coefficient of the circular side orifices was predicted using a new hybrid method. Combinations made in this study were divided into two sections: 1) the combination of two algorithms including Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) and providing the PSOGA algorithm 2) using the PSOGA algorithm in order to optimize the Adaptive Neuro Fuzzy Inference Systems (ANFIS) network and providing the ANFIS-PSOGA method. Next, by identifying the parameters affecting on the discharge coefficient of the circular side orifices, 11 different combinations were provided. Then, the sensitivity analysis conducted by ANFIS showed that the Froude number and the ratio of the flow depth to the orifice diameter (Ym/D) were identified as the most effective parameters in modeling the discharge coefficient. Also, the best combination including the Froude number (Fr), the ratio of the main channel width to the side orifice diameter (B/D), the ratio of the orifice crest height to its diameter (W/D) and the ratio of the flow depth to the orifice diameter (Ym/D) for estimating the discharge coefficient was introduced. For this model, the values of Mean Absolute Percentage Error (MAPE), Root Mean Square Error (RMSE) and correlation coefficient (R) were obtained 0.021, 0.020 and 0.871, respectively. Additionally, the performance of the ANFIS-PSOGA method was compared with the ANFIS-PSO and ANFIS methods. The results showed that the ANFIS-PSOGA method for predicting the discharge coefficient was the superior model

Experimental and numerical study of scouring pattern on the direct and polo-shaped groynes have been investigated in this paper. In this study, direct and polo-shaped groynes models with a length of 0.12 meter have been used in discharges of 10.5, 15, 20 liters per second in a direct flume. The results showed that the maximum scour depth formed around the groyne head of direct and polo-shaped types has increased with augmentation of flow discharge, which was 0.095 and 0.104 meter in the case of 20 L/s discharge respectively. Also, the width of scour hole was 2.25 and 2 times of effective length of the groyne in direct and polo-shaped groynes respectively. In this regards, maximum scour depth around the head of groyne was seen 0.87 and 0.79 times of the effective length of the groyne. Sand form located at downstream of the direct groyne at the distance of 0.09 and 0.15 meters from the side wall of direct groyne was stretched and extended to about 1.3 times of the channel width as well. While the length of the sand form for direct groyne was 1.15 times of the channel width. Overall, the dimensions of the scour hole around the polo-shaped groyne, was less than the direct groyne. In addition to understanding the hydraulic behaviour around the groyne, Flow3D software was used. Statistical survey of the results obtained by experimental and numerical models attested that the relative error of the numerical model could be about 20%, which shows an appropriate performance of using Flow3D for predicting the maximum scour depth.

Deterioration of groundwater resources in coastal regions due to the progression of saline water in aquifers in these regions is currently one of the important issues in providing water needs in these areas. In coastal regions, saline water enters the aquifer from below in shape of wedge. Due to the difference in the density between fresh and salty water, an interface zone forms between two fluids. In order to better understanding the importance of this issue, experiments and numerical investigations of density-depended flow and transport through a tank filled with a variety of sand, are great help in achieving this. In this research, the real sand tank was simulated using SUTRA model. This simulation includes configuration, discretization, property assignment and boundary conditions determination. Finally, the transverse macro-dispersivity coefficient was estimated for different scenarios of the solute transport in this tank. The purpose of this research is to analyze of the solute dispersion, in mixing salt and fresh water, and the effect of seepage velocity, concentration of pollutant source and heterogeneity of porous media on the flow dispersivity property. In this research, after studying the effect of different boundary conditions in SUTRA model on the development of the salt water plume, simulation of the model of heterogeneous sand tank and comparing its results with laboratory model and homogeneous model were performed. As a practical result of this research, the diagram of changes in the coefficient of transverse dispersivity against the source concentration and seepage flow velocity was plotted. In numerical simulation of heterogeneous Porous media, for all concentrations, with the exception of the concentration C₀= 35000, with increasing flow velocity, the values of the transverse dispersivity coefficient AT calculated by SUTRA decreased. Also AT for all seepage velocities, with the exception of seepage velocity u=4 m/day, increased with increasing source concentration. Also, the values obtained AT from the SUTRA model were more than the values of AT obtained from experiments. In numerical simulation of the homogeneous porous media, for all velocities, as the concentration source C₀ increases, the transvers macro dispersivity coefficient AT increases. According to the applied results, suitable solutions can be found to improve the quality of groundwater and prevent the mixing of fresh and saltwater resources.

In this research, by using FLOW3D, the performance of non-linear (arced) piano key (PKW-NL) in plan and linear piano key weir (PKW-L), with equal length of weir, was compared. Results showed that nonlinearity of the weir caused 20% increase in the discharge coefficient. Investigating the velocity contours for these two weir models also showed that maximum velocity within the PKW-NL weir structure is about 30% lower than the PKW-L weir. Also, the performance of non-linear piano key weir was evaluated under inward (PKW-IC) and outward (PKW-OC) curvatures to the channel. Results showed that in the case of PKW-IC weir, the discharge coefficient was increased by 8% as compared to the PKW-OC weir. Investigating the pressure contours for these two weir models also shows that the average pressure within the PKW-IC weir structure is about 5% higher than the PKW-OC weir. This increase in pressure leads to a decrease in the speed and better distribution of flow over the weir keys.

Furrow irrigation is the most common method of surface irrigation. However, the accurate estimation of the soil water infiltration equation is the most important challenge for evaluating this method of irrigation. In this study, a fast and simple method that is named soil intake families and presented by USDA-NRCS (RSIF), evaluated for estimation of the Kostiakove-lewis infiltration equation parameters based on soil information. Also, this method was developed based on irrigation condition and considering soil characteristics (D-RSIF). Two treatments including constant and variable inflow discharge were tested with 4 repetitions and different irrigation phases including advance, storage and recession were simulated by developed Zero-Inertia model using RSIF and D-RSIF methods. The results showed that using the zero- inertial model, the difference between simulated advance times and simulated runoff were significant at 5% level for D-RSIF and RSIF methods. For variable inflow discharge, the error of estimating runoff volume was 10%, 6%, 12% and 41% for RSIF, D-RSIF, multilevel calibration and two-point methods respectively. Also, the irrigation scheduling error, based on soil physics characteristics (RSIF) was 14% that means consuming water more than required.

Today, the preparation of flood zoning maps is one of the basic and important issues in the study of development projects in the world; it is considered before any investment by the related organizations. In this paper, flood zoning was performed using the two-dimensional model HEC-RAS and GIS in order to assess the risk of the construction of a railway station near the bank of the Iranshahr River, in a range of 2500 meters. Two-dimensional hydraulic application could create a more accurate flow pattern in comparison to the one-dimensional model used in the previous studies, especially in the flood plain areas. In this paper, due to the important role of the topography of the area in ensuring the accuracy of the calculation, a Digital Elevation Model (DEM) was used with very high precision (about 2 meters), as obtained from aerial photos. The results of this study indicated the onrush of flood, depth and flow velocity in different return periods. Based on the comparison of water surface profiles in the floodplains with the return period of 100 and 25 years, the maximum difference between the water levels was 0.5 m, which seemed to be reasonable by considering the low slope of the studied area. The results of this paper, therefore, showed that the location of the railway station was in medium risk and the outskirt of floodplain.