JWSS - Journal of Water and Soil Science

River discharge is among the influential factors on the operation of water resources systems and the design of hydraulic structures, such as dams; so the study of it is of great importance. Several effective factors on this non-linear phenomenon have caused the discharge to be assumed as being accidental. According to the basics the chaos theory, the seemingly random and chaotic systems have regular patterns that are predictable. In this research, by using methods of phase space mapping, correlation dimension, largest Liapunov exponent and Fourier spectrum power, a period covering 43 years of Zayandehrud River discharge (1971-2013) was evaluated and analyzed based on the chaos theory. According to the results, the non-integer value of the correlation dimension for Eskandari and Ghale Shahrokh stations (3.34 and 3.6) showed that there was a chaotic behavior in the upstream of Zayandehrud-Dam Reservoir. On the other hand, in the Tanzimi-Dam station, the correlation dimension curve was ascending with respect to the embedding dimension, showing that the studied time-series in the downstream of Zayandehrud-Dam Reservoir was random. The slope of the Lyapunov exponent curve for Eskandari, Ghale Shahrokh and Tanzimi-Dam stations was 0.0104, 0.017 and 0.0192, respectively, and the prediction horizon in the chaotic stations was 96 and 59 days. The non-periodical feature of time series was studied by using the Fourier spectrum power. The wide bandwidth, besides other indices, showed that river discharge in the upstream stations of Zayandehrud Reservoir was chaotic.

Soil erosion and its consequences are important factors in forest road network management. Cutslopes are the most important source of making sediment among different parts of the forest roads structure. For this research, a new and bare road in district No. 2, series No. 5 of NekaChoob forest, was selected; then the study data was measured. The study design was a completely randomized design in 10 plots with the size of 2 m² along 500 meters of road with the 8 natural rainfall events. The results of the Pearson correlation showed that among soil properties, the contents of the liquid limit at the 5% confidence level and the plastic limit at the 1% confidence level had positive correlations with runoff and soil loss. Also, organic matter at the 1% confidence level and the contents of the sand at the 5% confidence level had negative correlations with runoff and soil loss. With increasing the soil moisture and bulk density, runoff and soil loss were enhanced. The results of the multivariate model showed that soil loss could be estimated using the Plastic Limit and sand percentage variables with a the correlation coefficient of 0.948.

Local scour around the foundation of marine and hydraulic structures is one of the most important factors in the instability and destruction of these structures. False prediction of scour depth around bridges has caused financial losses in plasticization and endangered many people's lives. Therefore, an accurate estimation of this complex phenomenon around the bridges is necessary. Also, since the formulas presented by different researchers relate to laboratory conditions, they are less true and less accurate in other situations. Recently, many researchers have tried to introduce new methods and models called soft calculations in predicting this phenomenon. In this research, 146 different laboratory data series (three different laboratory conditions) were analyzed using a backup vector machine to predict scour depth around the bridge head. These data are presented in the form of various combinations of input parameters  which, respectively, represent thickness under the slippery layer, Reynolds number, critical velocity, Shields parameter, velocity Shear, average speed, flow depth, the average diameter of the particles and diameter of the bridge. The parameters in two different scenarios (the mode with dimension and mode) were introduced into the SVM network and the results of this machine were compared with those obtained from the experimental formulas and relations presented in this study. The results showed that in the first scenario, the combination of No. 5 with input parameters () and in the second scenario, the combination No. 5 with input parameters  () for the test stage were selected as the best model. It was also concluded from the results that the scenario two (the state with dimension) in predicting the scour depth around the vertical single-pillar provided a more accurate estimate than the first scenario (barrier state). At the end, the sensitivity analysis was carried out on the parameters and the parameters D, U*, V were selected, respectively, as the most effective parameters

Soil is one of the most important natural resources of countries in which erosion occurs. In this research, the effect of soil characteristics on the amount of erosion at the suborder level was studied. For this purpose, 77 soil samples (0-30 cm) were prepared and the parameters were determined in the laboratory. The semi-variograms of soil parameters and their spatial distribution maps were prepared with GS⁺ and GIS, respectively. The study area was divided into work units by combining land use and geology maps and water erosion was estimated at each unit by the EPM method. By drilling profiles in different parts of study area, soil suborders were determined by Soil Taxonomy and the average values of parameters in each suborder was estimated. The principle components analysis (PCA) was then used for data analysis. The results showed that three parameters of silt, organic carbon and electrical conductivity could account for 30.384% as the first main component; clay, sand and vegetation could explain 11.189% as the second main component; and slope and height covered 15.330% as the third main component; in total, 63.805% percent of erosion variation could be justified by three main components. The lowest and highest amounts of erosion (69.12 and 343.57 m³/km², respectively) were estimated in Xeralfs and Fluvents suborders. The erosion class of suborders at the study area was determined to be “few” and “medium”.

This study focused on proposing a new operational perspective within main and lateral irrigation canals based on the economic value of water. To achieve this objective, the operation-economic framework offered in this study consisted of two main components of the PMP model and Operation model. The estimated economic values of water in different regions of the network were employed as the starting point for connecting the economic model with the operation model. It is worth mentioning that the technical perspective targeting adequacy of water distribution within the canals was modified in this study to be applied for the operation-economic framework since the original forms of the indicator were based on physical inherent of the water. Roodasht Irrigation District, located at Zayandeh-Rud basin, was selected as the case study, and the proposed framework was tested on the district. The obtained results revealed that in response to implementing the proposed framework in water distribution within the canal under the water shortage condition, alfalfa and safflower were the two crops those cultivation was decreased drastically in comparison with the other crops. The primary reason for the decrease was the lower values of the economic value of water for these two crops. Also ,the results of the canal operation appraisal from the adequacy of water delivery revealed that for the traditional operating system (without considering the economic perspective), the maximum values of the adequacy indicator were obtained for the upstream four canal reaches. On the other hand, the off-takes numbers of 1, 6, 5, and 12 got the maximum values of the adequacy indicator when the proposed operation-economic framework was applied for the canal system.

The use of additives to modify the physical, chemical and mechanical properties of soil and soil stabilization is one of the most common methods that have a history. By adding one or more additives to the soil and carrying out the required measures, the engineering properties of soils could be improved due to chemical reactions. Selecting the type and amount of additive depends on several factors such as: soil type, stabilization purpose, additives inherent characteristics, etc.; these are determined based on the technical and economic aspects of the projects. In this study, the effects of the simultaneous use of three types of additives including lime, stone powder and polypropylene fibers on the unconfined compressive strength of a clayey soil were investigated.  To do this, four different levels of lime (0, 2, 3 and 5 percent by weight of soil) and four different levels of stone powder waste (0, 2, 5 and 10 percent by weight of soil) and Polypropylene fibers with different percentages in five levels of 0, 0.25, 0.5 and 1 percent by weight of soil were added into a high plastic clay soil classified as CH. Then, some physical and mechanical characteristics of different mixtures including plasticity, compaction and unconfined compressive strength were determined. The results showed that the samples were stabilized with lime and stone powder waste and reinforcement them with polypropylene fibers modified Atterberg Limits, optimum moisture and maximum dry density of the mixtures. Also, it was found that a combination of waste stone powder, lime and polypropylene fibers containing 5, 5 and 1 percent by weight of soil increased the unconfined compressive strength 8-fold, as compared to the natural soil. The curing time also had a significant impact on the compressive strength of the treated samples in which the 28-day compressive strength of was found to be about 2 times of the 7-day samples.

Digital soil mapping plays an important role in upgrading the knowledge of soil survey in line with the advances in the spatial data of infrastructure development. The main aim of this study was to provide a digital map of the soil family classes using the random forest (RF) models and boosting regression tree (BRT) in a semi-arid region of Ilam province. Environmental covariates were extracted from a digital elevation model with 30 m spatial resolution, using the SAGAGIS7.3 software. In this study area, 46 soil profiles were dug and sampled; after physico-chemical analysis, the soils were classified based on key to soil taxonomy (2014). In the studied area, three orders were recognized: Mollisols, Inceptisols, and Entisols. Based on the results of the environmental covariate data mining with variance inflation factor (VIF), some parameters including DEM, standard height and terrain ruggedness index were the most important variables. The best spatial prediction of soil classes belonged to Fine, carbonatic, thermic, Typic Haploxerolls. Also, the results showed that RF and BRT models had an overall accuracy and of 0.80, 0.64 and Kappa index 0.70, 0.55, respectively. Therefore, the RF method could serve as a reliable and accurate method to provide a reasonable prediction with a low sampling density.

Public health of common waters in protecting the human's health is considered as "human delinquent" and environmental and natural health as "green offender" (silent offender) due to the terrestrial nature and the lack of the monopoly of works; so, the consequences of violating it in the territory of a particular state are of particular importance in the international public law. Therefore, protection of the harm caused by the breach of the public health of common waters is imperative by international institutions and States members of the international community. The supportive policy is a branch of public policy that "puts" various legal protections from the perpetrators of the violations of norms and regulations "in the form of coherent policies using its principal principles. These principles are a set of doctrines and coherent strategies that determine the policy and consequently, the way in which laws and regulations are imposed; as with the qualitative measure, it provides for the monitoring of rules and regulations. To make the present study, a review of the principles that underlie the principles of public health policy in international treaties and procedures is presented. The principles outlined in these sources are categorized into three categories: "justice-oriented", "cooperative-oriented" and "fair-minded". These principles can be used in protecting Iranian water health rights.

Wind erosion is known as one of the most important land degradation aspects, particularly in arid and semi-arid regions. Soil properties, by affecting soil erodibility, can control the wind erosion rate. The aim of this study was to attribute the soil physical and chemical properties to the wind erosion rate for the purpose of determining the most important property. To this aim, wind erosion rates were measured in-situ at 60 points of Kerman province using a portable wind tunnel facility. The results indicated that wind erosion rates varied from 0.03 g m^-2 min^-1 to 3.41 g m^-2 min^-1. Threshold wind velocity decreased wind erosion rate following a power function (R²=0.81, P<0.001). Clay and silt particles, shear strength, mean weight diameter (MWD), surface gravel, dry stable aggregates (DSA<0.25mm), soil organic carbon (SOC), calcium carbonate equivalent (CCE) and the concentrations of the soluble Ca²⁺, K⁺ and Mg²⁺ were inversely proportional to the wind erosion rates following nonlinear functions. On the other hand, Wind erosion was significantly enhanced with increasing the sand fraction, soluble Na⁺, electrical conductivity (EC) and sodium adsorption ratio (SAR). According to the final results, among the studied soil properties, SAR and MWD were s the most effective properties controlling wind erosion in the soils of Kerman province. Therefore, it is recommended to consider suitable conservation practices in order to prevent the sodification and degradation of arid soils.

Drilling material from the tunnel of the Tehran-Shomal highway was estimated to be about 2.5 Million Cubic Meters by the project authorities. Sadly, from the beginning, the drilling materials had been deposited on the open space in the floodplain of the Chaloos river with slightest environmental considerations. During the previous years, weathering and leaching from the drilled materials besides the discharge of drain water from the tunnel had led to seriouse contaminations and the deterioration of the water quality of the Chaloos river. In this paper, the ecological risk of nonorganic pollutants due to drilled materials was investigated. The sampling was done from the excavated materials and river sediment in five different locations throughout a complete year. From the many pollutants, Nickel, Cadmium and Copper were chosen to be investigated. The results showed that almost 15 percent of the samples had a high degree of pollution, while 60 percent of them were clean and the other 25 percent included the highly contaminated ones. All samples were also estimated to have a low to high ecological risk.

Compost leachate is a liquid resulting from physical, chemical and biological decomposition of organic materials. The main objective of this study was to evaluate the influence of leachate compost on the physical, hydraulic and soil moisture characteristic curves. Also, the effect of leachate on the aerial organ fresh weight of corn was investigated. Leachate was added to clay loam and sandy clay loam soils at the rate of zero, 1.25 and 2.5 weight percent. The soil water characteristic curve and the estimation of the parameters of the van Gnuchten and Brooks and Corey models were performed using RETC software. Leachate increased the bulk density and decreased the available water of the clay loam soil. Only 1.25% of the leachate increased the available water in the sandy clay loam soil. Two levels of leachate decreased the bulk density of sandy clay loam soil. Leachate decreased the saturation hydraulic conductivity of the clay loam and increased this parameter of sandy clay loam soil. Leachate was more successful in increasing the aerial organ fresh weight of corn in the sandy clay loam soil. Therefore, leachate was more useful in sandy clay loam than in clay loam soil, and 1.25% treatment was better in the sandy clay loam soil. Also, the used leachate increased the repellency of both soils. Leachate caused the parameters of van Gnuchten and Brooks and Corey models to increase, as compared to the control in both soils.  

Water is the most crucial factor for agricultural development. Therefore, the economic evaluation of water resources is critical. The purpose of this paper was to determine the economic value of water resources, to evaluate the financial efficiency and to decide on the price of agricultural water in Arak plain. For this purpose, the economic value of water resources for wheat, barley, alfalfa and corn was identified in 2015- 2016, using the mathematical model developed in this research. The results showed that the financial efficiency was calculated for three alternatives: free-cost water, water cost equal to the 10% of the calculated price and water cost equal to the exact calculated price.  The irrigation efficiency of 40% financial efficiency was 2.38%, 1.68% and 0.47% , respectively, for the  aformentioned methods, and  the irrigation efficiency of 70% financial efficiency was 2.07, 1.92 and 0.71, respectively. Also, the sensitivity analysis of the financial efficiency was performed, with 10% change in the farmers income and costs. The results also revealed that irrigation efficiency and financial efficiency were not aligned when farmers had free water; however, they were aligned when the farmer paid 10% of the calculated price. Financial efficiency was more sensitive to changes in the farmers income when compared to the changes in costs.

Long-term drought effect is one of the main factors of global climate change, with  consequences for soil biogeochemical cycling of carbon and nitrogen and the  function of soil ecosystem under drought conditions. We hypothesized that 1) the Bromus inermis, Dactylis glomerata and festuca arundinacea species would differ in their rhizosphere responses to drought and 2) combined plant species and drought would have offsetting effects on the  soil biological traits. We tested these hypotheses at the long-term drought field expreiment at the  Lavark Farm of Isfahan University of Technology by analyzing soil microbial biomass carbon and nitrogen and activity of β-glucosaminidase in the rhizosphere of Bromus inermis, Dactylis glomerata and festuca arundinacea species. Soil microbial biomass carbon and nitrogen responses to drought depended on plant species,  such that the highest MBC was recorded in the Bromus inermis rhizosphere, while the  lowest was in the Dactylis glomerata rhizosphere, thereby suggesting the greater microbial sensitivity to drought in the Dactylis glomerata rhizosphere. Genotype variations (drought tolerate and sensitive) mostly affected the change in the β-glucosaminidase activity, but they were not significantly affected by drought treatment and plant species. In general, the positive effects of  the plant genotype could offset the negative consequences of drought for soil microbial biomass and traits.

Land subsidence as a hydrogeomorphology event is currently occurring dangerously in many plains of the country due to uncontrolled groundwater extraction from water bearing layers, and accordingly monitoring and studying this phenomenon seems to be necessary. In this study, land subsidence rate of the Najafabad aquifer was determined through the Differential Radar Interferometry (DInSAR) processing of the ASAR and PALSAR radar data and the results were validated by comparying with the differential leveling and groundwater level drowdown data. Processing of the ASAR sensor data estimates the land subsidence in the Najafabad plain at an average annual subsidence rate of 6.7 cm and a total of 41 cm during 6 years period and processing of the PALSAR data suggests an annual rate of 7.7 cm and total subsidence of 30 cm during 4 years period. Most of the occured displacements are related to the Tiranchi, Koushk, Ghahderijan, Goldasht and Falavarjan cities. The simultaneous groundwater level data with acquisition date of the radar satellite images between 2002 and 2014 shows a drawdown ranging from 0.5 to 46.5 meters in the south and east to north of the Najafabad city consistent with the estimated land subsidence areas.The DInSAR processing of the PALSAR data has led to a more accurate results with higher spatial resolution. Results of the radar data processing can be employed for the hazard zonation directly utilized for management and planning of control and preventive measures.

The study of floods has always been important for researchers due to the great loss of life and property. Investigation of flood bed can provide appropriate solutions to reduce this phenomenon to managers and researchers. In this research, the compound channel (with flood plain on one side of the main channel) Been paid, Therefore, two experimental models of compound channel in laboratory flume were examined by considering dimensional analysis. With the goal Investigation of lateral slope of flood wall in laboratory model In the first model, transverse slope 0 And in the second model, a value equal to 50% Was considered. Also in order to investigate the effect of longitudinal slope of river bed sediments Longitudinal slope in three steps 0.00 2, 0.004 and 0.006 Was changed. Examining the ADV speedometer data, the results showed that with increasing the longitudinal and transverse slope (slope of the flood wall) of the channel, the maximum longitudinal velocity changes to the floor of the channel. In order to investigate the effect of average sediment diameter on the scouring process during experiments Mm was used. The results showed that increasing the longitudinal and transverse slope had a great effect on increasing the volume of washed sediments 3 and 0.9 of sandy sediments with a diameter Along the canal and with the increase of these longitudinal and transverse slopes in the channel, more sediment transport volume occurs. In the following, using Investigation of dimensionless numbers obtained from dimensional analysis, dimensionless weight landing number was introduced to evaluate this value value of other hydraulic parameters and Was introduced. A relationship based on nonlinear regression with correlation coefficient Acceptable was introduced at around 0.88.

Water allocation needs to adhere to the principles of efficiency, equity, and sustainability, but, equity usually is less considered. Foumanat irrigation area with five command areas is one of the three areas of Sefidroud irrigation and drainage network that more than 90% of it is covered by paddy fields. Since water plays a key role in paddy fields, the lack of uniform distribution of water resources throughout the irrigation area during the rice cultivation period causes irrigation water scarcity and severe damage to some irrigation areas. In this study, the equity of groundwater withdrawal and the received surface water from Sefidroud irrigation and drainage canals according to the shared water resources among Foumanat’s command areas were evaluated using the Gini coefficient. Therefore, a water allocation optimization model was developed to maximize the equity in the allocation of groundwater and surface water of canals according to the minimum current economic benefit in the command areas. The results showed that in optimum conditions, the equity of groundwater and surface water resources allocation was increased by 46.3% and 43.7%, respectively. The evaluation of the optimal allocation of available water resources also showed that the amounts of groundwater withdrawal and the received surface water from canals are distributed equally among command areas.

The purpose of this study was to model biomass with soil parameters in Hir-Neur rangelands of Ardabil Province. Initially, considering the vegetation types and different classes of environmental factors, at the maximum vegetative growth stage, using one square meter plot, biomass was estimated by clipping and weighing method. For each transect, a soil sample was taken and transferred to the soil laboratory and the various parameters were measured by conventional methods. The relationship between soil factors and the rangeland biomass was analyzed and simulated using linear multiple regression. Among the measured soil factors, the Silt, EC, Ca, K_soluble, OC, POC, pH, Mg, TNV, clay, P, and volumetric moisture had the highest effect and percentage of biomass forecast (p<0.01). The accuracy of the simulated maps was analyzed using RMSE criteria and for grasses, forbs, shrubs, and total biomass were equal to 0.81, 0.65, 0.34, and 0.46, respectively. The results of this study, not only point out the importance of soil factors on the biomass but also as a baseline data for managing rangelands, supply-demand, and carbon balance can be used in the current section.

The simulation of the rainfall-runoff process in the watershed has particular importance for a better understanding of hydrologic issues, water resources management, river engineering, flood control structures, and flood storage. In this study, to simulate the rainfall-runoff process, rainfall and discharge data were used in the period 1997-2017. After data qualitative control, rainfall, and discharge delays were determined using the coefficients of autocorrelation, partial autocorrelation, and cross-correlation in R Studio software. Then, the effective parameters and the optimum combination were determined by the Gamma test method and used to implement the model under three different scenarios in MATLAB software. Gamma test results showed that today's precipitation parameters, precipitation of the previous day, discharge of the previous day, and discharge of two days ago have the greatest effect on the outflow of the basin. Also, the P_t Q_t-1 and P_t P_t-1 Q_t-1 Q_t-2 Q_t-3 combinations were selected as the most suitable input combinations for modeling. The results of the modeling showed that in the support vector machine model, the Radial Base kernel Function (RBF) has a better performance than multiple and linear kernels. Also, the performance of the Artificial Neural Network model (ANN) is better than the Support Vector Machine model (SVM) with Radial Base kernel Function (RBF).

Delineation of gully erosion susceptible areas by using statistical models, as well as optimum usage of existing data and information with the least time and cost and more precision, is important. The main objective of this study is to determine the areas accuracy to gully erosion and susceptibility mapping by using data mining of the bivariate Dempster-Shafer, linear multivariate statistical methods and their integration in Semirom watershed, southern Isfahan province. First, the geographical location of a total of 156 randomly gullies were mapped using preliminary reports, satellite imagery interpretation and field survey. In the next step, 14 conditioning parameters of the gullies in the study area were selected including the topographic, geomorphometric, environmental, and hydrologic parameters using the regional environmental characteristics and the multicollinearity test for modeling. Then, the Dempster-Shafer statistical, linear regression, and ensembled methods were developed using 70% of the identified gullies and 14 effective parameters as dependent and independent variables, respectively. The remaining 30% of the gully distribution dataset were used for validation. The results of the multivariate regression model showed that land use, slope and distance to drainage network parameters have the most significant relation to gully occurrence. The gully erosion susceptibility maps were prepared by individual and ensemble methods and they were divided to 5 classes of very low to very high rate. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to validate gully erosion susceptibly maps. The verification results showed that the AUC of ensemble method (0.948) is higher than Dempster-Shafer (0.924) and Multivariate regression (0.864) methods. Also, the the seed core area index (SCAI) value of the ensembled model from very low to very high susceptible classes have a decreasing trend that indicating a proper separation of susceptible classes by this model.

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.