JWSS - Journal of Water and Soil Science

Long-term use of treated wastewaters for irrigation adds compounds and/or ions to soils which might alter the soil physical, hydraulic and mechanical properties. Soil mechanical properties are closely linked with the plant growth. This study was conducted to investigate the effect of short-, mid- and long-term applications of the treated wastewater of Mobarake Steel Company in Isfahan on the soil penetration resistance and shear strength in the company green space. Soil penetration resistance and shear strength were measured using a pocket penetrometer and in situ shear box, respectively. The results showed that soil penetration resistance (i.e. soil hardness) at both dry and wet conditions significantly was increased upon short-, mid- and long-term applications of wastewater; 19 years of the application of wastewater resulted in the highest soil penetration resistance at wet condition, but the well water did not significantly affect it. Surface crust in the non-irrigated locations increased the soil penetration resistance, but the irrigated sealed soils were not significantly different from the virgin soil in terms of dry and wet penetration resistances. For the soil shear strength parameters, wastewater, well water and surface crust did not significantly affect soil cohesion (c), they but significantly affected the angle of internal friction (φ). Overall, soil shear strength parameters were not greatly affected by the irrigation water treatments because of the dominant effect of the soil fractions (texture and gravel content) and the microstructure.

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.

Sugarcane is cultivated in the wide area in Khuzestan province. In these areas, irrigated sugarcane cultivation consumes more than 30,000 cubic meters per hectare annually. This research was carried out to determine the effect of sugarcane cultivation on the soil development process and forms of iron oxides. Different sugarcane fields with different utilization times were selected and soil physico-chemical properties and different Fe forms were measured. The results showed that with enhancing the utilization time, the total amount of total iron oxides (Fe_d) and crystalline iron oxides (Fe_d-Fe_o) was increased. The average value of the Fe_d from 6958 mg/kg in the fields with a medium utilization history was decreased to 4560 mg/kg in fields with a short utilization history. Similarly, the average amount of crystalline iron oxide from 5888.3 mg/kg in the fields with a long utilization history was decreased to 5003.9 mg/kg in the fields with a short utilization hostory. This increase reflected the effect of sugarcane cultivation on the soil development process in the cultivated fields. The amount of non-crystalline iron oxides (Fe_o) was decreased from 443.9 mg/kg from the soil surface to 273.8 mg/kg to the subsurface. This increase was related to the more organic matter and the microbial activity in the surface soil. The amount of active iron (Fe_o/Fe_d) was dropped in all fields after the cultivation. Also, this ratio was dropped from 0.055 in the fields with a long cultivation history to 0.064 in the fields with a short utilized field. The results, therefore, showed that the increase of crystalline iron oxides was due to sugarcane and its heavy irrigation.

Due to the availability of limited water resources in the country, it is necessary to use unconventional water. On the other hand, application of minerals such as Zeolite (Zo) is necessary to simulate plant growth and reduce the harmful effects of wastewater. The present study was conducted to investigate the effect of irrigation by wastewater with Zo on cotton (Gossypium herbaceum) based on a randomized complete block design with factorial arrangement in Torbat Heydarieh, 2014. For this purpose, irrigation water treatment at 2 levels (I1: irrigation with normal water and I2: irrigation with effluent) and Zeolite (Zo) treatment at 2 levels (Z₀: No Zo application and Z₁: application of K⁺ Zeolite at 4% weight) were considered with three replications. The results showed that the irrigation water type had a significant effect on the seed index, yield, cotton weight, number of leaves per plant and the lint percentage. The rate of Zeolite (Zo) did not show any significant effect on any traits, such as Kiel percentage, seed index, cotton weight, number of leaves per plant and cotton yield. The interaction between the irrigation water and the amount of Zo had a significant effect only on the number of leaves per plant. The results also showed that the highest lint percentage, cotton weight and number of leaves per plant in the irrigation by the effluent with No Zo application (I₂Z₀) treatment with the values of 64.3 and 11.23 gr and 36.3 numbers and the lowest values for the seed index, yield and number of leaves per plant in irrigation by normal water with No Zo application (I₁Z₀) were obtained with the values of 0.52 and 78 gr and 24.8.

Infiltration is the most important characteristic in the design and management of any surface irrigation system. Since the hydraulic of flow in meandering furrows is different from the standard furrows, the accuracy of infiltration function parameter estimation methods should be examined for the optimal design and management of meandering furrow irrigation. The main objective of this study was to compare Elliot and Walker’s two-point and two-time methods for estimating the empirical infiltration function parameters of meandering furrow irrigation using four sets of field data. The estimated infiltration functions, as obtained by the two methods, were validated by performing the unsteady flow simulations and using the Slow-change/slow-flow (SC/SF) model. The results showed that Elliot and Walker prediction of the advance trajectories (with a mean RMSE of 0.68 minutes) was comparable to the two-time method (with an average RMSE of 0.66 min). The Nash–Sutcliffe efficiency coefficient for the simulated outflow hydrograph by the two-time and two-point methods was 0.89 and 0.50, respectively, indicating the excellent predictive power of the two-times method. In addition, the two-time method predicted the total volume of infiltration with the less relative error (-1.5%), in comparison to the two-point method (-47.2%). Therefore, the use of post-advance data (such as a two-time method) for infiltration function parameters estimation improves the flow simulation in the meandering furrows.

Landscapes are considered as a series of different land units with a size, shape and location arrangement that are permanently under the influence of natural events and human activities. Understanding the dynamics and heterogeneity of landscapes and environmental changes is of great importance. In order to quantitatively analyze and interpret the factors affecting the changes in the environment and terrain diversity, diversity indices were used to analyze the ecosystem. In this study, the relationships between soils evolution and geomorphic surfaces were investigated by applying pedodiversity indices in a part of a semi-arid region of Chaharmahal-Va-Bakhtiyari Province. In the studied area, three orders were recognized: Mollisols, Inceptisols, and Entisols. The results showed that soil evolution in the studied area was mostly influenced by topography, parent material and the underground water level; that is, in the higher lands, the lowest evolution was observed while in the plain ones, the soil of the higher evolution observed. In addition, the effect of geomorphic surfaces were obvious. Pedodiversity indices increased under the decrease of the hierarchy levels. In addition, the obtained equations revealed the nonlinear relationships in the area of geomorphic surfaces. The positive and nonlinear relationship between pedodiversity indices confirmed the nonlinear dynamic system in the studied soils.

Urban and industrial wastewaters are considered as the most contaminant of surface water. Entrance   of these pollutants to the river reduces the concentration of dissolved oxygen and aquatic life will be threatened. So, one of the main qualitative characteristics of water resources management is the concentration of dissolved oxygen. The base of the   developed model in this investigation is the convection- diffusion equation in soil. Terms of production and decay of dissolved oxygen were added to this equation. The final equation was discretized using the finite difference method with the implicit scheme. With applying the initial and boundary conditions, the equation set was solved by the Thomas algorithm. The calculations were done by programming in the MATLAB software. For the calibration and validation of the model, data obtained from two reaches of Zayanderoud River, including steel melt and Mobarakeh Steel factories, were used. The temporal and spatial variations of the dissolved oxygen were plotted and compared with the real data and the results of the MSP and CSP models. The results showed that the concentration of the dissolved oxygen could be well predicted through solving convection-diffusion equation with introducing two terms for the decay and production of oxygen. The comparison between the results of the model and two other models showed that the model led to better results in comparison to the MSP and CSP models.

Many studies have been done on various properties of dust and one of the most important characteristics of dust is the ability to carry different microorganisms from the source points. The aim of this study was to investigate the bacterial and fungal community of dust and to identify its dominance species in a single event of intense dust storm, in the northern regions of Sistan and Blauchestan Province (Sistan plain). Dust samples were accordingly collected by Siphon dust samplers after one of the most intense dust storms in 28-31 August, 2015, from 5 cities in the northern regions of Sistan and Blauchestan Province; after that, the microbial community of dust was determined by culturing in petri dish and its dominant bacterial and fungal species were identified. The results showed maximum aerobic and anaerobic bacteria population was observed in the Hirmand city dust (1875000 CFU/g and 156667 CFU/gr, respectively). The maximum aerobic fungi population was observed in the Zabol city (833 CFU/g) and the maximum anaerobic fungus population was observed in Zahak city (2167 CFU/g). The most frequent type of bacteria was Bacillus sp, which was followed by Streptomyces pactum. The most frequent type of fungi in this research was Penicillium sp and the second one was Aspergillus. The results showed the high and variated microbial community, especially pathogenic fungi associated with dust in this region.

Study of Turbidity Current, as one of the most important phenomena affecting the sedimentation in the reservoirs of dams, is essential. Since most of the research studies have been conducted under experimental conditions on rigid beds, the effect of erodible bed and the formation of the bed form on the turbidity current specifications is not yet clear. Therefore, in this Research, the study of the turbidity current in two conditions of rigid and mobile bed was conducted in order to determine water entrainment specification and the effective hydraulic parameters. The results showed that water entrainment changes depended on the variation of bed roughness and the type of bed form. Also, water entrainment of turbidity current was initially reduced by about 25% with the change in the bed shear stress, relative to the rigid bed, due to formation of small bed forms; then, it increased by about 30%, forming the larger bed forms; finally it decreased with increasing the flow strength and removing the bed forms. In addition, comparison of the results of the present study with previous research showed that the formation of bed forms increased water entrainment in a constant Richardson number up to 50%.

Detergents are the main organic pollutants in the industrial and domestic wastewater. Electro-chemistry methods are advanced purification methods developed with high efficiency features. The goal of this study was to investigate the possibility of using electrocoagulation and the complementary flocculation process to achieve the highest removal efficiency of the detergent COD. So, with iron electrode, synthetic samples at the concentrations of 500, 750 and 1000 mg/l (with COD of 217, 268 and 370 mg/l, respectively) and with the initial pH levels of 5, 7.3 and 9 were tested. Variable parameters during the electrocoagulation process included the current duration at 3, 5 and 10 minutes, and the current density was at 4, 10, 16 and 22 mA/cm². The primary results showed that in the optimum conditions, the coagulation process and complementary flocculation could reduce the sample’s COD with an initial concentration of detergent (500 mg/l) from 217 mgO₂/l to 81.30 mgO₂/l. The electrocoagulation method could reduce the chemical oxygen demand to below the standard limit of environmental discharge (200 mgO₂/l) and compensate for the possibility of the irrigation of green spaces due to water shortages.

Determination of water quality is an essential issue in water resources management and its monitoring and zoning should be considered as an important principle in planning. In this study, in order to investigate the quality of groundwater resources (springs, wells and qanats) in Semnan watershed, first, the water quality index for drinking and agricultural purposes was obtained by means of measuring SO₄, Cl, Na, Mg, PH, EC, SAR, TDS in 55 groundwater sources. For calculating the parameters weight in WQI, the fuzzy hierarchy analysis process was used with the Chang's development analysis. Due to the lack of sampling points for zoning of the entire area, regarding the existence of EC data for the majority of groundwater resources used in this catchment (354 sources), as well as the high correlation (Adjusted R²=0.99) between WQI with EC, the mentioned indexes of other resources were estimated based on the regression relationship with EC. To analyze the spatial distribution and monitor the zoning of the groundwater quality, the ArcGIS version 10.3 and Geostatistical method such as simple Kriging and ordinary Kriging were used; additionally certain methods including Inverse distance weighting and Radial Basis Function were utilized. The performance criteria for evaluating the used methods including Mean Absolute Error (MAE), Root Mean Square Error (RMSE), %RMSE and R² were used to select the appropriate method. Our results showed that the ordinary Kriging and Radial Basis Function were the best methods to estimate the groundwater quality.

Soil water retention curve (SWRC) reflects different states of soil moisture and describes quantitative characteristics of the unsaturated parts of the soil. Direct measurement of SWRC is time-consuming, difficult and costly. Therefore, many indirect attempts have been made to estimate SWRC from other soil properties. Using pedotransfer functions is one of the indirect methods for estimating SWRC. The aim of this research was to assess the effect of using soil particles percentage in comparison with the geometric characteristics of soil particles on the accuracy of the pedotransfer equations of SWRC and the critical point of it. Accordingly, 54 soil samples of Isfahan province from seven texture classes were used. The most suitable functions for estimating SWRC, parameters of van Genuchten and Brooks-Corey equations, and the critical point of SWRC were selected based on statistical indices. The results indicated that the pedotransfer equations fitted the SWRC data well and the outputs from them were in a good agreement with the independent (validation) SWRC data. The results revealed that using soil particles percentage (sand and clay), bulk density and organic matter content in the point estimation of SWRC was better than applying geometric properties of the soil particle diameter. On the other hand, in the estimation of parametric and critical point of SWRC, using the geometric properties of soil particle diameters resulted in more satisfactory results, as compared with using the soil particles percentage. The NRMSE values indicated that the accuracy of the pedotransfer equations in the lower matric head was greater than that of the higher matric head.

Studying the trends of water table in any region especially in arid and semi-arid regions is an important issue. This study focuses on assessing groundwater table changes in Tabriz plain. For this purpose, non-parametric Mann-Kendall test is used. In studing groundwater level the information of 14 pizometric wells in the period of 1991-2013 was used. Significant levels of 1, 5 and 10% were used for the trend test. Slope of trend lines is estimated using the sen's estimator method. The homogeneity of trends were tested using the Van Belle and Hughes method. The results showed that groundwater level in the most of pizometric wells have decreasing trend, That was significante in 1% sifnificance level. According to the research, trend of groundwater level was negative in all of the stations in April and maximum negative trend was belong to Dizaj Leily Khany station (Z= -6/47) that was significante in 1% sifnificance level. Also the minimum negative trend was belong to Ana Khaton station (Z= -0/322). The minimum groundwater level was -1.45 in Said-Abad station.

One of the management practices to reduce the harmful effects of chemical fertilizers and to protect soil and water resources is applying a combination of organic and chemical fertilizers that can better than using them separately. Therefore, in order to understand and identify the effectiveness of this management practice, it is necessary to examine runoff and sediment production. This study was carried out in an agricultural sloping land located in the North of Iran, near Sari city. For this purpose, runoff measurement plots of 1 × 5 m were set up under natural rainfall based on a randomized block experimental design. Soil samples were measured at 0-10 and 10-20 cm depths. In this study, parameters such as runoff (volume, nitrate content, sediment yields), soil physical features (porosity and infiltration coefficient), and soil chemical properties (EC, OC, N, CEC, pH) were measured. The results showed that among soil chemical and physical properties, just N, EC and pH significantly influenced the Municipal Solid Waste Compost. A PCA was carried out, showing that these treatments explained 74.35% of the total variance of the results. Accordingly, it could be stated that using soil and water conservation management practices can rapidly significantly improve the soil properties in the sloping lands.

Despite the great importance of potassium applied as a fertilizer in the orange orchards, no information is currently available regarding the rate of potassium release from rhizosphere and the bulk soils of such trees. The objectives of this study were to investigate the weathering of micaceous minerals and their non-exchangeable K release and also, to examine the status of different forms of K in the rhizosphere and bulk soils of orange orchards with different ages in Darab, Fars Province. Samples were, accordingly, taken from the rhizosphere and bulk soils of orange orchards with the ages of 5, 10 and 20 years; also, virgin soils (control) were obtained from three soil depths including 0–30, 30–60, and 60–100 cm. Water soluble, exchangeable and nonexchangeable K, and the clay mineralogy of the soils were determined. The results demonstrated that the concentration of soluble and exchangeable K in the cultivated soils was less than that in the control soil and that the concentration of nonexchangeable K in the soils of 20-year-old orchards was less, than that in other soils. Soluble and exchangeable K values decreased with depth in all soils. Clay mineralogy investigation also showed that the quantity of illite decreased and that of smectite and illite-smectite increased as the age of orange trees was raised. With increasing the age of orange trees and root development, more potassium could be taken up from soil and more changes occurred in the soil minerals. In order to avoid a very high decline in the reserved K in the soils under orange trees, particularly in the orchards with older trees, K fertilization has to be taken more seriously based on the soil testing results.

Shortage of irrigation water is a major problem constraining in agricultural production in arid and semi-arid regions. Deficit irrigation is one way to cope with water scarcity and increase water use efficiency. Determining the optimum applied water based on economic analysis is a major key to the deficit irrigation strategy. In this study, the required equations were derived to determine the optimum applied water for sugar beet when crop price is a function of the applied water. The results showed that the optimum applied water under land limiting conditions (144.98 cm) resulted in the maximum net benefit per unit area (2089741 Rials ha^-1). Applying the optimum water depth under land limiting resulted in 17.48% decrease in the applied water and 15.05% increase in the total net benefit, in comparison with the maximum yield condition. In water limiting conditions (land is not limiting), the total net benefit was maximized by applying the saved water to put larger areas of land under irrigation. Applying the optimum water depth under water limit condition resulted in 31.2% decrease in applied water and 45 and 52.36% increase in the planting area and the total net benefit, in comparison with the maximum yield condition, respectively. Sugar beet planting can be, therefore, profitable if the applied water depth is greater than 67.53 cm in this study area.

Creating a mulch layer on the sand dunes surface has long been applied to reduce their mobility. However, application of oil mulch in some countries, in addition to high costs, has many environmental problems. In this research, the hydrated lime slurry was used as a protective cover on the sand dunes. The slurry was prepared in three treatments with 3, 5 and 7% lime and sprayed uniformly on 2×5 m plots on the sand dunes surface. The average thickness of different types of mulch was measured by a caliper and then their abrasions were calculated in two-month intervals for three calcareous and controlling treatments at three locations. Statistical analysis was performed by using SPSS and the Excel software. The results showed that the 3% lime slurry layer had no resistance to wind abrasion and was comparable to the controlling sites. The results obtained for the 5 and 7% lime slurry mulch layers indicated that the increase in lime percentage raised the mulch resistance against the wind abrasion. The 7% lime slurry layer with a 6.3 mm thickness showed the highest abrasion resistance in the natural conditions.

Seismic study of canyon sites has always been one of the important fields of seismic studies because of massive structures such as dams that are built in such sites. Jointed rock mass in rock canyon sites is one of the main site effects that can change the seismic waves. In this research, we studied the influence of this factor on the scattering of seismic waves. To fulfil this goal, we employed a coupled method combining the finite element method in the near field with boundary elements in the far field. To simulate the behaviour of jointed rock mass, we used the linear elastic model. Based on the results of the numerical analyses, jointed rock mass could have significant effects on the seismic waves in some special conditions. These conditions are the angle of incident wave, the thickness of layers and the material properties of the jointed rock mass. So it is necessary to consider this factor in the seismic structure design in the canyon sites.

The aim of this study was to evaluate the spatial distribution of soil infiltration using geostatistics methods in a regional scale on 400 hectares of Mansour Abad Plain, in Larestan region, Fars Province. Sampling and parameters measurement were done for 78 points in a regular grid with a distance of 100*100 meters; for these variables, the best variogram model between linear, exponential, Gaussian and spherical models with the highest R2 and the lowest error was determined using GS+ and ArcGIS software. In this study, soil infiltration (cm/min) using the double ring method and some other soil properties including soil electrical conductivity (dS/m), pH, saturation percentage (%SP), particle size percentage (sand, silt and clay), and calcium (meq/lit), magnesium (meq/lit), sodium (meq/lit) were measured and determined. The spatial distribution of Kostiakov and Philip models parameters and theri zoning were determined using the geostatistic method. The results showed that, among different soil properties, the final infiltration rate had a high degree of variability in the study area, and the decision was based on the usual averaging methods, which could have a lot of error. Among applied infiltration models, Kostiakov model and Philip model were the best empirical and physical infiltratin models, respectively, in the studied area. The best semivariogram model for the steady state infiltration rate was Philip model, with the coeficients of S and A, and a coefficient of Kostiakove model was gaussian; for the b coefficient, Kostiakove model was exponential. Spatial structure of the final infiltration rate, a and b coefficients of Kostiakove model, and S and A coefficients of the Philip model, was strong. The best interpolation method for the final infiltration rate was cokriging with the cofactor of silt percentage, for the S coefficient of Philip model was inverse distance weighting (IDW); for a and b coefficients of Kostiakove model, kriging and IDW were suitable, respectively.

In this study, drought characteristics of Arak, Bandar Anzali, Tabriz, Tehran, Rasht, Zahedan, Shiraz and Kerman stations during the statistical period of 1956 to 2015 were studied by Reconnaissance Drought Index (RDI) and Standardized Precipitation Index. Precipitation and temperature data were needed to calculate RDI. Precipitation data was also required to estimate SPI. In this study, Drinc software was used to calculate RDI, SPI and potential evapotranspiration (PET). The software calculated PET by the Thornthwaite method. One of the main challenges in drought monitoring is to determine the indicator that has a high reliability based on its monitoring purpose. Therefore, in this research, two methods used for selecting the appropriate index based on the minimum rainfall and normal distribution were evaluated. The results of the evaluation of the minimum rainfall method for selecting the appropriate index showed that most drought indices with the occurrence of minimum rainfall level indicated severe or very severe drought situations; in most cases, it could not lead to selecting an exact and unique index. Based on the results of the normal distribution method for the stations of Arak, Tabriz, Rasht, Zahedan, Shiraz and Kerman, SPI index, and for the stations of Bandar Anzali and Tehran, RDI index were selected as the most appropriate ones.