JWSS - Journal of Water and Soil Science

Groundwater supplies a major portion of two basic human needs: drinking and agricultural water. Forecasting, monitoring, evaluating the performance and planning of this vital resource require modelling. The lag time of the groundwater level fluctuations against the rainfall is one of the essential data of the models. The purpose of the present study was to evaluate the piezometers behaviour by using the Pearson cross-correlation method between SPI and GRI indices in the Shiraz alluvial plain in order to determine the mentioned lag time. The results showed a similar behaviour for 86.2% of the piezometers. In 79.3% of the piezometers, groundwater level was declined one month after the rainfall event. The best correlation coefficient between the aforementioned indices was observed along the southwestern to the northeastern axis of the plain. The northern alluvial plain has a better correlation, as compared to the southern section because of the northern-southern slope of the plain. The central area of the plain had the highest correlation coefficient. The maximum correlation coefficients occurred at a time scale of 48 months. Also, since 2004, due to the decline in the atmospheric precipitation in the Shiraz plain, the SPI index has surpassed the drought level, although the trend has not been significant. However, the GRI does not follow this trend, showing a significant hydrological drought. The reason can be the disproportionate water extraction to recharge ratio in the alluvial aquifer of the plain.

Astragalus fasciculifolius is one of the most distributed plant species in the arid and semiarid regions of southern Iran. It may be well grown on roadside. This investigation was carried out to study the effect of road and its traffic intensity on the soil physicochemical properties and plant nutrients availability of roadside and to monitor the concentration of nutrients in the aerial parts of Astragalus fasciculifolius. Thirty soil and plant samples from roadside and 100 m distance from road were randomly collected and some physicochemical soil properties and nutrients availability were determined. Concentrations of the nutrients in the aerial parts of the plants were also determined. The results indicated that roadside soils had more sand and calcium carbonate equivalent than the adjacent lands. Soils of the main roadside had less K and more Fe, Mn, Zn and Cu than the adjacent lands; this difference in local road was observed only for Fe and Cu. Nutrients concentration in the aerial parts of the plants was affected by road, and P, K, Mn and Zn showed significant increases in the roadside plants. Concentrations of P, Fe, Zn and Cu in plants grown in main roadside and concentrations of Fe and Zn in plants grown in the local roadside were correlated with their contents in the soils. The effect of roads on soil properties change and nutrients availability may be related to the addition of road bed and emission of vehicles. Generally, it could be concluded that roadside soils had more suitable water and nutrition conditions for the growth of Astragalus fasciculifolius, as compared to the soils of the adjacent lands.

Shortage of water resources and deterioration of water quality have urged the need to develop new technologies for the removal of contaminants from water. Heavy metals produced by municipal and industrial activities are among the most toxic contaminants present in the natural and waste waters. Different methods have been developed for the elimination of heavy metals from water resources and industrial waste waters. Adsorption is an effective and economic method for the water purification purposes. Nowadays, clays and natural polymers have been widely used as the adsorbents for heavy metals, due to their eco-friendly nature, natural abundance, low cost and high specific surface area. If these adsorbents are used as a hybrid material, some of their physical and chemical restrictions would be alleviated. In this study, polyacrylic acid–bentonite hybrids and natural bentonite were compared in terms of Pb adsorption in the batch and fixed-bed column systems. Besides, the effect of pH on Pb retention was investigated in both systems. The results of the batch studies showed that Langmuir and Freundlich isotherm models were appropriate in ing quilibrium Pb sorption data. Pb sorption by the sorbents was increased with the rise in solution of pH from 4 to 6, showing the greatest Pb sorption capacity at pH values of 4 (83.29 mg g^-1) and 6 (103.3 mg g^-1). Different indices of filtration and adsorption, including average relative effluent concentration, relative adsorption index, relative transmitted index, and filtration coefficient, were calculated from the break-through curves, indicating that the polyacrylic acid-bentonite nanocomposite was superior in the Pb sorbtion, as compared to bentonite. Also, a higher pH value resulted in the greater Pb removal from the solutions.  

The flow fields over a trapezoidal labyrinth weir (two-cycle) and a piano key weir were simulated using Flow3D, studying the impact of each model on the flow field in the weirs and the coefficient of discharge in comparison with the available experimental data. Moreover, the models were investigated experimentally in a 12.5 m long, 0.3 m wide, and 0.4 m high rectangular flume under clear-water conditions. The results showed good agreement between the data from the numerical and experimental models. The piano key weirs had a higher coefficient of discharged compared with labyrinth weirs. The coefficient of discharge was observed to increase by 26 percent as the height of the PKW was increased by 50 percent (from 5 to 7.5 cm). This increase was 24 percent for labyrinth weirs.

In order to increase the available Phosphorous (P), chemical fertilizers are applied; however, P chemical fertilizers are transformed into low available forms over time. Organic amendments could be effective in improving the efficiency of P fertilizers. The aim of this study was to investigate the effect of P fertilizers and vermicopost on the availability and fractions of P and maize (Zea Mays L.) indices in a calcareous soil. This study was performed in a factorial completely randomized design with three replicates. The experimental factors included chemical fertilizer (0 and 50 mg/kg P) and vermicopost (0 and 1 %W). After 2 months of planting in greenhouse, the shoots of maize were removed and the maize indices (P concentration, dry matter and P uptake) were determined. Then, the soil samples taken from each pot, P available, and P fractions were evaluated by a modified method developed by Hedley et al (1982). The results showed that the effect of the interaction beyween P fertilizer and vermicopost on the available P was significant. Also, the interaction of P fertilizer and vermicopost on the soluble and exchangeable P (P<0.05) and organic P (P<0.01) was significant. By applying the P fertilizer or % 1 vermicompost, all P fractions (except Ca bound P) were increased. The results, therefore, showed that the effect of the interaction between P fertilizer and vermicopost on P concentration, dry matter and P uptake was not significant (P>0.05). Vermicopost application increased the dry matter from 6.9 to 10.5 g pot^-1, while application of 50 mg kg^-1 P as fertilizer increased the dry matter from 7.7 to 9.7 g pot^-1. Also, by adding vermicopost (11.1%), the i P uptake was increased, as compared to 50 mg kg^-1. The results, therefore, indicated that the beneficial effect of vermicompost on the dry matter and P uptake in maize was more than that of the chemical fertilizer. Moreover, P fertilizer and manure could influence P fractions and P availability. 

Soil pollution by heavy metals is a serious environmental problem that threatens the human health. The present study was carried out to investigate and detect the contamination of heavy metals of arsenic, copper, lead, zinc and iron due to human and natural activities in the sediment of lake bed and the surface soils of the eastern part of Urmia Province, West Azarbaijan Province. A total of 20 soil samples and surface deposition from the depths of 0 to 30 cm were collected randomly from the studied areas. After preparing the samples, extraction was carried out to determine the concentration of the heavy metals in the soil by using hydrochloric acid and nitric acid, and the total concentration of metals was measured using ICP-OES. The results of the calculation of the contamination factor showed that copper, iron, zinc and lead in the class of low and medium pollution and arsenic in 65.5% of the samples were very high in the class. The high concentrations of copper, lead and zinc contamination in the margin of the city and the contamination of arsenic in the lake bed were observed. The analysis of the contamination factor maps and contamination index with land use and geological map showed that copper, lead and zinc were mostly affected by human activities and arsenic influenced by the maternal materials in the region.

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.

In general, engineering designs need to optimize the factors affecting the under-study phenomenon; however, this is often a costly and time-consuming process. In this regard, new methods have been developed to optimize with fewer tests; thus, they can make the whole process more affordable. In this study, Taguchi and Taguchi-GRA methods were used to design the geometric parameters of the protective spur dike in order to optimize their efficiency in reducing the scouring in a series of spur dikes. The results of both methods showed the optimal ratio of the length of the protective spur dike to the length of the first spur dike was 2.5 and the angle of the protective spur dike was 90 °. However, the ratio of the length of the protective spur dike to the length of the main spur dike in the Taguchi method was 0.8 and in the Taguchi-GRA method, it was 0.6. In addition, using variance analysis showed that the distance between the protective spur dike from the first spur dike, the protective spur dike angle, and the length of the protective spur dike were, respectively, the most effective on the performance of the protective spur dike. The results of this study, therefore, indicate that both methods are highly effective in optimization and, therefore, can be useful in the hydraulic engineer studies.

Today, to reduce the risks of contaminants, new remediation techniques have been focused on low-cost and environmentally friendly manners. Given the frequency of access, inexpensiveness and good physical and chemical properties, biochar has a high potential for the remediation of water pollutants. In this paper, the efficiency of chitosan engineered biochar (Bc-Ch) and pristine biochar (Bg-Bc) prepared from sugarcane bagasse biomass (Bg) in the Cd²⁺ removal in aqueous solution was investigated. To this aim, the effects of contact time, adsorbent dosage and solution pH on cadmium removal were evaluated by adsorption isotherms and Kinetic models. The results indicated that the Langmuir isotherm and the pseudo-second-order kinetic model could be well fitted with the process of cadmium biosorption. The maximum adsorption capacities of Bc-Ch, Bg-Bc and Bg ,according to Langmuir model, were found to be 32/78 mg/g, 11/57 mg/g and 2/23 mg/g, respectively. For these absorbents, the pseudo-second-order kinetic model showed the best fit to the experimental adsorption data. This study, therefore, indicated that the chitosan engineered biochar could be used as an effective, low-cost, and environmentally-friendly sorbent to remediate heavy metals contamination in the environment.

For sustainable soil management, the effects of slope position and land use change on soil and water resources are essential. In this research, three land uses including degraded pasture, drought and apple gardens were selected to determine the effect of slope position and land use on some physical and chemical properties of soil in the Koohrang area of Chaharmahal and Bakhtiari province. Each of the applications was divided according to the position of the slope, and from three applications and organic matter (OM), saturated hydraulic conductivity (Ks), water repellency (RI), dispersible clay (DC) and weighted average aggregate diameter (MWD)  were studied as the  physical and chemical properties of soil. The results showed that Ks had the greatest coefficient of variation. Also, the results of the mean comparison revealed that all of the measured physical and chemical properties had a significant difference in different slope applications and positions at 5% level. In general, the garden and the base position of the slope had better qualitative conditions than other land uses and slope positions. Rangeland degradation and change in the use of pasture from dryland cultivation led to a decrease in soil quality, which could reduce soil utilization and exhaust some of the land from the production cycle. The results of the correlation between chemical and physical properties of soil showed that in general soil organic matter had the highest correlation with other parameters.

In this research, the impact of the Alagol wetland on the water treatment of Atrak River was studied. From June, 2016, to May, 2017, on the fifteenth day of the month, four samples of water were collected from the middle and the outlet of the wetland. Also, the wetland was fed only in the months of September, November and February. The parameters of acidity, electrical conductivity, phosphate, nitrate, dissolved oxygen, biochemical oxygen demand, chemical oxygen and ammonia were measured. The water pH at the entrance and exit was significantly different. EC was higher at the entrance, and its value was decreased in the middle and output. DO in the outlet of the wetland was higher than that in the middle and inlet, indicating the improved water quality and high dissolved oxygen in the wetland output. NO₃, NH₄, PO₄, BOD and COD were higher at the entrance to the wetland; also, it was decreased in the outlet and middle, and the difference was significant. Further, according to the results of September, November and February, which were fed to the wetland, water quality in the middle and outlet of the wetland was improved toward the entrance of the wetland. According to the results, Alagol wetlands could reduce the phosphorus, ammonia, BOD, COD and DO, and their concentrations were lower than the limit. However, given that the salinity at the entrance of wetland was too high, its amount in the output was higher than the standard limit and the wetland could not significantly reduce salinity. The results of this study showed that that of water pollution in the inlet, except that the dissolved oxygen parameters and the temperature were high and decreased in the middle outlet. Due to the quality of the wetland outlet, Alagol wetland water could be used for fish farming centers.

In order to plan and manage the land and its changes, it is necessary to identify and evaluate the factors affecting it. Land use / cover changes are one of the main factors in global environmental change that is defined as a change in the type of land use; it is one of the major factors changing hydrologic flow, land erosion and destruction of biodiversity. The main purpose of this study was to assess the trends of land use changes in Beheshtabad Watershed of Chaharmahal and Bakhtiari Province with an area about 3847 square kilometers by using remote sensing and GIS during a 25-year period. In this research, first, analyzing and pre-processing the satellite images of Landsat 5 TM sensors from 1991 and 2008 were done, and Landsat 8 of OLI sensor of 2016 was applied. Then, by using the hybrid classification method, 5 land use classes including pasture lands, urban-building lands, agricultural lands, garden lands and bare lands, land use maps for the three time periods were prepared. The overall accuracy of the obtained land use maps for 1991, 2008 and 2016, was 92.17%, 94.29% and 93.41%, respectively, indicating the acceptable accuracy of the maps. Then, the process of land use change and the contribution of each land use classes and the percentage of changes in each land use class were determined in two study periods. The results of this study showed some changes occurred in the studied watershed. The total area of pasture lands during two periods indicated the decreasing trend, but urban-building and garden lands during two periods represented the increasing one. Agricultural lands during the first period indicated the decreasing trend and during the second period showed the increasing trend, while bare lands during the first period showed the increasing trend and during the second period, reflected the decreasing trend. In general, it should be noted that in the Beheshtabad watershed, we could see an increase in the replacement of pastures by urban-building class, rainfed agriculture, gardens, and bare lands, the incidence of destruction in the region.

In the present study, six soil profiles belonging to five soil types were dug, described and sampled. Soil samples were analyzed for the determination of different physicochemical properties and total and DTPA-extractable iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), lead (Pb), and cadmium (Cd). Considering the variability of pH and calcium carbonate equivalent, the examined soils were alkaline and calcareous. A considerable change in the values of the DTPA fraction of Fe (1.4-25.8 mg/kg), Zn (0.01-3.3 mg/kg), Cu (0.32- 6.2 mg/kg), Mn (1-11.8 mg/kg), Cd (0.05- 0.12 mg/kg) and Pb (0.22- 2.56 mg/kg) as well as in the total fraction of Fe (10.6-20.6 g/kg), Zn (35- 67.5 mg/kg), Cu (9 to 26.40 mg/kg), Mn (262- 588.8 mg/kg), Cd (0.5- 1.75 mg/kg) and Pb (17- 31.3 mg/kg) was observed in  different soils. The content and pattern of both DTPA and total fraction of the metal were varied among the soil types, which could be related to several processes such as the diversity of weathering rate, geomorphologic condition, soil formation process, different physicochemical properties of soils, and the inputs of different agrochemical compounds. The concentration of both DTPA and total fraction of the metal were in the acceptable maximum level in the majority of the soil samples.

In this study, the discharge coefficient of sharp-crested weirs located on circular channels was modeled using the ANFIS and ANFIS-Firefly (ANFIS-FA) algorithm. Also, the Monte Carlo simulations (MCs) were used to enhance the compatibilities of the soft computing models. However, the k-fold cross validation method (k=5) was used to validate the numerical models. According to the input parameters, four models of ANFIS and ANFIS-FA were introduced. Analyzing the numerical results showed that the superior model simulated the discharge coefficient as a function of the Froude number (Fr) and the ratio of flow depth over weir crest to the weir crest height) h/P(. The values of the mean absolute relative error (MARE), root mean square error (RMSE) and correlation coefficient (R) for the superior model were calculated 0.001, 0.002 and 0.999, respectively. However, the maximum error value for this study was less than 2%. 

Understanding the quality of groundwater resources, which are the largest available freshwater reservoir, is one of the needs in planning and developing water resources. The purpose of this research was to study the quality changes of groundwater resources in the upstream aquifers of Zayandehrood Dam (1995-2016) and to evaluate water quality in terms of drinking and agricultural consumption and evaluation of IRWQIGC. For this purpose, EC, TDS, SAR, PH, TH, Cl, CO₃, Ca, Mg, Na, K, HCO₃ and NO₃ parameters and heavy elements including zinc, copper, lead, cadmium and arsenic were investigated from laboratory samples. In the upstream aquifers of the Zayandehrood Dam, the water classification was mainly agricultural in the C2-S1 range, and it was generally acceptable in the drinking classes. The amount of heavy elements was allowed. The average amount of nitrate in the Chehelkhaneh, Damanehdaran, Boein-Miandasht and Chadegan aquifers was calculated to be 43.77, 48.08, 35.53 and 26.36 mg / l, respectively, and the maximum nitrate levels in these areas, however, were often exceeded. Nitrate zoning and IRWQIGC were performed by the kriging method. The lowest index values, which fell into relatively poor classes, were in the south and southwestern parts of Boein-Miandasht and south and south-west of the Chehelkhaneh, and in the central parts of Damanehdaran, and the south of Chadegan.

Due to the limited water resources and growing population, food security and environmental protection have become a global problem. Increasing water productivity of agricultural products is one of the main solutions to cope with the difficulties. By optimizing applied water and nitrogen fertilizer, the pollution of groundwater could be deceased and the water productivity could be increased. The aim of this research was to determine the relationships between water productivity (IRWP) and water use efficiency (WUE) and different amounts of applied water (irrigation + rain fed) and nitrogen (applied and residual). This study was conducted on wheat (Triticum aestivum L., cv. Shiraz) in Shiraz University School of Agriculture, based on a split-plot design with three replications, in 2009-2010 and 2010-2011 periods. Irrigation treatments varied from zero to 120% of full irrigation depth, and nitrogen fertilizer treatments varied from zero to 138 kg ha^-1 under basin irrigation system. The experimental data of the first and second years were used for the calibration and validation of the proposed relationships, respectively. The calibrated equations using the dimensionless ratios of irrigation depth plus rainfall, actual evapotranspiration and nitrogen fertilizer plus soil residual nitrogen to their amounts in full irrigation and maximum fertilizer amounts were appropriate for the estimation of water productivity and water use efficiency. The values of the determination coefficient (R²) for water productivity and water use efficiency (0.88 and 0.93, respectively), and the values of their normalized root mean square error (NRMSE) (0.2 and 0.13, respectively) showed a good accuracy for the estimation of IRWP and WUE.

In arid and semi-arid ecosystems, isolated trees significantly influence the soil properties and can have a great impact on the soil fertility as well as the conservation and improvement of soil quality. This investigation was conducted to examine the influence of wild almond (Amygdalus arabica Olive.) trees having different ages on the physical and chemical soil properties. Soil samples were taken from the depths of 0-20, 40-60, 80-100 and 120-140 cm at two distances from the tree crown including the basal area (referred to as the rhizosphere) and the canopy edge in 3 replications for the 30, 50, and 130 year-old stands and also, in a control site, all in the Anjarak area, southeast of Baft city, Kerman Province. Soil properties including pH, EC, organic matter, calcium carbonate equivalent, available and non-exchangeable potassium and soil texture were measured in all samples. The results indicated that the measured soil properties in different depths in the study area had been influenced by the age and the canopy size of the wild almond trees. The highest and the lowest amount of pH were found in the control soil and the soils covered by 130 year-old trees, respectively. Besides, the electrical conductivity of the soil under the tree crown was more than that of the soil in the canopy edge. The accumulation of C, N, and other nutrients under the tree canopies resulted in the creation of fertility islands surrounding the trees. Furthermore, the soil physical and chemical properties were greatly improved with the increase in the tree age of Amygdalus arabica Olive. As the conclusion, wild almond trees could have very positive effects on soil properties. Therefore, it is essential to protect the trees. Otherwise, the risk of soil quality reduction would be increased and soils might become more susceptible to soil erosion.

Sand mining from rivers is one of the biggest concerns in the science today. Certain principles and rules for choosing the right place for mining materials and the amount of this mining are missing in the design codes. Therefore, mining of river materials from sites with less potential and near structures has been occasionally seen. In the present study, it has been attempted to reinforce the structure to control the impact of the mining of material, which results in the increased scour by changing the flow pattern around the structure. The experiments were carried out in two simple and armed modes, in sand bed with a grain size of 0.78 mm, with a length of 4.25 meters, inside a canal of 13 meters in length and 1.2 meters in width. The extent of scouring along the longitudinal and transverse directions in different times from the start to the scouring equilibrium was investigated for all substrates under sub-critical flow conditions (range 0.5-0.25). The results showed that the use of a cable-protected method in the upstream pit led to 29.6% reduction in the maximum scour depth at the front and 34% reduction in the back of the pier; also, in the downstream of the pit, it reduced the maximum scour depth by 15% at the front of the pier. Therefore, the cable arrangement used at the piers surface, according to the current research method, resulted in a significant reduction in the depth and extent of scouring in the pier group of the bridge.

Inclined drop is one of the supercritical flow producers used in open channels to reduce slope and elevation of the ground. Given that the application of horizontal and vertical screen in the downstream of this drop as an energy dissipater can be effective in the n energy dissipation of flow, in the present study, 180 different experiments were performed to investigate the energy dissipation of flow. The results showed that the angle of the drop had no marginal impact on energy dissipation and the relative depth of downstream of inclined drop equipped with a vertical screen, but increasing the porosity of screen caused enhancement in both parameters. Also, for the inclined drop equipped with a horizontal screen, by increasing angle and decreasing the porosity of screen, the energy dissipation and relative depth of downstream were raised. Also, for inclined drop equipped with a horizontal screen, by increasing the angle and decreasing the porosity of screen, the energy dissipation and relative depth of downstream were enhanced. For a constant relative critical depth, the relative depth of downstream and the energy dissipation of the inclined drop equipped with a horizontal screen considered the function of the wetted length of screen and length of the drop. For vertical screen, it is only a function of screen porosity.

The purpose of this study was to investigate the relationship between time and spatial features of meteorological, hydrological and agricultural droughts in Karoon 1 Dam basin. Meteorological and statistical data were accordingly selected to evaluate the drought situation between 1993 and 2016. The results showed that hydrological droughts occurred in the meteorological drought and had a very high correlation with this year's meteorological drought. The most severe droughts occurred between 2006 and 2011. Studies also showed that every three years, the basin was accompanied by a meteorological drought and then a hydrological drought. The results also showed that the highest correlation was observed with the 12-month meteorological index, with a delay of 3 months, and the 6-month meteorological and hydrological index with a delay of 3 months and a three-month hydrological drought index with a delay of two months. Therefore, it could be concluded that hydrological droughts showed a delay of almost two to three months in the entire catchment area; since this period was 4 months or more, the correlation between these two indicators was eliminated and decreased. Also, due to drought zones, during the period from 1993 to 2009, most of the droughts were caused by rainfall reduction in the southwest of the province, and this was associated with a reduction in runoff in its hydrometric stations. Of course, in 2009-2012, the runoff status had been temporarily improved, and from 2012 to 2017, the drought situation had again returned spatially to the previous routine.