Journal of Water and Soil Science

Experimental Investigation of the Effect of the Pier Group Skew Angle on Local Scour Around the Piers under Steady Flow

L. Hashemi

Local scour around bridge piers is one of the most significant factors for the bridges’ destruction. Therefore, it is necessary to investigate the scour depth around the bridge piers. The effect of the skew angle of the single-column pier group related to the flow direction in two different arrangements including 1×2 and 1×3 piers on the maximum scour depth around the pile group was investigated in this study. The experiments were carried out under steady flow conditions. The pier group was placed in the 1×2 arrangement at the skew angles of 0 to 90 degrees and in the 1×3 arrangement at the skew angles of 0 to 45 degrees. The results showed that increasing the skew angle of the pier group is almost ineffective on the maximum scour depth around the first pier. However, it has a great effect on the maximum scour depth, its temporal development, and the expansion of the scour hole around the second and third piers in different arrangements of the pier groups. The maximum scour depth of the pier group in both different arrangements occurred at a skew angle of 30 degrees, in the arrangement of 1×2 around the second pier and by 13.33% more than the first pier and in the arrangement of 1×3 around the third pier and by 21.57% more than the first pier.

Temporal Variation Pattern of Runoff and Surface Sediment and Piping Erosion in Silt Loam Soil under Different Slopes Using Artificial Rain Simulator

M. Pajouhesh

Studying the process of soil erosion and evaluating its effective factors is one of the most important prerequisites for proper management of soil and water resources. This study was conducted to investigate the production of surface and pipe runoff and sediment using artificial rainfall on silt loam soil in the laboratory. So, the soil was collected from the study area and transported to the laboratory. Laboratory experiments were performed on a soil bed in a rectangular flume with three pipes, at slopes of 2%, 6%, 10%, 14%, and 18% under simulated rain (30 mm/h) for one hour. Related graphs were drawn in Excel to analyze the results, and Spearman's correlation test was used in SPSS software to check the correlation between runoff and sediment values in each slope. The results showed that with the increase in slope, the sum of surface and pipe runoff and sediment increased over time. For example, in a slope of 2%, the runoff and sediment in the initial moments of the experiment increased from 0 to 1.3 liters and 26.2 g m^-2 at the end of the experiment. Also, the correlation coefficient between runoff and sediment in the slopes was 0.98, 0.62, 0.4, 0.93, and 0.15, respectively, which was significant in some, but in others, it was not significant because of soil loss.

Effect of Mycorrhizal Inoculation on the Uptake of Some Heavy Metals by Parsley (Petroselinum sativum) in Contaminated Soil Treated with Kerosene

N. A. Zakavi

Arbuscular mycorrhizal fungi are highly important in improving plant growth and decreasing the negative effects of contaminants. The objective of this study was to evaluate the effect of inoculation of mycorrhizal fungus on the concentration of lead (Pb) and cadmium (Cd) by parsley (Petroselinum sativum) in heavy metal-contaminated soil in the presence of kerosene. This study was carried out as a factorial experiment based on the randomized complete design with four replications under greenhouse conditions. Experimental factors were included: 1- microbial inoculation in two levels with mycorrhizal fungus (Rhizophagus irregularis) and control (without inoculation), and 2- kerosene in four levels of 0, 4, 8, and 12 mL kg-1 soil. The results showed that mycorrhizal inoculation led to a significant increase in root (61.1 to 150.1%) and shoot dry weight (9.1 to 51.5%), shoot P, Zn, and Cu concentration and root Pb (18.7 to 97.9%) and Cd (13.3 to 98.6%) concentration, while significantly decreased shoot Pb (10.0 to 29.2%) and Cd (19.6 to 72.1%) concentration. The root bio-concentration factor (BCF) (7.74%) was higher than compared to shoot BCF. The mycorrhizal inoculation decreased the translocation factor (TF) of Pb and Cd. The TF<1 shows that the mycorrhizal fungus immobilized Pb and Cd in the roots and prevented their translocation from the root to the shoot. Hence, mycorrhizal inoculation can be effective in contaminated soils through bioconcentration of Pb and Cd in the root and decrease their translocation to the parsley shoot.

Field Comparison Studies of the Rate of Evaporation Between Colorado Sunken Evaporation Pan and Class A Evaporation Pans in the Arid Areas (Case Study: Semnan City)

H. Karami

One method used to estimate the evaporation rate involves employing various types of evaporation pans, including the standard Colorado Sunken and Class A evaporation pans. This study aimed to investigate and compare the evaporation rates from two pans, Class A and Colorado Sunken, in Semnan City. The Colorado Sunken evaporation pan was utilized as the test pan, and the test was conducted in an open space near the Faculty of Civil Engineering at Semnan University, located in Semnan City. Evaporation measurements were recorded daily for 123 days, from June 1, 2017, to September 31, 2017. The evaporation amount from the Class A pan was obtained from the synoptic station of Semnan city, situated 2.39 km away from the test site, and was subsequently analyzed. Meteorological data, including maximum and minimum temperature, maximum and minimum relative humidity, wind speed, sunshine hours, and air pressure, were also collected from the Semnan synoptic station and compared with the experimental evaporation data. The results indicated no significant difference in the daily evaporation amount between the Class A pan and the Colorado Sunken pan during the tested periods. The best statistical distribution, based on Kolmogorov–Smirnov test, for the Class A evaporation pan and the buried Colorado pan, were selected as Error with (k-s=0.05019) and Gamma with (k-s=0.05552). The coefficient of determination between the two pans was estimated to be approximately 93%. Further analysis revealed that the rate of evaporation is most closely associated with the maximum daily temperature. Pearson's correlation coefficient for the maximum temperature with the Class A evaporation pan and the Colorado Sunken pan was found to be 0.623 and 0.647, respectively.

Phytoremediation of Pb-Contaminated Soils Using Chrysypogon zizanioides in Lashkardar Protected Area, Malayer County

B. Attaeian

Mine exploitation has led to the rangeland's destruction. In this study, the phytoremediation of Pb-contaminated soils by Chrysypogon zizanioides was investigated in the soil around the lead mine of Lashkar region, located in Malayer county. In the initial measurement, the amount of soil Pb contamination in the rangeland was estimated to be 600 milligrams per kilogram of dry soil. By evaluating the environmental effects of lead in the region, the coefficients of geoaccumulation index, pollution degree, and potential ecological risk were observed in the infinite to very high range. The research was conducted in a completely randomized design with 4 Pb pollution levels (0, 300, 600, and 1600 mg/kg) in 4 replications in the greenhouse of Malayer University for 130 days. At the end of the period, lead concentration in soil, root, shoot, BCF bioaccumulation index, TF transfer coefficient, shoot, and root productivity in vetiver plants were measured. The results showed the increasing effect of soil Pb concentration on the amount of root and shoot Pb concentrations. At the level of 1600 mg/kg contamination, the Pb concentration in the shoot and root reached 242.94 and 242.02 mg/kg, respectively. At most levels of contamination except the level of 1600 mg/kg, the BCF indicators in the root and shoot and the TF coefficient were less than one. TF <1 indicates the lack of high concentration of Pb in harvesting organs and the health of the aerial production. So, vetiver is recommended for the rangeland reclamation in the study area.

Investigating the Impact of Land Use and Land Cover Changes on Wetlands Using Satellite Data (Case Study: Jazmorian Wetland)

V. Rahdari

Unbalanced development of different land use/cover in basins without considering the contribution of all components, can cause serious damage to the stability of the entire basin. The development of agricultural areas by increasing the amount of water use and creating dams upstream of rivers are the most important threats to wetlands in many places. Jazmorian wetland is one of the seasonal wetlands in the south-east of Iran. The most important source of water supply for this wetland is the Halil-Rood River. To investigate the land use/cover changes of Jazmurian wetland and

Halil-Rood River, the time series of Landsat satellite data for the years 1354, 1374, 1387, and 1401 were used in the present research. The Landsat satellite images were classified using a hybrid classification method and the land use/cover of the study area maps were prepared. The accuracy of the prepared maps for the latest image was calculated by preparing the error matrix, calculating the kappa index, and the overall accuracy of more than 0.8 and 9%, respectively. The investigation of the prepared maps showed that the area of land under water increased from 1354 to 1374 and then decreased from 119,552 hectares in 1374 to 723 hectares in 1401. The area of agricultural land increased from 2131 hectares in 1354 to 133913 hectares in 1387 and declined to 105795 hectares in 1401. The results of this study show that in this period, with the construction of a dam upstream of the Halil-Rood River, and the development of agricultural lands, the water volume level of the wetland decreased, and the wetland completely dried up in 1401. The present study indicates the necessity of considering different components of a watershed in development planning to achieve sustainable development.

Assessment and Spatial Modeling of Land Subsidence Hazard Using the LiCSBAS Model and Random Forest Algorithm (Case Study: Marvdasht Kharame Plain)

C. B. Komaki

In the future, the risk of land subsidence due to water resources shortage crisis and improper water resources management will become more and more dangerous. It is necessary to assess and identify areas susceptible to subsidence risk and take necessary actions to reduce risks related to land subsidence. In this study, first, the risk of land subsidence was identified and evaluated using a radar interferometry method called LiCSBAS. Then, the spatial relationship between the occurrence of land subsidence hazard and effective factors such as ground elevation, slope, slope aspect, lithology, land use, groundwater decline, distance from rivers, distance from faults, topographic moisture index, and arc curvature was investigated using the random forest (RF) model. In the end, the land subsidence hazard sensitivity map was prepared after calibrating the random forest algorithm. The analysis of LiCSBAS interferometric time series data from 2015 to 2022 showed that the center of the Marvdasht-Kharameh plain and adjacent agricultural areas are continuously subsiding and the mean deformation rate map showed a subsidence rate of 11.6 centimeters per year. The results of determining the spatial relationship between subsidence occurrence and effective factors confirmed the positive impact of distance from rivers, urban and agricultural land uses, depth of bedrock (aquifer thickness), groundwater decline, and alluvial and fine-grained formations on this phenomenon. Also, the results of subsidence modeling using the random forest algorithm showed that factors such as bedrock depth, groundwater decline, land use, and geology have the greatest impact on the potential for subsidence occurrence in the study area. Also, based on the results, about 3 to 4 percent of the areas are in the very high and extremely high-risk classes of land subsidence, especially in the center and suburbs of Mervdasht. Therefore, water resources management and control and developing a systematic program to reduce subsidence risk and aquifer recharge conservation in Merudasht-Kharameh Plain is essential.

Using the Data of Meteorological and Satellite Station in Determining the Intensity of Rainfall in the Kan Basin

S. S. Eslamian

The relationship between intensity-duration-frequency of rainfall is a significant tool for estimating flood discharge. According to the sparsely available rain gauge stations and the development of technology, it is possible to use satellite rainfall data with different temporal and spatial resolutions. PERSIANN rainfall data with a time resolution of 1 and 6 hours were used in this research. Also, the spatial resolution of these data is 0.04 x 0.04 degrees. Rainfall data from synoptic stations around the Kan basin were also used. Three common continuous probability distributions of Gamble, Pearson type 3, and Log Pearson type 3 with return periods of 2, 5, 10, 25, 50, and 100 years were investigated to calculate and check the IDF curve. In general, the precipitation intensity obtained from Gumble's method was more than Pearson Type 3's method. Log Pearson type 3 distribution did not provide acceptable results in this research. The two interpolation methods of inverse distance weighting and empirical Bayesian kriging were used to generalize the frequency intensity curves to the entire Kan basin. The results showed little difference between these two methods, except for Pearson type 3 probability distribution.

Investigating the interaction Effect of Irrigation Water Quality and Type of Irrigation System on the Soil Physical and Chemical Properties under the Conditions of Using Treated Municipal Wastewater

Y. Choopan

Reducing the effects of the misuse of urban wastewater is to use it in agriculture along with the subsurface irrigation system, which effects on the soil also require extensive investigations. Therefore, the present research was performed in a randomized complete block design with two factors of the type of irrigation source (well water W1 and treated urban wastewater W2) and the type of irrigation system (surface S1 and subsurface drip S2) in three replications (R) for a soil depth of 0-40 centimeter during two crop seasons. The results showed that the potassium, sodium, salinity, and sodium absorption ratio were significant at the 1% probability level in the comparison of system type and irrigation source type, whereas the values of pH, calcium, and magnesium were not significant in the comparison of system type and irrigation source type. The lowest value of calcium, magnesium, sodium cations, chlorine, phosphate, and sulfate anions was obtained in the W1S1 treatment. Also, the highest parameters of salinity, calcium, magnesium, phosphate, potassium, and chlorine were observed for the W2S2 treatment. It can be concluded that irrigation with urban wastewater has improved the chemical properties of the soil, and the type of irrigation system has had minor changes.

Prediction of Reference Evapotranspiration (ET0) Variations in Yazd Province Using Niazab System's Data

B. Moravejalahkami

Evapotranspiration variations (ET₀) were investigated and analyzed using Minitab16 software for the 2010-2019 period using the Nizab system's data in Yazd province, and then ET₀ was predicted until 2027. Based on the results, the increase of ET₀ in cities of Yazd province was affected by the enhancement in wind speed and weather temperature, and the decrease in relative humidity from 2010 to 2019. To determine the appropriate model, Ardakan, Abarkooh, and Taft cities were selected as a representative in each climatic group, and ET₀ data for the years 2010 to 2015 were considered as the input data of the software and ET₀ data for the years from 2016 to 2019 were used to validate the determined model. The prediction of the determined models showed an increasing trend of ET₀ for cold seasons in Ardakan and Abarkoh by 2027. Also, the model prediction showed a decreasing trend of ET₀ for hot seasons in Taft by 2027. Also, the ET0 will not change significantly in cold seasons. In Abarkoh and Ardakan cities, autumn-spring crops such as wheat and in Taft city, spring-summer crops such as sunflower will be more affected by ET₀ variations.

Determining the Coefficients of Philip's Equation and the Optimal Roughness Coefficient Using the Simulation of the Advancing Phase in Border Irrigation with the Dynamic Wave Model

M. Shayannejad

Surface irrigation is one of the most common irrigation methods. Due to the low efficiency of surface irrigation, water loss is significant in this system. It is necessary to know the characteristics and coefficients of water infiltration rate in the soil for accurate and adequate planning of surface irrigation. One of the equations used in this field is Phillip's infiltration equation. In this study, the infiltration coefficients of Phillip's equation and Manning's roughness coefficient in border irrigation are determined based on the comparison of the actual advance curve with the advance curve calculated with the dynamic wave model, and the results were compared with the double cylinder method and the two-point method of Ebrahimian et al. (5). The actual infiltration volume was obtained from the difference between the inlet and outlet volumes. The error of the mentioned method in calculating the infiltration volume was 5.53%. Meanwhile, the errors in the double cylinder and two-point Ebrahimian (5) method were 59.62% and 19.08%, respectively. In heavy soils, the longer the length of the border increases, the method is more accurate in estimating Philip's coefficients, while in light soils, the advancing time, which in addition to length is a function of permeability, input discharge, and the slope of the bottom of the bed is increased, the accuracy of the method in estimating Philip's penetration coefficients is increased.

Experimental Investigation of Embankment Wedge Failure’s Stability under the Effect of the Number and Spacing of Geotextile Layers in the Reinforced Retaining Wall

M. Zeinivand

The design of retaining walls depends on the amount of driving pressure from the backfill of the wall. Therefore, estimating this pressure is an essential factor in its design. In this research, the changes in the slope of failure, the place of the failure wedge, and the reduction of the failure line along the length and depth of the embankment were investigated on the retaining wall embankment reinforced with geotextile during ten tests in a laboratory study. The parameters under investigation in this article are the number of layers and the distances between the geotextile layers. The results showed that the presence of geotextile layers reduced the length of the fracture line up to 41%. It has also improved the value of the fracture angle and reduced the formation of the rupture wedge in the lower depths up to a maximum of 16%. The translational movement of the wall in the actuation state has a greater distinction between the fixed point and the failure zone, and the reinforcing layers are also effective in increasing the bearing capacity and stability of the retaining wall.