JWSS - Journal of Water and Soil Science

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

High concentrations of heavy metals in street dust are considered to be a serious risk to the human health and the environment. In this study, 30 dust samples were collected from the pavements in the main streets of Abadan to determine the level of pollution of heavy metals in the street dust. Heavy metal concentrations were analyzed by inductively coupled spectroscopy (ICP-OES) method. The level of heavy metals pollution was estimated based on enrichment factor, pollution index and Nemro Integrated Pollution Index. The average concentrations of heavy metals such as Pb, Zn, Cu, Cr, Cd, Ni, V, As and Co were 59.13, 287.50, 112.97, 50.03, 0.52, 56.77, 35.83, 7.10 and 7.53 mg/kg, respectively. Based on the average enrichment factor (EF), Ni, Cu and Pb had high levels of contamination and Zn contamination was high. According to the mean of pollution index (PI), heavy metals of Zn and Pb had a high contamination. According to the Nemro Integrated Pollution Index (NIPI), 96.66% of the samples had a high degree of contamination. The spatial distribution pattern of the heavy metals concentration showed that in the areas with high population densities, high traffic volumes and urban shopping centers, heavy metal pollution was severe.

Assessment of soil quality helps to make a balance between soil function and soil resources, improving soil quality and achieving the sustainable agriculture. For the quantitative evaluation of soil quality in the Shahrekord plain, Chaharmahal va Bakhtiari province, 106 compound surficial soil samples (0-25 cm) were collected. After the pre-treatments of soil samples, 11 physico-chemical soil characteristics/indicators as the total data set (TDS) were measured using the standard methods. Statistical analysis showed the usefulness of Principle Component Analysis (PCA) transformation. The minimum data set (MDS) was selected using PCA. Analytical Hierarchy Process (AHP) was carried out for the quantitative determination of indicator priorities and weights. Soil quality of the samples was calculated by introducing TDS and MDS into Integrate Quality Index (IQI) and Nemero Quality Index (NQI). The results showed the soil quality of the land uses was as Rangelands> Drylands<Irrigated croplands. The correlation coefficient between IQI-TDS and IQI-MDS was 0.97, while this value for NQI-TDS and NQI-MDS was 0.98. The correlation coefficient between IQI-TDS and NQI-TDS was 0.87 and that between IQI-MDS and NQI-MDS was 0.91. Classification of the resulted soil quality map IQI-TDS revealed that 12.5 % and 15.5 % of the plain were in very high and low quality conditions, respectively.

Despite the recent droughts in Isfahan province, climatic changes and the rising trend of population growth, as well as development of industrial and agricultural activities, are exposed to the water crisis. Thus, in order to tackle this problem, the essential strategies should including exploring virtual water and water foot print for strategic crops in agricultural sector should be taken into consideration for the management of water supplies at risk. This study was aimed to examine virtual water and ecologic fingerprint of water for the wheat crop in Isfahan Province from the farming year 2006-7 through 2014-15. For this purpose, the quantity of virtual water was extracted using net irrigation demand by NETWAT software and the rate of irrigation efficiency was computed to be 48%. The results indicated that only in 2007, Isfahan province was an exporter of virtual water for the wheat crop, so this province exported about 0.15 billion cubic meters of virtual water to other provinces by wheat exportation, but Isfahan province was the only virtual water in the years (2008-15) and this was due to the annual population rise and the existing drought in this zone. During this period, the rate of the mean annual rate of ecological footprint of water was 5.87 billion cubic meters and Isfahan Province stored this volume of water from the given internal supplies annually, with the mean rate of 0.65 billion cubic meters of virtual water importation at that year.

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

Nowadays, the Beerkan computational algorithms (BESTslope and BESTsteday) are known as the suitable indirect methods for estimating soil saturated hydraulic conductivity (Ks) and sorptivity (S), as well as the scale parameter (hg) in van Genuchten soil water retention equation through the data collected in the Beerkan infiltration experiment and other required data. The purpose of this study was to compare these algorithms in estimating Ks and S, as well as the soil water content corresponding to the suctions of 33 kPa, 100 kPa, 200 kPa, 300 kPa and 1500 kPa. For this purpose, a total of 40 Beerkan infiltration experiments were carried out in Sistan dam research field. From all Beerkan experiments, 30 tests in loam and sandy loam textures having a relative error less than 5.5% (Er <5.5%) were selected for further analysis. The statistical criteria RMSE, ME and ωr2 were used to compare the measured and estimated water content values at each suction. The results showed that the BESTsteday algorithm, which had a more simple calculating process than the main algorithm (i.e. BESTslope), could provide the Ks and S values and the soil water content of the near field capacity with an acceptable accuracy. The model performance in estimating water content corresponding to the 1500 kpa suction head (i.e. _θfc) was not acceptable for both algorithms. Moreover, the relative error of estimating soil water content (Er(_h,θ)) was decreased gradually by an increase in clay %.

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.

Sediment selectivity during transport may provide basic information for evaluating on-site and off-site impacts of the soil erosion. Limited information is, however, available on the selectivity of sediments in rill erosion, particularly in the rainfed furrows. Toward this, the sediment selectivity was investigated in three soil textures (loam, loamy sand sand clay loam) under 10% slope using 90 mm.h-1 rainfall intensity for 40 min. Soil samples were passed from a 10 mm sieve and packed in to the erosion flume with 0.4m × 4 m in dimensions. Particles size distribution (PSD) was determined in the sediments (PSDs) and compared with the original soil PSD (PSDo). The proportion of PSDs and PSDo was stated as PSDs/PSDo to show the selectivity of soil particles by rill erosion. Based on the results, all three soils appeared as the coarse particles (coarse sand and very coarse sand) in sediments with the PSDs/PSDo>1, indicating the higher selectivity of these particles by rill erosion. Loamy sand was the most susceptible soil to rill erosion among the studied soils, which generated a higher runoff (0.0035 m².s^-1) and sediment load (0.1 kg.m-1.s-1) during rainfall. The PSDs of this soil were similar to those of the original soil PSD. This study revealed that the stability of aggregates could be regarded as the major soil factor controlling rill erosion rate and the sediment selectivity in the semi-arid soils. With an increase in the water-stable aggregates, soil infiltration rate and as a consequence, shear stress of flow could be decreased in the rills.

Determination of land suitability is one of the land evaluation methods that can determine the best use of land in each area. The purpose of this research was to determine the land suitability of Mirza Kuchak Khan's cultivation and industry fields based on the soil quality indicators and a geographic information system (GIS), and compare the results with those obtained by methods of land evaluation and root strategies. For this purpose, information on soil profiles and the amount of organic matter, phosphorus, nitrogen, potassium, zinc, drainage, texture, depth, topography, surface rocks and gravel, impervious layer depth, hydraulic conductivity, water holding capacity, electrical conductivity, reaction PH), calcium carbonate, and exchangeable sodium percent of the study area were collected. Land suitability classes based on the quality indices of fertility, chemical quality, and physical quality of soil were defined. The results showed that 27.4% of the land belonged to the very good class (S1), 62.83% of the land could be assigned to the suitable class (S2), 11.7% of the land was put in the low proportion class (S3), and 2.66% the land was in the inappropriate class (N). Also, based on the comparison of the results of the method based on the soil quality with the square root method, Kappa coefficient was 0.82, while it was equal to 0.38 for the Storie method.

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.

Location of soil moisture sampling in irrigation management is of special importance due to the spatial variability of soil hydraulic characteristics and the development of root system. The objective of this study was determination of the suitable location for soil moisture sampling in drip-tape irrigation management, which is representative of the average moisture in the soil profile (θ_avg) as well. For this purpose, soil moisture distribution (θ_ij) at the tassel stage of maize and one irrigation interval (68-73 day after plant) were measured at the end of season. The results showed more than 70% length of the root of plant was located in 30 cm of the soil depth. By accepting ±10% error in relation to the averaged soil moisture, some region of soil profile was determined which was in the acceptable error range and also near the averaged soil moisture (0.9θ_avg<θ_Rec<1.1θ_avg). By overlapping θ_Rec in one irrigation interval, the appropriate location for soil moisture sampling was the horizontal distance from drip-tape line to 20 cm and the depth of 10-20 cm from the soil surface. To determine the appropriate place for soil moisture sampling, the development of root system and the maximum concentrated root length density in the soil profile extracting the maximal soil moisture should be taken in to account, parallel with the averaged soil moisture.

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.

In this study, some experiments were carried out in a rectangular plexiglass flume to study the effect of the cable around a vertical tripod and two piles groups with different angles. In this research, a series of experiments were performed by placing a cylindrical vertical pileand two piles groups with different angles separately in two modes including with cable and without cable. The experiments were carried out using three types of cable with various diameters, number of threads and thread angles at a constant discharge in clear water. In each experiment, scour depth at the end of the test was measured; then, the scour depth was calculated in different conditions using the obtained data. The best configuration in the vertical pier and piers group was found for the cable-pier diameter ratio of 0.1, the thread angle of 15° and the triple threads. The result indicated that the scour reduction was enhanced as the cable diameter and threads were increased and the thread angle was decreased. So in the piers group of 28 and 38°, scour depth was reduced to about 43, 49 and 56%.

Agriculture production with high quality and adequate income for farmers and the least harmful effects in environment are the main objectives of agriculture optimization. The main objective of this study was ranking, optimization and land allocation of Gonbadkavoos’s Drylands for strategic products such as wheat, barley, oilseed rape‎ and soybean under environment and socio-economic scenarios. Because the available information on fertilizer and pesticide consumption was not sufficient and reliable, this data was collected through face-to-face interviews with farmers. The results showed that some slightly and moderately hazardous pesticides were consumed in study area. In this study, the optimized combination of agriculture products was applied by using the modeling approach and considering environmental and socio-economic aspects in Gonbadkavoos County.‎ This approach uses MCAT software, which is based on multi-criteria techniques and metaheuristic algorithms. The results of the environmental scenario‎ show‎ ed that barley, oilseed rape‎ and soybean, with little difference,‎ had the highest benefit-to-cost ratio and profitability, respectively. The slight difference could be related to the use of fertilizers and pesticides. In the socio-economic scenario, oilseed rape, wheat and barley had the highest benefit-to-cost ratio and land allocation, respectively. The represented approach using the decision support system (MCAT) can help planners to design optimal cropping systems and aid good management of fertilizers and water consumption.

A significant amount of the oil meal is produced annually in the oil industry. Oil meal addition into the soil can improve the soil organic matter and micronutrients concentration. This study was conducted to investigate the effect of olive, sesame and black cumin meal (0, 2 and 5 g 100g^-1 soil) on the soil Cu, Zn and Fe concentration in saline and non-saline soils by a greenhouse experiment. The soil basal respiration, organic carbon, carbohydrate and DTPA extractable Cu, Zn and Fe concentration were measured after 60 days of incubation. The results showed that the greatest organic carbon and carbohydrate content were observed in olive and black cumin treatments and the lowest was observed in the sesame treatment. Using oil meal in the soil improved the micronutrient concentration, as compared to the control treatment. Sesame meal had the greatest effect on the DTPA extractable Cu and Zn concentration increment. The DTPA extractable Fe concentration was the highest in the sesame treatment and the lowest in the black cumin one. In addition, salinity decreased the DTPA extractable Fe and Zn concentration, as compared to the non-saline soil. As the conclusion, oil meal incorporation in to the soil improved the soil organic carbon and micronutrient concentration. However, their effect depends on the meal quality and soil salinity.

The current study was conducted to compute SPI and SPET drought indices due to their multi-scale concept and their ability to analyze different time-scales for selected meteorological stations in Karoon Basin. Regionalization of SPI and SPEI Drought indices based on clustering analysis was another aim of this study for hydrological homogenizing. Accordingly, to run test through data and determine similar statistical periods, 18 stations were selected. SPI and SPEI values were plotted in the sequence periods graphs and their relationships were analyzed using the correlation coefficient. The results were compared by Pearson correlation coefficient at the significance level of 0.01. The results showed that correlation coefficients (0.5-0.95) were positive and meaningful for all stations and the correlation coefficient between the two indices were increased by enhancing the time-scales. Also, time-scales enhancement decreased the frequency of dry and wet periods and increased their duration. Through regionalization of basin stations based on clustering analysis, the stations were classified into 7 classes. The results of SPEI regionalization showed that the frequency percentage of the normal class was more than those of dry and wet classes.

Evaluation of groundwater hydro chemical characteristics is necessary for planning and water resources management in terms of quality. In the present study, a self-organizing map (SOM) clustering technique was used to recognize the homogeneous clusters of hydro chemical parameters in water resources (including well, spring and qanat) of Kerman province; then, the quality classification of groundwater samples was investigated for drinking and irrigation uses by employing SOM clusters. Patterns of water quality parameters were visualized by SOM planes, and similar patterns were observed for those parameters that were correlated with each other, indicating a same source. Based on the SOM results, the 729-groundwater samples in the study area were grouped into 4 clusters, such that the clusters 1, 2, 3, and 4 contained 73%, 6.2%, 6.7%, and 14.1% of groundwater samples, respectively. The increase order of electrical conductivity parameter in the clusters was as 1, 4, 3 and 2. The results of water quality index based on the entropy weighting (EWQI) showed that all of the samples with excellent and good quality (36.3% of samples) for drinking belonged to the cluster 1. According to the Wilcox diagram, 435-groundwater samples (81.7%) in the cluster 1 had the permitted quality for irrigation activities, and the other 285-groundwater samples were placed in all four clusters, indicating the unsuitable quality for irrigation. The Piper diagram also revealed that the dominant hydro chemical faces of cluster 1 were Na-Cl, Mixed Ca-Mg-Cl and Ca-HCO₃, whereas the clusters 2, 3, and 4 had the Na-Cl face. This study, therefore, shows that the SOM approach can be successfully used to classify and characterize the groundwater in terms of hydrochemistry and water quality for drinking and irrigation purposes on a provincial scale.

Selection of drainage equation with acceptable accuracy has always been a challenge for designers to design subsurface drainage systems. In this research, seven steady state drainage equations were used for predicting daily and cumulative drainage rate on a farmland of sugarcane in Imam agro-industrial Company. These drainage equation included Hooghoudt, Ernst, Kirkham and Dagan that have been developed in the past and Mishra and Singh, Henine and Yousfi et al that recently developed. The statistical indices consist of P-value, RMSE, R2 and Percentage Error of estimating cumulative drainage rate were calculated for Hooghoudt equation 0.9501, 1.49 (mm/day), 0.80 and -0.19%, respectively. For Ernst equation 0.0001, 2.46 (mm/day), 0.34 and 16.98%, respectively. The result of performance of drainage equations revealed that Hooghoudt and Ernst equation were as the equations with the highest and lowest accuracy in predicting drainage rate, respectively. Also from the newly developed equations, the Yousfi et al equation was found with relatively well accuracy to predict the drainage rate. This equation was placed in second rank after Hooghoudt equation and other equations showed poor performance. Thus, with selection of the appropriate drainage rate, the Hooghoudt equation is suggested for designing of drain spacing in medium to heavy textured soils such as sugarcane agro-industrial.

A well healthy environment can quietly affect the life quality and human community. In recent decades the need for and utilizing fossil had increased and thus the environmental pollutions including for soil has also increased. Petroleum contaminated soils are not suitable for agricultural, residential and social usage and cause economical, ecological and agricultural damage. To cope with this challenge, the use of additives such as carbon nanotubes has expanded to soil, but the use of these elements has raised concerns about their risk to biological processes and systems, such as effects on physiology and plant growth, and there have not been much studies on this issue. In order to investigate the interaction of soil petroleum pollution and carbon nanotubes on some plant characteristics such as wet mass, dry matter and plant length, seed and maize seedling were separately treated with 0, 10, 20 and 40 mg/l carbon nanotubes at the beginning. In pots containing soil with three levels of petroleum pollution, 2.43, 2.76 and 4.16% were cultivated with 3 replications. A completely randomized design was used in the form of factorial experiments. Wet mass, dry matter and length of shoot and root of plants were determined. The results showed that petroleum pollution had a negative effect on the growth characteristics. It was also observed that application of carbon nanotubes to maize (whether seed or seedling) depending on the concentration of these materials, could have different effects on plant growth parameters.