Showing 517 results for Ni
M. Mohammadi, B. Lorestani, Soheil Sobhan Ardakani, M. Cheraghi, M. Kiani Sadr,
Volume 25, Issue 4 (12-2021)
Abstract
Polychlorinated biphenyls (PCBs) can adversely affect human and environmental health according to long-term half-life and persistence in the environment. Therefore, this study was conducted to detect, identify, and health risk assessment of PCBs in surface soils collected from the vicinity of Arad-Kouh processing and disposal complex, Tehran, in 2020. A total of 30 surface soil samples was collected from 10 sampling sites near the Arad-kouh complex. After extraction of analytes, the gas chromatography/mass spectrometry (GC–MS) method was used to determine PCBs in soil samples. Based on the results, 15 congeners of PCBs were detected in the analyzed soil samples. Also, the minimum, maximum, and mean concentrations of total PCBs (µg/kg) were 269, 434, and 359, respectively. Moreover, the results of PCA and significant contribution values of low molecular weight homologs indicated that the presence of PCB compounds in the soil samples was connected with combustion processes in the soil. Besides, as among the detected PCBs, the TEF values only established for PCB105 showed that exposure to contaminated soil could be lead to a moderate level of carcinogenic risk through PCB105. Given that PCBs have adverse effects on the environment and human health, detecting, determining the concentration, source identification, and periodical monitoring of these compounds in different mediums to human health maintenance is strongly recommended.
K. Ghaderi, B. Motamedvaziri, M. Vafakhah, A.a. Dehghani,
Volume 25, Issue 4 (12-2021)
Abstract
Proper flood discharge forecasting is significant for the design of hydraulic structures, reducing the risk of failure, and minimizing downstream environmental damage. The objective of this study was to investigate the application of machine learning methods in Regional Flood Frequency Analysis (RFFA). To achieve this goal, 18 physiographic, climatic, lithological, and land use parameters were considered for the upstream basins of the hydrometric stations located in Karkheh and Karun watersheds (46 stations with a statistical length of 21 years). The best Probability Distribution Function (pdf) was then determined using the Kolmogorov-Smirnov test at each station to estimate the flood discharge with a return period of 50-year using maximum likelihood methods and L-moments. Finally, RFFA was performed using a decision tree, Bayesian network, and artificial neural network. The results showed that the log Pearson type 3 distribution in the maximum likelihood method and the generalized normal distribution in the L moment method are the best possible regional pdfs. Based on the gamma test, the parameters of the perimeter, basin length, shape factor, and mainstream length were selected as the best input structure. The results of regional flood frequency analysis showed that the Bayesian model with the L moment method (R2 = 0.7) has the best estimate compared to other methods. Decision tree and artificial neural network were in the following ranks.
E. Sabbagh Tazeh,
Volume 26, Issue 1 (5-2022)
Abstract
The utilization of organic amendments in the reclamation of saline-sodic soils can reduce the necessity for the application of chemical Ca+2 sources. In this research, soil leaching experiments were conducted in CRD as split factorial. The main factors were 1) amendment type including manure and compost, 2) amendment rate including 1, 3, and 5 percentage w/w, and 3) leaching stage with 5 levels including without leaching, once, twice, three times, and four times leaching, every time with one pore volume and with 30 days’ intervals. All columns were incubated for 30 days after the addition of amendments and then were leached. The parameters in each column were studied in three depths as a subplot. After 120 days, EC and ESP of soils amended with both types of conditioners reduced under 5 dS m-1 and 15%, respectively. After 150 days, the exchangeable K and Mg were reduced by both conditioners. Exchangeable Ca increased significantly in both amendments at the end of the 5th month. The efficiency of 1% by weight of two conditioners in improving the salinity and sodicity characteristics of soils was the same as other rates. There was not a significant difference between leaching by 3 and 4 pore volume in both conditioners in the most of parameters. In leaching treatment with three pore volumes using 1 percentage w/w of manure and compost, soil EC decreased by 80% and 71% and soil ESP by 44.5% and 35%, respectively.
S. F. Hashemi, R. Zalaghi, N. Enayatizamir,
Volume 26, Issue 1 (5-2022)
Abstract
This study investigated the effect of the inoculation of the soil with some phosphorus solubilizing microorganisms (PSM) on inorganic P fractions in sandy soil enriched with inorganic and organic amendments. A factorial experiment arrangement was performed in a completely randomized design with three replications, using two factors: microorganisms (control, Entrobacter cloacae, Brevundimonas, and piriformospora indica) and amendments (control, (5%) apatite, (5%) apatite + (3%) zeolite, (5%) apatite + (1%) molasses). A 60-days incubation was performed after the application of treatments. Inorganic P fractionation and alkaline phosphatase activity of soil were measured at the end of the experiment. Phosphorus distribution in soil was as follow: octacalcium phosphate > apatite P > dicalcium phosphate > Olsen p > aluminium phosphate > iron phosphate. The application of apatite increased all of the P mineral fractions. The application of zeolite-appatie was very effective and although did not increase Olsen P (probably because of the low cation exchange capacity of soil), had a significant effect (p<0.05) on other P forms and caused dicalcium phosphate to increase (69.2%) and apatite P and octaclcium phosphate to decrease (34.8% and 60.0%, respectively) compared to apatite application. Application of molasses resulted in significant increases in dicalcium phosphate and octacalcium phosphate (48.9% and 29.3%, respectively) and decreases in apatite P and Olsen P (62.1% and 63.9%, respectively). Microbial inoculation resulted in a significant increase in Olsen P and dicalcium phosphate and a decrease in octacalcium phosphate and apatite P; showing the ability of these organisms to increase the phosphorus availability. Entrobacter and Piriformospora indica were more effective than Brevundimonas. It seems that microorganisms in different substrates had used different mechanisms; such that in apatite and apatite-molasses treatments microbial inoculation resulted in an increase in alkaline phosphatase activity, but in zeolite-apatite treatment, pH had decreased indicating the organic acid production by microorganisms.
S. Ebrahimiyan, M. Nohtani, H. Sadeghi Mazidi, E. Soheili,
Volume 26, Issue 1 (5-2022)
Abstract
The basis of land management is the geomorphological zoning of the land surface, which is determined based on the same geomorphological characteristics of the zoning. Ground zoning detect land features by basic surface features such as height, slope, and slope direction. In this study, quantitative zoning of the land surface with small coefficients to the surface has been used to identify suitable areas for artificial feeding in the mountainous region of Gohar and Dasht-e Gorbayegan in Fars province. Quantitative zoning of the land surface has been performed by Evans-Shri coefficients due to the accurate determination and separation of types, faces, and surface features of the land has an important role in determining the exact land use. In this research basic models included linear, circular, and divergent models. These basic models with the dimensions of the final windows are ranked second in the MATLAB software to the level the ground is fitted to determine the fit of these models, the parameter of total squared difference has been used. In addition, the suitability of the study area for flood distribution in five different classes was determined using fuzzy logic. The most suitable areas for feeding downstream of the cones had five parameters with a maximum score of 20. The inappropriate class related to the lower plains of alluvial fans have a minimum score of five input classes in fuzzy logic, which is equal to zero.
N. Azadi, F. Raiesi,
Volume 26, Issue 1 (5-2022)
Abstract
Biochar as an efficient strategy for the improvement of soil properties and organic waste management may reduce the potential effects of abiotic stresses and increase soil fertility. However, the effects of this organic amendment on soil microbial indicators under combined salinity and pollution have not been studied yet. Therefore, the objective of this study was to evaluate the influence of sugarcane bagasse biochar on some soil bioindicators in a Cd-polluted soil under saline and non-saline conditions. A factorial experiment was carried out with two factors, including NaCl salinity (control, 20 and 40 mM NaCl) and sugarcane bagasse biochar (soils unamended with biochar, amended with uncharred bagasse, 400 oC biochar, and 600 oC) at 1% (w/w) using a completely randomized design. Results showed that salinity increased the mobility of Cd (12-17%), and subsequently augmented its toxicity to soil microorganisms as indicated by significant decreases in the abundance and activities of the soil microbial community. Conversely, sugarcane bagasse biochar application reduced the concentration of soil available Cd (14-18%), increased the contents of soil organic carbon (89-127%), and dissolved organic carbon (4-70%), and consequently alleviated the effect of both abiotic stresses on soil microbial community and enzyme activity. In conclusion, this experiment demonstrated that the application of sugarcane bagasse biochar could reduce the salinity-induced increases in available Cd and mitigate the interaction between salinity and Cd pollution on the measured soil bioindicators.
A. Ghobadi, M. Cheraghi, S. Sobhan Ardakani, B. Lorestani, H. Merrikhpour,
Volume 26, Issue 1 (5-2022)
Abstract
The qualitative assessment of groundwater resources as the most important sources of drinking and agricultural water is very important. Therefore, the present study was conducted to evaluate the quality of heavy metals in groundwater resources of the Hamadan-Bahar plain in 2018 using water quality indices. In so doing, a total of 120 groundwater samples were collected from 20 stations during the spring and summer seasons and the values of physico-chemical parameters were determined based on the standard methods and also the content of heavy metals was determined using inductively coupled plasma spectroscopy (ICP). The results showed that the mean concentrations of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn (µg /L) in the samples in the spring season were 5.08, 0.260, 1.05, 2.70, 1.50, 0.490, 1.50, 7.48, and 1.75, respectively, and in the summer season were 20.7, 0.220, 0.950, 7.12, 1.34, 0.490, 1.29, 8.23, and 2.08, respectively and except for As in the summer season, the mean content of other elements was lower than maximum permissible limits established by WHO for drinking water. Meanwhile, the mean values of Cd, HPI, HEI, MI, and PoS indices in the spring season with -7.51, 9.91, 1.42, 1.42, and 328, respectively, indicate the water quality was categorized as low, low, low, low and moderately affected and in the summer season with -5.90, 10.0, 3.04, 3.04, and 673, respectively, were categorized as low, low, low, moderately affected, and high pollution. Due to the extensive use of agricultural inputs, especially chemical and organic fertilizers and chemical pesticides containing heavy metals by farmers in the study area, the possibility of increasing the concentration of heavy metals in the soil and their penetration into groundwater aquifers will not be unexpected in the medium term. Therefore, periodic monitoring in groundwater resources of the study area is recommended.
M. Masoomi, M. Pourgholam-Amiji, M. Parsinejad,
Volume 26, Issue 1 (5-2022)
Abstract
In this study, the Drainmod-S model was used to vary soil salt concentration and the effect of underground drainage on the amount of leaching in a physical model (large lysimeter). A soil extractor was installed at depths of 40, 50, and 70 cm at a distance of 35 cm from the drainage to measure the salinity of the soil solution. In this study, three scenarios were applied including salinity profiles under conventional conditions (mid-season and end-season drainage), soil salinity profiles under different drainage conditions, and prior scenarios with saline irrigation. The second and third scenarios were applied in four drainage stages, respectively. These stages include transplanting and mid-season drainage (days 15 to 20), mid-season drainage (days 35 to 40), mid-season and end-season drainage (days 55 to 60), and end-season drainage (days 75 to 80). The results showed that after simulating the total solute concentration overtime at a depth of 40 cm and comparing it with the measured values, the coefficient of determination (R2) was 0.77 indicating an acceptable Drainmod-S model simulation. This parameter for simulating solute concentration at 50 and 70 cm depth was 0.76 and 0.75, respectively. The mean absolute error parameter (MAE) value was also negligible.
I. Hasanpour, M. Shirvani, M.a. Hajabbasi, M.m. Majidi,
Volume 26, Issue 2 (9-2022)
Abstract
Low organic matter content and alkaline pH of calcareous soils in arid and semi-arid regions are the main reasons for the low nutrient availabilities for plants in these soils. One way to improve the chemical properties and fertility of calcareous soils is the application of organic substances such as biochar produced from pyrolysis of organic wastes. However, biochars have an almost predominant alkaline pH, which exacerbates plant nutrient deficiencies in calcareous soils when used for a long time. Pyrolysis of some organic wastes under controlled temperature conditions can lead to the production of acidic biochar. The effect of acidic biochars on several chemical properties of two calcareous soils in Isfahan province was investigated in the present study. Treatments included two types of biochar (pine cone and rice husk), three levels of biochar addition (one, three, and six percent), two types of soil (a sandy loam (Tiran) and a clay loam (Lavark)), and two incubation periods (one and six months). The results showed that applying biochar could slightly decrease soil pH but raised soil electrical conductivity. In addition, the amount of organic carbon, total nitrogen, and available concentration of manganese in all treatments and the concentrations of available phosphorus, potassium, iron, zinc, and copper in the most of treatments showed a significant increase compared to the control. Amending soil with biochar at a 6% rate caused the most significant changes in the measured parameters in both soil types. In general, the results of this study indicated that acidic biochar produced from pine cones and rice husk can be used as a suitable conditioner to improve the chemical properties and fertility of calcareous soils.
F. Golabkesh, A. Nazarpour, N. Ghanavati, T. Babaeinejad,
Volume 26, Issue 2 (9-2022)
Abstract
The current study aims to find the best methods of using remote sensing and supervised classification algorithms in long-term salinity monitoring of salinity changes in the Atabieh area with an area of 5000 hectares in the west of Khuzestan province. The procedure is based on the separation of different levels of saline soils utilizing information obtained from Landsat 7 and 8 satellite images (2001 to 2015) along with salinity data taken from the study area, and salinity indices including SI1, SI2, SI3, NDSI, IPVI, and VSSI. The results show the expansion of the saline zone trend in the soils of the study area, among which, soils with EC of more than 16 dS m-1 (very saline) have the highest frequency. The area of saline soils has increased significantly over the past 15 years, with a saline land area increasing by more than 90%. The percentage of salinity class is low (S1). According to this study, the only significant index in soil salinity at a 95% confidence level is the SI3 index, which has been able to have a good estimate of the increasing changes in soils in the region. The results of the supervised classification showed that the support vector machine (with an overall accuracy of 95.78 and a kappa coefficient of 0.89) is more accurate. After the vector machine method, the methods of minimum distance, maximum likelihood, and distance of Mahalanobis have the highest accuracy, respectively. Based on salinity maps obtained in years in 2001, 2005, 2010, and 2015, it can be said that the salinity rate in the whole of the study area was progressing and at the same time the salinity area in the middle and high classes increased decreased and on the other hand, the salinity area in the high class in 2001 gradually increased and distributed in 2015 throughout the region.
M. Abdi, H. Sharifan, H. Jafari, Kh. Ghorbani,
Volume 26, Issue 2 (9-2022)
Abstract
The irrigation schedule of crops is the most effective way to increase agricultural water use efficiency. In irrigation planning, determining the irrigation time is more important and difficult than determining the depth of irrigation water. Among all methods of determining the irrigation time of crops, the methods which used plants are more accurate than other methods. In this study, the wheat water stress index has been used which is based on the air vapor pressure deficit and the difference between vegetation and air temperature (Tc-Ta). First of all, the diagram and the relationship between the top and bottom baselines were extracted, then the water stress index of wheat was drawn in the Karaj region. Secondly, to determine the optimal water stress index of wheat, four treatments including I1: 30% of maximum allowable depletion of moisture, I2: 45% of maximum allowable depletion of moisture, I3: 60% of maximum allowable depletion of moisture, I4: 75% of maximum allowable depletion of moisture were performed in four replications. The amount of water stress index of each treatment was calculated during the season separately, and the CWSI of the treatment with the highest water use efficiency was used to determine the irrigation time of wheat. The results showed that the relationship between the upper and lower baseline for wheat in the Karaj region is Tc-Ta = 3.6 0c and
Tc-Ta = -0.27VPD - 2.64, respectively. The treatment of 45% of maximum allowable depletion of moisture had the highest water use efficiency and the optimal water stress index for wheat was obtained at 0.36 in the Karaj region.
E. Masoumi, R. Ajalloeian, A.a. Nourbakhsh, M. Bayat,
Volume 26, Issue 3 (12-2022)
Abstract
Since clay is widely used in most construction projects, the issue of improving clay soils has considerable importance. This study aimed to optimize the variables affecting the properties of geopolymer and improve their mechanical properties using Isfahan blast furnace slag. Taguchi's statistical design method was used to model three process variables (blast furnace slag, water, and alkali sodium hydroxide agent) with four different values in the mixing design. Geopolymer was used to optimize the uniaxial compressive strength. Sixteen geopolymer compositions determined by mini-tab software were prepared and their uniaxial compressive strength was measured. The obtained results were modeled by analysis of variance, and then the interactions of the three variables on the uniaxial compressive strength of geopolymer were investigated using two and 3D diagrams. Then, the variables were optimized and the proposed values for the optimal sample were examined at temperatures of 25, 50, and 70°C and at times of 3, 7, 14, and 28 days of operation. A comparison of the results predicted by the models and the results of the experiments confirmed the validity of the models. Also, the scanning electron microscopy (SEM) images showed that the porosity will reduce from 7 to 28 days. It indicated that the use of the geopolymerization method has a significant role in stabilizing weak clay soils with low plasticity. The effect of fibers and geopolymer to reinforce was also investigated and for better evaluation, it was compared with soil stabilization with Portland cement. The results showed that in the most optimal geopolymer composition, the bearing resistance of clay has increased by more than 3400%. Meanwhile, fibers along with geopolymer with optimal percentage and length (0.1% by weight of geopolymer composition and length of 12 mm) were able to increase the uniaxial compressive strength of clay by nearly 4000%, which shows the excellent effect of using cellular fibers parameter whit the geopolymer in this research.
A. Balvaieh, L. Gholami, F. Shokrian, A, Kavian,
Volume 26, Issue 4 (12-2022)
Abstract
Changes in nutrient concentrations of soil can specify optimal management of manure and prevent environmental and water resources pollution. The present study was conducted with the objective of changing macronutrients concentrations of Nitrogen, Phosphorus, and Potassium with amendments application of polyvinyl acetate, bean residual, and a combination of polyvinyl acetate + bean residual for time periods of one, two, and four months. The results showed that the application of soil amendments had various effects on changing Nitrogen, Phosphorus, and Potassium. The maximum amount of Nitrogen related to the treatment of bean residual at the time period of four months before simulation (with a rate of 44.62 percent) and minimum amount of nitrogen related to Polyvinyl acetate treatment at the time period of one month (with a rate of -1.92 percent). The minimum rate of Phosphorus was measured at the treatment of bean residual at the time period of one month before simulation (with a rate of 0.95 percent). The maximum amount of Potassium related to the treatment of Polyvinyl acetate at the time period of four months before simulation (with a rate of 189.35 percent) and the minimum amount of Potassium related to the combination of bean residual + Polyvinyl acetate at the time period of one month after simulation (with a rate of 40.66 percent). Therefore, the application of amendments has various effects on changing soil macronutrients at different time periods.
M. Farzamnia, M. Miran Zadeh,
Volume 26, Issue 4 (12-2022)
Abstract
The present study was carried out in the Mahyar region of Esfahan Province to determine optimum drip tape spacing for the wheat crops on a silty clay loam soil respecting grain yield as well as yield components, water use efficiency, and variations in the salinity within the soil profile. The experiment was performed for three years from 2017 to 2019 with a randomized complete block design with three replicates and four treatments. The treatments consisted of three tape spacings (A) at 45, (B) at 60, (C) at 75 cm, and the Control (D) was irrigated with the basin method. The same volume of irrigated water was applied to the drip treatments, A, B, and C in every irrigation interval, whereas for treatment D, the local farmers’ practice was followed. Based on the results from compound variance analysis, the treatment effect on both grain yield and biological yield, and on water use efficiency and harvest index was significant at 1% and 5% level of confidence, respectively. The mean water use efficiency in treatments A, B, C, and D was measured as 0.79, 0.79, 0.73, and 0.78 kg m-3; thus, treatments A, B, and D outperformed treatment C. A comparison between the salinity of the soil profile at the beginning and the end of the growing season revealed that the basin irrigation method was more effective on salt leaching than the drip tape system. The results of this study indicated that concerning water use efficiency and crop yield, drip tapes spaced at 45 or 60 cm outperformed those which were 75 cm apart. On the other hand, the work required for irrigation system installation as well as the amount of drip tape residues left on the field at the end of the growing season is larger for tapes spaced at 45 cm compared to those which are 60 cm apart. This will have a significant impact on farmers’ budgets and environmental issues. Therefore, it is recommended to lay the tapes 60 cm apart for the irrigation of wheat crops on silty clay loam soils.
N. Moradian Paik, S. Jafari,
Volume 26, Issue 4 (12-2022)
Abstract
Changes in land quality factors were investigated according to the change in land use of two conventional cropping systems in Khuzestan (Dimcheh region, periodic cultivation system, sugarcane, forest, and deforesting in Zaras region). The results showed that by the change of forest land use, organic carbon from 0.93 to 0.55%, cation exchange capacity (CEC) from 19.6 to 13.3 cmol/kg, C/N from 7.4 to 3.8%, the mean weight diameter of aggregate (MWD) from 1.7 to 1.3%, and microbial respiration from 0.11 to 0.06 mg of CO2 /gr of soil per day decreased and in contrast, the dispersible clay from 4.6 to 19.3% increased. PCA analysis for the parameters showed that five factors justified more than 90% of the variance in the values of FC, PWP, AW, and AF. In the Dimcheh region, the average volumetric moisture content of FC from 31.3% to 27.3%, available water from 12.9% to 9.8%, dispersible clay from 56.1% to 12.3%, and bulk density reduced from 1.6 to 1.4%, organic carbon from 0.45 to 0.78%, C/N from 6.3 to 10.0%, microbial respiration from 0.01 to 0.04 mg of CO2 /gr soil per day and MWD of aggregates increased from 0.77 to 1.3 mm. Five factors including FC, AW, BD, DC, and OM explained more than 90% of the variance.
V. Habibi Arbatani, M. Akbari, Z. Moghaddam, A.m. Bayat,
Volume 26, Issue 4 (12-2022)
Abstract
In recent years, indirect methods such as remote sensing and data mining have been used to estimate soil salinity. In this research, the electrical conductivity of 94 soil samples from 0 to 100 cm was measured using the Hypercube technique in the Saveh plain. 23 types of input data were used in the form of topographic and spectral categories. Land area parameters such as the Topographic Wetness Index (TWI), Terrain Classification Index (TCI), Stream Power Index (STP), Digital Elevation Model (DEM), and Length of Slope (LS) were considered as topographic inputs using Arc-GIS and SAGA software. Also, salinity spatial and vegetation indices were extracted from Landsat 8 images and were considered spectral inputs. The GMDH neural network was used to model salinity with a ratio of 70% for training and 30% for validation. The results showed that the soil salinity values were between 0.1 and 18 with mean and standard deviation of 5 and 4.7 dS/m, respectively. Also, the results of modeling indicated that the statistical parameters R2, MBE, and NRMSE in the training step were 0.80, 0.06, and 42.1%, respectively. The same values in the validation step were 0.79, 0.13, and 48.7%, respectively. Therefore, the application of spectral, topographic, and GMDH neural network indices for modeling soil salinity is effective.
A. Shahbaee Kotenaee, H. Asakereh,
Volume 27, Issue 1 (5-2023)
Abstract
Precipitation is one of the main elements of the Earth's hydro-climatic cycle and its variability depends on the complex and non-linear relationships between the climate system and environmental factors. Understanding these relationships and doing environmental planning based on them is difficult. Therefore, classifying data and dividing information into homogeneous and small categories can be helpful in this regard. In the present study, an attempt was made to prepare precipitation, altitude, slope, slope direction, and station density data for 3423 synoptic, climatological, and gauge stations in Iran in the 1961-2015 years’ period. These data were entered into fuzzy (FCM), self-organizing map neural network (SOM-ANN) models and precipitation-spatial zoning. The outputs of the two models were compared in terms of accuracy and efficiency. The results obtained from the output of the models have divided the rainfall conditions of Iran into four zones concerning environmental factors. Evaluations also showed that both models had high accuracy in classifying precipitation parameters; However, the fuzzy model has a relative advantage over the neural network model in the accuracy of results.
F. Esmaeili, M. Vafakhah, V. Moosavi,
Volume 27, Issue 1 (5-2023)
Abstract
Digital elevation models (DEMs) are one of the most important data required in watershed modeling with hydrological models and their spatial resolution has a significant impact on the accuracy of simulating hydrological processes. In the present study, the effect of spatial resolution of five DEMs derived from the topographic map (TOPO) with a scale of 1:25000, ALOS PALSAR, ASTER, SRTM, and GTOPO with a spatial accuracy of 10, 12.5, 30, 90, and 1000 m, respectively, on the estimation of parameters of geomorphological and geomorphoclimatic unit hydrographs models has been evaluated in Amameh watershed. Thirty-four single flood events were used during the years 1970 to 2015. The results showed that in the GUH method, the application of the TOPO and ALOS PALSAR DEMs had the best results with root mean square error (RMSE) of 1.7 and 1.8 m3/s and Nash-Sutcliffe Efficiency (NSE) of 0.4 and 0.3, respectively. While the GTOPO DEM had the least efficiency with RMSE of 2.8 m3/s and NSE of -2. Similarly, the lowest and highest RMSE in the GCUH method belonged to TOPO and GTOPO DEMs with RMSE of 3.8 and 18 m3/s and NSE of 0.2 and -6, respectively. Generally, the GUH method had more favorable results than the GCUH method in all DEMs.
Y. Esmaeli, F. Yosefvand, S. Shabanlou, M.a. Izadbakhsh,
Volume 27, Issue 2 (9-2023)
Abstract
The objective of the current study was to zone flood probability in the Marzdaran watershed. Since the allocated budget for management work is limited and it is not possible to carry out operations in the whole area, having a map that has prioritized different areas in terms of the probability of flood occurrence will be very useful and necessary. A well-known data mining model namely MaxEnt (ME) is applied due to its robust computational algorithm. Flood inventories are gathered through several field surveys using local information and available organizational resources, and the corresponding map is created in the geographic information system. The twelve predisposing variables are selected and the corresponding maps are generated in the geographic information system by reviewing several studies. The area under the curve (ROC) is used to evaluate the modeling results. Then, the most prone areas of flood occurrence which are prioritized for management operations are identified based on the prepared map. Based on the results, about 100 km2 of the study area is identified as the most prone area for management operations. The results showed that the accuracy of the maximum entropy model is 98% in the training phase and 95% in the validation phase. The distance from the river, drainage density, and topographic wetness index are identified as the most effective factors in the occurrence of floods, respectively.
V. Moradinasab, S. Hojati, A. Landi, A. Faz Cano,
Volume 27, Issue 2 (9-2023)
Abstract
Parent material and topography are among the soil-forming factors that affect soil evolution by influencing different parameters. This study was conducted to compare the effect of marl and calcareous parent materials in different slope positions, including the summit, shoulder, foot-, and toe-slopes on soil clay mineralogy in the Karoon 3 Basin, east of Khuzestan Province. Four soil profiles in each of the two topo-sequences were dug. They were sampled based on their genetic horizons and some physical, chemical properties, and clay mineralogy were measured. The results showed that the type and abundance of clay minerals identified for both parent materials were more affected by topo-sequence position. The composition of minerals identified in the topo-sequence with marl parent materials included kaolinite, palygorskite, smectite, chlorite, mica, and quartz, and in the topo-sequence with calcareous parent materials, palygorskite, smectite, chlorite, mica minerals, and quartz, and most of the identified minerals were also observed in all positions in the C horizon. However, in marl parent materials kaolinite, and calcareous parent materials, smectite seems to have been formed pedogenically. The result of the association between Weaver and Beck indicated that most of the clay minerals are in the equilibrium of Palygorskite.
