Showing 1096 results for Ro
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.
B. Shahinejad, A. Parsaei, A. Haghizadeh, A. Arshia, Z. Shamsi,
Volume 26, Issue 3 (12-2022)
Abstract
In this research, soft computational models including multiple adaptive spline regression model (MARS) and data group classification model (GMDH) were used to estimate the geometric dimensions of stable alluvial channels including channel surface width (w), flow depth (h), and longitudinal slope (S) and the results of the developed models were compared with the multilayer neural network (MLP) model. To develop the models, the flow rate parameters (Q), the average particle size in the floor and body (d50) as well as the shear stress (t) as input and the parameters of water surface width (w), flow depth (h), and longitudinal slope (S) were used as output parameters. Soft computing models were developed in two scenarios based on raw parameters and dimensionless form independent and dependent parameters. The results showed that the statistical characteristics in estimating w, the best performance is related to the MARS model, whose statistical indicators of accuracy in the training stage are R2 = 0.902, RMSE=1.666 and in the test phase is R2 = 0.844, RMSE=2.317. In estimating the channel depth, the performance of both GMDH and MARS models is approximately equal, both of which were developed based on the dimensionless form of flow rate as the input variable. The statistical indicators of both models in the training stage are R2 » 0.90, RMSE » 8.15 and in the test phase is R2 » 0.90, RMSE = 7.40. The best performance of the developed models in estimating the longitudinal slope of the channel was related to both MARS and GMDH models, although, in part, the accuracy of the GMDH model with statistical indicators R2 = 0.942, RMSE = 0.0011 in the training phase and R2 = 0.925, RMSE = 0.0014 in the experimental stage is more than the MARS model.
Mrs Soghra Bagheri, M.r. Ansari, A. Norouzi,
Volume 26, Issue 3 (12-2022)
Abstract
Soil erosion has been one of the most important problems of watersheds in the world and is considered one of the main obstacles to achieving sustainable development in agriculture and natural resources. Identifying and prioritizing regions sensitive to soil erosion is essential for water and soil conservation and natural resource management in watersheds. The present research was performed in 2021 year to prioritize the soil erosion susceptibility in 12 sub-watersheds of the Roudzard watershed in Khouzestan province using morphometric analysis and multiple criteria decision-making (MCDM) methods. In this regard, 11 morphometric parameters including shape parameters such as compactness constant (Cc), circularity ratio (Rc), form factor (Rf), elongation ratio (Re), linear parameters such as drainage density (Dd), stream frequency (Fs), drainage texture (Dt), bifurcation ratio (Rb), Basin length (L), Length of overland flow (Lg), and topographic parameter including Ruggedness number (Rn) were extracted and their relative weights were calculated using Analytic Hierarchy Process (AHP). The prioritization sub-watershed to soil erosion was performed using TOPSIS, VIKOR, and SAW methods, and the results were combined using rank mean, Copeland, and Borda methods. The final prioritization was compared with the amount of specific erosion in the MPSIAC model by determining Spearman's correlation coefficient. The result of the evaluation of morphometric parameters by using the AHP model showed that drainage density (0.161), drainage texture (0.158), and stream frequency (0.146) had the greatest effect on the erodability of the sub-watersheds. In contrast, the form factor (0.049), Elongation Ratio (0.036), and shape factor (0.026) had the least effects on erodability of the study area. In this research, the Spearman correlation coefficient between the final result of prioritizing the sub-watershed and the MPSIAC model was obtained as 0.8 in p-value<0.01. The results of prioritization of the sub-watersheds in terms of their sensitivity to soil erosion showed that sub-watersheds 11, 12, and 10 with an area of 191.83 km2 are categorized as very sensitive to soil erosion due to high value of linear parameters, low value of shape parameters, sensitive geology formation, and poor vegetation cover and located in rank 1 to 3, respectively. According to the results sub-watersheds 11, 12, and 10 have the highest amount of specific erosion equal to 16.03, 12.48, and 11.6 tons per hectare per year, respectively. Therefore, these sub-watersheds are a priority for watershed management operations. The results of the present study showed that MCDM methods and morphometric analysis are suitable tools for identifying areas sensitive to soil erosion and using the combined methods of the results and it is possible to take advantage of each of the different multi-criteria decision-making methods.
S. Parvizi, S. Eslamian, M. Gheysari, A.r. Gohari, S. Soltani Kopai, P. Mohit Esfahani,
Volume 26, Issue 3 (12-2022)
Abstract
Investigation of homogeneity regions using univariate characteristics is an important step in the regional frequency analysis method. However, some hydrological phenomena have multivariate characteristics that cannot be studied by univariate methods. Droughts are one of these phenomena their definition as univariate will not be effective for risk assessment, decision-making, and management. Therefore, in this study, the regional frequency analysis of drought was studied in multivariate methods using SEI (Standardized Evapotranspiration Index), SSI (Standardized Soil Moisture Index), and SRI (Standardized Runoff Index) indices in the Karkheh River basin from 1996 to 2019. The indices calculated probabilistic distribution between the variables of evapotranspiration, runoff, and soil moisture using multivariate L-moments method and Copula functions and considered meteorological, agricultural, and hydrological droughts simultaneously. The results of multivariate regional frequency analysis considering the Copula Gumbel as the regional Copula showed that the basin is homogeneous in terms of severity of SEI-SSI combined drought indices and is heterogeneous in terms of severity of SEI-SSI combined drought indices. However, after clustering the basin into four homogeneous areas in terms of characteristics of SPI (Standardized Precipitation Index), the basin is homogeneous in all areas in terms of univariate SEI, SSI, and SRI indices and is heterogeneous in the third and fourth clusters of SRI and SSI drought indices. Pearson Type (III), Pareto, normal, and general logistics distribution functions were found suitable to investigate the characteristics of SEI, SSI, and SRI drought indices in this case. Finally, large estimates of the types of combined droughts and their probability of occurrence showed that the northern and southern parts of the Karkheh River basin will experience short and consecutive droughts in the next years. Droughts in areas without meteorological data can be predicted in terms of joint probability using the multivariate regional frequency analysis method proposed in this study.
H. Noury Hasanabady, M.r. Kavianpour, A. Khosrojerdi, H. Babazadeh,
Volume 26, Issue 3 (12-2022)
Abstract
Using a rough bed for spillway compare to common dissipation methods such as stilling basins, stepped spillways, ski jumps, and bed elements may be more efficient to boost energy dissipation. In this research, the impact of spillway continuous bed roughness on energy dissipation was investigated. For this purpose, a non-dimensional relationship was developed, and by calibrating the numerical model based on the present experimental study, energy dissipation over the spillway for three slopes of 15, 22.5, and 30 (degree) with six roughness sizes of 0.0, 0.005, 0.0072, 0.0111, 0.016, and 0.022 (m) and three discharges of 170, 110, and 90 (lit/s) was investigated. Based on the present results, using a rough bed spillway will increase energy dissipation. Also, the ratio of energy lost per meter length of rough bed spillway to that of smooth spillway increases by chute slope. The results showed that the highest amount of relative energy consumption in the presence of roughness was related to the slope of 22.5 degrees and 22.2 mm for roughness (85%), and the lowest relative energy consumption was observed in the control state (25%). As a result of the present study, a natural rough bed without concrete coating has befitted in terms of environmental aspects, construction cost, and energy loss.
G.m. Samadi, F. Mousavi, H. Karami,
Volume 26, Issue 3 (12-2022)
Abstract
The impact of different management options on the region and the existing conditions can be evaluated with minimal cost and time to select the most practical case using various tools including mathematical models. In this study, the SWAT hydrological model was performed from 2009 to 2019 using climatic, hydrological, and hydrometric data in the Malayer catchment, and the final model was validated by SWAT-CUP. To reduce the amount of uncertainty in the input parameters to the MODFLOW model, using the values of surface recharge from the implementation of the SWAT hydrological model, quantitative modeling of Malayer aquifer was performed more reliably in GMS software by using MODFLOW model. After modeling the study area in the 2009-2018 period and calibrating the model in the years from 2018 to 2019, the mean values of absolute error (MAE) were 0.35-0.65 m, and root means square error (RMSE) was 0.62-0.94 m, which seems acceptable considering computational and observational heads equal to 1650 m. Results of water level changes in observation wells located in the Malayer region indicate that the groundwater level in the aquifer has decreased by an average value of 9.7 m in the 10-year study period.
H. Babajafari, Sh. Paimozd, M. Moghaddasi, M. Hosseini Vardanjani,
Volume 26, Issue 3 (12-2022)
Abstract
Drought is one of the most complex natural disasters due to its slow onset and long-term impact. Today, the use of remote sensing techniques and satellite imagery has been considered a useful tool for monitoring agricultural drought. The objective of the present study was to evaluate spatial and temporal monitoring of agricultural drought in the lake Urmia catchment area with the ETDI drought index which is calculated from Nova satellite images based on actual evapotranspiration from the SEBS algorithm and compared with the ground index SPI. For this purpose, 248 AVHRR sensor images and NOAA satellites during the statistical period of 1998-2000 and 17 meteorological stations with a statistical period of 30 years were used to calculate the indicators. To determine agricultural lands, six thousand points were marked for different uses and their actual evapotranspiration was calculated using the SEBS algorithm. The results showed that with the onset of the drought period in 1998, the ETDI index indicated 9.4% in weak drought conditions in May and 90.6% in normal conditions. Over time, in June of 1998, the situation was different with 95% in a weak drought situation and 5% in a normal situation for the city of Tabriz. In July, the entire catchment area experiences a slight drought. Then, in August, 84% of the basin is in normal condition and 16% in Tabriz and Urmia are declared weak drought. It was also founded that the ETDI drought index due to the combination of visible and infrared bands and its combination with terrestrial data has a physical meaning and has high certainty and predicts drought faster and more accurately.
A. Yousefi, M. Maleki-Zadeh, A.r. Nikooie, M.s. Ebrahimi,
Volume 26, Issue 4 (3-2023)
Abstract
This study determines the amount of irrigation water saved as a result of the subsidy policy to adapt from flood to drip irrigation. We developed a positive mathematical programming model (PMP) to evaluate the effect of economic incentives on farmers’ decisions to choose the type of irrigation technology, cropping pattern, and "water use" and "water consumption" in rural Garkan Shomali district, which is part of the Najafabad aquifer. We collected data through farm surveys, desk research, and expert interviews. The results showed that a reduction in the financial costs of converting flood irrigation into drip irrigation can lead to farmers investing in this technology. In the current water allocation scenario, the subsidy policy increases the water consumption of drip-irrigated crops by 28%, of which 19% is non-consumed water before subsidy payment and the rest is related to the reduction of furrow-irrigated lands. Also, under non-volumetric water delivery conditions, the operating costs reduce and the net income of the farms increases because of the increase in efficiency and the development of the area under cultivation, which increases water consumption while the water use is constant. In the volumetric water delivery scenario, with the increase in subsidies, the net income of the farms will increase without developing the area under cultivation and only because of the increased yield. Therefore, subsidy policy increases irrigation efficiency at both the farm and regional levels and is an effective tool for dealing with drought conditions.
A. Balvaieh, L. Gholami, F. Shokrian, A, Kavian,
Volume 26, Issue 4 (3-2023)
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. Pasandi, H.r. Pakzad, A.m. Halvaie Lengeh, M.r. Taherizadeh,
Volume 26, Issue 4 (3-2023)
Abstract
The relationship between the concentration of heavy metals and physicochemical factors was studied in the fine-grained sediments of the tidal section of the Mehran delta where mangrove trees have grown. Surface sediments of the tidal zone of the Mehran delta were sampled. The grain size distribution, calcium carbonate, organic matter contents, pH/Eh, and heavy metals concentration were determined in the mud fraction of the sediments. The presence of high calcium carbonate in sediments is an effective factor in the abundance of Mn, Cd, and Pb. Clay and organic matter as adsorptive have contributed to the high concentration of Zn, Cu, while Fe oxy-hydroxides have affected the concentration of Co, Cr, and Ni. According to the index of Enrichment Factor (EF), the average enrichment of the elements in the studied sediments from high to low order is Cr, Ni, Cd, Zn, Mn, Pb, Co, and Cu. According to the Pollution Load Index (PLI), none of the delta sediments including sediments from inside and outside of the mangrove forestare classified as polluted to the heavy metals. According to the Igeo Index, most samples, and only Cd, Cr, and Ni show slight pollution in some samples. Accordingly, there is no current threat of contamination of potentially toxic elements of natural and anthropogenic origins to the mangrove environment and Mehran delta.
M. Hayatzadeh, M. Eshghizadeh, V. ,
Volume 26, Issue 4 (3-2023)
Abstract
The land use change as well as changes in climatic parameters such as temperature increase affect many natural processes such as soil erosion and sediment production, floods, and degradation of physical and chemical properties of soil. Therefore, it is necessary to pay attention to different aspects of the effect of these changes in studies and macro decisions of the country. In the present study, the SWAT conceptual model was used to test and analyze the existing scenarios in the Marvast basin. After calibrating the model, the two scenarios were tested. The first scenario is in the field of agricultural management and conversion of gardens to agricultural lands and the second scenario is a 0.5-degree increase in temperature by assuming other conditions are constant. The calibration and validation results of the model with the Nash-Sutcliffe test showed 0.66 and 0.68 respectively, which indicate the acceptable performance of the model in the study area. Then, the results of using two scenarios of land use change and heating, especially in recent years showed the effect of 30 percent of the climate scenario on the increase of flooding in the basin. The scenario of changing the use of garden lands to agriculture in two cases of 20% and 50% change of use of 10% and 12% was added to the flooding of the basin. The results indicate that in similar areas of the study area which is located in a dry climate zone, a possible increase in temperature can have a significant effect on flooding in the basin. However, the indirect impact of the human factor in increasing greenhouse gases and flooding in the basin should not be ignored.
F. Zarei, M.r. Nouri Emamzadehei, A.r. Ghasemi Dastgerdi, A. Shahnazari,
Volume 26, Issue 4 (3-2023)
Abstract
The pattern of root distribution in layered soils is one of the significant issues in the calculations of soil water and irrigation management and planning. The objective of this study was to determine the pattern of root distribution of soybean in layered soils and its effect on water uptake. The research was conducted in a completely randomized design with 15 treatments consisting of three different textures of soil (light, heavy, and medium) in four replications. The pattern of root distribution was monitored by the sampling of columns at the end of the growth period of the soybean. It was observed that the presence of the layer with medium texture has led to better plant development and growth after comparing the treatments in terms of plant growth. In general, root length density decreased with increasing soil depth, except in cases where there were different layers of soil, and root length density takes place in the following order: root length density in layers with medium texture≥ heavy texture≥ light texture. The rate of root water uptake rate was highest in the sandy layers, intermediate in clay, and lowest in loamy texture. Also, the rate of root water uptake rate increased significantly with increasing depth regardless of treatments. It can be concluded that the pattern of root distribution and plant growth is significantly affected by soil texture and its stratification.
S. Bigdeli, K. Ebrahimi, A. Hoorfar, A.a. Davudirad,
Volume 26, Issue 4 (3-2023)
Abstract
In this study, the accuracy of the Adaptive Network-Based Fuzzy Inference System (ANFIS) in integrating with the Gray Wolf Algorithm (ANFIS-GWO) in predicting groundwater level was evaluated for the first time using unpublished observational data from 1998 to 2018 in the Zarandieh aquifer, central Iran. Three observational wells were randomly selected for analysis. Assessment of evaluation criteria demonstrated that among the proposed scenarios using the hybrid model, the D scenario was selected as the optimal scenario with input data including the previous month's groundwater level, precipitation, temperature, and groundwater extraction. In the D scenario, parameters including MAPE, RMSE, and NASH were 0.29 m, 0.47 m, and 0.99, respectively for the first observational well. Also, C scenario with input data including the previous month's groundwater level, precipitation, and groundwater extraction for the second observational well, for the same parameters mentioned above equal to 0.20 m, 0.26 m, and 0.99. As well for the third observational well, the A scenario with input data including the previous month's groundwater level for the same parameters equal to 0.29 m, 0.41 m, and 0.99 as the optimal scenarios were selected using the ANFIS-GWO model. Based on the results, the Gray wolf algorithm in training the ANFIS model was able to reduce the average forecast error by equal to 0.03 (RMSE) and 0.02 (MAPE) meter and increased the average NASH value equal to 0.01 and increased the accuracy of predictions.
R. Daneshfaraz, M. Bagherzadeh, M. Jafari,
Volume 26, Issue 4 (3-2023)
Abstract
The present study aimed to investigate and compare the laboratory results of energy dissipation and length of vertical Drops equipped with horizontal Screens with the results of standard stilling basins of type one, two, three and four simple vertical Drops. For this purpose, 64 different experiments were performed on vertical Drops equipped with a horizontal Screen at relative distances of 0, 0.25, 0.5, and 0.75 from the edge of Drops, with a porosity of 40 and 50% of the Screen and a height of 20 cm .The results showed that in all experiments and at a constant flow, increasing the distance of the Screen from the edge of Drops does not have much affect the energy dissipation of the current. On average, the downstream energy dissipation for the present study has increased by more than 20% compared to the simple vertical Drop, which can be an excellent alternative to the downstream stilling basin. Among the models of the present study, the most significant reduction in the relative length of the Drops was achieved by the vertical Drops model with a horizontal Screen with a relative distance of 0.75. On average, when using horizontal Screen at four relative distances from the edge of Drops, the relative length of the Drops is reduced by more than 73% compared to the vertical Drops equipped with a standard stilling basin.
T. Mohammadi, V. Sheikh, A. Zare,
Volume 26, Issue 4 (3-2023)
Abstract
Trend analysis of stream flow provides practical information for better management of water resources on the eve of climate change. Therefore, the present study investigated river flow variations during three decades as well as projections of future discharge in the Gorganrood watershed. The Man-Kendall method has been used to detect the trend and methods of Pettitt, SNHT, and Buishand to identify points of a sudden change in discharge time series in 8 stations of Aq Qala, Galikesh, Gonbad, Haji Ghoshan, Nodeh, Ramyan, Sadgorgan, and Tamar. The Mann-Kendall trend test showed the existence of a significant negative trend (flow reduction) on a daily and annual scale in all stations. Monthly, the strongest negative trend in Aq Qala, Galikesh, Gonbad, Haji Ghoshan, and Ramyan stations was related to July, but in Nodeh and Tamar stations, it was related to August and February, respectively. A decreasing trend was observed in all stations on a seasonal scale, but this trend was not significant in some seasons. The results of the analysis of change points in discharge showed that the change points in the data used in this study are more of a decreasing and in some cases incremental type and some stations, no change points have been identified at all. Therefore, the number of decreasing changes in the studied hydrometric stations is significantly higher than the incremental changes and is more visible from 1993 to 1997 and 2005-2007 in three and four stations, respectively. Also, the most incremental changes among the stations are related to the Aq Qala station in 2017 with a flow rate of 234 cubic meters per second. Investigation of the flow of the basin in the past decades showed significant monotonic and abrupt changes which are mostly toward decreasing the basin’s discharge. The downward trend in discharge values at different time scales for all hydrometric stations of the Gorganrood watershed, which will be more severe in the future due to global climate change, and increasing the region's water needs for various future use due to population growth and the expansion of industries can also be considered as a serious warning for policymakers, planners, and local managers to prevent a possible water crisis in the region in the future with proper planning.
E. Javiz, A. Jalalian, M.r. Mosaddeghi, E. Chavoshi, N. Honarjoo,
Volume 26, Issue 4 (3-2023)
Abstract
One of the most significant environmental crises in arid, semi-arid, sub-humid, and even humid regions is the destructive phenomenon of desertification and in the arid and semi-arid regions is wind erosion. These problems exist in large areas of Iran and it is necessary to use an environmentally friendly and economic method to solve this problem. In this study, calcium bentonite clay was used for the first time in Iran and perhaps in the worlds in the critical region of Sajzi, which covers an area of 65 hectares. Experiments were performed on the crusts after one year of mulching with bentonite clay. The results showed that wind erosion has a negative and significant correlation with the mean weight diameter and geometric weight diameter of aggregate, aggregates with diameters greater than 0.25 mm, shear strength, and penetration resistance. On the other hand, the results of the permeability test using double-ring and by three models (Kostiakov, Horton, and Philip) showed that the lowest mean square error (SSE) and the highest coefficient of determination (R2) belonged to the Kostiakov model in the mulch-applied and control samples. This result indicated the superiority of the Kostiakov model compared to Horton and Philip's models. Wind erosion intensity was also measured in situ using a portable wind tunnel at 20 points in the Sajzi region. The findings showed that mulch application has controlled more than 95% of soil erosion.
H. Nazaripour, M. Hamidianpour, M. Khosravi, M. Vazirimehr,
Volume 26, Issue 4 (3-2023)
Abstract
In this study, the decade variability of frequency and severity of drought in Iran has been investigated. The one-month scale data from the standardized precipitation-evapotranspiration index (SPEI 01) in the period 1956 - 2015 have been used. Based on the common numerical thresholds, the characteristics of the frequency and severity of drought for each pixel have been calculated and they are the basis for the analysis of the drought situation. Then, the frequency of drought severity classes was calculated and its trend was investigated using the non-parametric Mann-Kendall test. The findings indicated the spatio-temporal variability of drought frequency and intensity patterns in Iran. The frequency of mild droughts has decreased from south to north and from east to west; while the frequency of more severe droughts has increased from north to south and from west to east. The frequency of mild droughts in the southeast, northwest, and northeast has increased by 5 to 40 percent. While the frequency of more severe droughts in most parts of Iran has increased between 10 and 20 percent. Variability in the frequency of more severe droughts is more pronounced in the Central Plateau catchment area as well as in the Persian Gulf-Oman Sea. The trend of drought intensity is decreasing (drought intensification) at the same time as the prevailing rainfall regime in Iran. A significant increase in drought intensity (wet season intensification) is observed only in southeastern Iran at the same time as the monsoon regime. However, extra-arid and arid regions of southeastern Iran are affected by the frequency and severity of drought and have a high degree of vulnerability.
K. Shirani, R. Arfania, Y. Fereydoni, R. Naderi Samani, M. Shariati, M. Faizi,
Volume 26, Issue 4 (3-2023)
Abstract
Groundwater is always considered one of the important water resources, especially in arid and semi-arid regions of the world, such as Iran. In recent decades, it has decreased drastically due to excessive use. The objective of this study was to determine the best interpolation method and evaluation of the spatiotemporal variations for the groundwater level in the Sahneh-Biston plain of Kermanshah province during three decades from 1991 to 2020. At first, four Gaussian, linear, spherical, and power semi-variograms were obtained for observations. Then, the best semi-variogram and interpolation methods were selected among the evaluated methods for zoning the groundwater level in the region. The lowest value of the sum of RMSE, MBE, and MAE error criteria and the highest coefficient of determination (R2) between observations and estimates in all three decades and the average of the entire period were calculated and considered to evaluate the most appropriate semi-variogram and interpolation methods for spatial distribution. The results showed that the ordinary kriging method with Gaussian semi-variogram is the best method to estimate the groundwater level in the Sahneh-Biston plain. The average difference between the minimum and maximum groundwater levels based on the observation wells of the study area and the zonation method is from 1279 to 1372 meters and 1289 to 1409 meters during the studied period time, respectively. The groundwater level is placed in more depth with the proximity to the central and southern regions. The maximum decrease and increase of groundwater level variations have been 12 and 19 meters during three decades, respectively. Also, the underground water level variations during these three decades showed that both the second and third decades compared to the first decade and the third decade compared to the second decade have increased in more than 50% of the region. This increase can be caused by the optimum management and water use in these years. Therefore, groundwater level monitoring provides effective help for experts and users in planning and optimal management of groundwater for the sustainable development of water resources.
Z. Nazari, M. Moeinaddini, S. Zare, R. Rafiee,
Volume 27, Issue 1 (5-2023)
Abstract
Due to the environmental problems caused by wind erosion, it is necessary to stabilize the dust centers with mulches. The objective of the present study was to determine and compare the optimum vinasse mulches based on mechanical indicators for sensitive soil stabilization to wind erosion. In this research, vinasse (0, 100, 200 g) is combined with bagasse (0, 25, 50 g), ash bagasse (0, 25, 50 g), filtercake (0, 12.5, 25 g), and one-liter water (81 treatments). At first, the treatments were determined in the appropriate range of salinity and acidity (35 treatments) and in the next step, the mechanical indicators have been measured after mulching on laboratory trays (2×30×100 cm). Optimum mulches have been determined based on five indicators by mean comparison (Duncan). The mean comparison showed that treatments 33, 30, 34, 32, and 19 show the mean difference between the groups based on layer thickness, impact resistance, compressive strength, and shear strength properly. It can be concluded that vinasse (100 and 200 g) with 50 g bagasse reduces the crack coefficient greatly, and the application of vinasse, bagasse, and filtercake does not affect the compressive strength and impact resistance.
A.r. Emadi, S. Fazeli, M. Hooshmand, S. Zamanzad-Ghavidel, R. Sobhani,
Volume 27, Issue 1 (5-2023)
Abstract
The agricultural sector as one of the most important sectors of water consumption has great importance for the sustainability of the country's water resources systems. The objective of this study was to estimate the river water abstraction (RWA) for agricultural consumption in the study area of Nobaran in the Namak Lake basin. The RWA was estimated using variables related to morphological, hydrological, and land use factors, as well as a combination of their variables collected through field sampling. Data mining methods such as adaptive-network-based fuzzy inference systems (ANFIS), group method of data handling (GMDH), radial basis function (RBF), and regression trees (Rtree) were also used to estimate the RWA variables. In the current study, the GMDH24 model with a combined scenario including the variables of river width, river depth, minimum flow, maximum flow, average flow, crop, and the garden cultivated area was adopted as the best model to estimate the RWA variable. The RMSE value for the combined scenario of the GMDH24 model was found to be 0.046 for estimating RWA in the Nobaran study area. The results showed that the performance of the GMDH24 model for estimating RWA for maximum values is very acceptable and promising. Therefore, modeling and identifying various variables that affect the optimal RWA rate for agricultural purposes fulfills the objectives of integrated water resources management (IWRM).
