hydrogeology
Zahra Sedghi; Ata Allah Nadiri; Sina Sadeghfam; Somayeh Asadi; Frank Tsai
Abstract
Nitrate is one of the pollutants of drinking water sources in the Maku-Bazargan-Poldasht region as a result of human and agricultural activity. Investigations show that the maximum nitrate content in the water resources of the Maku-Bazargan-Poldasht region has increased from 33 mg/liter to 167 mg/liter ...
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Nitrate is one of the pollutants of drinking water sources in the Maku-Bazargan-Poldasht region as a result of human and agricultural activity. Investigations show that the maximum nitrate content in the water resources of the Maku-Bazargan-Poldasht region has increased from 33 mg/liter to 167 mg/liter at the regional level since 2000, or 15 years ago. Is. This area's drinking water is sourced from a variety of poorly maintained wells, springs, aqueducts, and surface water bodies. The results of this analysis, which collected samples from a number of water sources, show the area's high level of water source pollution. This study is the first to assess the carcinogenic risk of nitrate, which is present at high amounts in the study area. This study is the first to assess whether nitrate, nitrite, and ammonium are carcinogenic due to the high amounts of nitrogen compounds in the study area. The goal of the current study was to evaluate the levels of nitrate, nitrite, and ammonium in the drinking water sources of the Maku-Bazargan-Poldasht region and investigate any potential health issues related to nitrate and nitrite. This was done in compliance with USEPA regulations. An effort was made in this study to present a nitrogen compound risk map that is not carcinogenic, and if such a risk exists, future research by scientists should focus on it and determine the best course of action.
hydrogeology
babak shahinejad; Hojjat Allah Yonesi; maryam mirbeyksabzevari
Abstract
One of the common methods of controlling the side erosion and rivers training is the use of spur dikes. It is important to consider several different and conflicting objectives in river engineering studies simultaneously. For this purpose, the optimum design of the dimensions of constructed spur dikes ...
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One of the common methods of controlling the side erosion and rivers training is the use of spur dikes. It is important to consider several different and conflicting objectives in river engineering studies simultaneously. For this purpose, the optimum design of the dimensions of constructed spur dikes in Zanjanrood was considered with the aim of minimizing the cost and maximizing the sediment discharge. In the model, a combination of morphological model, design and optimization model of multi-objective harmony search algorithm were used and to evaluate the cross-section stability were used hypothetical theories. Calibration and validation of the model were performed by Zanjanrood data with Van Rijn sediment equation and Gill scouring equation. Sensitivity analysis of the model were performed for the parameters of discharge, slope and initial width of the river. By comparing different scenarios obtained from the Pareto front, better answers were provided than the plan implemented in Zanjanrood and the studies of other researchers. Finally, one of the points of the Pareto front must be selected for construction and execution. Choosing the right number depends on the designer's opinion and the existing priorities. in one of scenario that chosen as the optimal design, it has the lowest Euclidean distance compared to other scenarios with the ideal point. This scenario offers 244.58% lower cost and 25.48% more sediment discharge than Zanjanrood plan.
hydrogeology
amirsaeed Hoseini; saeid Hakimi Asiabar; Mojgan Salavati
Abstract
Abstract The goal of this study was to investigate the relationship between vegetation and soil erosion and changes to the hydro-geochemical properties of water. Soil erosion is closely related to the type of vegetation and land use, and can change water quality in a region. For this, the present study ...
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Abstract The goal of this study was to investigate the relationship between vegetation and soil erosion and changes to the hydro-geochemical properties of water. Soil erosion is closely related to the type of vegetation and land use, and can change water quality in a region. For this, the present study collected and analyzed 15 water samples from the permanent waterways of Pirbadush and Gashun of the Qolyan River in the Qalikuh region of Lorestan, Iran. According to studies, from higher parts of the highlands of the region down towards downstream areas, water quality is reduced with the reduction of vegetation and increase of soil erosion and progressive Quaternary sediments, and with the entry of more cations and anions from sediments to water, and increased electrical conductivity, the total dissolved solids and turbidity. Thus, greater levels of vegetation in the highlands of this region increase soil permeability and reduce soil erosion. In this region, the reduced vegetation depends on the type of bedrock, and in some areas excessive grazing, in addition to altitude changes, thus increasing pollutants such as nitrates. Increased nitrates in the regional water depend on anthropogenic (livestock grazing) and geo-genic (expanded oil shales and the erosion of Quaternary deposits) factors. As a consequence, the regional water quality is more influenced by environmental and geo-genic factors, with anthropogenic factors less contributing to it.
hydrogeology
Mahshid Moavi; heeva elmizadeh
Abstract
From the point of view of fractal behaviors, the property of replication over time creates patterns in the bed of the basin that show unique performance during the maturity of a basin, depending on the reproductive characteristics and how they change. For this reason, in this study, investigates the ...
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From the point of view of fractal behaviors, the property of replication over time creates patterns in the bed of the basin that show unique performance during the maturity of a basin, depending on the reproductive characteristics and how they change. For this reason, in this study, investigates the bifurcations of drainage networks of the Ramhormoz basin using Tokunaga model and fractal dimension correlation, has been done. Ramhormoz River is one of the sub-basins of Jarahi basin located in the southwest of the country. This river originates from 50 km southeast of Izeh and flows to the southwest. In this study, river networks were extracted from Arc GIS software, and then input data were entered into the software to calculate two-dimensional fractal numbers using correlation function. In this regard, first Ramhormoz basin is divided into eastern and western parts and then using the Tokonaga method, irregular network and curve of Ramhormoz river are drawn in a regular, geometric and corresponding tree form. According to the length of the streams, the fractal dimension was calculated for both parts of the Ramhormoz basin. The fractal dimension of the correlation between the Ramhormoz basin and its eastern and western parts has been calculated between (1.42 to 1.68) with a high correlation coefficient, which indicates a relatively high turbulent behavior of the basin and its parts. The calculated fractal dimension represents the average bifurcation ratio and the short time to reach a constant flow.
hydrogeology
Fariba Esfandyari Darabad; Zeinab Pourganji; Raoof Mostafazadeh; Maryam Aghaie
Abstract
Floods as destructive natural hazards need to be predicted in accurate way through evaluation of the hydrological response of watersheds to the effective input rainfall. Due to the variety of rainfall-runoff models, it is very important to choose a suitable model that can simulate the hydrological behavior ...
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Floods as destructive natural hazards need to be predicted in accurate way through evaluation of the hydrological response of watersheds to the effective input rainfall. Due to the variety of rainfall-runoff models, it is very important to choose a suitable model that can simulate the hydrological behavior of the watershed. In this study, various rainfall-runoff transformation methods have been evaluated, including triangular, broken triangular, variable triangular and SCS-curvilinear unit hydrograph methods in Nenekaran watershed, Ardabil province. In this regard, the Wildcat5 hydrological model have been used to this purpose. The precipitation amount at the 25-year return period was calculated using Cumfreq software. After preparing the land use map of the study area using satellite images, the area of each land use in the area has been calculated using ArcGIS software. The precipitation value and the time of concentration were considered constant during the simulation procedure. The results showed that the SCS method had the highest runoff of 44.50 cubic meters per second. The minimum time to the peak was 2.19 hours and the variable triangular method had the lowest peak flow rate. The simple triangular method has a maximum time to peak of 4.51 hours, which shows the great difference between the hydrograph of the SCS method and the other three methods. The difference in the nature of the methods, the watershed condition, and the suitability of estimating tc and CN parameters should be considered in rainfall-runoff transformation methods.
hydrogeology
Mousa Abedini; Sajjad Javadi; Raoof Mostafazadeh; AmirHesam Pasban
Abstract
Today, soil erosion is one of the major problems of watersheds and agricultural areas and natural resources, which causes land degradation and decreases soil fertility. Therefore, the purpose of this study is to investigate the relationship between vegetation and geomorphic indices with the values of ...
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Today, soil erosion is one of the major problems of watersheds and agricultural areas and natural resources, which causes land degradation and decreases soil fertility. Therefore, the purpose of this study is to investigate the relationship between vegetation and geomorphic indices with the values of erosion and sediment in the watershed of Koot-e-Tootraghi basin, which was done by using the capabilities of GIS to extract the geomorphic characteristics of the basin. For this purpose, erosion and sedimentation rates were calculated using the modified Psiac model (MPSIAC). Also, in order to extract physiographic and geomorphic features including: TWI topographic moisture layers, SPI current strength, SLOPE slope, domain curvature, profile curvature and sub-basin plan curvature, from the height digital model with a spatial accuracy of 30 meters, as well as other layers used in the MPSIAC model including1:25000 topographic maps, 1:100000 geological maps were used. According to the box diagram, the indices related to curvature have little changes in the studied area. Also, the indices related to curvature have little changes in the studied area. Based on the results, there is a positive and significant correlation of 0.47 (p-value less than 0.01) between the standard index of vegetation cover and topographic humidity index. In addition, there is a significant correlation (0.63) between waterway power index and slope. It was also found that the relationship between the slope and the normalized index of vegetation has an inverse and significant relationship (0.48) (p-value less than 0.01.).
hydrogeology
Alireza Ildoromi
Abstract
The purpose of this study is to simulate and sedimentation status of Ebro River of Ekbatan Dam in Hamedan using GSTARS 2.1 mathematical model.For this purpose, they measure the hydrodynamic part of the sediment from the water and hydrometry of the measuring station Ebro and data on water level cultivar ...
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The purpose of this study is to simulate and sedimentation status of Ebro River of Ekbatan Dam in Hamedan using GSTARS 2.1 mathematical model.For this purpose, they measure the hydrodynamic part of the sediment from the water and hydrometry of the measuring station Ebro and data on water level cultivar changes in 2006 and cross-sectional geometric data collected in 2006 and 2019 and sediment transport equations in 13-year production period have been used.Studies show that the cross section of the river is changing from V-shaped to U-shaped from 2005 to 2019..Examination of sedimentation rate during 13 years (2006-2019) shows that the cross-sectional level of the river is about 24.6 cm and using Wyang's sedimentary relationships changed by 22.8 and 20.2 cm, respectively, which indicates a good agreement of the model in the evaluation and Simulation of cross-sectional change due to erosion and sedimentation.Studies show that the values of slope and velocity in the middle of the study area are less than the beginning and more than the end, so the amount of sediment in the middle is more than the beginning and less than downstream of the region.It is recommended to use FLUVIAL 12 and HEC-RAS methods to select and apply the most practical method.
hydrogeology
Rasool Hasan zadeh; Friba Esfandyari; sayyad Asghari saraskanrood; Zahra Miri
Abstract
the object-oriented method in preparing the land use map of Darre Rood catchment area using Landsat 5 and Landsat 8 images in a period of 30 years, from 1990 to 2019 and its effects on changes in Darre rood river discharge it placed. The images were classified into fourteen classes and the changes in ...
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the object-oriented method in preparing the land use map of Darre Rood catchment area using Landsat 5 and Landsat 8 images in a period of 30 years, from 1990 to 2019 and its effects on changes in Darre rood river discharge it placed. The images were classified into fourteen classes and the changes in the area of the classes revealed that the classes of irrigated agriculture, rainfed agriculture, rocky areas, residential areas, gardens and lakes with increased area and barren lands, pastures, forest lands and riverbeds decreased They were. To find out the changes in the river flow trend, SCS method was used which was implemented in SWAT model and according to land use in 1990 and 2019 in SWAT model was determined according to the digital elevation layer of the basin and all the necessary parameters to the model. Which included soil layers and land use changes and climate data were called into the model and two separate scenarios for 1990 and 2019 were used. The results showed that with the change of land use, the amount of CN in the second scenario compared to the first scenario increased by 5% and increased from 02.70 to 5.73, which due to the change in land use in favor of the basin becomes more impermeable to rain. Compared to 1990. Also, due to the increase in the type of vegetation, the amount of deep penetration has decreased from the first scenario to the second scenario from 257.09 to 97.9.
hydrogeology
kamran Razaei Tavabe; azam heydari; mohamad javad sayahpour
Abstract
Quality protection of surface and groundwater as one of the most valuable national resources is vital. For this purpose, Parishan basin was selected as a sample of semi-closed inland Zagros basins and geographical weight regression (GWR) modeling was performed using 25 observation wells of the relationship ...
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Quality protection of surface and groundwater as one of the most valuable national resources is vital. For this purpose, Parishan basin was selected as a sample of semi-closed inland Zagros basins and geographical weight regression (GWR) modeling was performed using 25 observation wells of the relationship between water quality parameters and geological constructs. In this model, water quality parameters such as (EC, TDS, SAR, CL, Na, K, 4 SO) are used as dependent variables and geological formations are used as independent variables. The modeling results showed that the highest correlation based on qualitative parameters such as potassium, chlorine and electrical conductivity is related to the center and east of Parishan basin. Water quality is also effective. Then, by forming the Moran index autocorrelation, the relationship between water quality parameters and geological structures was evaluated. The model with high variability accuracy established a direct relationship between these two parameters and by doing this step, the model validation was confirmed. Finally, based on the prepared maps and the high power of the GWR model, managers and planners can use it to identify sensitive points of changing water resources for spatial modeling.
hydrogeology
Mirali Mohammadi; Mahsa Mohtadi
Abstract
The purpose of present research work is to study the hydraulic properties of River Simineh and its process using HEC-RAS model, in a combination with ArcGIS software using HEC-GeoRAS extension to simulate the hydraulic parameters of river having a catchment area of 3726 km2. For that mean, since multi-dimensional ...
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The purpose of present research work is to study the hydraulic properties of River Simineh and its process using HEC-RAS model, in a combination with ArcGIS software using HEC-GeoRAS extension to simulate the hydraulic parameters of river having a catchment area of 3726 km2. For that mean, since multi-dimensional models require long time and high cost in river bends, by using a combination of satellite images and HEC-RAS model a multi-dimensional simulation was prepared. Among those, 58 cross-sections are considered along the river lane that main data required in this research are elevation maps, satellite images, boundary conditions and River Simineh hydrometric stations. The results showed that at the upstream of river, the discharge was 316.3 m3/s and water level was 12.85 m, and at the downstream the flow rate and water level are 313.6 m3/s and 11.52 m, respectively. On the other side of the river bend, the water level variation is around 50 cm and the flow velocity is directly proportion to a distance from the river bank; so that the maximum flow velocity of 2.2 m/s occurred at a distance nearby 1.5 m. To verifying the model, a statistical parameter of NSE coefficient for the water level and flow depth were 0.805 and 0.845, respectively; which shows the accuracy of model. Those results indicate a high accuracy of HEC-RAS model in hydraulic simulation of River Simineh flow. Also, simulations prepared in GIS background have significant impacts on the accuracy of outputs
hydrogeology
Zahra Yunesian; fariba hemmati; Mohammad Mahdi Hossein Zade
Abstract
are connected at the end of the basin and form the Darbadam River. According to the results obtained for the central angle, in the first part between 2010 and 2021, the Meandri River pattern was developed and there was no change in the pattern class, but in the second and third parts in 2010, the river ...
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are connected at the end of the basin and form the Darbadam River. According to the results obtained for the central angle, in the first part between 2010 and 2021, the Meandri River pattern was developed and there was no change in the pattern class, but in the second and third parts in 2010, the river pattern is not developed meandering, which in 2021 has become the developed meandering river patternBased on the average curvature coefficients in all three sections studied, the Darbadam River has a meandering pattern. Due to the characteristics of the region, such as the presence of resistant rock layers, the high slope of the region and also the mountainous topography, has led to low transverse displacement of meander in the region. However, in some parts of the river, due to human activities, including land use change, vegetation degradation and overgrazing, there has been a change in the river pattern.
hydrogeology
Alireza Donyaii
Abstract
The drop in water level in the aquifers of Kermanshah province has been so severe that it has reached about 10 meters in some places. The purpose of this study is to evaluate GRACE satellite data to estimate the groundwater storage of Ravansar aquifer in Kermanshah province. Therefore, in this study, ...
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The drop in water level in the aquifers of Kermanshah province has been so severe that it has reached about 10 meters in some places. The purpose of this study is to evaluate GRACE satellite data to estimate the groundwater storage of Ravansar aquifer in Kermanshah province. Therefore, in this study, while examining the water level of Ravansar aquifer observation wells and also the spatial zoning of these changes, the current situation of the region was evaluated using Kriging method in GIS software. Then, in order to evaluate the GRACE satellite data, the JPL, GFS, CSR, and CRI algorithms were coded in Google Earth Engine cloud computing environment, and then the monthly and annual changes of liquid water Equivalent (LWE) were calculated. Also, the amount of Soil Moisture (SM) was estimated from the GLDAS hydrological model and by subtracting the amount of soil moisture from the estimated values of GRACE , the amount of changes in groundwater storage compared to its observational values was obtained. This study showed that not only can GRACE data be used to estimate the rate of changes in groundwater storage in aquifers, but also the data are of acceptable accuracy. Comparison of the results of different algorithms showed that the JP algorithm with a correlation coefficient of 0.73 has the highest correlation with observational data. According to the JPL , the values of changes in groundwater storage estimated from GRACE compared to the observed values show a decrease in groundwater storage of -1.8 cm.
hydrogeology
maryam bayatikhatibi; Faeze Rostami; Khalil Valizadeh Kamran
Abstract
In the Drastic model, the vulnerability index was obtained from 57 to 165, which is in the descriptive division into classes without risk to high risk of pollution, which if we consider three classes without risk of pollution to low pollution, we can say 44% of the total area of the plain is located ...
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In the Drastic model, the vulnerability index was obtained from 57 to 165, which is in the descriptive division into classes without risk to high risk of pollution, which if we consider three classes without risk of pollution to low pollution, we can say 44% of the total area of the plain is located on these three classes. Also, three classes of low to high, occupy 46% of the plain area. In fuzzy modeling, after scaling and overlapping seven input layers, we prepared the final map, which according to the index of this modeling, 47% of the total area of the plain has high vulnerability, that the result obtained is very similar to the result of DRASTIC method, but by comparing the two methods, it becomes clear that the fuzzy model is more accurate than the drastic method. In both maps, the northwestern to southwestern parts where the city of Tabriz is located, have the highest potential for pollution and the southwestern parts, which include the Sahand Mountains, have the lowest potential for pollution. Finally, using GQI index and according to drinking standard WHO and using ten parameters: hydraulic conductivity, chlorine, calcium, bicarbonate, magnesium, potassium, total soluble solids, sodium, sulfate and total hardness which are taken from wells in the plain, In high-risk areas, due to the high percentage of total soluble solids, total hardness and high hydraulic conductivity, water quality has also decreased and descriptively, the water quality of Tabriz plain is in the acceptable to appropriate range.
hydrogeology
azam Heydari; Iraj Jabbari
Abstract
Irregular abstraction of groundwater aquifers in the country has caused a sharp decline in the aquifer water level and the destruction of aquatic aquifers. In this study, in order to investigate the groundwater level of Marvdasht-Kharameh aquifer, located in Fars province, in relation to the uncontrolled ...
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Irregular abstraction of groundwater aquifers in the country has caused a sharp decline in the aquifer water level and the destruction of aquatic aquifers. In this study, in order to investigate the groundwater level of Marvdasht-Kharameh aquifer, located in Fars province, in relation to the uncontrolled abstraction of groundwater from the data of 81 piezometric wells in the period (2018-2018), the Modflow model was simulated. Also, the results of calculating the water balance of 7,500 wells in the basin indicate that the amount of 1100 million cubic meters of water from the aquifer constant storage has been reduced over a period of 10 years. According to the prepared interpolation maps, the highest rate of groundwater loss has occurred in Dorodzan, Ramjerd and Shool areas. Therefore, it is in line with the statistics of the Fars Regional Water Organization that there are wells with high discharge in these areas. According to the maps prepared from Marvdasht aquifer, due to the alluvial nature of the groundwater aquifer, the effect of water level drop can be observed from a short distance. On the other hand, in the intermediate maps, the coefficient of hydraulic conductivity parameter indicates that the rate of aquifer drop in the northwest, center and southeast of the basin has the highest value, which is appropriate with 11% relative error confirms modeling. Finally, by performing two scenarios of 10 and 30% reduction,
hydrogeology
maryam baranpour; Bijan Khalili Moghadam; Amin zoratipour
Abstract
Abstract:The climate change is a complex atmospheric-oceanic phenomenon on the global scale. Climate change and global warming is one of the most important factors affecting the degradation of water and soil resources in arid and semi-arid regions; Which increases the occurrence of dust phenomenon. The ...
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Abstract:The climate change is a complex atmospheric-oceanic phenomenon on the global scale. Climate change and global warming is one of the most important factors affecting the degradation of water and soil resources in arid and semi-arid regions; Which increases the occurrence of dust phenomenon. The aim of this study was to evaluate the performance of two statistical downscaling models of SDSM and LARSWG for quantitative screening in predicting climate scenarios and also predicting climate change in the dust center of south and southeast of Ahvaz. In line with this goal, one of the three-dimensional paired oceanic models - AOGCM atmospheric general circulation called HadCM3, The results showed that the simulated data of both models, compared to the observed data, were significant compared to the long-term mean of the base period and had a high correlation with a high coefficient of determination (R2) for all parameters from 0.87 to 0.98. Finally, by confirming the existence of climate change in Khuzestan province , SDSM model due to direct use of HadCM3 models and large scale NCEP data and the type of simulation process and also Combined structure in data mining scale with RMSE, MAE and ME 0.97, 0.18 and 0.021, respectively; It has higher accuracy than LARSWG model in simulating climatic data in the dust center of southern Ahvaz. The SDSM model was also more successful in simulating daily temperature data and wind speed, and the LARSWG model had a better prediction of the daily precipitation parameter.
hydrogeology
Sina Ziaye Shendershami; Abazar Esmali Ouri; Raoof Mostafazadeh; Ardavan Ghorbani
Abstract
The aim of this study was to investigate the factors affecting the decrease and change of groundwater level in Ardabil plain in two periods 1995 to 2005 and 2005 to 2015. The monthly precipitation data of Ardebil, Nir, Namin, Abi baglo, Hir, Samiyan stations in the Ardabil plain during the statistical ...
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The aim of this study was to investigate the factors affecting the decrease and change of groundwater level in Ardabil plain in two periods 1995 to 2005 and 2005 to 2015. The monthly precipitation data of Ardebil, Nir, Namin, Abi baglo, Hir, Samiyan stations in the Ardabil plain during the statistical period of 1995-2015 and monthly data of the height of the station in 24 Piezometric well ring were chosen for the plain. Landslide OLI and TM satellite imagery was used to prepare land use map for the target periods in June 1993, 2005, and 2015. The results of land use changes in the years 1993, 2005, and 2015 in the Ardabil plain showed the highest watery agriculture with 48156.26, 50678.66, and 58356.68 and area water level, respectively, were with 168.75 ,88.65 and 380.95 ha, lowest level Which indicates the high level of agricultural land involvement in the decline of agricultural land in the Ardebil plain. The study of the process of Piezometric Wells showed that in the plain of Ardabil, the maximum height of the surface of the station (1437 m) is related to the southern parts of the plains around the village - Noshahr-Kargan and the minimum height (1300 m) is related to the village of Khalifaulo Sheikh. The highest level of cultivation is also focused on user plans in these areas.
hydrogeology
hamidreza babaali
hydrogeology
Hadi Nayyeri; Mamand Salari; Zhila Chardawli
Abstract
The soil erosion issue and lands' degradation is one of the most important issues in natural sciences. Soil erosion is the predominant geomorphic process on many land surfaces. In order to assess the environmental and economic consequences of soil erosion, quantitative data are needed. In this research, ...
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The soil erosion issue and lands' degradation is one of the most important issues in natural sciences. Soil erosion is the predominant geomorphic process on many land surfaces. In order to assess the environmental and economic consequences of soil erosion, quantitative data are needed. In this research, soil erosion is studied with of morphometric parameters. For this aim, Gheshlagh river basin iin Kurdistan province, was studied. Areas with a rating of more than 2 that entered directly into the main river were plotted as sub-basins for morphometric calculations. These areas included 47 sub-basins. The number of 16 morphometric parameters were calculated to determine the morphometric conditions of the basin and were considered as the input layer. Then, the results of these parameters were aggregated by four multi-criteria decision models TOPSIS, VIKOR, SAW and CF. In all four, the northern sub-basins were classified as areas with low and very low susceptibility to erosion. These basins are often located in volcanic rocks. In a general view, according to all four models studied, the basins in the lithology of dark gray shale (Sanandaj shale). Their sensitivity to erosion have been classified from moderate to very high. the final results showed that the multi-criteria decision-making methods, by presenting a classification, divide the region into several classes in terms of the degree of erosion sensitivity, and the VIKOR method, due to the greater coefficient of variation, has more accurate than the others.
hydrogeology
hamzeh saeediyan; Hamid reza Moradi; abdal salehpoor
Abstract
1-IntroductionSoil infiltration situation indicates soil behavior against water reaching the soil surface. This phenomenon determines the amount of both the water reaching the soil surface and rainfall losses. Soil infiltration of a basin has unique parameters based on its climate, soil conditions, and ...
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1-IntroductionSoil infiltration situation indicates soil behavior against water reaching the soil surface. This phenomenon determines the amount of both the water reaching the soil surface and rainfall losses. Soil infiltration of a basin has unique parameters based on its climate, soil conditions, and buildings. Soils are a set of discontinuous particles among which pores exist so that water can move from a point with more energy to a point with less energy; this property is called the passage of water through continuous pores. Gachsaran marl formation has a thickness of about 1600 m and consists of salt, anhydrite, colorful lime marl, and some shale from a lithology point of view. The age of this formation is lower Miocene (Ahmadi, 1999: 714). Estimation of soil infiltration using various erosion components can be a useful method to determine soil infiltration in the shortest time and at the lowest cost.2-MethodologyIn this study, soil infiltration was estimated using erosion different components in different land uses in deposits of Gachsaran formation by selecting a part of the Kuhe Gach watershed of Izeh city with an area of 1202 hectares. The relationship between soil infiltration and erosion different components, such as sediment rate, runoff rate, and runoff and erosion threshold, in different land uses of Gachsaran formation was determined by the multivariate regression. Then, different erosion components were sampled at six points with three replicates and different rainfall intensities of 0.75, 1, and 1.25 mm/min in three land uses of rangeland, residential area, and agricultural land using a rainfall simulator. SPSS and Excel software was used for statistical analysis. A portable Kamphorst rainfall simulator used in this study has a plot size of 625 cm2, which determines the characteristics of soil, erosion, and water infiltration, and is suitable for soil research. It is used as a standard method to determine the soil infiltration of surface deposits in the field. The experimental plot area was selected 625 cm2 with a smooth gradient. The preparation of the testing area was followed by installing and setting the rainfall simulator and then starting a chronometer upon observing the precipitation on the screen. The amount of plot infiltration was determined at 10-min intervals (Kamphorst, 1987: 407).3-Results and DiscussionThe estimation of soil infiltration was acceptable and appropriate in some models in this study, which have a lower regression coefficient. Therefore, it is not possible to make appropriate comments about the estimation of the models only using regression coefficients and other statistical coefficients nor the significance levels of observational and estimated data as well as the minimum square mean of errors (MMSEs); in some cases, the MMSEs are not sufficient and require more studies (Jain and Kumar, 2006: 272). Despite scientific advances and improvement of measuring equipment, regression models are still used by researchers in different fields due to simplicity.4-Conclusions The results showed that the most positive and negative effects of different erosion components on estimating soil infiltration were related to sediment rate, runoff, and erosion threshold in all three mentioned land uses in three precipitation intensities (0.75, 1, and 1.25 mm min). Meanwhile, the role of sediment rate in estimating soil infiltration was slightly higher than runoff, and erosion threshold and runoff rate had no role in estimating soil infiltration in this method due to a high correlation of data.
