Mohsen Armin; Hadis Valinejad; Vajihe Ghorbannia Kheybari
Abstract
1-Introduction On a national scale, soil erosion in Iran, has an important effect on agricultural production, sedimentation in dam reservoirs, soil degradation and so on. Severe soil erosions and the subsequent high deposition of sediments in dam reservoirs and reduced soil fertility are serious environmental ...
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1-Introduction On a national scale, soil erosion in Iran, has an important effect on agricultural production, sedimentation in dam reservoirs, soil degradation and so on. Severe soil erosions and the subsequent high deposition of sediments in dam reservoirs and reduced soil fertility are serious environmental problems with dangerous economic consequences for the country. The situation of sedimentation in Iranian dams indicate that their design have often focused on civil engineering and structural aspects and no attention has been paid to the issue of erosion and sediment yield in the basin of dams, which makes a large amount of sediment be deposited in many of these dams for many years; this causes a lot of sediment after many years to be deposited in many of these dams` reservoir, as a result of which, the useful life of the dam is greatly reduced. The present study aimed at estimating soil erosion in the Tang-e-Sorkh dam watershed with a total area of 39,000 hectares in the east and south-east of Boyer Ahmad County in Kohgiluyeh and Boyerahmad province using the RUSLE model and the remote sensing (RS) and Geographic Information System (GIS) capabilities in order to plan protective measures in the dam watershed. 2-Methodology Digital altitude, precipitation, physico-chemical properties of soil and satellite imagery data were used to estimate soil losses using RUSLE model in the Tang-e-Sorkh basin. First, the boundary of Tang-e-Sorkh watershed was drawn on a topographic map with a scale of 1: 50,000 in the geographic information system environment. The meteorological stations in and around the watershed were then identified and marked on the map. RUSLE has calculated the average annual soil erosion expected on a sloping land using Equation (1). A=R.K.L.S.C.P (1) Where A is calculated as the average spatial loss of soil and the average time of soil loss per unit area is expressed in terms of units selected for K and the time period selected for R. In practice, these units are usually selected so that A is expressed in tons, per hectare, per year (t ha-1 year-1). R Runoff-rain erosivity factor is expressed in MJ mm ha-1 h-1 year-1, K Soil erodibility factor which is the amount of soil loss per unit area of erosion index for a given soil- is obtained by measuring in a standard plot with a length of 22.1 meters, a slope of 9% and a permanent fallow and is expressed in t ha h ha−1 MJ−1 mm−1. L is the slope length, S is the slope, C is the plant cover management factor and P is the protective measures factor. The parameters L, S, C and P are without units. The layer of parameters of the RUSLE model includes rainfall erosivity (R), soil erodibility (K), slope and length of the hill (LS), vegetation management (C), and soil conservation operations (P) have been prepared in geographic information system environment and after overlayering, the amount of erosion was estimated locally. 3-Results and Discussion The amount of rainfall erosivity was from 179.62 to 327.77 MJ mm ha-1 h-1 year-1. Erodibility factor was from 0.08 to 46.0 t ha h ha−1 MJ−1 mm−1. The minimum and maximum values of slope and hill length were 0.08 and 12.42, respectively. The minimum and maximum values of vegetation management were 0.33 and 0.54, respectively. The minimum and maximum values of soil conservation operations were 0.5 and 1, respectively. The amount of soil erosion in the studied area varied between 0.0033 and more than 100 tons per hectare per year at the pixel level. About 80% of the studied area had an erosion rate of 35 tons per hectare per year, with the highest amount in the western and northeastern parts of the country, which was due to high rainfall erosivity and soil erodibility in the area. 4- Conclusions It can be said that in the current situation of Tang-e-Sorkh watershed, due to the lack of real sediment statistics, the best model for estimating erosion and sediment yield with the aim of introducing soil protection measures at the basin level was RUSLE model. The proposed method and the results of this research can be used as a dam maintenance planning system. The RUSLE model could predict the potential of soil erosion as a cell-by-cell, which was very useful when trying to identify the spatial pattern of current soil losses within a large area. Spatial information systems can be used to separate and inquiry these locations to assess the role of effective variables in the amount of soil erosion potential observed. Regarding the results, decision makers need to manage the risk of soil erosion in the most effective way; and management scenarios can adopt the best ways to improve and rehabilitate the basin based on the priority of different areas of the basin.
hojatolah younesi; ahmad godarzi; behzad javadi
Abstract
1-IntroductionFlood is a natural phenomenon that human societies have accepted as an unavoidable event caused by a number of factors, depending on the climatic and natural conditions of the region. It is believed that the relationship between rainfall and runoff is significantly different from one basin ...
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1-IntroductionFlood is a natural phenomenon that human societies have accepted as an unavoidable event caused by a number of factors, depending on the climatic and natural conditions of the region. It is believed that the relationship between rainfall and runoff is significantly different from one basin to another. Given that, in order to prevent the occurrence of such harmful phenomena, it is not possible at present to make changes in the factors and elements of the atmosphere. Therefore, any principled and useful solution should be sought on the ground, especially in watersheds. From this point of view, areas with "high potential" for flood production should be identified. Accordingly, the first measure to reduce the risk of floods for the sustainable settlement of the population is to control floods at their source, namely, the watershed sub-basins. Thus, it is essential to identify floodplains within the basin; however, due to the large size and scope of the watersheds, is not possible to carry out modeling, implementation and remediation operations throughout the basin. Thus, it is advised to use various computerized models to prevent floods.2-MethodologyIn this study, it has been attempted to combine GIS and multi-criteria decision-making systems (MCDM) to identify areas with different degrees of flood risk for sustainable settlement of the population in each of the cities of Khorasan Razavi Province, Iran. For this purpose, first the data of 6 effective parameters including Maximum discharge with 2, 3, 5, 10, 25, 50, 100 and 200 year return periods obtained from HEC-HMS software output, drainage density, land use and vegetation, CN, slope and permeability of the study area were prepared in GIS software environment. Then, using ANP method and pairwise comparison, the weight of each criterion and the weight of the classes of each layer were calculated in Super Decision software, respectively. Then, using GIS software analysis functions, the whole range was zoned for each of the specified criteria. Ultimately, through combination of the zoned maps and based on the weights of the ANP, the final map was prepared in five classes of low-risk flooding and high-risk flooding areas.3-Results and DiscussionThe results area of the cities exposed to floods with a very high degree as well as flood risk zoning with a return period of 2 years in the entire Khorasan Razavi province show more than 86% of areas with low and very low flooding, 12.2% of medium areas and 1.8% with high. While the results of flood zoning in the 200-year return period show 41.3% low flooding, 31.4% moderate flooding, 13.3% high flooding and 14.1% very high flooding in the entire province.4-ConclusionsThe results of this study were analyzed using field visits and ground control, which indicates that all selection criteria are met revealing the usefulness of combining MCDM methods with GIS in identifying areas with different degrees of flood risk.Keywords: Flood risk, Population settlement, Couple comparison, Khorasan Razavi
Geomorphology
Mousa Abedini; Ehsan Ghale
Abstract
1-IntroductionDue to increasing land-use changes, mainly for human activities, it is necessary to monitor vegetation changes, evaluate their trends and their environmental impacts for future planning and resource management. With the increase in population and the development of technologies, human beings ...
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1-IntroductionDue to increasing land-use changes, mainly for human activities, it is necessary to monitor vegetation changes, evaluate their trends and their environmental impacts for future planning and resource management. With the increase in population and the development of technologies, human beings are, currently, considered the most important and powerful tool of environmental change in the biosphere. Land use is the type of land use in the current situation, which includes all land uses in various sectors of agriculture, natural resources, and industry. Due to the provision of a wide and integrated view of an area, reproducibility, easy access, high accuracy of information obtained, and high speed of analysis, using satellite data is a good way to prepare a land-use map, especially in large geographical areas. One of the most widely used methods of extracting information from satellite images is classification, which allows users to generate different information. According to the type of classification method of the study area, the characteristics of the educational points get different results to separate the thematic phenomena and extract information more accurately.2-MethodologyMordagh River, which is known as Mordi Chai in the region, originates from the southern slope of Sahand Mountain located in East Azerbaijan and flows south. By connecting the sub-branches, it continues its way to the city of Maragheh, passes through the city of Malekan, and enters Lake Urmia. In the present study, Landsat satellite images, TM, and OLI sensors from 2000 and 2020 were used to identify the area and prepare a land-use map. To prepare for classification and processing on them, the necessary pre-processing was first done on the images. Images were pre-processed in ENVI5.3 software using the FLAASH method. Finally, ENVI5.3 software was used to classify the base pixel and eCognition Developer 64 software was used for object-oriented classification. To evaluate the classification results, the Kappa coefficient and overall accuracy were used to evaluate the classification accuracy of the maps. 3-Results and DiscussionAccording to the obtained results, it is observed that the most area in the study area in 2000 with the method of minimum distance belongs to the use of medium and dense rangeland. The lowest area for the year 2000 is the use of residential areas. In 2020, the highest area of land use is 173.875 square kilometers. The lowest area is related to the use of snow with a rate of 0.199 square kilometers and the use of residential areas, which compared to 2000, has an increase of up to 5.54 square kilometers. In the maximum likelihood method in 2000 and 2020, the highest areas are related to medium rangeland and soil uses, respectively. The lowest area for 2000 is related to vegetation and for 2020 is snow use. In addition, in the support vector machine method, the highest and lowest areas for 2000 are related to medium rangeland and vegetation uses, respectively, and for 2020, medium rangeland and snow uses have the highest and lowest areas, respectively. According to the maps obtained from the object-oriented method, the highest area in 2000 is related to medium rangeland with 156.406 square kilometers and then dense rangeland with 96.514 square kilometers. The lowest area is related to the use of residential areas with 11.141 square kilometers. In 2020, the highest area is related to the use of dense rangeland (126.907 square kilometers). In addition, the lowest area is snow use with an amount of 5.199 square kilometers.4-Conclusions According to the results of this study and other studies, it can be suggested that the object-oriented classification method for land-use change studies is a more appropriate and accurate method than the pixel-based method. One of the most important reasons for achieving high accuracy in the object-oriented classification method is that in this method, in addition to spectral information, information related to texture, shape, position, and content is also used in the classification process. The study of pixel-based classification showed that in selecting educational examples, the more uniform the user is and free of mixed pixels, the more accurate the classification process is. So that the land use classification and vegetation in the pixel-based method had the highest accuracy, which due to the uniform surface of both land use and homogeneous texture, the selection of training samples in these uses with the highest accuracy and have played an important role in improving overall accuracy and kappa coefficient. Based on the results of the extent of different classes related to the land use of the basin studied in 2000 and 2020, we see a decreasing trend of dense rangeland, medium rangeland, and vegetation and increasing land use of residential areas and soil. What is very clear in these maps is the excessive reduction of pastures and their conversion to other uses.Given the growing population and the need for food and economic issues, this transformation is obvious and it cannot be said that this change can be prevented.
Hydrogeomorphology
Erfan Bahrami; mehdi dastourani
Abstract
Estimation of flood hydrographs in the ungauged watersheds is a challenging issue in flood planning and management. Various models have been developed in this filed and it is necessary to evaluate the performance of models developed in different regions of the world with different climatic, hydrological ...
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Estimation of flood hydrographs in the ungauged watersheds is a challenging issue in flood planning and management. Various models have been developed in this filed and it is necessary to evaluate the performance of models developed in different regions of the world with different climatic, hydrological and physiographic features in order to comment on their performance in different regions. The Gamma synthetic unit hydrograph model is a developed model for estimating flood hydrographs in the ungauged watersheds with limited studies in the world. In this study, the Gamma synthetic unit hydrograph model for estimating flood hydrograph characteristics in Qareh-Sou watershed located in Kermanshah province in Iran has been investigated. Criteria for percentage error in peak discharge, percentage error in volume, mean absolute error, mean bias error, coefficient of determination and Kling-Gupta were estimated to evaluate the accuracy of simulation results. Based on the results, the mean values of the criteria expressed are 6.28, 17.4, 0.89, 0.54, 0.74 and 0.75, respectively, indicating that the Gamma synthetic unit hydrograph model is quite accurate in estimating the characteristics of the flood hydrograph in this study. In addition, the visual comparison of computational and observational hydrographs illustrates the remarkable accuracy of the Gamma synthetic unit hydrograph model in estimating the shape of flood hydrographs in the studied events.
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
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.
Geomorphology
Saeid Roustami; Babak Shahinejad; Hojatolah Younesi; Hassan Torabipoudeh; Reza Dehghani
Abstract
Flood is one of the natural phenomena that causes a lot of human and financial losses in the world every year and creates many problems for the economic and social development of countries. Therefore, in order to reduce the damage, control and guidance of this phenomenon, estimating flood discharge and ...
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Flood is one of the natural phenomena that causes a lot of human and financial losses in the world every year and creates many problems for the economic and social development of countries. Therefore, in order to reduce the damage, control and guidance of this phenomenon, estimating flood discharge and identifying the factors affecting it is very important. In this study, in order to estimate the flood discharge of Kashkan catchment located in Lorestan province, new hybrid artificial intelligence models including artificial neural network - innovative gunner, artificial neural network - black widow spider and artificial neural network - chicken crowding during the period 1300-1400 were used. To evaluate the simulation performance, statistical indices of determination coefficient (R2), absolute mean error (MAE), Nash-Sutcliffe productivity coefficient (NSE), bias percentage (PBIAS) were used. The results showed that hybrid artificial intelligence models improve the performance of the single model. The results showed that the artificial neural network- innovative gunner model has more accuracy and less error than other models. Overall, the results showed that the use of hybrid artificial intelligence models is effective in estimating flood discharge and can be considered as a suitable and rapid solution in water resources management.
mehrdad hassanzadeh; mehdi momeni reghabadi; amir robati
Abstract
1-IntroductionGroundwater pollution is one of the most serious and important issues in urban and agricultural areas due to land use. For this purpose, in order to obtain methods and garbage water from the pollutants that removes them, the use of methods for garbage water vulnerability assessment ...
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1-IntroductionGroundwater pollution is one of the most serious and important issues in urban and agricultural areas due to land use. For this purpose, in order to obtain methods and garbage water from the pollutants that removes them, the use of methods for garbage water vulnerability assessment such as AVI, GODS, DRSTIC, SINTACS, etc. were developed. Intrinsic vulnerability is assessed according to the hydrological and hydrogeological characteristics of the region, such as the characteristics of the aquifer and the stresses imposed on it. Occurs with inherent vulnerability components. The most common methods of assessing vulnerability index include DRASTIC, GOD, SINTACS, SI and AVI rating methods. In this study, the vulnerability of the aquifer has been investigated using DRASTIC and SINTACS models, and in order to validate the results of the methods used, electrical conductivity concentration data were used. 2-MethodologyHajiabad plain is located 160 km north of Bandar Abbas and between 35, 55 to 00 and 56 longitudes and latitudes 17, 28 to 21 and 28 north, from the north to the heights of Bibi Dokhtaran mountain from the west to Sirjan-Bandar Abbas road from To the east to the heights of Anfuzeh mountain and from the south to the congomara hills and the average width is 4 km. The climate of the region is warm and the average temperature of the region is 19.8 degrees Celsius and the average annual evaporation of the plain is 2464.7 mm. In order to study the hydrochemical properties of groundwater in the region, 16 samples of water analyzed from groundwater study wells by the Regional Water Organization of West Azerbaijan Province for the water year 93 were used.3- Results and DiscussionVulnerability maps of Drastik and SINTACS models were prepared by applying weights related to each parameter and combining layers using the overlap function. According to the SINTACS map, the vulnerability of the plain is estimated from 115 to156, the plain is in the range of medium, medium to high and high vulnerability. According to the vulnerability classification with SINTACS model, it shows that parts of the center of the plain (near Aliabad and Hajiabad villages) are in the upper floor and the northern slope of the Hajiabad plain basin has the middle floor. Most of the plain area was in the range of moderate to high vulnerability. The results showed that the Syntax model has more flexibility than the Drastic model and the probability of vulnerability is slightly higher than the Drastic model. The final map of Drastik model estimated the vulnerability of the plain from 94 to 128. The highest vulnerability is in parts of the center of the plain (near Aliabad and Hajiabad villages) and the lowest in the northern slope of Hajiabad plain basin and according to the range of Drastic vulnerability index provided by Aller Et al, (1987), vulnerability of the region is divided into 3 categories between low to medium risk. In order to study more closely and also to compare the classical methods used in this study, the method of calculating the correlation index (CI) in the aquifer and electrical conductivity data were used. For this purpose, electrical conductivity values were divided into three categories of low, medium and high electrical conductivity. Adaptation of wells with three levels of EC pollution and vulnerability categories predicted by DRASTIC and SINTACS methods was brought for Hajiabad aquifer. Based on the value of the correlation coefficient between the map produced using the drastic model with the electrical conductivity map, 39 and the same value was obtained for the Syntax model 35, which are slightly different from each other.4-Conclusions In this study, both drastic and syntactic methods predicted the potential risk in Hajiabad aquifer with almost equal accuracy. Having the correlation index between the electrical conduction point data and the vulnerability map, it showed that the Drastic model provided better vulnerability than the SINTACS model. Contamination potential in both studied models is low in the northern and southern regions. This can be due to high groundwater depth and low hydraulic conductivity. Comparing the models with the coefficient of determination between the electrical conductivity concentration and the vulnerability parameters showed that the highest correlation was in the slope layer, depth to the water table and the material of the unsaturated medium.Keywords:Aquifer vulnerability, SINTACS Method, Groundwater, Hormozgan5-References Aller, L., T. Bennet, J.H. Lehr, R.J. Petty, and G. Hackett. (1987). DRASTIC: a standardized system for evaluating groundwater pollution potential using hydrogeological settings. EPA/600/2–87/035. US Environmental Protection Agency, Ada, OK, USA.
Said Jahanbakhsh ASL; Mohammad Hossein Aalinejad; Vahid Sohraabi
Abstract
1-IntroductionDetermining the temporal change of snowmelt or agriculture water equivalent of snow, predicting flood, and managing the reservoirs of a region is of utmost importance. Some major parts of the western sections of the country are located in the mountainous region and most of the precipitations ...
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1-IntroductionDetermining the temporal change of snowmelt or agriculture water equivalent of snow, predicting flood, and managing the reservoirs of a region is of utmost importance. Some major parts of the western sections of the country are located in the mountainous region and most of the precipitations of this region occur in the form of snow in winter. The runoff resulting from snowmelt has an important role in feeding the rivers of this region and it has a significant share in developing agriculture and the economy.Scientific studies have shown that climate change phenomena have significant effects on precipitations, evaporation, perspiration, runoff, and finally water supply. As the demand increases, climate changes, greatness, frequency, and the damage resulting from extreme weather events, as well as the costs of having access to water increase, as well. Therefore, evaluating the runoff resulting from snowmelt and the effect of climate change seems necessary for managing water resources.2-MethodologyGamasiab basin is located in the northeast part of the Karkheh basin originating from the springs in the vicinity of Nahavand. Its basin has an area almost equal to 11040 square kilometers that have been located in the east part having 47 degrees and 7 minutes to 49 degrees and 10 minutes geographical longitude and from the north part, it has 33 degrees and 48 minutes to 34 degrees and 54 minutes geographical latitude. This basin has an altitude between 1275 to 3680 meters.In this study, snow-related data required for simulation were derived from the daily images of the MODIS sensor. To this end, first, the snow-covered area of the Gamasiab basin was measured during the 2016-2017 water years using the process of satellite images obtained from the MODIS sensor in the google earth engine system. All geometric justifications and calibration processes of images were applied precisely in the mentioned system. In the next step, the output of the GCM model scenarios was utilized for calculating temperature and precipitation changes in future periods. These CMIP5 kind models were under the control of two RCP45 and RCP85 scenarios and were downscaled with LARS-WG statistical model.Moreover, to investigate the uncertainty of models and scenarios, the best models and scenarios were selected for producing temperature and precipitation data of future periods; accordingly, the outputs of the models for future periods (2021-2040) having the basis period of (1980-2010) were compared using statistical indexes of coefficient of determination (R2) and Root Mean Square Error (RMSE). The results were entered into the SRM model as the inputs. In addition, temperature and precipitation data of meteorological station of the studied region as well as the daily discharge of the river flow of hydrometric station of Chehr Bridge (as located in the output part of Gamasiab basin) were used during the statistical period of October 2016 to May 2018. 3-Results and Discussion Using Digital Elevation Model (DEM) of the region and the appendage of Hec-GeoHMS in GIS software, firstly, flow direction map, flow accumulation map, and stream maps were drawn and the output point (hydrometric station of Chehr Bridge) was introduced to the border program of the identified basin and the basin was classified based on the three elevation regions.Producing temperature and precipitation data of future periods requires a long-term statistical period; accordingly, the meteorological station of Kermanshahd was selected since it was in the vicinity of the studied region. To be confident in the ability of the model in producing data in future periods, the calculated data had to be compared with the observed model and data in the studied stations. The capabilities of the LARS-WG model in modeling the mentioned parameters of this station confirmed the observed data. Moreover, the ability of the model in modeling precipitation was very good and acceptable; however, the most modeling error was related to the precipitation in Mars.In the next phase and compared to the basic periods, the mean of changes in average precipitation and temperature was measured in the studied stations during January and Juan of 2015 to 2017(for which simulation had occurred); as an index of changing the climate, this was entered into the SRM model under climate change conditions. During the simulation period (January to Juan), it had been predicted that the precipitation parameter would decrease and the temperature parameter would increase.4-ConclusionThe results of this study indicated that using the MODIS sensor could provide an acceptable estimation of the snow cover level of the Gamasiab basin, which lacked snow gauge data. Moreover, the results of simulation with the SRM model showed that the model could simulate the snow runoff in the studied region. As the main purpose of the study, the effect of temperature and precipitation in future periods was well stated considering the uncertainty of CMP15 series models and scenarios. The results of temperature changes indicated an average increase of 1.8 C. the results of precipitation also indicated an average decrease of more than 5%. However, decreasing precipitation in the cold months of the years had been predicted severely so that the reduction of precipitation in February was of utmost importance for feeding the snow cover and rivers, which had been estimated to be 20%. This happened while increasing precipitation was mainly related to the hot months of the year whose amount was insignificant and didn`t have that much effect on the runoff. Accordingly, due to the increases in temperature and decreases in precipitation in cold seasons, the results of runoff simulation have indicated a 24% reduction for 2016-2017 and a 29% reduction for 2017-2018 water years.
Alireza Donyaii; Amirpouya Sarraf
Abstract
1- Introduction Climate evolutionary theory reveals that climate change has already been evident in the planet's history, but when opposed to historical climate changes, the climatic changes of the last century have two unique characteristics. First, through the nature of the ongoing climate change, ...
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1- Introduction Climate evolutionary theory reveals that climate change has already been evident in the planet's history, but when opposed to historical climate changes, the climatic changes of the last century have two unique characteristics. First, through the nature of the ongoing climate change, human actions play a significant role Second; the speed of recent climatic changes is greater, so that, many changes will be occurring in the Earth's atmosphere during a short term [Telmer et al. 2004]. Nowadays, global warming has significant effects on precipitation and runoff yield and water resources due to the increased concentration of greenhouse gases [Donyaii et al. 2020]. The average meteorological parameters, in particular the annual or seasonal components of temperature, precipitation and runoff, play a significant role in the hydrological cycle and are typically used as an indicator for climate change evaluation on the water supplies available to Iran now and particularly in the future [Donyaii et al. 2020]. Based on the IPCC Fourth Assessment Report Models [AR4], a number of studies have been undertaken to examine the effect of climate change on the hydrological components of watersheds in Iran. In contrast with the Fifth Assessment Study [AR5] models, these models, along with older pollution scenarios, have limited resolution. Therefore, in the watersheds of Iran, climate change experiments with higher resolution climate models under the latest pollution scenarios [RCPs] of the AR5 seem appropriate. According to historical evidence of Gorganroud's high flood capacity in the province of Golestan, Iran, the recognition of the impact of climate change on the watershed's hydrological regime is important for water resource planners. 2- Methodology 2-1- Study area and data set The Gorganroud Watershed is located in Golestan Province, Iran. In this study, the Soil and Water Assessment Tool [SWAT] was employed for hydrological simulation of the watershed based on the downscaled outputs [using the Bias Correction and Spatial Disaggregation [BCSD] method] of fifth assessment report climate change model [MIROC-ESM] for historical and future periods. The trend analysis of hydro-climatic records was done according to the non-parametric Mann-Kendall test. The future projection was conducted for the near [2025-2050], mid [2051-2075], and far [2075-2100] future periods related to historical records in the period of 1985-2005. 2-2- SWAT set-up and calibration, validation and uncertainty analysis In this study, runoff was estimated using the Soil Conservation Service [SCS] method. The Manning equation and Muskingum method were utilized to calculate flow velocity and routing phase, respectively. On the other hand, the SUFI-2 algorithm was employed to calibrate and analyze the sensitivity, and uncertainty of the SWAT model. The sensitivity analysis is based on linear approximation and the degree of uncertainty is calculated by two factors called r-factor and P-factor. The calibration and validation were performed using runoff data in the periods of 1995-2015 and 2016-2019, respectively. The coefficients of determination [R2] and Nash-Sutcliffe [NS] were used as the objective function to determine the goodness of fitness. 2-3- Climate Change scenarios and AR models In the AR5 new emission scenarios based on emission forcing level until 2100 were employed. In order to investigate the future climate change, the Model for Interdisciplinary Research on Climate-Earth System Models [MIROC-ESM] was selected among the newest extracted models presented in the AR5, because the result of this model in Gorganroud watershed showed the highest agreement with observational data. This model consists of four emission forcing scenarios [RCP2.6, RCP.4.5, RCP6.0 and RCP8.5. 3- Results and Discussion 3-1- SWAT sensitivity analysis, calibration and validation analysis Seventeen parameters were chosen for SWAT sensitivity analysis using the 500 simulations of SUFI-2. Results showed that the parameters CN, SOL_BD and SOL_K have the highest relative sensitivity. Based on the results, the coefficients R2 and NS for runoff simulation were estimated to be 0.79-0.77 and 0.74-0.71 in the calibration and validation stage, respectively. Therefore, the results of the model are acceptable and its uncertainty metrics is satisfactory in general. The study results showed that the model has estimated the amount of peak discharge less than the actual amounts, which is confirmed by the average monthly simulated discharge during calibration and validation periods. The results also showed that more than 50% of the observational data in both calibration and validation phases are bracketed by the 95PPU uncertainty estimation band, which indicate a rather acceptable degree of certainty in simulation. 3-2- Climate change simulation results and trend analysis In the near and mid-future, there are increasing changes under the RCP2.6 scenario, but the trends of rainfall are not statistically significant at the 5% level. In the far- future a significant increasing trend is observed under the RCP2.6 scenario, meanwhile in far-future under the RCP4.5 scenario there are increasing changes, but the trends are not statistically significant. In the mid and far future under the RCP6.0 scenario, a significant increasing trend has been observed. Finally, in the mid- future under the RCP8.5 scenario, there is a significant increasing trend. However, the increasing changes in the near and far-future periods are not statistically significant at the confidence level of 95%. The trend analysis of variables indicates that the amount of rainfall will decrease in this watershed during the future periods by the end of the 21st century. The most decreasing alterations in the rainfall and the highest increase in the temperature are achieved under the highest concentration of greenhouse gases [RCP8.5]. Moreover, in the near, mid, and far future, the runoff changes are decreasing under the RCP2.6 scenario, but the trend is not statistically significant. In the mid and far-future periods under the RCP4.5 scenario, there is a statistical significant decreasing trend in runoff; however, the decreasing variation in the near future is not significant. In the near, mid, and far future under the RCP6.0, runoff variations are declining, but the trend is not statistically significant. In the far-future period, under the RCP8.5, there is a significant decreasing trend; however, in the near and mid-future, runoff declining changes are not statistically significant. Reduced rainfall and increased temperature in the watershed will reduce the rate of runoff in the future periods in such a way that the security of the inhabitants of the region will be severely affected. 4- Conclusions Results of evaluation criteria [R2 and NS] showed that the SWAT performance for the simulation of runoff in the Gorganroud watershed was not satisfactory, but it was in an acceptable range. Climate change simulation indicated a decreasing trend for rainfall in all future periods, but this trend was not statistically significant. The temperature variable in all RCPs had an increasing trend. However, temperature trend analysis under the RCP4.5 scenario during the near and mid- future and under the RCP6.0 scenario during the near, mid, and far-future showed a significant upward trend. Runoff under the RCP4.5 scenario during the mid to far-future and under the RCP8.5 scenario during the far-future period followed a significant downward trend. Runoff during the near-future period under the RCP4.5 scenario and throughout the near to mid-future under the RCP8.5 scenario, had declining variations, but its trend was not statistically significant. In general, these results indicated that the amount of temperature will follow an increasing tendency; while rainfall and runoff will follow a decreasing movement in this watershed by the end of the 21st century.
Zohreh Maryanaji; Abozar Ramezani
Abstract
1- Introduction Natural hazards cause enormous damages every year. Among the natural hazards, floods, earthquakes, and droughts have special importance in financial and human losses. Meanwhile, according to the available statistics and information, floods in some parts of the world, especially in Asia ...
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1- Introduction Natural hazards cause enormous damages every year. Among the natural hazards, floods, earthquakes, and droughts have special importance in financial and human losses. Meanwhile, according to the available statistics and information, floods in some parts of the world, especially in Asia and Oceania, have the highest damage. Iran is one of the arid and semi-arid regions of the world with particular climatic conditions. Inappropriate spatiotemporal distribution of rainfall in such regions has caused devastating floods. In this study, flood vulnerable areas are identified by determining the effective parameters of flood using Shannon entropy model. The results of this study can be used in flood zoning and forecasting and planning and management of water resources in the region. 2- Materials & Methods In multi-criteria decision-making problems having and knowing the relative weights of the existing indicators is a significant step in the problem-solving process. (Relations 1 to 6). (1) Aij= (2) (3) (4) Ej= i=1,2…,m (5) wj=dj/∑dj (6) wj= Entropy method is one of the multi-criteria decision-making methods for calculating the weight of criteria. This method requires a criterion-option matrix. The steps of Shannon entropy method consist of five steps of the decision matrix, normalization of the decision matrix, calculation of the entropy of each index, the calculation of deviation, and calculation of weight value Wj. In the Shannon method using the experience and knowledge of experts appropriate factors are determined and weighed. After collecting the questionnaire data and considering the geography of the study area, the scores of each factor are adjusted. 3- Results & Discussion Natural parameters of flood occurrence in Hamadan province include: climate, snowmelt, slope, soil type, Gravilius coefficient, and vegetation. Due to the climatic characteristics of the province, most of the province's rainfall is due to the Mediterranean systems. In winter, the rains are in the form of snow, and in the early spring the melting of snows is accompanied by spring rains which most of the time causes the rivers to overflow. Due to the severe destruction of vegetation in the province, the potential of the region in flooding has been increased. In general, it can be said that the occurrence of floods in any region is due to the confrontation and alignment of human and natural factors. This study only examines the natural causes of flood. The study of the effect of each parameter in the occurrence of floods based on the data-expert method showed that the six factors studied in these studies do not have the same effect on reducing or increasing floods in the basins. 4- Conclusion Based on scoring the natural factors that cause floods, according to the intensity of their impact, the flood-prone areas of the province have been identified. Based on the combined data model and Shannon entropy, the highest weighting was given to the maximum 24-hour precipitation. Vegetation factors, snow melting time, basin slope, soil type and Gravilius coefficient were identified as the most effective natural factors in causing floods in Hamadan province, respectively. Based on the final weights, a hazard map was drawn using the GIS. According to the hazard map, the very high risk regions are located in the central and southern parts of the province. Also, the northern areas including the cities of Razan, Kaboudar Ahang and Dargazin are located in high risk area. Using the results of this study, it is possible to identify the approximate time of flood occurrence and flood-prone areas in Hamedan province.
Mohammadjavad Vahidi; Rasoul Mirabbasi Najafabadi; Mohsen Ahmadi
Abstract
1- Introduction Soil erosion has significant environmental impacts and economic losses on crops and reservoir capacity, and affects water quality both directly and indirectly (Issaka and Ashraf, 2017: 3). Therefore, identifying factors affecting soil erosion and ranking the prevention methods in rural ...
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1- Introduction Soil erosion has significant environmental impacts and economic losses on crops and reservoir capacity, and affects water quality both directly and indirectly (Issaka and Ashraf, 2017: 3). Therefore, identifying factors affecting soil erosion and ranking the prevention methods in rural areas provide valuable information for managers and planners for soil conservation (Asadi et al., 2016: 99). Soil erosion, on the one hand, is affected by natural features and, on the other hand, by human activities. The type of precipitation regime and water erosion, erosion-sensitive formations, low natural vegetation cover, topographic conditions of natural factors, incorrect use or overuse of lands, poor pasture grazing, plowing of low-yield rainfed fields, and implementation of construction projects, such as road construction, building construction, and mining, without considering the principles of soil protection are the factors caused by human intervention in the country (Darabi et al., 2018: 201). The most appropriate scientific methods can be selected to prevent soil erosion in accordance with the opinion of relevant experts and scientists. Another important issue is the use of appropriate criteria and sub-criteria to obtain final responses. In fact, if the study method is selected properly, but the criteria and sub-criteria used are not of the desired quality, the results are not reliable and the final output will cause deviations in the final decision. Therefore, it is necessary to extract all required criteria and sub-criteria from the research literature and validate them by experts. Among the methods used to control soil erosion are contour plowing, mulching, mixed cultivation, adding organic fertilizers and manure, grass cultivation, terracing, and cultivation on contour lines (Begum Nasir Ahmad et al., 2020: 104). Darmian County is one of the important agricultural centers of South Khorasan province. As reported previously, 93.3% of the total area is in the severe desertification class (Parvaneh, 2009: 150). According to most studies on multi-criteria decision making techniques (MCDM), the VIKOR technique results in a lower percentage and intensity of changes and yields more valid results (Nazmfar and Padarvandy, 2015: 36; Kim and Ahn, 2019: 126). Therefore, this technique was used in the present study. Keshtkar et al. (2017: 133) conducted a study with the aim of prioritizing the biological management options of Delichay watershed using MCDM. They identified four biological management activities and developed 16 management scenarios in the region. Also, the social, ecological, economic, and physical criteria were assigned the first to fourth priorities, respectively, and scenario number 10 (grazing management and pit-seeding) was determined as the top scenario in the first priority. Vulević et al. (2015: 317) prioritized soil erosion vulnerable areas in the Topčiderska River Watershed, northern Serbia, using multi-criteria analysis methods, and identified the most vulnerable sub-basins due to a significant presence of arable and very steep arable lands, which, therefore, had priority for protection. Also, Zhang et al. (2020: 1331) identified priority areas for soil and water conservation planning using multi-criteria decision analysis in the Xinshui River watershed, China. They selected six assessment indicators, including slope gradient, precipitation, NDVI, land use, soil texture, and slope aspect. They concluded that more attention should be paid to the slope of farmland and grassland during the planning and management of soil and water conservation projects. Darmian County is an important region in terms of agricultural and horticultural products and severe erosion that threatens the products and natural resources in rural areas. In this research, therefore, an integrated approach based on the multi-criteria decision making methods, including Best-Worst (BWM) and the VIKOR methods, is presented according to expert’s opinions to analyze the factors affecting soil erosion and ranking the prevention methods in the rural region of Darmian, South Khorasan Province. 2- Methodology In this study, the weights of the identified criteria and sub-criteria from the research literature and experts’ opinion were first determined using the BWM and then the VIKOR method was used for ranking the erosion prevention methods. According to the review of the literature, many methods have been proposed to rank the methods of preventing soil erosion. However, these methods usually have a relative level of uncertainty due to a high level of decision maker involvement in the production of final answers. However, the best-worst method has a very strong approach in determining the weight of criteria compared to other decision-making methods (Rezaei, 2016: 126). Best-worst method: This is one of the powerful methods in solving the multi-criteria decision making problems used to obtain the weights of options and criteria (Rezaei, 2016:126). This method compensates for the weaknesses of methods based on pairwise comparisons (e.g., AHP and ANP) such as incompatibility. In addition, it reduces the number of pairwise comparisons significantly by only performing reference comparisons. In recent years, the best-worst method has been used by many researchers to determine the weights and rankings of options in various fields. VIKOR method: This method is an adaptive ranking technique that is often used in situations with different conflicting criteria (Opricovic, 1998: 5). This method creates a compromise solution based on "proximity to the ideal solution and mutual agreement through concessions". This method has been widely used by many researchers to rank options (Arab Ameri et al., 2018: 1400; Gupta, 2018: 47; Opricovic and Tzeng, 2004: 445). It uses linear normalization that specifies a summation function indicating the distance from the ideal solution. 3- Results and Discussion The criteria and sub-criteria used in this research (based on a review of the research literature) are presented in Table 1. Table (1): The criteria and sub-criteria affecting soil erosion Sub-criteria Criteria Sub-criteria Criteria Aggregate stability Technical Destruction of vegetation Environmental Water penetration capacity Surface water flows Depth of soil Runoff volume Clay particles Chemical Destruction of ecosystems Soil organic carbon content Drought Climatic Non-use of livestock manures Social Fire Rainfall Overgrazing Land slope A consensus method was used to achieve valid results, as for gathering information, a committee of experts was asked to evaluate the performance of the options against the criteria (Table 1) using the scales listed in Table 2. Table (2): Verbal scale for pairwise comparisons of best-worst methods and Victor techniques Scale for the best- worst approach EquallyImp. Equal to moderately Imp. Moderately Imp. Moderately to strongly Imp. Strongly Imp. Strongly to very strongly Imp. Very strongly Imp. Very strongly to extremely Imp. Extremely Imp. 1 2 3 4 5 6 7 8 9 Scale for Victor technique Verbal expressions Degree of Imp. for negative effect criterion Degree of Imp. for positive effect criterion Least Imp. 5 1 Moderately Imp. 4 2 Strongly Imp. 3 3 Very Strongly Imp. 2 4 Extremely Imp. 1 5 P.S. Imp. = Important Calculating the weights of the criteria using the best-worst method Out of all the criteria, the best and worst criteria were selected by experts through mutual agreement. The priority of other criteria was also determined by the worst criteria. After collecting the best-worst method questionnaires, the weights related to the criteria and sub-criteria were obtained using the GAMS optimization software version 24.3 by the BARON solver. The degrees of priority for all the criteria were achieved to calculate the optimized local weights. The results showed that the "technical" and the "chemical" criteria had the highest (0.293) and the lowest (0.085) local weights, respectively, among all the examined criteria. Prioritization of erosion prevention methods using the VIKOR method After achieving the weights of the criteria, the methods of erosion prevention were prioritized in the next step based on the weights of these factors using the VIKOR method. According to the computational results, the technical and the chemical criteria (with scores of 0.293 and 0.085) had the highest and the lowest ranks, respectively. In the final prioritization of the erosion prevention methods, Biochar and injection of organic maters were in the first and second ranks, respectively, and artificial rain was at the lowest rank. 4- Conclusion In this research, a new combined approach is presented based on the best-worst method and VIKOR technique to identify the factors affecting soil erosion and to rank the prevention methods based on the opinions of experts and scientists in the field of agricultural development. According to the obtained results, "technical", "climatic", and "environmental" sub-criteria are the three important factors in evaluating erosion prevention methods. In the next step, the options were finally ranked using the VIKOR method, indicating that the top three options are "Biochar", "Arch planting", and "injection of fertilizers and organic matter", respectively. Considering that the development of infrastructure to select scientific methods to prevent soil erosion in rural areas is one of the effective factors in the development of agricultural science in the country, studies in this area should be given more attention. It is expected that the results of this research can provide a suitable tool for managers to make correct decisions.
RS
Abstract
Changes in land cover and land use due to human activities have left adverse effects on the environment. The eastern regions of Ardabil province are a clear example of this phenomenon. The purpose of this research is to analyze spatial and temporal changes in land cover and land use and its effects on ...
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Changes in land cover and land use due to human activities have left adverse effects on the environment. The eastern regions of Ardabil province are a clear example of this phenomenon. The purpose of this research is to analyze spatial and temporal changes in land cover and land use and its effects on the temperature of the surface of the earth in Lake Neor. To estimate land use and land cover, random forest models (RTC), maximum likelihood model (MLC) and support vector machine (SVM) were used and the efficiency of each was estimated by the Kappa coefficient and it was observed that the SVM model has the highest Kappa coefficient (0.87) Bands 6, 5 and 10 of Landsat 8 were also used to extract the LST index, and it was observed that the western part of the lake faced an increase in the temperature of the earth's surface. During the time period of 2002, 2013 and 2022, significant changes were observed in the water area of Neor Lake and its nearby vegetation. Barren lands had the largest extent in all studied periods. Vegetation has increased by 1.04 square kilometers based on SVM model. The surface area of the lake was estimated as 3.19 square kilometers based on the MLC model in 2002. The area of the water zone in the MLC model has decreased by 1.56 square kilometers between 2002 and 2022, and this decrease is 0.67 and 0.69 square kilometers for the RTC and SVM models, respectively.
RS
Abstract
Extraction of the water zone in the western parts of Afghanistan through remote sensing images is an efficient way to investigate and monitor water resources and its impact on the water resources of eastern Iran, especially the wells of Sistan and Baluchestan. In this research, from OLI sensor of Landsat ...
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Extraction of the water zone in the western parts of Afghanistan through remote sensing images is an efficient way to investigate and monitor water resources and its impact on the water resources of eastern Iran, especially the wells of Sistan and Baluchestan. In this research, from OLI sensor of Landsat 8 satellite and TM sensor of Landsat 5 satellite, Normalized Difference Water Index (NDWI), modified Normalized Difference Water Index (MNDWI), normalized difference moisture index (NDMI), automated water extracted index (AWEI), new water index (NWI), and water ratio index (WRI) have been used to extract water areas. In the worst case, the area of the Arghandab dam has decreased by only 2.44 km upstream and the NDMI index has shown an increase of 0.65 square km in the moisture resources of this dam. However, the surface of the well in the southern half of Zabul has decreased from 55.94 square kilometers to 17.82 square kilometers, which shows a decrease of 38.12 square kilometers. This shows a sharp decrease in the level of the semi-well. This has caused more heat to be emitted in the dry areas. But the minimum temperature has decreased from 17.47 degrees to 11.87 degrees Celsius, which has experienced a decrease of 1.95 degrees Celsius. The LST index has a negative correlation with all the indices and the highest correlation with the NWI index was -0.941 in 1994. The lowest correlation was also obtained at the rate of -0.65 related to the NDMI index.
Geomorphology
leila aghayary; sayyad Asghari Saraskanrood; Batool Zeynali
Abstract
control and monitoring solutions. By using field studies, geological and topographical maps, and by reviewing the researches and studies done in this field, as well as examining the existing conditions in the studied area, 9 factors of elevation, slope, slope direction, lithology, distance from the fault. ...
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control and monitoring solutions. By using field studies, geological and topographical maps, and by reviewing the researches and studies done in this field, as well as examining the existing conditions in the studied area, 9 factors of elevation, slope, slope direction, lithology, distance from the fault. , the distance from the river, the distance from the communication roads, land use and rainfall were investigated as factors affecting the occurrence of landslides. Therefore, the purpose of this research is to investigate and analyze the most important factors involved in creating the risk of landslides in Garami city and to identify the prone areas that will probably be involved in landslides in the near future. In this research, the zoning of prone areas was done with the Aras multi-criteria algorithm in the Edrisi software environment, and according to the results of landslide risk zoning; The criteria of land use, slope, and lithology are the most important factors involved in creating the risk of landslides in the study area with weight coefficients of 0.187, 0.152, 0.152, and 0.142, respectively, and are 361.99 and 450.32, respectively. A square kilometer of the area has a very high probability of danger. Finally, it can be said that the most important factor involved in increasing the amount and potential of landslides in Germi city is the change of land use and the increase of agricultural land and livestock pastures.
Hydrology
Raoof Mostafazadeh; Mostafa Zabihi Silabi; Mohamad Kazemi
Abstract
The increasing human needs and changes in climate patterns have led to the construction of water storage structures to meet the water demand in many regions worldwide, including Iran. Consequently, the hydrological regimes of rivers in various parts of Iran, due to human activities such as dam construction, ...
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The increasing human needs and changes in climate patterns have led to the construction of water storage structures to meet the water demand in many regions worldwide, including Iran. Consequently, the hydrological regimes of rivers in various parts of Iran, due to human activities such as dam construction, have undergone alterations in recent decades. Understanding the effects of dams on river hydrological regimes is essential for river flow management and the preservation of river ecosystems. In this regard, the present study assesses the changes in the health of the Urmia's Shahrchai River flow during three periods: pre-dam construction, dam construction, and dam operation, from 1951 to 2017, through calculating different flow health related indices. The results indicate that the deviation of all hydrological health sub-indices in the post-dam construction period is higher than the pre-dam construction period. Moreover, the deviation of flow regime sub-indicators was predominantly low to moderate until 1998 and varied from low to very high after 1998. Additionally, the highest deviation of studied flow health-related indices occurred during the reference and dam operation periods for flood occurrence and minimum monthly flow, respectively, while during the dam construction period, it pertained to minimum monthly flow. Furthermore, the findings suggest that the hydrologic health of Shahrchai River flow decreased by approximately 16% and 45% during the dam construction/operation periods, respectively, compared to the reference period. The results of this study can be utilized in the understanding of flow alteration and the sustainable regulation of the Shahrchai River flow regime.
Hydrogeomorphology
Masoumeh Rajabi; Fatemeh Rangraz Forough
Abstract
There are various types of tourism depending on the motivation for travel, one of which is health tourism. Health tourism has grown significantly in recent years due to the spread of machine life and psychological pressures. This type of tourism includes individuals and groups who travel for medical ...
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There are various types of tourism depending on the motivation for travel, one of which is health tourism. Health tourism has grown significantly in recent years due to the spread of machine life and psychological pressures. This type of tourism includes individuals and groups who travel for medical treatment, such as using mineral and warm waters, spending time in recovery, and so on. As one of the natural resources, hot springs are a part of health tourism that are used to treat various medical conditions. The current research focuses on the hot springs of East Azerbaijan province. The study is descriptive-analytical in terms of methodology and applied in terms of purpose. Due to its geographical location, climatic features, and geological and tectonic conditions, East Azerbaijan province is considered one of the important centers of hot springs, which are concentrated around Sahand mountain and Bozgoush mountain range in the northeast of Kalibar. This research uses the Comanescu method, library research, Internet-based surveys, documentary studies, and surveys of 20 experts from the Regional Water Organization and the Provincial Tourism Department, Motalleq Hot Springs, Bostan Abad, Asbforoushan, Allah. Haq, Isti Su Liqvan, Yel Sui, Top Tapan, and Dash Alti were selected and evaluated. The results revealed that the Motalleq Hot Spring, with a total score of 86, has the highest score among the eight selected springs. The Asbforoushan hot spring comes in second with 84 points, the Yel Sui hot spring comes in third with 82 points.
Geomorphology
Jamshid Yarahmadi; Mohammad Khosroshahi
Abstract
The extended periods of drought, decrease in vegetation, and enlargement of the salt playa at Lake Urmia have resulted in the formation of local dust hotspots on the periphery of Lake Urmia in East Azarbaijan province. The objective of this study was to examine the spatial and temporal distribution of ...
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The extended periods of drought, decrease in vegetation, and enlargement of the salt playa at Lake Urmia have resulted in the formation of local dust hotspots on the periphery of Lake Urmia in East Azarbaijan province. The objective of this study was to examine the spatial and temporal distribution of wind erosion in East Azarbaijan province using the DSI index. To achieve this, a set of weather data recorded over the past 30 years at specific codes in meteorological stations was compiled. Subsequently, the Mann-Kendall test was employed to assess the presence of a trend in the data series. Following this, the frequency of dust storms was calculated using the DSI index, and a spatial distribution map was generated in the GIS. The results of the Mann-Kendall test indicated that the slope of the trend for both local and extra-local dust storms in the province is on the rise. However, only the trend in extra-local dust storms is statistically significant at the 95% confidence level. The findings of the research revealed that the majority of the observed dust storms originate from outside the local area in East Azarbaijan province. Nevertheless, there has been a relative increase in the frequency of local dust storms in recent years, which can be attributed to the prolonged droughts resulting in reduced vegetation and the expansion of the playa of Lake Urmia. In this context, the highest frequency of dust storms has been observed at the Tabriz, Sahand, and Maragheh meteorological stations near Lake Urmia.
Hydrogeomorphology
Mohammad Hossein Rezaei Moghaddam; Davoud Mokhtari; meysam skandarialni
Abstract
Hydrological models are an effective tool for managing water resources as well as water balance components among research works. Today, basin hydrological models have been developed, but choosing the right model to simulate a specific basin has always been a challenge. Therefore, it is necessary to choose ...
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Hydrological models are an effective tool for managing water resources as well as water balance components among research works. Today, basin hydrological models have been developed, but choosing the right model to simulate a specific basin has always been a challenge. Therefore, it is necessary to choose a model that can simulate the hydrological processes with the simplicity of the structure and using minimal factors. Northwest Iran was simulated by AWBM and SWAT models. The AWBM model is an integrated model that simulates the runoff in catchment areas using two variables, rainfall and evaporation, and on the other hand, the SWAT model is a continuous and semi-distributed model that simulates hydrological processes using the physical characteristics of the basin (soil, land use, slope) as well as several water and meteorological information such as rainfall, temperature. The results of runoff simulation in the calibration and validation periods were evaluated using two Nash Sutcliffe statistical indices (NSE) and R2 coefficient of determination. By comparing the results of the statistical indicators used in the study, it was found that the SWAT model has better results in the simulation of monthly runoff in the validation and validation periods.
Geomorphology
maryam bayatikhatibi
Abstract
The long-term effects of the existing stations in the Urmia Lake watershed were investigated. In order to identify the origin areas of fine walnut production and track dust storms in the studied area, horizontal visibility data below 1000 meters of meteorological data and Lagrangian HYSPLIT model in ...
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The long-term effects of the existing stations in the Urmia Lake watershed were investigated. In order to identify the origin areas of fine walnut production and track dust storms in the studied area, horizontal visibility data below 1000 meters of meteorological data and Lagrangian HYSPLIT model in retrograde mode were used at different stations and at different levels of the atmosphere. It was used regularly and also the highest amount of dust containing 26 pressure tsars (100-1000 hectopascals) and available with a time step of 12 hours. At the same time as the first dust entered the study area, the wind direction was investigated for 24 hours before that. In the studied area (Banab and Malekan cities), the focus of wind erosion was investigated using AOD data from MACC database with a spatial accuracy of 0.125 × 0.125 geographic degrees and a daily time scale. In this study, MODIS Terra and Aqua satellites with a wavelength of 550 nm were used to generate AOD data. Day-by-day review of MODIS satellite images and the implementation of the fine dust characterization index revealed the occurrence of specific dust storms over Urmia Lake and southeast of the lake on different days. Investigations showed that extensive salt dust spreads in all parts of Lake Urmia, including the southeast of the lake in the limits of Bonab city, and the dust in this part is spread in the bed of atmospheric currents to the east and southeast for a distance of more than 140 km.
Hydrogeomorphology
Aghil Madadi; sayyad Asghari Saraskanrood; Hossein Hajatpourghaleroodkhany
Abstract
the purpose of this research is to reveal the changes in land use and the destruction of forest cover and its effects on soil erosion in the watershed of Ghaleroodkhan Fuman.In the next step, using the object-oriented classification method and the nearest neighbor algorithm by eCognition software, land ...
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the purpose of this research is to reveal the changes in land use and the destruction of forest cover and its effects on soil erosion in the watershed of Ghaleroodkhan Fuman.In the next step, using the object-oriented classification method and the nearest neighbor algorithm by eCognition software, land use maps were extracted in 1992 and 2023. In the next step, by identifying the effective factors involved in the erosion of the area and preparing the information layers of each criterion in GIS, the valuation and standardization of the layers were done using the fuzzy membership function and the weighting of the criteria, using the CRITIC method. Eventually; The final analysis was done using the MARCOS method. The forest cover of the studied area has experienced a decrease of about 1700 hectares in its area. Also, residential use with an increase of 27.17 square kilometers has changed the most during the 30-year period of study. In addition, the most important land use change in the basin has been the destruction of forests and their conversion to agricultural lands, pastures and settlements, as well as the conversion of agricultural lands to residential areas, and this method of land use change and conversion, along with other natural factors in the area, Such as; The distribution of loose and erodible formations, high slope, adequate rainfall and the abundance of river have played the greatest role in increasing the soil erosion potential of the Ghaleroodkhan basin.
