پژوهشی
Mohammad Hossein Rezaei Moghaddam; Davoud Mokhtari; Nasrin Samandar
Abstract
Land use change is one of the important factors in changing the hydrological flow, basin erosion and biodiversity destruction. Therefore, knowing the effect of land use change on discharge and suspended load is an inevitable necessity. The main purpose of this study is the efficiency test of the model ...
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Land use change is one of the important factors in changing the hydrological flow, basin erosion and biodiversity destruction. Therefore, knowing the effect of land use change on discharge and suspended load is an inevitable necessity. The main purpose of this study is the efficiency test of the model and its usability as a simulation of the process of land use change on discharge and sediment is from the soil and water assessment model (SWAT) and SUFI2 program. Model simulation was performed for 29 years from 1987 to 2015, the first 5 years of which were selected for model calibration and the last 5 years for model results validation. Four statistical indices, r_factor, P_factor Nash-Sutcliffe (NS) and coefficient of determination (R2), the ratio of squared root-to-standard deviation (RSR) and the percentage of skewness (PBIAS) were selected monthly to evaluate the model. The accuracy of monthly simulation using NS evaluation index in the calibration and validation stage for flow and suspended load is equal to 0.65 and 0.49, respectively. The results of the study were considered acceptable according to the interpretive domains used in previous studies and indicate the satisfactory efficiency of the SWAT model in simulating the components of the impact of land use change on sediment and discharge in the Ojan Chay Bostanabad watershed. The results showed that the height of surface runoff increased by 1.15 mm and the sediment concentration increased by 1.5 tons per hectare per year.
پژوهشی
sayedeh masumeh mousavi; Mohammad Hossein Rezaei Moghaddam; Masumeh rajabi
Abstract
Landslides claim the lives of thousands of people around the world each year, causing enormous damage to people and governments. Landslide risk zoning divides landslides into specific and distinct areas of potential and actual degrees in terms of risk, this process is based on recognizing the qualitative ...
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Landslides claim the lives of thousands of people around the world each year, causing enormous damage to people and governments. Landslide risk zoning divides landslides into specific and distinct areas of potential and actual degrees in terms of risk, this process is based on recognizing the qualitative characteristics of the area and quantitative modeling based on the data of the study area. This can be the basis for long-term planning at the regional and local levels.The purpose of this study is to investigate and zoning landslide risk in the Yellow River Basin located in the east of Khuzestan province using fuzzy logic method; For this purpose, first through field visits, geological maps and topography and by reviewing previous sources and reviewing the conditions of the region; Nine factors: elevation, slope, direction of slope, distance from fault, distance from river, distance from road, precipitation, lithology and land use were considered and selected as effective factors on landslide occurrence. Landslide hazard zoning maps were prepared using fuzzy gamma operator with values of 0.7, 0.8, 0.9. Then, the obtained maps were classified into 5 classes: very high, high, medium, low and very low.The results of the qualitative sum showed that the 0.9 fuzzy gamma operator is more suitable than other fuzzy operators. The results of the classified maps showed that 21.56% of the area in the high-risk zone and 43.24% of the area The area is located in a low risk zone.
پژوهشی
Geomorphology
heeva elmizadeh; Hadi Mahdipour
Abstract
The purpose of this research is the automatic recognition of morphic patterns of drainage network in the center of Qeshm Island using High Resolution Panchromatic Remotely Sensed (HR-PRS) and fuzzy clustering algorithms. It also investigates the efficiency of these methods in the GeoEye-1 satellite imagery ...
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The purpose of this research is the automatic recognition of morphic patterns of drainage network in the center of Qeshm Island using High Resolution Panchromatic Remotely Sensed (HR-PRS) and fuzzy clustering algorithms. It also investigates the efficiency of these methods in the GeoEye-1 satellite imagery segmentation of the study area in order to detect geomorphic features in areas with cloud and shadow coverage. In this regard, fuzzy segmentation of HR-PRS panchromatic images of the study area, after radiometric and geometric preprocessing using FWS, MSA, IDF and CFM algorithms, was performed in MATLAB software. Finally, the studied fuzzy clustering algorithms with fuzzy parameters are applied to the input HR-PRS images and the results are discussed. The results show that the Classical Fusion Method and FCM (CFM) clustering algorithm has the best performance in the field of fuzzy segmentation and detection of the studied indices. . As a result, the image borders are well defined. The reason for this is the use of fuzzy numbers as well as efficient clustering methods in this method. These results also show that remote sensing technology, by providing multi-time images, can be a very good basis for monitoring and detecting environmental changes, detecting effects and accurately extracting information from images. Also, the use of clustering algorithms and fuzzy features is a suitable and optimal method for integrating HR-PRS satellite image information from a geographical area with the aim of segmentation.
پژوهشی
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.
پژوهشی
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
مطالعه موردی
Geomorphology
vahid rahmatinia; Bakhtiar Feizizadeh
Abstract
In this study, 5 main DEM derivatives of 12.5 m ALOS satellite (slope layer, slope direction layer, curvature layer, cumulative flow layer and altitude layer) as well as Sentinel-2 satellite images and NDVI vegetation index were used as auxiliary layers. Segmentation in this area was performed using ...
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In this study, 5 main DEM derivatives of 12.5 m ALOS satellite (slope layer, slope direction layer, curvature layer, cumulative flow layer and altitude layer) as well as Sentinel-2 satellite images and NDVI vegetation index were used as auxiliary layers. Segmentation in this area was performed using segmentation multi resolation method. In this segmentation, the height layer was given a value of 3, the curvature layer was given a value of 2, and the other layers were given a value of 1. Then, using Layer Values and Geometry algorithms and assign class commands, landforms located in the western and southwestern slopes of Zagros (Aligudarz city area) have been classified. The results showed that the use of Layer Values and Geometry algorithms and assign class commands have a good ability to isolate and classify landforms, so that 8 types of landforms (slopes, ridges, water areas, precipices, peaks, ridges, lowlands and lowlands) Kappa coefficient was 0.87 and overall accuracy was 91.71%. The ridge landforms form the largest part of the region and are the dominant landforms of the region and have a good distribution in different parts, but the peak landforms with the minimum area have formed only a limited part of the study area.
پژوهشی
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.
پژوهشی
Hydrogeomorphology
Ehsan Alvandi
Abstract
In this research, Modeling the effects of management Actions to improve the status of water and soil resources of Tuyserkan watershed in mDSS software environment have been studied.For this purpose, first, the status of the watershed system was analyzed through the DPSIR approach.In order to predict ...
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In this research, Modeling the effects of management Actions to improve the status of water and soil resources of Tuyserkan watershed in mDSS software environment have been studied.For this purpose, first, the status of the watershed system was analyzed through the DPSIR approach.In order to predict the effects of each management activity from the indicators obtained from Four physical, social, economic and ecological criteria were used.Finally, in order to prioritize the proposed management activities, TOPSISand SAWtechniques have been used in the mDSS software environment.According to the results of the DPSIR approach, the most important pressures affecting the system Land use change,Capture and vegetation loss have been introduced.Also one of the most important effects on the status of the watershed system is the criteria for vegetation loss, reduced groundwater recharge and increased risk of flood damage.Finally, according to the results of the DPSIR approach, to improve the status of water and soil resources A set of solutions for biological rangeland improvement and biomechanical operations to store rainfall in the basin was proposed.According to the opinions of experts and environmental conditions of the region from a set of solutions for biological improvement of rangeland and biomechanical operations Seven management activities(Rangeland exclusion,Afforestation,Orchard development,Forage cultivation,Contour furrow,Pile seeding and Seeding)were selected to store rainfall.According to the results obtained from the prioritization of management activities in all proposed methods,Afforestation activity has the highest score and is in the initial priority and the activity of Contour furrow has the lowest score and Is in the final priority.
