Geomorphology
Leila Khodaei Geshlag; shahram roostaei; Davod Mokhtari; Khalil Valizadeh Kamran
Abstract
Introduction Risk management and landslide assessment begin with a comprehensive identification and monitoring of their movements and mapping them, which can be used as a basis for achieving knowledge about their spatial and temporal distribution. The integrated vision of the radar remote sensing images ...
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Introduction Risk management and landslide assessment begin with a comprehensive identification and monitoring of their movements and mapping them, which can be used as a basis for achieving knowledge about their spatial and temporal distribution. The integrated vision of the radar remote sensing images has made them a powerful tool for preparing distribution maps, assessing the risk of landslides, and evaluating the instabilities reoccurring at various time intervals. Therefore, this study aimed to identify, monitor, and measure the extent to which the region is at the risk of slope instabilities in the period of 2009-2011 in the Ahar-Varzeghan region in the Ahar Chay heights using the Interferometry Synthetic Aperture Radar (InSAR) technique. Data and Method The studied area is a part of Ahar Chay watershed with an area of 1593 km2, which makes it the largest watershed in the East Azerbaijan province. The said area has an east longitude of 35´ 46° to 10´ 47° and north latitude of 20´ 38° to 45´ 38°. This area is located on northern slopes at an altitude of more than 2730 m, and in the Alpaut and Chaligh areas with an altitude of less than 1260 m. Various types of data were used in this research, including radar imagines, ENVISAT-ASAR, and data captured by Global Positioning System (GPS) in field research. Besides, topographic maps of 1.25000 associated with the country's land surveying organization and geological maps of 1:250000 related to the country's geological and mineral exploration organization were used to examine the area's geology and morphology. Besides, SAR scape ENVI4.8 and Arc/GIS software environments were used to prepare and process radar images, and provide the displacement maps associated with the landslides. INSAR is a remote sensing technique developed to study the earth's surface movements in the 1992 Landers, California earthquake. When this technique is adopted, two or more SAR images are used to generate a digital elevation model or prepare a map of the movements of the earth's surface. Also, this technique measures the phase difference between two different waves, and this phase difference is attributed to the change in the distance between the sensor and the earth target or the movements of the earth's surface. SAR images show the movements of the earth's surface in the direction of the satellite's line of sight. However, SAR images can be used in both ascending and descending modes, which enable them to measure the earth's surface movements in three directions: vertically, from the north, and east. The following steps must be taken to measure the movements of the earth's surface and/or develop a digital elevation model using the InSAR technique: SAR image formation: - Interferogram generation - Ambiguous phase extraction - Phase recovery in the generated interferogram - Elimination of the effect of the topographic phase on the interferogram - Displacement phase extraction Results and Discussion The InSAR technique has been used in this study to identify the range of slope instabilities and the rate of displacement of unstable landslides. Based on the research findings, radar images and differential interferometry processing methods could potentially identify unstable active areas and calculate the rate of displacement. In this study, the results of the ASAR radar image processing were used to calculate the rate of displacement from 2009 to 2011. Figure 9 showed the displacement rate for the period of 2006-2011. It should be noted that positive and negative numbers in this figure indicated the rate of upward and downward movements, respectively. According to this figure, the highest and lowest rates of downward movements were associated with 2009 and 2011, respectively. In other words, the rate of downward movements had decreased by 2011. However, the rate of upward movement in the region was the highest for the years 2009 and 2010. Also, the lowest rate of upward movement recorded for this area was in 2011. Conclusion The present study utilized the InSAR technique to identify the range of landslides and to estimate the displacement of unstable landslides. The results of this study showed that radar images and differential interferometry processing methods could potentially identify unstable active areas and calculate the rate of displacement. In this study, the results of the ASAR radar image processing were used to calculate the rate of displacement between 2009 and 2011. Then, the validity of the results of the InSAR technique was measured by adapting the displacement maps to field operations and Google Earth. According to the research findings, the highest rate of fall or downward movement occurred in approximately 8 cm in the southern areas. Moreover, the highest rate of elevation or upward movement occurred in about 5 cm in the east northern areas in 2009. The highest rate of falls in this year was associated with areas with old landslides, among which the villages of Depigh, Nasirabad, and around Sariaraghan were more affected than other areas. These instabilities in the village of Depigh were mostly located around the bed of the Ahar Chay river, in a way that severe landslides in this area caused enormous rocks to accumulate on the surface of the river bed.
Geomorphology
Masoumeh Rajabi; shahram roostaei; Mohsen Barzkar
Abstract
Introduction Rivers are one of the best geomorphic landscapes in which the connection between the system of forces and the forms of unevenness can be clearly understood (Chorley et al., 2000: 163). Various sites, especially sedimentology, are important. Zab River is one of the most water-rich rivers ...
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Introduction Rivers are one of the best geomorphic landscapes in which the connection between the system of forces and the forms of unevenness can be clearly understood (Chorley et al., 2000: 163). Various sites, especially sedimentology, are important. Zab River is one of the most water-rich rivers in the country, which due to the high discharge, causes a lot of damage annually due to floods on agricultural lands located in the river. This river, by changing its course in the bed and creating erosion along the bed, exposes the lands around the bed to destruction, and considering that the farmers of the region use the river water for agriculture, it is of great economic importance for them.Therefore, it is necessary to classify and determine the boundaries of the riverbed and thus understand the existing processes and morphological knowledge of it. Therefore, it is necessary to classify and determine the boundaries of the riverbed and, as a result, to understand the existing processes and its morphological knowledge. Data and Method River classification according to Rosegan method: Rosegan classification is divided into four levels: In this research, for the morphological classification of Zab river, first by scrolling along the study area, an almost uniform set of geomorphic units is identified. Then, using GPS in three paths upstream, middle and downstream of the study area were segmented. After intercepting the river route and then entering the required data into the WMS9.1 and HEC-RAS software environment and executing the hydrological model, the geometric properties of 24 transverse sections of the total sections in all intervals The studied route was extracted and all the parameters required for classification and geometry of the duct in those intervals were calculated. To determine the overflow discharge of the intervals, the discharge with different return periods obtained from the relationship between Fuller and smada software with The prepared sections were given to HEC-RAS software and then based on one of the methods to determine the full cross section (level at which the ratio of width to depth to depth in an orthogonal device is minimized) the overflow flow is determined Took. Accordingly, in each cross section of the curve, the ratio of width to depth of flow versus depth for each section was plotted and the minimum point on the curve was selected as the discharge of the full section. After determining this discharge in each transverse section, using frequency analysis, the full section discharge has been determined for the whole river. Finally, by introducing flow characteristics, geometric characteristics and manning coefficient of each section in HEC-RAS software, flow simulation was performed and data related to cross-sections and water surface profiles including width to depth ratio, indentation index Bed, cross-sectional area in overflow, overflow width, maximum depth, flood plain width and water level slope, etc. were calculated. The implementation steps of the HEC-RAS model are shown in Figure 2. Results and Discussion According to field and laboratory studies, Zab River is in the alluvial group in terms of classification based on the type of bed sediments (rocky and alluvial). In summer, due to dehydration, fine-grained sediments are placed on coarse-grained sediments, as a result of which sand particles get stuck between the sand particles and cause the bed to solidify. These sediments are sandy but in winter Due to the flood, fine particles are displaced along with the flood and large particles remain at the bottom of the bed, so the type of sediments on the bottom of the Zab River are sandy. To obtain the average size of duct material, 15 samples were taken along the river at different distances and granulated in the laboratory. Due to the fact that the intervals 4 in the upstream and 11 in the middle part of the studied route have a mixed bed of irregular rapids or erosion basins and the bed (profile) and sides are relatively stable and have a limited sediment transport system with type B Roses are compatible. Also, moderate roughness and narrow valleys with a gradual slope are other reasons for confirming this claim. Intervals 1, 2, 3, 4, 5 upstream, 10, 12, 13, 14 in the middle and 17, 20, 21, 22, 23, and 24 downstream of the studied route with respect to stability They and their sediment load and limited transport are Type C compliant. The predominant morphological feature of these areas is wide valleys with alluvial terraces associated with the flood plain, which are again the characteristics of this type. Section 18 is located in the downstream part of the studied route in type D, which is witnessed by the following reasons. The river is arterial in this area and rock fragments are rarely seen in the bed. The ducts also have erodible edges and high suction load. The morphological appearance of most areas has this type of wide valleys with alluvial and clovial cones. Interval 12 is located in the middle part of the studied route in type E. Here the ducts show significant sinusitis and the ratio of width to depth is low. The river is stable in this area and one of the reasons is the development in the floodplain with dense grass cover on the vertical shore of the duct. The predominant morphological feature of this section is the type of wide valleys with grasslands. Conclusion The characteristics of these intervals indicate their conformity with the Rosgen model. High instability of the riverbed in the range of intervals of types C and D is a threat to agricultural lands and surrounding structures. The results of evaluating the stability conditions of the intervals of the study area in the third level of Rozgan showed that in the upstream path of the study area, the intervals of 2, 5, and 8 intervals have more stable conditions at a good level than other intervals. Flow conditions in the intervals 1, 3, 6, 7 are at the intermediate level and in the interval 4 are at the weak level, which have more unstable conditions. In the intermediate path, the range 11 is better and more stable, and the 10, 12, 13, and 15 ranges are at the intermediate level, which is less stable. In the downstream direction, the studied areas are intervals 19, 21 and 22 at a good level and with more stable conditions, intervals 18, 20, 23 and 24 at a medium level and range 17 at a weak level and instability conditions. The results of Zab River evaluation based on Rozgan classification system at levels two and three showed that the canal patterns in Zab River and consequently the effective parameters in classifying and separating the canals are consistent with Rozgan system. However, there are differences in the values and parameters that are due to specific conditions of local influencing factors. However, the Rozgan system is responsible for the morphological knowledge of the Zab River and similar fluvial systems. کرد. Therefore, this model has the ability to quantitatively predict the geomorphism of the Zab River and rivers with similar conditions.
Geomorphology
Davod Mokhtari
Abstract
Introduction Along with geotourism,the scientific community is still in search of answers suitable for the purpose, why travel to the geotouristic areas, interests and motivations, needs and desires and demographic characteristics of geotourists. On the other hand, there are different interpretations ...
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Introduction Along with geotourism,the scientific community is still in search of answers suitable for the purpose, why travel to the geotouristic areas, interests and motivations, needs and desires and demographic characteristics of geotourists. On the other hand, there are different interpretations and the plurality of opinions in this regard, some confusion in the literature is provided. Materials and Methods This article attempts to analyze and the expression of a range of dimensions and characteristics of a geotourist and collecting and providing comments and suggestions in the literature, Certain information from geotourists for researchers and practitioners in the field provided. The research method is descriptive content analysis. During this study, the position and status of theoretical foundations of geotourists have been described in terms of the nature and scope of geotourism. Discussion and Results Everyone, as the executive or audience of geotourism, is obligated to observe all its principles and dimensions. Minimizing the consequences, negating environmental and cultural awareness, creating positive experiences for visitors and hosts, attracting direct financial support for safeguards measures, creating financial rewards and empowering local peoples, enhancing the political, environmental, and social environment of host societies, supporting Citizenship rights are the most important of these principles. On the other hand, one of the goals of geotourism is to teach geosciences. Given the challenge, designing tools and providing solutions that can combine these two, namely, leisure and training, is necessary. Attention to the typology of geotourists leads to a better understanding of the dimensions of geotourism and contributes to the development and marketing of geotourism. It also provides some insight into the choice of tourism destination and the creation of a competitive atmosphere for these purposes. The experience of successful geotourism depends on the needs of the tourist and, in this case, it is more probable to re-visit geosite. Having a set of phenomena and tourist attractions with geological, geomorphologic, biological, heritage and cultural features is one of the most important features of each geotourist site. Therefore, offering a diverse set of attractions that is known in the literature of geotourism as "ABC[1]", and covers non-polluting phenomena (geological and geomorphological), living (animals and plants), and cultural (artificial attraction), from geotours side is necessary for geotourists. The development of geotourism should not affect the conservation of geotourist sites. Therefore, developers and land managers must, in any way, establish a balance between the conservation and development of geotourism. In the meantime, creation of geotourist training ground is one of the important tasks of geoscientists working in the field of geotourism. Undoubtedly, it is necessary to use simple and adaptive instruments for the geotourists to explain and teach geology and geomorphology for geotourists. This paper attempts to present an image of geotourists and their characteristics by reviewing resources and collecting globally written documents. The increasing trend of interest in visiting geotourist sites, increasing geological and geomorphologic information, visiting diverse cultures, enjoying outdoor activities, and settling in simple residences, in spite of the persuasion of tourists to geotourism, led the geotourists to take individual trips to instead of participating in the tour group. Perhaps because of this, the lack of such tours in Iran and even the world, or if they exist, will not meet the needs and aspirations of geotourists. Conclusions The results showed that the real geotourist is one who in order to geotourism purposes and proportionate to the nature and scope of it, protect and support the five key aspects of the geographical features of the area, the environment, culture, aesthetics, science and education and well-being of local people. This paper tries to provide researchers and practitioners with a geotourism perspective with comprehensive analysis of the dimensions and characteristics of a geotourist and the collection and presentation of ideas and suggestions in the subject literature. [1]-‘ABC’ attractions including Abiotic (non-living features such as geological attractions), biotic features (including fauna and flora) and Cultural (including built attractions).
Geomorphology
Ahad Ranjbari; Mousa Abedini; Davod Mokhtari; Khalil Valizadeh Kamran
Abstract
Introduction
Similar to other parts of Iran, Azerbaijan Plateau is active tectonically due to the Eurasia-Arabia cluster convergence, and its hydrogeomorphological impacts are evident as a strike-slip fault, folding, horst, graben, changes in the topography, and drainage system (Abedini, 2016: 75). ...
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Introduction
Similar to other parts of Iran, Azerbaijan Plateau is active tectonically due to the Eurasia-Arabia cluster convergence, and its hydrogeomorphological impacts are evident as a strike-slip fault, folding, horst, graben, changes in the topography, and drainage system (Abedini, 2016: 75). Therefore, investigating and understanding the function of faults can significantly contribute to analyzing the tectonic activities, the occurrence of earthquakes, their geomorphic hazards as well as the environmental planning and management, the adaptation of the land use, and constructions regarding the tectonic situation of the regions and reduce their hazards.
The current research aims to identify the geomorphic hazards caused by the tectonic activities, especially the behavior of faults, for the planning and management before the occurrence of hazards and their resulted crises. In this regard, the principal purpose of this research is to study and identify the faults of the Qoshadagh fault zone and their geomorphic impacts in the northwest of Iran and a part of the structural block of Aras Fault Zone (Berberian & Yeats, 1999).
Data and Methodology
Three methods of manual, automatic, and mixture were used to precisely extract the region's faults, affected by the doublet seismic activities of 12 August 2012 with the magnitude of 6.4 and 6.2 Richter that had only 6 kilometers and 11-minute distance from each other (Donner et al., 2015). Moreover, survey study and manual measurement of the replacements were used. Hence, Envi 5.1 software was used to apply the techniques and process of images. Also, PCA Geometrica was used to automatically extract the lineaments, and ArcMap 10.4.1 was applied to draw the output map. In the automatic method, Landsat 8 satellite image of OLI sensor with 33 rows and 168 paths was fused with its panchromatic band (15 meters). Then, the edge detection, thresholding, and extraction of fractures were conducted using algorithms. The map of lineaments was prepared using filtering, PCA, and RGB color model in the manual or visual method, and, was adapted using the automatic method. Images of Sentinel-B2 and Spot were also used due to some properties to ensure. Finally, the obtained lineaments were checked by the field data.
Discussion and Conclusion
After analyzing the automatic method results, applying the lineaments manually along with the field controls, the obtained result is displayed in an overlaying map. Then, by investigating the obtained lineaments and removing the repetitive and incompatible lineaments automatically, and consultant with the tectonics experts and geomorphologists familiar with the region, the lineaments with 80% possibility of being a fault were drawn in a final map of the region’s faults. It is evident that the extraction of the definite faults of the region requires different RS sources, such as radar data, GPS, gravimetric satellites, etc. Rose diagram was used to understand the length and direction of the faults. As a result, the length of the faults was more in 100-280 degree and 145-325 degree, and no-fault was extracted along the 80 degrees, although this length can be seen in the field observations. The results of the field study, overlaying some of the geomorphological effects, including the obstruction and deviation of the waterways, formation of the pressure ridges, and fault pools, have confirmed and improved the software outputs.
Results
Using purposive remote sensing along with the field studies can play a significant role in identifying the structural ruptures that are usually hardly visible and emphasize the spatial-temporal changes after the earthquake and its role in reducing the ground hazards (Yang et al., 2017). In this regard, the faults of the Qoshadagh zone were extracted using automatic, manual, and semi-automatic methods with satellite images. The obtained results were compared with the field study and adapted to the effects and fractures caused by the earthquake and the new faults were also identified. The obstruction and deviation of the waterways, fault edges, tension, and pressure ridges, etc., are the most significant evidence that contributed to extracting the fault lineaments using the satellite images. In the current study, the faults of the region were displayed as the fault system instead of single fault lineaments that were in line with the previous studies with a different purpose (Copley et al., 2012; Ghods et al., 2015). Also, the privilege extension of faults in western and eastern directions was identified. Using automatic and manual methods is not sufficient. Therefore, the mixture method was used to obtain better and more precise results. It is evident that the extraction of the definite faults of the region cannot be obtained only by having optical images and other RS resources are required, such as radar data, GPS, and gravimetric satellites (with a high spatial separation). Furthermore, the field control and survey and investigating the geomorphologic forms must be considered an inseparable part of these studies.
Geomorphology
somayeh karimi; Masoumeh Rajabi; Mohammad Hossein Rezaei Moghaddam
Abstract
Introduction Soil erosion is a process of moving soil by water or wind - when the soil particles are detached and is one of the main forms of soil destruction around the world which restricts sustainable development of the earth resources by creating negative environmental effects (Marques et al, 2018). ...
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Introduction Soil erosion is a process of moving soil by water or wind - when the soil particles are detached and is one of the main forms of soil destruction around the world which restricts sustainable development of the earth resources by creating negative environmental effects (Marques et al, 2018). Every year more than 75 billion tons of soil is eroded from the earth's surface which is amounted to 134 tons per square kilometer (Sobhani, 2002,18). In Iran too nearly 2 billion tons of valuable soils are lost annually and damages resulted from soil erosion is amounted to 56 billion dollar (Gholami, 2002,20). Karst areas have their special conditions due to their special hydrological and geomorphological conditions. Alvand basin is a distinguished karset basin in the west of Kermanshah province and the problem of soil erosion has existed in this basin for long time and exerted destructive effects on the environment. It is feared that by continuing current trend and its intensification due to human activities and destruction of oak forests, this basin faces with stone desertification in addition to disturbance in karst water resources and hydraulic constructions of the basin face with problems resulted from sediment. Meanwhile no study has been conducted in the Alvand basin surface to assess soil erosion by taking in to account karst condition, then conducting this research is essential and necessary. The goal of this study is to evaluate and zone soil erosion by taking karst geomorphological condition in Alvan basin in to account. Methods and materials Library, descriptive-analytical, field methods as well as SMLRK model were used. Above model includes influential internal parameters (infiltration, erodibility and morphology) and external parameters (land use and rainfall erosivity). In this study above model is conducted in two modes with and without involvement of infiltration parameters. For verification of the maps error matrix of two maps were calculated. Research data includes Landsat satellite image, 10 meters DEM, geological and pedological map and rainfall data from climate stations of the region. Results and Discussion In the zoning map obtained from equation (5) infiltration parameter which covers karst aspects has been neglected (Fig.7). Classes with low and very low erosion constitute 44.68% of the basin area, class with moderate erosion 21.9% of the basin area and classes with high and very high erosion 33.4% of the Alvan basin area. Totally, nearly 55% of the Alvand basin area is exposed to the risk of moderate to high soil erosion. Low erosion class conforms to plains’ surface and hilly regions of the basin. These regions generally have agricultural and rangeland and semi-dense forests use. Texture of the soil in these regions is heavy with lot of mineral materials and very deep. This karst class morphologically has low sleep and the directions are back to the sun and are less in the realm of the karst regions. Zone with moderate erosion conforms to erosive plains in the west of the basin, hilly regions and low hillsides of the zone’s mountains. The usage of these regions is usually rangeland- forest and includes parts of the karst regions of the basin. From morphological point of view, it has medium slope and soil texture is moderate with mineral materials and moderate depth. Zone with grate erosion exists both in karst and non-karst areas. These regions are usually steep and have rangeland and thin forest use with light soil texture and shallow. Karset regions are located in Sirvan, Ghalaje, Sarkesh, Deh Nooshak, Navakooh and Dalahou heights. Highly erosive zones conforms to rocky and steep regions with thin rangeland use, soil texture is light and very shallow (Fig.7B). Low and very low erosive zones occupied 38.75% , moderate erosive zone 29.86% and high and very highly erosive zones 31.37% of the Alvan basin surface (table. 8). Land use, morphology, geomorphological, rainfall and soil condition in each of these zones is the same as erosive zones of the previous map. Conclusion In SMLRK model unlike most common models, karst geomorphological conditions have been involved in its sub-parameters. In this research final map of the erosion results from this model has been provided in two ways with and without involvement of the infiltration parameters. In the final maps of the soil erosion obtained from two methods, there are five erosive zones. Providing soil final erosive map for the Alvand basin using infiltration parameters causes changes in the surface of the erosive zones and their special distribution. With involvement of the infiltration parameters in modeling soil erosion of the Alvand basin, surface of low and high erosive zones in the map with five factors compared to the soil erosion maps with four factor has decreased and surface of the very low, moderate and very high erosive zone has increased 2.04%, 7.96% and 5.98% respectively. In order to evaluate exactitude of the obtained maps their error matrix and similarity degree were calculated (Table 9). Accordingly, two maps and their classes were compared based on pixel and total sum of table diagonal is divided to total sum of the tables which expresses similarity degree of two maps. Similarity degree between two maps is 54.85% which reflects the main effect of infiltration parameter in amending result. Indeed, karst developed areas in east and north heights of the basin with involvement of infiltration parameter are located in highly erosive zone. Therefore, karst zoning results obtained from involvement of the infiltration parameter and consequently karst geomorphology have better performance and the results of this mode of model reflects more soil erosion in the area having karst geomorphology.
Geomorphology
sayyad asghari; delnya palizban; Hadi Emami; ehsan ghaleh
Abstract
Introduction Landslide is a term that encompasses a variety of amplitude motions and causes the movement of a mass of material in the slopes. And creep is classified. Natural slope instability is one of the geomorphological and geological phenomena that plays an effective role in deforming the ...
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Introduction Landslide is a term that encompasses a variety of amplitude motions and causes the movement of a mass of material in the slopes. And creep is classified. Natural slope instability is one of the geomorphological and geological phenomena that plays an effective role in deforming the earth's surface. Identifying areas with potential for landslides and their zoning is one of the key steps in managing environmental hazards and reducing the damage caused by this phenomenon, because this phenomenon causes financial and human costs, soil and land degradation and increased sediment production at the basin outlet. It becomes. Iran with its predominantly mountainous topography, high tectonic activity and seismicity, diverse geological and climatic conditions, has the most natural conditions to create a wide range of landslides. The purpose of this study is to zoning the risk of landslides on the Sarab-Nir road. In this research, two models of network analysis and fuzzy logic are examined and evaluated. It is hoped that eventually, by preparing a landslide risk zoning map, it will be of great help to planners and managers in order to reduce potential damages and find safer locations for development, construction and road construction. Methodology Sarab-Nir road is located between East Azarbaijan province and Ardabil province and is a communication route between these two provinces, whose geographical coordinates are 37 degrees and 94 minutes to 38 degrees and 03 minutes north latitude and 47 degrees and 53 minutes to 48 degrees and 01 minutes. It is east longitude. In this study, network analysis model was used to determine areas prone to fall and zoning. In order to better understand the causes of landslides and also to organize the research in the field, the study area was visited and 15 geographical points from different areas of the study area were recorded. The geographical location of the points prone to fall was also recorded with GPS. Then, according to the network analysis model, information layers were prepared in ArcGIS software. The information layers for landslide risk zoning are: fault, slope, slope direction, distance from road, and distance from waterway, land use, geology (lithology), precipitation, altitude and vegetation. The elevation file or digital model of the elevation of the area was prepared with an accuracy of 30 meters from the USGS site and the desired DEM is a digital file obtained from the ASTER sensor and according to this DEM, the information layer such as streams, slope and direction The slope was obtained. Results and Discussion Four maps have been developed to investigate landslide hazards, which are rainfall, slope, elevation and land use layers. After creating information layers in order to prepare the final landslide hazard map, fuzzy information layer maps were created. In this study, in order to determine the effect of different classes of criteria on landslide sensitivity zoning, the layers are based on the type of performance of each in the landslide event using fuzzy membership functions in the range of zero to 1 fuzzy. Were made. The results obtained from the information layers and finally the landslide hazard map show that altitudes of more than 2000 meters have the highest share of landslides, and altitudes of 1400 meters have been significant landslides due to the instability of the slopes against Climatic and environmental factors. Also, most of the landslides occurred at a distance of 3 to 6 km from the faults, which shows the importance of faults against landslides. About 40% of landslides occur in very high-risk classes. This indicates that the model has a high capability in predicting landslides. It is necessary to explain that most of the landslides occur in the area of Saein pass, which have very favourable conditions for the occurrence of range movements that start from 25 km of mirage and continue for a distance of 15 km of Nir. Conclusion Factors such as slope, precipitation and geology play a more important role in landslides than other factors. Slopes of 60 to 80% have the greatest impact on landslides, which are more pronounced at altitudes above 2000 meters. Therefore, altitudes above 2000 meters have the most landslides. Also, due to the direct relationship between altitude and climatic fluctuations in these altitudes, the amount of precipitation is higher and, of course, has a great impact on the occurrence of landslides. In these areas, vegetation is at a minimum and due to the cold region, the vegetation in these areas is very small, which prepares the conditions for landslides and due to the presence of sedimentary formations such as sandstone, Siltstone mudstone with tuff interbreeds in the area, the conditions for landslides have become more prone and because these formations lose their stability sooner and are strongly influenced by physicochemical factors, they are more prone to landslides than other formations. To be. According to the results, the low risk floor with the highest value, 405.44 square kilometers, occupies approximately 30.87 percent of the area, but the very high risk floor with 288.2 square kilometers and the high risk class with 23.23 square kilometers. , Occupy a total of 37.25% of the area of risk classes.
Geomorphology
Nayer Aghabeigi; Abazar Esmali Ouri; Raoof Mostafazadeh; mohammad Golshan
Abstract
Introduction Estimation of the rivers sediment load has high complexity due to effecting different parameters in this aspect. Regarding the power relationship between discharge data and suspended sediment load use of sediment rating curves is one of the most common methods for determining the sediment ...
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Introduction Estimation of the rivers sediment load has high complexity due to effecting different parameters in this aspect. Regarding the power relationship between discharge data and suspended sediment load use of sediment rating curves is one of the most common methods for determining the sediment yield in ungauged watersheds. Sediment condition shows the upstream characters and using of the obtained data makes a relation between erosion and sediment load. The different parameters such as climate, land use, data accuracy and the applied methods have the effect on the sediment rating curve shape. Agriculture activities such as tillage in the direction of slope lead to accelerated erosion in the watersheds, especially in the Mediterranean area. These decades many studies assessing the effects of climate changes in the future period and it affects on runoff. In this study, the main objective is to obtain sediment changes during the future decade (2011-2030) using the curve rating in sediment estimating. For this purpose, the IHACRES hydrologic model and the LARS_WG climate model were used. Material and Methode The IHACRES model for seven hydrometric stations was calibrated and validated. This model is a rainfall and runoff erosion that require a little data for running including minimum and maximum temperature, rainfall, discharge and study are. This model defined as a lumped model and highly common in watersheds with scarce data. With running this model in all of the models the model parameters were calibrated. Also, the LARS_WG model was used for determining the weather changes that are occurring in the Samian watershed. This watershed has near to 4 thousand square kilometers that have many sub-watersheds. In this study, the watersheds in the west of the Samian watershed were selected for modeling. The average of rainfall in this area is between 220 and 457 mm, and the weather temperature changes in this region are high and that is between -32 to 34 C°. The results of LARS_WG showed the weather changes in each part of the hydrological model inputs that these changes were applied to the IHACRES model and the discharge flow rate was estimated for the future. On the other hand, using the observed discharge and sediment yield were calculated the sediment curve rate. By changes in flow discharge at the study stations, were calculated the suspended sediment discharges for the future period. results and discussion The results of the LARS_WG model showed that the amount of precipitation decreased to 3.68 percent and the minimum and the maximum temperature increased by 16.48 and 5.39 percent, respectively. Decreasing of the input precipitation in most part of the world particularly in Iran watersheds mentioned in many studies. One of the other the most important effect of the climate change in this area is minimum and maximum temperature increase that leads to evapotranspiration increasing and soil moisture loss. The results of the IHACRES model showed that this model has the suitable capability for simulation runoff in the study area, therefore, it was used for estimating the future runoff regarding climate changes. The model output showed that during the next decades the average flow rate in the hydrometric stations will decrease by a total of 16 percent and the number of peak flood events will increase, that the highest increase between the study watersheds observed in the Yamchi hydrometric station with a mean of 2.09 m3s-1 and 16 peak events with over 6 m3s-1. Using the obtained results of the climatic model, hydrological model and the sediment rating curve the suspend sediment changes were estimated for the future period. The result shows that these climatic changes will lead to a 47 percent reduction in the average of suspended sediment load at study stations. Conclusion The consequences of the climate changes have the significant effect on water resources quality and quantity. The aims of this study were calculating the weather changes and it's ruling on discharge and sediment yield changed. the results of this study indicate the effect of climate change on the Ardabil province watersheds is remarkable. Considering the environmental impacts of climate change and dependence on human life on the environment it is necessary to implement an appropriate approach for decent management in Watersheds.
Geomorphology
Hamide Gholam Heidari; Mozhghan Entezari; Haji Karimi; Mohammadhosein Ramasht
Abstract
Introduction Maroon plain, located in Maroon basin is situated in Khuzestan, and Kohgiluyeh and Boyer-Ahmad provinces; and Jaber plain is positioned in northwest Ilam City in Ilam Province. The existence of Gachsaran Formation and gypsum karstic phenomena (the most important of which are sinkholes) in ...
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Introduction Maroon plain, located in Maroon basin is situated in Khuzestan, and Kohgiluyeh and Boyer-Ahmad provinces; and Jaber plain is positioned in northwest Ilam City in Ilam Province. The existence of Gachsaran Formation and gypsum karstic phenomena (the most important of which are sinkholes) in the mentioned plains, can have a very devastating effect on man-made structures. The morphometric study of these phenomena can allow comparison of various parameters of the sinkholes and lead to some hypotheses about their evolution. In this research, the sinkholes of both plains were classified according to Basu and Switch methods; based on Basu Model, they are categorized in elongated and bowl-shaped sinkholes, and on the basis of Switch method, they can be classified as bowl-shaped, pit-shaped and funnel-shaped groups. The results of the univariate linear regression analysis between the morphometric components of the sinkholes showed that the components of the area with large diameter, area with small diameter, depth with area, and depth with large diameter, indicate the highest values of significant correlation with determination coefficients of 0.922, 0.873, 0.699, 0.581, respectively. The maximum significant relationship at the error probability level, less than 0.1 is between the components of the area and large diameter for 2nd-degree and 3rd-degree relationships with determination coefficients of 0.997 and 0.998 and the estimation error of 0.07 and 0.08. The results of stepwise multiple linear regression analysis between the morphometric components of the sinkholes indicated that the highest value of determination coefficient is related to the area, small diameter, large diameter, and depth with determination coefficient of 0.997, and estimation error of 0.024, while the least values of determination coefficient is related to slope with depth, and large and small diameters with determination coefficient of 0.584 and the estimation error of 0.091. Therefore, the area, large and small diameters, and depth can be suitable parameters for modeling. Karst is a geomorphic and hydrological system that is formed by the dissolution of soluble rocks such as limestone, dolomite, and gypsum (Eziot et al., 2014). Gypsum and anhydrite are among the rock types which can be karstified easily and quickly (White, 1988). Given the development of evaporate formations such as Gachsaran, Kalhor, Hith, salt domes, etc. in Iran and particularly Zagros basin, and as well, the presence of gypsum and anhydrite as their main constituents, their importance in engineering geological issues including dams, tunnels, roads and railways, structures, mines and so on is evident. There is a close relationship between karst geomorphology and its evolution, so that karst morphology phenomena are abundant and developed in the area (Karimi 2010, Ghobadi 2009). Generally speaking, four different mechanisms are characterized for the formation of sinkholes; they are as follows: solution from above, collapse from the bottom, soil transport, and removal of buoyant support. Sometimes the formation of the sinkholes is due to a combination of different mechanisms. It seems that the above-mentioned mechanisms can also be applied to gypsum sinkholes; the only difference is the formation speed of the landform (Gunay, 2002). In the present study, it is attempted to classify the various sinkhole types of Jaber and Maroon plains based on their morphology, and as well to determine the most suitable parameters for modeling. Methodology To survey the morphometry of gypsum sinkholes, after field studies and measuring the sinkhole characteristics of Maroon and Jaber plains, the required parameters were prepared by SPSS software (Table 1). Initially, using the obtained data, the sinkholes of two study areas were categorized by Basu and Switch methods, then the regression analysis of the morphometric parameters of the sinkholes was performed in SPSS software. For this purpose, univariate linear, 2nd-degree, 3rd-degree, and multivariate methods were used, and consequently, the most suitable models with higher preference values were presented. Results and discussion The results demonstrate that according to Basu method, the sinkhole types of the study area are circular and elongated. As well, based on the Switch method, and the diameter to depth ratio, the sinkholes of these areas are of bowl-shaped, funnel-shaped, and pit-shaped types; the number of pit-shaped sinkholes is greater than the other two types. The results of the univariate linear regression analysis between the morphometric components of the sinkholes show that the components of area with large diameter, area with small diameter, depth with area, and depth with large diameter, indicate the highest values of significant correlation by determination coefficients of 0.922, 0.873, 0.699, 0.581, respectively. The maximum significant relationship at the error probability level, less than 0.1 is between the components of area and large diameter for 2nd and 3rd degree relationships with coefficients of determination of 0.997 and 0.998 and the estimation error of 0.07 and 0.08. Also, the results show that the least significant 2nd-degree and 3rd-degree relationships are between environment and slope with determination coefficients of 0.025 and 0.081 and estimation error of 0.022 and 0.022. Besides, the results of stepwise multiple linear regression analysis between the morphometric components of the sinkholes demonstrated that the highest value of determination coefficient is related to the area, small diameter, large diameter, and depth with determination coefficient of 0.997, and estimation error of 0.024, while the least values of determination coefficient is related to the slope with depth, and large and small diameters with determination coefficient of 0.584 and the estimation error of 0.091. Conclusion According to the obtained results of the Basu method, the sinkholes of the Jaber plain are circular in shape and the Maroon plain sinkholes are classified among the elongated ones; certainly, the mechanism of formation of the sinkholes has directly influenced their shape and morphometry. The presence of creeks on the formations and gypsum layers has resulted in elongated sinkholes; in the Jaber plain where most of the sinkholes have been formed on the Knick line, the intersection point of a centralized slope flow and the gypsum layer has formed circular sinkholes. The results of field studies show that the depths of the Jaber plain are deeper; the reason can be the higher thickness of the gypsum layers of the Jaber plain compared with those of the Maroon plain and more importantly is that these layers are situated in Knick line and exposed to a powerful centralized slope flow. But the sinkholes of the Maroon plain are steeper, and the sinkholes of the Jaber plain enclose more area. After field observations as well as quantitative calculations of the ratio of the small and large diameters of the elongated sinkholes, the proportion of these two parameters is roughly calculated as 1/3. Quantitative results of univariate linear analysis between the morphometric components the sinkholes as well as the significant relationship at the error probability level, less than 0.1, for 2nd-degree and 3rd-degree relationships, and the results of stepwise multiple linear regression analysis between the morphometric components of the sinkholes express that the area, large and small diameters, and depth can be appropriate parameters for modeling.
Geomorphology
mojtaba yamani; mosa abbasi
Abstract
Introduction Hard floods increase the strength of canals, erosion rates and sedimentation in the rivers. Late in the evening and early morning of April 26, 2016, the Gadar basin experienced lightning and hard storms directly across the basin, causing only a few hours of rainfall in the basin. Due to ...
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Introduction Hard floods increase the strength of canals, erosion rates and sedimentation in the rivers. Late in the evening and early morning of April 26, 2016, the Gadar basin experienced lightning and hard storms directly across the basin, causing only a few hours of rainfall in the basin. Due to the high rainfall of April 1976 with a maximum of 197 mm, the soil was saturated and caused direct runoff to the canals. The flood caused significant biological and geomorphic disturbances in the riverbeds, which caused complete loss of vegetation in some parts of the river. Even in the areas where the alluvium was left, many plants were destroyed. The floods caused major changes in the morphology of the Gadar main waterways and rivers, which have been unprecedented in recent decades. This study aimed to provide a model to determine the amount of geomorphic turbulence caused by catastrophic flood in the Gadar River during the flood event of 96 years. Data and Methology The data were collected from library methods, statistical data, imagery and field surveys. Aerial photographs were selected to determine the extent of geomorphic perturbations caused by the catastrophic flood at 35 km from the main river before and after the flood. Post-flood morphological changes using aerial imagery revealed that digitizing the area where catastrophic flood perturbations occurred along the Gadar River was clearly visible. For the essential management using the Mitsen model, recurrent periods including 100 and 500 years flood bed and flood plain were used to determine the geomorphic turbulence of the river. In the disturbance area of the riverbank, the highest amount of disturbance was in group 4 (10965793 m 2) and the lowest was in group 5 (657247 m 2). These large-scale patterns are also consistent with increasing river distances for 100- and 500-year flood return periods. The highest amount of geomorphic perturbation was related to Class D covering a total of 4972105 square meters, while Class B perturbation with an area of 578969 square meters covered the least perturbation. The highest amount of geomorphic perturbations belonged to Group A for flood bed area with 46.58% covering an area of about 1694712 m 2 while the lowest D perturbation was with Group 57 with 3.57%. The total area is 178931 square meters. For the 100 and 500 year floodplains, similar to the floodplain area, the highest and lowest turbulence rates belonged to Group A and B, respectively. Results and Discussions Most of the perturbations and locations with maximum geomorphic perturbations were caused by catastrophic flooding of the Gadar River. within the flood bed area and these perturbations for all groups of the river bed and geomorphic The distance from the river and the movement to the 100- and 500-year floodplain returns decreases. This trend is particularly evident in most of the river and geomorphic turbulence. There is a particular trend between groups 1, 2 and 3 of the perturbation and the geomorphic groups B and C that place the subduction sites in this perturbation group. Floods have the capacity and ability to transport moderate amounts of sediment or moderate erosion, but as a large force that can completely erode alluvial riverbeds and remove vegetation, it is not sufficient so it will be just outside the flood plain erosion threshold This is probably due to increased plant resistance and root reinforcement and its effect on floodplain roughness and decreased bed flow velocity. Most floodplain erosion occurred in the bed and adjacent to the canal of the study. Since floodplain erosion involves the riverbank and geomorphic sections, the most severe type of D-group geomorphic perturbation process was approximately 58% with two groups of 4 and 5 rivers, respectively, as partial and complete flood plain erosion, respectively. By comparing the native Gadder model with the Mitzen model, it can be seen that the Gadar River indigenous classification model is similar in some respects to that of the Mitzen, but also has some differences. In the Mitzen model, the topographic features, river cover, anthropogenic disturbance and the geomorphic disturbance of the bed sediment and the morphology of the river are not fully considered while in the Gadar basin the presence of lands adjacent to the riverbed. The river bed with different coverages along with the sediment type of the bed and banks plays an important role in the extent of flood control or expansion. Conclusion Most of the disasters caused by the catastrophic floods in the Gadar River include Group 5 for river disruption and Group D for geomorphic disruption, which occurred mainly in the floodplain area, which is confined to all river banks and geomorphic section distances from the river. And the movement toward the 100- and 500-year flood plain return periods has declined. In group 5, 90.2% of the turbulence occurred in the floodplain, while only 8.6% occurred in the 100-year floodplain and 0.6% in the 500-year floodplain. Similarly, in Group D, 92% of the geomorphic turbulence occurred in the floodplain, and only 8% of the turbulence occurred in the other floodplain groups, so most of the severe turbulence was in the canal bed and less severe turbulence mainly in the The 100- and 500-year flood plain return periods are located outside the flood plain.
Geomorphology
Seyyed Asadallah Hejazi; Masoumeh Rajabi; Asma Sharbaf Behtash
Abstract
Introduction Tourism is one of the activities that demand for it is increasing. Tourism as a non-smoking industry, has less destructive environmental impacts but for some, tourism is an important threat to cultural and biological diversity. This idea caused the concept of sustainable tourism development ...
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Introduction Tourism is one of the activities that demand for it is increasing. Tourism as a non-smoking industry, has less destructive environmental impacts but for some, tourism is an important threat to cultural and biological diversity. This idea caused the concept of sustainable tourism development and the forms of alternative tourism to be raised. For this reason, the development of ecotourism as a form of alternative tourism is essential for achieving the goals of sustainable tourism development. Identifying and planning the suitable ecotourism areas as an effective tool and solution can play an essential role in sustainable tourism development. Although Iran has a variety of natural attractions, but it hasn't been able to make good use of this advantage. One of the most suitable ecotourism areas in Iran and East Azerbaijan Province is the Northern Slopes of Bozghoush Mountains. This area has a lot of natural attractions such as high peaks, numerous hot springs and green spaces which can be a destination for hiking, adventure tourism, ski, water therapy and leisure activities. In spite of such attractions, none of these activities is known in the real sense; on the other hand, comprehensive planning has not been done in this area. Although several tourists go to the northern slopes of Bozghoush Mountain in spring and summer but there isn't any suitable infrastructures in this area. This indicates the necessity of investigating in this region and the main thing for encouraging investors is identifying, prioritizing and informing them. Such actions lie in the context of scientific research. So far, several studies has been done on geomorphology and geology of this region but there hasn't been any study to identify suitable ecotourism areas. The present study has aimed to reach this goal. The goal of this study is identifying the ecotourism capabilities of the northern slopes of Bozghoush Mountain using Vikor technique in order to identify the most suitable areas for ecotourism activities. Methodology The research method of this study is descriptive-analytical and in terms of purpose, it is practical. In order to achieve the research goals, the most important criteria of site selection for mountaineering, hiking and ski was identified by library research and expert survey, and then the weight of each criteria was determined by the Analytic Hierarchy Process (AHP). In the following, in order to integrate layers in ArcGIS, VIKOR method has been used. To determine the final weight of the criteria, a questionnaire was designed and it has been filled by 30 experts. The experts were familiar with both the AHP method and the features of study area. Five questionnaire were corrupted and 25 of them were valid. The hierarchy structure was formed in the Expert Choice. Then the data obtained from questionnaire which was a pairwise comparison, was added to the software. In the following, in order to integrate layers in ArcGIS, VIKOR method has been used. Finally, by overlaying the maps of mountaineering, hiking and ski, the most suitable areas of ecotourism was determined. Conclusion The northern slopes of Bouzghoush Mountain located in East Azerbaijan Province have high ecotourism potential, which allows tourists to do activities such as mountaineering, hiking and ski. In the present study, in order to site selection and prioritize the ecotourism areas, the activities were divided into three types and evaluated by Vikor technique. Various criteria were selected by literature review and weighted in Expert choice using AHP method. Finally maps of mountaineering, hiking and ski were obtained and by overlaying the maps, the final map of suitable ecotourism areas was achieved. The results show that in terms of suitable site selection of ecotourism, 15.43 percent of area is in very suitable condition, 35.52 percent in suitable condition, 39.91 percent in average condition and 9.14 percent in unsuitable condition. The most suitable area covers the hot springs of Asbforoushan and Allah Hagh, as well as Jelda Bakhan and Ardeha villages. These sites tops the list of priorities for development.
Geomorphology
Nayer Aghabeigi; Abazar Esmali Ouri; Raoof Mostafazadeh; mohammad Golshan
Abstract
Introduction Estimation of the rivers sediment load has high complexity due to effecting different parameters in this aspect. Regarding the power relationship between discharge data and suspended sediment load use of sediment rating curves is one of the most common methods for determining the sediment ...
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Introduction Estimation of the rivers sediment load has high complexity due to effecting different parameters in this aspect. Regarding the power relationship between discharge data and suspended sediment load use of sediment rating curves is one of the most common methods for determining the sediment yield in ungauged watersheds. Sediment condition shows the upstream characters and using the obtained data makes a relationship between erosion and sediment load. The different parameters such as climate, land use, data accuracy, and the applied methods have an effect on the sediment rating curve shape. Agriculture activities such as tillage in the direction of slope lead to accelerated erosion in the watersheds, especially in the Mediterranean area. These decades many studies assessing the effects of climate changes in the future period and it affects runoff. In this study, the main objective is to obtain sediment changes during the future decade (2011-2030) using the curve rating in sediment estimating. For this purpose, the IHACRES hydrologic model and the LARS_WG climate model were used. Material and Methode The IHACRES model for seven hydrometric stations was calibrated and validated. This model is rainfall and runoff erosion that require a little data for running including minimum and maximum temperature, rainfall, discharge and study are. This model defined as a lumped model and highly common in watersheds with scarce data. With running this model in all of the models the model parameters were calibrated. Also, the LARS_WG model was used for determining the weather changes that are occurring in the Samian watershed. This watershed has near to 4 thousand square kilometers that have many sub-watersheds. In this study, the watersheds in the west of the Samian watershed were selected for modeling. The average of rainfall in this area is between 220 and 457 mm, and the weather temperature changes in this region are high and that is between -32 to 34 C°. The results of LARS_WG showed the weather changes in each part of the hydrological model inputs that these changes were applied to the IHACRES model and the discharge flow rate was estimated for the future. On the other hand, using the observed discharge and sediment yield were calculated the sediment curve rate. By changes in flow discharge at the study stations, were calculated the suspended sediment discharges for the future period. results and discussion The results of the LARS_WG model showed that the amount of precipitation decreased to 3.68 percent and the minimum and the maximum temperature increased by 16.48 and 5.39 percent, respectively. Decreasing the input precipitation in most parts of the world particularly in Iran watersheds mentioned in many studies. One of the other the most important effect of climate change in this area is minimum and maximum temperature increase that leads to evapotranspiration increasing and soil moisture loss. The results of the IHACRES model showed that this model has a suitable capability for simulation runoff in the study area, therefore, it was used for estimating the future runoff regarding climate changes. The model output showed that during the next decades the average flow rate in the hydrometric stations will decrease by a total of 16 percent and the number of peak flood events will increase, that the highest increase between the study watersheds observed in the Yamchi hydrometric station with a mean of 2.09 m3s-1 and 16 peak events with over 6 m3s-1. Using the obtained results of the climatic model, hydrological model and the sediment rating curve the suspend sediment changes were estimated for the future period. The result shows that these climatic changes will lead to a 47 percent reduction in the average suspended sediment load at study stations. Conclusion The consequences of climate change have a significant effect on water resources quality and quantity. The aims of this study were to calculate the weather changes and it's ruling on discharge and sediment yield changed. the results of this study indicate the effect of climate change on the Ardabil province watersheds is remarkable. Considering the environmental impacts of climate change and dependence on human life on the environment it is necessary to implement an appropriate approach for decent management in Watersheds. Keywords: Rating curve, climate change, LARS-WG, discharge, IHACRES.
Geomorphology
Shahram Roustaie; Davod Mokhtari; Zahar Ashrafi Fini
Abstract
Introduction Landslide is one of the most important and disastrous natural hazards which can bring many financial losses and heavy casualties worldwide every year. Entropy means a quantity of disorder between causes, results or decisions taken in different situations, it can be highly effective particularly ...
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Introduction Landslide is one of the most important and disastrous natural hazards which can bring many financial losses and heavy casualties worldwide every year. Entropy means a quantity of disorder between causes, results or decisions taken in different situations, it can be highly effective particularly in geomorphological studies such as landslide, where existing data are confused with uncertainties. Material and Methods Topographic maps 1: 25000 scaled, geological map of Makran and Marzanabad scale map 1: 100000 and ASAR images from ENVISAT since 2003 till 2009 in the region were used as the main data in this model. Active landslide also detected in the basin. Then, 17 zones were selected via field visiting and Google earth software images. Also location of landslides recorded using GPS. Analyzing the data and providing the required maps were done using Arc Gis10 and SAGA. A total number of 13 effective parameters were selected based on condition of studied areas for next step. Then slide layer, slide direction, elevation, geology, land use, distance to fault, distance from the river and distance from the road obtained by Arc Gis10 analysis, vegetation layer (NDVI) measured by ENVI4.2 software and the layers of surface area ratio (ASR), topography index (TPI), Topographic Wetness Index (TWI) and slide length index (SLS ) were analyzed by SAGA software. After providing the information layers and importing the landslide locations, the properties of each slip extracted due to the mentioned layers and scoring was regarding to the role of each factor in the occurrence of slide. And the primary matrix was formed according to the entropy method. The decision matrix contains information which can be evaluated by entropy as a criterion. Then by calculating the entropy matrix and weight of 13 factors (WJ), the (HI) index will be obtained as landslide risk hazard Results and discussions At first due to the characteristics of the occurred landslide, each class was scored from the information layers which were obtained by examining the region after two field visits, study of aerial photographs and satellite imagery and identification of the affecting factors and their roles to create slip. Then the information layers used in the research were categorized and scored as a raster data and utilized as the main data in the formation of an entropy matrix for further analysis. To convert qualitative values into quantitative a bipolar scale is used. The bipolar interval scale is a general method for ranking quantitative and qualitative indexes. Measurement in this technique is based on a 10-point scale so that zero specifies the lowest possible value which is practically comprehensible and ten represents the maximum possible value of the intended index. The middle point is also the point of dividing the scale into favorable and unfavorable data. Conclusion Prioritizing the effective factors using the Shannon entropy index indicates that data layers such as slides direction, land use, elevation, slope, normalized vegetation index and the distance from the river had the greatest effect on the landslide occurrence in the area. And the topography, moisture index, geology, distance from fault and road, and the rest of the information layers had the least effect. Based on landslide hazard map of Taleghan watershed, very low to low risks regions are some areas in the northeast, central and southwest regions, while most of the studied areas have a moderate to very high risks. In general, site locations which could be at risk in the event of a landslide are limited to residential areas, roads, rivers, lakes and power lines. There are various land use in the region and Residential and demographic areas are at the top of the priority list. One the other hand there is Taleghan dam which can create a much greater potential risk if landslide happens at its location.
Geomorphology
negin aali; Masoumeh Rajabi; Mir asadolah Hejazi; Shahram Roustaie
Abstract
Introduction Natural parameters are the main and determining factors in the physical development of mountainous cities. One of the mountainous cities of Iran, which has physically developed due to these parameters, is the city of Marivan. Marivan is located in the west of Kurdistan province, near the ...
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Introduction Natural parameters are the main and determining factors in the physical development of mountainous cities. One of the mountainous cities of Iran, which has physically developed due to these parameters, is the city of Marivan. Marivan is located in the west of Kurdistan province, near the western borders of the country, at a distance of 16 km from Iraq, between 25 degrees and 21 minutes to 35 degrees and 48 minutes north latitude and 45 degrees and 58 minutes to 46 degrees and 45 minutes east longitude. According to the last population and housing census conducted in 2016, it has a population of 151188. The city is located at the starting point of the Marivan-Esfandeghe geological region and is located in the geological-morphological structure of the young Zagros. Therefore, identifying and evaluating the factors influencing the physical development of this city is really important. To do this, the characteristics of elevation, slope and direction of slope, fault, focal points of earthquake occurrence, main and secondary waterways have been used.With regard to its location in northwestern Iran after the eight-year Iran-Iraq war, the study city has experienced significant physical growth and development due to its unique and pristine vital and natural location, which led to the development of this city. Regardless of geological constraints. At present, the city has the potential to benefit from high potentials in the fields of natural and cultural tourism, including (Zarivar Natural Lake, Bashmakh Regional Area, and Border Market, Bilo Plain, Garan Dam, Oramanat and Bazaar for supplying foreign supplies and products. It has become one of the dynamic and active economic-tourism hubs in the west of the country and there is a growing growth and development in the city; therefore, it is inevitable to pay attention to geomorphological factors and determine optimal directions for the development of this city. Methodology According to the National Physical Plan of Region 5, the city is in a relatively high risk of earthquakes, and with respect to available and cited maps, there are 7 sub-faults in the northern part of Marivan and 2 main faults in the western part of the city. For this reason, the physical development of the city is subject to certain restrictions. Marivan is also in a relatively high risk of earthquakes in terms of location in relation to natural hazards.It is an applied research and the method of work is descriptive-analytical and also the fuzzy logic model has been used to evaluate and model suitable areas for development so that each layer is fuzzy according to fuzzy membership functions in GIS environment. And then multiplication and addition operations and different values of fuzzy gamma have been performed on these layers. After overlapping and multiplying the fuzzy layers, a zoning map of the appropriate development route of the city was prepared and divided into 5 classes including completely suitable, relatively appropriate, appropriate, inappropriate and completely inappropriate for the physical development of the city.In the study, library methods, documentary and field studies have been used to collect the desired information and data. To evaluate the optimal development of urban lands, slope indicators, slope direction, fault zoning, main and secondary waterways, erosion, earthquake-prone points in and around the area have been used. The fuzzy and hierarchical analysis process (AHP) was used. Results and discussion In order to evaluate and weigh the information layers and to determine and score the impact factor of geomorphological indicators affecting urban development while extracting and reviewing the criteria examined in various valid researches and articles, scientific opinions and views of ten experts and specialists were counted and monitored. In order to determine the importance of each of the studied indicators on the location and physical development of Marivan city, the opinions and views of the experts were given based on the superiority of one factor over another and based on expert judgment, scores between 1 and 9 were given. The equivalence of expert scores based on fuzzy method was done by the authors of the article with the help of AHP & FUZZY software.Since 1996, due to the increasing growth and development of the city and the formation of informal settlements, the development of the city has taken place without considering geomorphological considerations, and this has caused the spatial-physical development of Marivan in the northern parts near the existing faults. The development of the city has taken place at relatively high risk. Conclusion Summarizing the research, it has been determined that the southern lands of this city have less proportion to the development of the city due to its proximity to Zarivar Lake and its location along the main and secondary waterways and its proximity to the earthquake centers. And to some extent, the East enjoys a higher level of development.
GIS&RS
Shabnam Mahmoudi; Davod Mokhtari; Mohamad Hossein Rezai moghadam; Abbas Moradi
Abstract
Introduction Erosion involves the retreat or advancement of the coastline, is the one of the recent problems of communities along the coast and the existing infrastructure located near the estuary system. Environmentally, coastal areas are of great importance and value due to their sensitive and productive ...
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Introduction Erosion involves the retreat or advancement of the coastline, is the one of the recent problems of communities along the coast and the existing infrastructure located near the estuary system. Environmentally, coastal areas are of great importance and value due to their sensitive and productive ecosystems. Short-term or long-term coastline changes are important in the situation and geometry of coastlines and coastal management. Awareness of coastline behavior helps to manage beaches when designing and constructing coastal facilities and determining the safe margin of the coast. This article tries to modeling the changes in the coastline of East and West Bandar jask(southern Iran) in a timespan, a step towards coastal management for the planning and operation of facilities of Jask Port, which can be follow the future development of the area. Methodology The study area is part of the coast of Jask city located in Jask county in southern Iran. For this purpose, the extent of coastline changes to determine the boundary line between land and water was examined. To be more precise, spectral operators were used in the Arc map environment and Landsat satellite imagery; the next step was to polygonize the shoreline according to the fixed landline on land. In addition, Google Earth satellite imagery was used to examine and mark some case-by-case changes, such as cape changes in the western part of the port of Jask and so on. Results and Discussion The dynamics of coastlines and their variability (affected by lithology and wave activity), the shape of coastlines and their effect on erosion and location of coastal sediments, resources and location of sediment accumulation and hydrodynamics of areas close to coastlines, the intensity of seasonal winds and its role in transmission Sediment transfer and erosion mechanisms, and ultimately, human activities, are among the factors influencing coastline changes. The shape of the shores was examined using the Hausdorff-Pesikovtch method. Accordingly, the rate of change in the area of polygons on the east coast (progress) is higher than on the west coast (retrograde). The reason for the progress on the East Coast could be the construction of new piers, tidal performance, the shape of the beach and how it is positioned against the waves. Overall, Oman's beaches are uplifted, which could be the reason for the retrograde; however, the drying up of the coast in order to build piers and breakwaters has led to the advance of the coast. conclusion Prove the existence of progress on the east coast due to the construction of three new piers (after 2006) and the presence of retrograde on the west coast due to the existing natural mechanisms of the region such as the uplift of Oman coast, is the most important finding of this study. The shape of the beach and the way it escapes from the waves due to the prevailing wind direction (from the southeast) on the east coast has intensified the effect of the human factor.
Geomorphology
Masomeh Rajabei; Davod Mokhtari; mir ebrahim hashemian
Volume 23, Issue 70 , March 2020, , Pages 123-143
Abstract
Alluvial fans are the most obvious Landforms of fluvial geomorphology which react to changes in tectonic as geomorphic phenomena, and they can be used as a tool for identifying of the tectonic aspect of regions. In this research at first, alluvial fans and their drainage basins located in the northern ...
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Alluvial fans are the most obvious Landforms of fluvial geomorphology which react to changes in tectonic as geomorphic phenomena, and they can be used as a tool for identifying of the tectonic aspect of regions. In this research at first, alluvial fans and their drainage basins located in the northern slopes in Bozqush were extracted in terms of morphometric (area, volume, distribution) and physiographic features (length, area, height) and the relative status of regional tectonic activity was evaluated by using 5 Geomorphic Indicators (α, AF, Bs, Hi, SL).The required parameters consisted of (R, S, H and α) and the other parameters were collected through DEM as well as digital geological maps. The Church Giles methods and Stream power model were used for computing the volume of alluvial fans and the uplift rate of watersheds by using ArcGIS, CAD and MATLAB softwares. Then Correlation was established between the results. Results showed that there is no significant relationship between the catchment area (BA) and the Volume of Alluvial Fans (V); in contrast, a significant and direct relationship was observed with a correlation coefficient 78% between the basin uplift rate and volume of fans. In this regard, by providing geological maps and location of the faults and its overlap with watershed and alluvial fans, It was found that the formation of large alluvial fans (Bijand, Elahagh) is consistent with upper two reverse and normal strike-slip fault lines (at the outlet of the basin). According to the results, in the current Morph-climatic conditions, tectonic can be considered as a major factor in increase or decrease of the volume of alluvial fans.
Geomorphology
shahram roostaei; christineh jananeh
Volume 23, Issue 70 , March 2020, , Pages 169-188
Abstract
Landslides and slope instabilities are among the important natural hazards, which cause human and financial casualties and loss of economic resources every year. These hazards mostly occur in natural slopes or those manipulated by human. Landslide hazard zonation is one of the methods by which, areas ...
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Landslides and slope instabilities are among the important natural hazards, which cause human and financial casualties and loss of economic resources every year. These hazards mostly occur in natural slopes or those manipulated by human. Landslide hazard zonation is one of the methods by which, areas prone to landslide occurrence can be determined and plannings can be done using the obtained zonation maps to reduce the casualties. The aim of this contribution is to study landslide hazard zonation within the Baleghluchai watershed in NW Iran. First, the main factors including the slope and its direction, geology, soil, climate, distance from the road and river and land usage were determined. The method of current investigation was Fuzzy AHP in the GIS environment, based on which, after preparing data layers using the above-mentioned parameters and giving weights to them in the GIS environment, the landslide potential map, as well as classification was carried out by Fuzzy AHP method. Results showed that the largest part of the watershed (32.21%) has low landslide potential, while about 13.5% of it has very high potential. Areas with very high and high landslide potential (327.39 km2 area) are mainly located in the northwest of the watershed, with some small areas distributed in the south and east, while areas with very low and low potential (504.06 km2) are mainly found in the central to northwestern and southern parts of the watershed.
Geomorphology
mohammad mahdi hosein zadeh; somaiyeh khaleghi; milad rostami
Volume 23, Issue 67 , April 2019, , Pages 129-149
Abstract
River channel change, bank erosion and bank sedimentation are natural process of alluvial rivers that cause destruction of agricultural lands and destroyed of structures around the river bank. The aim of this research is estimation of bank retrogression rate and bank erosion in Galali river (the reach ...
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River channel change, bank erosion and bank sedimentation are natural process of alluvial rivers that cause destruction of agricultural lands and destroyed of structures around the river bank. The aim of this research is estimation of bank retrogression rate and bank erosion in Galali river (the reach between Galali and Shirvaneh village) due to assessment of changes and estimation of potential changes in frequency of bank failures (Safety Factor) and sediment load from the river bank in two different scenario and 12 hours and three reaches by BSTEM model. The big floods can be caused bank erosion in this river and this issue is so important because there are some dams have been constructed in downstream of this river so estimation of erosion and sediment load is very important. Results show that total eroded areas in first scenario are 0.244, 0.372 and 0.054 m2 in reaches 1, 2 and 3 and the total eroded areas in second scenario are 0.272, 0.1 and 0.054 in reaches 1, 2 and 3 respectively. According to bank stability and safety factor, all of three cross-sections are unstable in first scenario and safety factor is less that 1 but safety factor increase in second scenario so that safety factor is around 1 in reaches 1 and 2 and in reach 3 is more than 1. Therefore, by protection works on the erodible banks can be reduced the total volume of the sediment load from eroded bank.
Geomorphology
musa abedini; shahram roostaei; Mohammad Hossein Fathi
Volume 22, Issue 66 , January 2019, , Pages 187-205
Abstract
Diagnosis and classification of landslides is a critical need in the risk analysis before and after the disaster. And primarily through land surveying or traditional interpretation of images was done. In this paper to identify and classify types of object-oriented approach landslide has been paid. The ...
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Diagnosis and classification of landslides is a critical need in the risk analysis before and after the disaster. And primarily through land surveying or traditional interpretation of images was done. In this paper to identify and classify types of object-oriented approach landslide has been paid. The data used in this study consisted of false color images obtained from satellite data Resourcesat-1 with spatial resolution of 5.8 meters and digital elevation models with 2.5-meter resolution satellite image of 10 meters of Cartosat-1 was used. This method was used for the North West basin and then used without further reforms in the eastern part of the basin. A total of three sliding using this method accurately identified 71.11% and 91.4% classification accuracy has been detected. In this way, the landslide early detection of high accuracy and speed, hence has great potential to assist in risk analysis, disaster management and decision making process after the earthquake or heavy rainfall, can be used related entities, including crisis management headquarters, natural resources and watershed institutions.
Geomorphology
gholam hassan jafari; Mahdei Abbasei
Volume 22, Issue 65 , November 2018, , Pages 117-139
Abstract
Review of river terraces is main issues related to river geomorphology. They are areas with low slope that is parallel to the axis of the river valley and are in the higher levels of the river bed and created through cutting the river bed and response to changes in external factors such as climate, tectonics ...
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Review of river terraces is main issues related to river geomorphology. They are areas with low slope that is parallel to the axis of the river valley and are in the higher levels of the river bed and created through cutting the river bed and response to changes in external factors such as climate, tectonics and base level. Ghezel owzan River is as one of the longest river systems in the country, responded well to changes in external factors (climate, tectonics and base level). For this purpose, after dividing the river into nine periods, Profile was drawn on the terraces adjacent faults in order to study in terms of height level and symmetry. In order to assess the effect of Tectonic activity on Ghezel owzan Catchment area, Four sub-basin are studied: Divandareh, Zanjan rood, Gharanghochay and Hashtchin- Tarom, from Upstream to downstream , With the help of two indicators, River Gradient length (SL) and Valley floor width to valley height (Vf) by determined sections, The results indicate the relationship building terraces with tectonic factors. This means that form terraces in downstream river is more a reflection of the effects of neo-tectonics and tectonic if they originate, reflecting the effects of tectonics. Feedback such activities is in basin downstream for nested alluvial fans and vertical-walled terraces in bedrock and in the mirage nested terraces in alluvial sediments with low sides slope.
Geomorphology
Mohammad Hossein Rezaei Mogaddam; Mohammadreza Nikjoo; Davod Mokhtari; Ahmad Fakeri Far; Kazem Koshdel
Volume 22, Issue 64 , September 2018, , Pages 81-101
Abstract
The streams of rivers are extremely complex in nature. Rivers are beneficial for natural vegetation, animals, living organisms and human communities. The river provides the possibility of drinking water and irrigation of agricultural fields. Rivers are considered as active land cultivators with erosion ...
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The streams of rivers are extremely complex in nature. Rivers are beneficial for natural vegetation, animals, living organisms and human communities. The river provides the possibility of drinking water and irrigation of agricultural fields. Rivers are considered as active land cultivators with erosion and sedimentation. Some of the negative effects of rivers such as floods are considered as a natural disaster. Such natural disasters have been shown when the river by anthropogenic activities by changing the shape of the river and arched their plans change. Meandering parts of the rivers are vulnerable to floods. Therefore, river studies are very important in terms of hydraulic characteristics, sediment, width to depth ratio, morphology and arched plan. Kaleibar Chai basin has located on the North West of the country. This research pays attention to the arcuate plan of Kaleibar River from the city of Kaleibar to Jananloo village (one of the branches of Aras River). The study region is part of Kaleibar Chai River with 72 km of length. The channel consists of right, waving, meandering, and braided patterns. The study of horizontal plan of the river in relation to different active processes shows the mutual relationship between hydrological parameters and the materials in the river. The continual changes in sinuosity index in the channel are indicators of variations in the river behavior. For doing this research we used Google Earth and DEM 10m images. The river was divided into 4 openings in which topographic conditions were considered. The river sinuosity index was calculated for all 4 openings in GIS software under the formula: TSI= . In this equation TCI is topographic sinuosity index, CL is the length of the river channel, Al is the aerial length of the beginning and ending part of the channel. The maximum sinuosity index for different lengths of the Kaleibar Chai River was estimated at 1.05 to 1.83. The heterogeneity of bed materials causes erosion and deposition on the river bed of Kaleibar Chai. Erosion and depositional processes occur in the area during the spring and fall floods. The variety of materials and their sizes cause erosion and the collapse of the brinks and the loop in sinuosity index, which finally lead to channel changes. The study of sinuosity index and the identification of rivers patterns help ease the planning procedure
Geomorphology
Hadi Nayyeri; Mohamad Salari
Volume 22, Issue 64 , September 2018, , Pages 289-310
Abstract
The study, according to the importance of tectonic – geomorphology studies, deals with the assessment and classification of active tectonic of watershed in Kurdistan province with a comparative – quantitative approach based on the parameters of drainage network. The study includes quantitative ...
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The study, according to the importance of tectonic – geomorphology studies, deals with the assessment and classification of active tectonic of watershed in Kurdistan province with a comparative – quantitative approach based on the parameters of drainage network. The study includes quantitative estimation of parameters associated with tectonic drainage network and the use of hierarchical cluster analysis.The research findings showed that the studied basins are classified, tectonically active, in two different clusters. Relative comparison between the clusters show that the basins located on the first cluster have more tectonic activity with more different slopes.In this regard, the second cluster basins have less tectonic activity, more homogeneous and forming faster-cluster threshold.According to the results, it seems that the situation of the first cluster basins, with the higher tectonic activity, are due to their spatial distribution and, consequently,their impressionable of different tectonic focus particularly active faults. Also, the situation of the second cluster basins is interpreted with respect to their more homogeneous spatial position corresponding to the central region of the study area and slower activity of Sanandaj – Sirjan zone.
Geomorphology
Mohammad Ali Zanganeh Asadi; Abolghasem Amirahmadi; ali akbar shayan yeganeh
Abstract
Geotourism, encourages tourism into geosite and conservation of geodiversity and an understanding of earth sciences. One way to effectively protection and conservation geodiversity is that valuable parts such as geoheritage (geological and geomorphological heritage) are protect and conserved. Most ...
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Geotourism, encourages tourism into geosite and conservation of geodiversity and an understanding of earth sciences. One way to effectively protection and conservation geodiversity is that valuable parts such as geoheritage (geological and geomorphological heritage) are protect and conserved. Most of human-scale geological materials are non-renewable. Geoparks are special territories with a development plan that their aim is protection of geological heritage (and other natural resources) while preserving the cultural identity of local communities. Iran has a wide range of geological and geomorphological phenomena that geotourism recently formed and located during the early stages of development. The paper attempts to analyze and evaluate based on geomorphosites and geosites in West of Khorasan Razavi, one of the common methods (method Brilha), could be offered the optimal mechanism for the protection and benefit of geodiversity (geoconservation).
Geomorphology
Somayeh Soltani-Gerdefaramarzi; Somayeh Asgari Varzideh; Mehdi Tazeh
Abstract
River morphology is the science of knowing the river system in terms of general shape, dimensions and characteristics of hydraulic geometry, the direction and longitudinal profile of the bed, as well as the mechanism of its changes. Morphological study is needed to understand the current conditions and ...
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River morphology is the science of knowing the river system in terms of general shape, dimensions and characteristics of hydraulic geometry, the direction and longitudinal profile of the bed, as well as the mechanism of its changes. Morphological study is needed to understand the current conditions and the potential for future river changes in the future, and perhaps it is only that it is possible to predict the natural behavior of the river in relation to natural changes or actions arising from the implementation of various river engineering projects. Most of the water structures such as dams, bridges and pumping stations are located in the margins of rivers that can be affected by changes in river morphology. Application of remote sensing images and Geographical Information Systems (GIS) can be effective to achieve a more accurate analysis. Today, land use change, vegetation cover and morphological changes of rivers in River Engineering Sciences are of great importance using remote sensing and GIS techniques. Yamani and Sharafi (2012) showed that morphological changes and erosion of the Herrud River from the upstream downstream has decreased. Also, the geological and lithological structures of the bed and river bank are the most important factors in the stability of the bed. Yousefi et al. (2013). In order to investigate the changes of some Meander parameters in the Karun River using Landsat satellite images, morphological parameters of 20 Meanders were determined in an interval of 128 km length of Karun River after the preparation of a land use map for each period. Rashidi et al. (2016) studied geomorphologic changes of the Karoon River bed and its causes from 1334 to 1391. The results indicate significant changes in river morphology including latitudes, meanders, and sedimentary islands due to the decrease in the discharge, the construction of multiple bridges along the path, geological factors and vegetation. The study of past research shows that the study of river morphology in other countries has also been of great importance. Clerici et al. (2015) examined the morphological changes of the Taro River in Italy over the last two centuries and showed that human beings have made the most of the changes for agricultural and industrial purposes, the construction of multiple bridges and casualization. According to the research, the main issue of this research is to investigate the changes in the Gamasiab River, which in recent years has threatened the communication paths, landscapes and, in summary, human structures along the river banks. Therefore, the objective is to study the variation of the morphology of the Gamasiab river from the point of view of the central radius and angle, and the number of archs during the 1990-2013 period, and the extent of the development of the piers.
Geomorphology
Rashid Saeidabadi
Abstract
The aim of current study are numerical simulation of the role of the Urmia Lake in climatic parameters in surrounding areas of the Lake. For analysis of climatic impacts of the Lake in Northwestern Iran the synoptic data in 5 station in the west and east of the lake were used. For simulation of the impacts ...
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The aim of current study are numerical simulation of the role of the Urmia Lake in climatic parameters in surrounding areas of the Lake. For analysis of climatic impacts of the Lake in Northwestern Iran the synoptic data in 5 station in the west and east of the lake were used. For simulation of the impacts of Urmia Lake in mean temperature and precipitation in surrounding areas the Regional Climate Model (RegCM4) and TAPM model and two time series years include 2003 and 2006 have been used. Then by using the models outputs and observed data performance, the models have been calibrated. For modeling the impacts of the Urmia Lake in climatic elements in surrounding areas, two scenarios were considered. First: Existence of the lake at it’s the maximum extent; two: Aquatic body of Urmia lake removed and substituted by an area having coverage of gravel and sand with a texture of loam and also desert. The results of this study indicate that the RegCM model has a good performance than TAPM in simulation of temperature and precipitation in the North West of Iran. By changing the Lake landuse, precipitation of the region will decrease which in spring is more than other seasons. Another impact of landuse change in northwest of Iran is change in mean temperature. This parameter in cold period of year will decrease and in warm period will increase.
Geomorphology
Rafat Shahmari
Abstract
Open the mountains of effort (north-south) as well as its geographical position has caused to the natural environment on the slopes of the mountains efforts (east-west) are different. The difference between natural features could, in the proximity of water catchment area in the long term a major impact ...
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Open the mountains of effort (north-south) as well as its geographical position has caused to the natural environment on the slopes of the mountains efforts (east-west) are different. The difference between natural features could, in the proximity of water catchment area in the long term a major impact on the performance of morphodynamic have some water basins. The most significant of these effects, the phenomenon of regressive erosion in the eastern slopes of the mountains efforts in the area of perplexity, the Parliament, Dgrman cache and Aq tea is occurring and its effects on the ridge area to capture some of the Western slopes overlooking river Ardabil plain obvious, that if this process is to expand the most impact and potential damage to water resources will Ardabil plain and subsequent irreparable consequences.The results showed. On the eastern slopes of the mountains efforts in particular, Dgrman basins cache and Aq tea most regressive erosion is taking place. As the ground levels in 1436 and 1404 and 1405 and 1360 and 1348 and 1350 m events captivity rivers occurred, and, if this is in the not too distant future water resources villages Granny bound, head head, Rpatph and blue Bigelow around Ardabil Airport and even much of the Middle Eastern desertcoming to the Caspian Sea.
