QUANTITATIVE GEOMORPHOLOGICAL RESEARCHES
Year:2017 | Volume:6 | Issue:2 |Papers Count:10

Introduction: Streams typically have similar suites of channel morphologies, with repeatable patterns of occurrence that have resulted in numerous classification efforts (Roper et al., 2008: 417-427). Recent approaches for river classification focus on watershed analysis related to land management and stream restoration, using a hierarchical approach that nests successive scales of physical and biological conditions and allows a more holistic understanding of basin processes (Shroder, 2013: 739). One of the most widely used hierarchical channel classification systems was developed by Rosgen (Shroder, 2013: 742). In the current study, Gara Sou river channel plan form are studied by using Rosgen geomorphological model in combination with HEC-RAS model.Materials and methods: This study is based on fieldworks and topographic maps of scale 1: 2000 (Ardabil Regional Water Authority). To determine the friction coefficient distribution of channel and floodplain, land cover maps was generated using Google Earth satellite imagery. Rosgen (1985, 1994, and 1996) hierarchical system was used to analysis of river channel morphology. The Rosgen system uses six morphological measurements for classifying a stream reach-entrenchment, width/depth ratio, sinuosity, number of channels, slope, and bed material particle size. In this research, some of these parameters were calculated using HEC-RAS hydrodynamic model. For steady, gradually varied flow, the primary procedure for computing water surface profiles between cross-sections is called the direct step method. The basic computational procedure is based on the iterative solution of the energy equation. Given the flow and water surface elevation at one cross-section, the goal of the standard step method is to compute the water surface elevation at the adjacent cross-section. The flow data for HEC-RAS consists of flow regime, discharge information, initial conditions and boundary conditions (HEC, 2010).Results and discussion: According to calculations made in seven reach has been in class C and E, hierarchical model Rosgen. Gara Sou River in class C has a wider and shallower channel and floodplain width significantly developed. Gara Sou River in class E also has a deep and narrow channel (width to depth ratio) but floodplain width developed. In reach (1) floodplain width due to low geological control variable. In this reach was due to power of river, the bed river is cobble and gravel that leads to the river bed is in the Armoring range. With regard to slope variables and bed material, it is placed in the class C. in this class have a mean energy and high sediment load. Energy waste by meandering, bed forms (Pool- Riffle) and vegetation occurs. In the reaches of 2, 3, 4 and 5 width floodplain will be a significant development. In the reaches type of bed river is changed to gravel and sand and more of gravel and sand are. River slope in this reaches are between 0.02 and 0.039. In this reaches (2, 3, 4, and 5) river in the most part located class of C4b Rosgen model and only in some sections of the river have been E4b class. Average width to depth ratio is calculated 16.14 for the total reaches. In this reaches riparian vegetation are mostly dense shrubs that this high density of riparian vegetation plays an important role in the stability of the banks river in this reaches. In the end of reach (5) and reach (6) river slope between 0.001 and 0.02 is located and bed River is sand that often makes the river in this section in class C5 in hierarchical Rosgen model. Average width to depth ratio is calculated 15.46 for the total reaches. In reach (7) river slope to less than 0.001, but the bed river is still sand. According to the results, the major part of this reach is located class C5c and only in small portions cross sections of the E5 is placed class.Conclusion: In this study, Gara Sou River channel was classified using geomorphological Rosgen model on the first and second levels. Despite the widespread use Rosgen model, has been criticized by some researchers. Problems with the use of the classification are encountered with identifying bank full dimensions, particularly in incising channels and with the mixing of bed and bank sediment into a single population. Gara Sou River in parts of Type E has a low sediment supply, average potential bank erosion control and vegetation are very high. The rivers carry sediment are very efficient and river is low energy, loss of energy through the meandering, bed forms and vegetation occurs. Also this river in parts of the Type C has a high sediment supply, very high potential bank erosion control and vegetation is very high. In fact, vegetation combined with the bank erosion, determines the amount of lateral adjustment and sustainability of this river.

Introduction: The coast is a dynamic environment continually adjusts to the effects of weather, tides, seasons and climate change. The coastal area cannot withstand too much misuse it is inherently unstable and liable to change. Rapid changes in coastlines and morphological aspects an important feature of these areas, particularly around ports and other structures are manmade. Protection of ocean and marine coastal regions is a vital part in any coastal management program for sustainable development. The coastline is the most dynamic aspects of the Earth's surface. Thus, mapping the coastline and the changes it is very necessary for planning and efficient use of the beaches. On the other hand, in our modern world, coastal engineering sciences and assessment of coastal sediments and erosion are considered to be vital elements in management of national coastal areas. A large part of sediments of Caspian Sea coast are subject to erosion as a result of environmental forces (fluctuations in sea level and coastal waves and currents as well as wind). The rate and severity of erosion hazards varies depending on the morphological and geography and hydrodynamic properties of coastal areas. The case study in this research is situated at coordinates of geographical longitude from 53, 10, and 00 up to east 53, 24 and 00 and geographical latitude 36, 47, and 00 up to north 36, 52, and 00 the southeast coasts of the Caspian Sea on the ports of Amirabad and Neka in the East of Mazandaran Province.Methodology: Change detection helps in ascertaining shoreline trend analysis and its future prediction. The main purpose of this research is assessment of coastline changes in the south east coasts of the Caspian Sea during 1987-2015. Thus, satellite imagery (Landsat 5, 7 and 8, TM sensor for June 1987 with bands 1 to 4, ETM+ [Landsat 7] for July 2001 with bands 1 to 8 and ETM [Landsat 8] for August 2015 with bands 1 to 11), topographic maps (with scale: 1:50000 and 1:250000) and geographical information system software in Arc GIS 10 and Erdas Imagine 9.1 software, have been used. The use of satellite images is an effective technique for study and assessment the occurred changes in the coastal zone. So, in this study, in order to monitoring changes in the coastline, Landsat satellite images (TM and ETM+Sensors) for 1987, 2001 and 2015 have been used. In order to determine the amount of change in the coastline in the study area, the best band combination and one band was chosen to extract the shoreline. Then, the change and move coastline on the images of 1987 and 2001 and 2015 in eight points and was measured by observing the distance of 2000 m. Then, the amount of sedimentation and erosion in the area were also calculated.Result and Discussion: The results indicated who the coastline during the period under review, from 1987 to 2001 and from 2001 to 2015 is progress to the sea in the most parts and only in the eastern ports of Amirabad and Neka eroded. The greatest amount of progress and retreat of the shoreline of the years 2001-1987, respectively, are 450 and 68 m. While these values during 2015-2001, respectively 311 and 112 m has been. Also, the rate of sedimentation and erosion in the area of 1987-2015 respectively has been about 5.69 and 0.53 square kilometers.Conclusion: The results of this research show that most of the changes occurred in the study area in the period 2001-2015. Analyzing satellite images of the study area show that due to the construction and development of the ports of Amir Abad and Sadra drastically changed, so that the coastline in most parts toward of the sea progressed and main phenomenon in the study area has been sedimentation. The interpretation of satellite image data indicates that areas at opposite sides of the Amir Abad and Neka ports had different responses to depositional and erosion processes. Beach modification impacts have aggressively developed at the central part of study area groynes at the Amir Abad port have caused sediment accretion at the west side but erosion processes could develop as the beach retreats on the east side. The maximum progress amount in coastline of the study area is occured in the western part of Amir Abad port during the period 2001-1987, which at 450 meters has been changed. Also, the results show that significant volume of the sedimentation is deposit in west section of the Amir Abad and Neka ports. But, east section of these ports is faced with erosion. Moreover, the most change during the period time studied is related with volume sedimentation in the western section of Amir Abad and Neka ports that it somewhere reaches to 130 hectare. The results of this research can be applied in development plans for engineers and issues in the integrated coastal zone management for study area.

Introduction: Present Landform has been affected by climate conditions over time. Therefore, they show the characteristics of sequence and periodicity of it in the past. According to, using the landforms, we can reconstruct climate condition and its changes. Geomorphological glacier landforms are one the most terraces that show the changes of climate in the past. Nevertheless, Central of Iran has located in a dry region at the moment, especially central of Iran, but there are some specified landforms in the region that represent spreading the glacier in the center of Iran in Pleistocene. These includes abrasive and depositional relicts. The goal of the study is the investigating of present landforms in the central of Iran-Kazab Basin in the west of Yazd City- to know processes that have created them in the past, especially the landforms that have created by glaciers. Kazab basin has located in the south-west of Yazd city in the west slopes of Shirkuh Mountain along 31o 53´ to 32o 7´of northen latitudes and 53° 52´ 42" to 54° 7 of eastern longitudes.Materials and Methods: This research has been performed on basis of field studies and direct observation of glacial landforms. But, we studied topographical and geological maps, DEM, satellite images as well as aerial photographs, at first. The resulted information of the maps controlled with GPS System in the field. Then, we measured some boulders and pick up some sample of sediments and examine them in the geomorphological laboratory in the department of geograpgy in Yazd University.

Extended Abstract:Introduction: Binalood Mountain Range is a trusted system located in the north east of Iran. It is part of the dry and semi-arid mountains of the country. The slopes of this mountain range due to different lithological conditions and rock resistance against weathering and erosion, climatic characteristics and severe changes anthropogenic, including land use, has a good position for occurrence of geomorphological hazards there are some kinds of domain instability, especially these instabilities there are frequent events that poke a threat to life, equipment, facilities and transportation routes within the desired range. According to statistics, slippery slopes and various types of instability in the mountainous areas of the Binalood Zone since the 1370 have been exacerbated. Therefore, it makes doubling the importance of addressing the subject. According to field studies in the northern and southern slopes of Binaloud, the exacerbation of the risk of mass movements of the range, and in particular of the risk of slipping, has a widespread frequency and range than other environmental and geomorphic hazards. Factors such as grazing over the livestock capacity and tract created by kicking the soil caused by the movement of the livestock, falling slopes, with unconventional horticulture on the terraces of alluvium and on steep slopes, Severe land use changes, especially in sloping slopes, are one of the most important factors in day-to-day and the intensification of sloping movements and the occurrence of destructive currents in the northern and southern slopes of Binalood. Binalood mountain range The geographic location of the mountain range is semi-arid with a length of 143.75 km With the northwest trend - south-east extending from south east and from Quchan to northeast of Neyshabur.Methodology: The research method used in this research is an analytical and inductive system And to the feasibility of occurrence of sloping instabilities as one of the most important geomorphic hazards in the northern and southern slopes of Binalood Which has a devastating impact on the settlements of the human communities. in the region In order to identify the factors influencing this phenomenon, 11 variables such as variables Slope, slope of geological layers, lithology units, distance from fault, land use and coverage, consistent lines and homogeneity, altitudes and other factors. Based on the topographic map of 1/25000 at different levels of natural and human studies, In this regard, firstly, the hydrological basins in the study area were found to be in the realm of research in total of 33 catchment areas including 23 basins in the northern slope and 10 catchments in the southern slopes were identified.Results and discussion: Investigating the variables in the Binaloud region in the form of reference land, and lateral spatial modeling were arranged in GIS software and processed in Autocad software Therefore, the produced production maps are evaluated by the ANP method and subjected to the following expeater selection software in the form of main criteria and sub criteria. In the ANP method, we accurately analyzed the parameters in pairs and compared to the 11 variables of the present study, the results showed that the parameters of slope, altitudes, lithology units, faults, land use and land cover, and .... Respectively, have the highest gained weight. Finally, these maps were overlapping and zoning in GIS software with fuzzy logic and fuzzy aggregate operator. The hazard zonation map generated from this model, as a reference map, is adapted to the initial map prepared through field observations, spatial coordinates with GPS, and aerial photo interpretation. Its results were analyzed and analyzed from the perspective of environmental management.Conclusion: Finally, based on the statistical results extracted from these maps, testing the assumptions about the probability of occurrence of slopes and especially landslides And its effect on environmental management, using Spearman and Kendall tests in SPSS software, the results of which prove the hypotheses With a probability higher than 95%. According to the results of this study, the gradient is the most effective factor in the incidence of domain inconsistencies in each other and due to the geologic form of the formation, the most frequent occurrence of landslides occurs in the northern and southern silty and subtropical slopes of the southern slopes of the southern slopes. And the best environmental management approach to reduce the risk of insecurity in the Binaloud Mountain Range, to identify vulnerable zones of danger, land allocation, and land use capability and to prevent land use change based on sub-optimal results.

Introduction: Observation and interpretation of geomorphic and sedimentary features and processes conducted after and possibly during the flood event are fundamental to developing a better understanding of the mechanisms responsible for channel changes Extreme flood events increase stream power and the rates of erosion and accumulation in the river channel. The geomorphological effect of a flood depends on the size of the stream, magnitude, and frequency of the flood event and on the physical properties of the channel, banks, and floodplain. In October 2015, following the occurrence of severe and sudden rainfall, three large and devastating floods occurred with a maximum instantaneous discharge of 230 m3 / s from 6 to 8 October in Ilam province. The floods caused major changes in the morphology of Ilam's main streams and rivers and caused various sediments and deposits in the bed and rivers of Ilam. Since few studies have been done in this field, this research was conducted with the aim of investigating the geomorphic sediment response of Mountain Rivers on the creation of flood landforms upstream of Ilam dam to severe flood events.

Extended Abstract:1- Introduction: Special and sensitive role of vegetation cover in ecosystem sustainability and moderating hazards such as floods, erosion and pollution of water resources persuades us to understand the environmental variables affecting the growth and development of it. This issue particularly is important for susceptible mountainous catchments. In these environments, geomorphic variables as special representative of environmental factors have close and interweaved relation to vegetation cover. So, knowledge of the relationships between geomorphology and vegetation can help us to better manage and maintain the mountainous ecosystems. The understanding requires analysis the spatial relationships and scientifically accurate spatial modeling. In this regard, the emergence and development of remote sensing (RS) and geographic information system (GIS) have widely improved modelling the spatial variations of vegetation cover. However, a few issues that are fundamental and important in geomorphic-vegetation relations must be noticed. Maybe, the scale is the most important issue in phytogeomorphic researches. This study aimed to assess and determine the relationships between geomorphology and vegetation cover using spatial regression approach in Arasbaran catchments (3 catchments: Naposhtehchhay, Ilginehchay and Mardanqumchay). We have particular stress for effect the scale on the relations and comparison of predictive regression models in multiple scales based on catchment and subcatchment divisions.

Extended Abstract: Geodiversity is a difference in the properties of rock, climatic conditions and landform susceptibility. Today, geological protection has been widely applied and mark as a new approach to protect geological heritage (Which is part of the natural heritage). In Iran not only the geological conservation methods have not been developed, the methods of evaluation and description of the geological heritage also has not been prepared. Thus, understanding the importance of these documents and preserve (what is called common heritage of humanity) is very essential. Conservation of nature and includes two varieties: Land variety and Biodiversity. In this regard, based on identifying the factors affecting terrestrial diversity, a map of land diversity of Mashhad city has been derived based on Landform's susceptibility. Therefore, based on the subjects described, land variety map of Mashhad province has been derived in present study to identify the factors affecting land diversity. In this regard, overlying and Vikor methods have been evaluated. Results show that the results of these methods are good agreement with each other.

Introduction: The Monitoring on route changes trend and geometric pattern of rivers is essential for identifying and evaluating eventual problems and risks in order to maintain and optimize utilization of natural resources and it is among the priorities of Geomorphology Studies. The purpose of this study is analysis of affecting factors in Kalghan Chai River and Assessment of river power and effects on the river morphology influenced by human actions is changing the river shape. The Kalghan Chai Basin is part of the Ghezel Ozen basins, which is the Garango River is its main drainage. This is located at the position 28° 46 to 30 46 east longitude and 34 37 to 46 37 north latitudes on the eastern slopes of the Sahand Mountains. In this research, studied region is range between Kalghan Dam to connect Garango River.Material and methods: In study in order to achieve research goal were used techniques and different methods, materials of research are include of Satellite Image, Topographic map, Geological map, flow Hydrological data, data provided from Dem and field data. In this research were used methods of River Power Analysis, River specific power, Sinuosity Index, Central angle, Route Sinuosity in order to channel pattern and dynamic analysis. In order to study the river power and its effect on the erosivity, River discharge was calculated in different return periods. Then the river power was calculated by the following equation: The flow power can also be expressed in units of the bed surface if the width of the river (W) is divided, Therefore, in order to express the power of the river at any point, it is necessary to calculate the special power of the river, is calculated by the following equation: w=γQS/W. To study the shape and pattern of the river, coefficients Sinuosity Index, Central angle, Route Sinuosity were used. Then the Sinuosity Index size for each arc was calculated by the following equation: The center angles of the arches on each of the intervals were calculated using the following equation. The sinuosity of the river route was also calculated using the following equation:Results and discussion: The analysis of the characteristics of river meandering on the basis of Sinuosity Index showed that the Sinuosity Index of the study area was 1.31. And more than 90% of the curvature range is from 1.05 to 1.5, and the curvature is more than 1.5, 89% of the meandering of the study area. There are no curvatures of less than 1.05 and no more than 2 in any of the studied meanders. Therefore, the pattern of the river in study area is sinuosity. The sinuosity analysis of the river interval also showed that of the 20 interval studied, there is no Meandering interval, And 7 interval are straight pattern the rest of the interval has a sinuosity pattern. River Power Analysis showed which has the maximum River power of the Sections 20, 21 and 22, the lowest of river power are at Sections 11, 12, 13, 14 and 15. The lowest of specific river power in the sections of 19, 21 and 6. And the maximum river power in the section of 9.Conclusion: Results indicated that forming of channel pattern and dynamic in studied area was controlled by hydrological processes cased flow and sediment discharge, lithological resistance of river bed and sides and the role of human factors for capture and occupation of the river bed to create gardens and farms as well as at some sections the main factor shaping is the Chanel of removal of sand from the river bed. The results of flood power and specific power analysis showed by reducing the width of the river crossing, river power increases, and the flood power depends on morphological characteristics of the river The results of this study can be used to identify of interval Maximum River power and interval affected by river erosion.

Introduction: Iran Country located in arid and semiarid region in terms of quality and quantity Of water and always faced to the problem of shortage of water resources. Khorramabad river is one of the most important rivers and water resources in the Western part of Iran is located in a mountainous region.The River as one of the vital arteries of the city of Khorramabad for managers and planners is very important. Classification is one of simple and applied methods in transfer of knowledge and management tasks. River management plans and engages to natural processes have the most effects on environmental, social and economic conditions. By considering recent year’s flash floods in Khorramabad city which have damages on human beings and properties, and this fact that the river has an important role in supply of water in the region and west part of the country, it is necessary to.Methodology: In this study, based on three factors, landscape, pattern river and limitations of river bed of Khorramabad river, we using field observations of the study area, the correction of geometric and mosaic of four sin of satellite images data of Kartosat P5, IRS satellite data by 2.5 resolution of the river basin, we present a classification scheme by a tree stage classification and by using Spss software we have clustering finding and compare it to real states of river by field observations. Classification factors for geomorphic pattern were: landscapes, plan, of river bed and finally limitation of river bed. So landscapes categorized to high mountains, low elevation and plains. In second categorizing we used river pattern as main factor and find tree reaches. Generally, Khorramabad River has 12 segments, include 3 meandering sections, one anastomosing section and 8 straight parts.Results and discussion: according to our classification method the case study river, Khorramabad by a 64 km length, have 32.72 km of straight section, 25.2 km of meandering pattern, and 1.08 km of anastomosing plan. There was not braided river pattern in the study area. By considering bed confinement (limitation), we find 9 segments which segments 2,4,5 and 6 were inside the first class, segments 7,8 and 9 in second class, segment 3 and segment 1 in third and fourth class respectively. The main factor of separation of these segments and making classification was the landscape factor. River pattern was the main factor in the 3rd segment of the river.Conclusion: This classification for rivers can help users and water resources planners and mangers to spend less time and cost for categorizing and managing water resources, but field geomorphic observations and modifying systems results and statistical findings is a main toll that should be used to make a reasonable and reliable classification.