Hydrogeomorphology
Masoumeh Rajabi; Fatemeh Rangraz Forough
Abstract
There are various types of tourism depending on the motivation for travel, one of which is health tourism. Health tourism has grown significantly in recent years due to the spread of machine life and psychological pressures. This type of tourism includes individuals and groups who travel for medical ...
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There are various types of tourism depending on the motivation for travel, one of which is health tourism. Health tourism has grown significantly in recent years due to the spread of machine life and psychological pressures. This type of tourism includes individuals and groups who travel for medical treatment, such as using mineral and warm waters, spending time in recovery, and so on. As one of the natural resources, hot springs are a part of health tourism that are used to treat various medical conditions. The current research focuses on the hot springs of East Azerbaijan province. The study is descriptive-analytical in terms of methodology and applied in terms of purpose. Due to its geographical location, climatic features, and geological and tectonic conditions, East Azerbaijan province is considered one of the important centers of hot springs, which are concentrated around Sahand mountain and Bozgoush mountain range in the northeast of Kalibar. This research uses the Comanescu method, library research, Internet-based surveys, documentary studies, and surveys of 20 experts from the Regional Water Organization and the Provincial Tourism Department, Motalleq Hot Springs, Bostan Abad, Asbforoushan, Allah. Haq, Isti Su Liqvan, Yel Sui, Top Tapan, and Dash Alti were selected and evaluated. The results revealed that the Motalleq Hot Spring, with a total score of 86, has the highest score among the eight selected springs. The Asbforoushan hot spring comes in second with 84 points, the Yel Sui hot spring comes in third with 82 points.
sayedeh masumeh mousavi; Mohammad Hossein Rezaei Moghaddam; Masumeh rajabi
Abstract
Landslides claim the lives of thousands of people around the world each year, causing enormous damage to people and governments. Landslide risk zoning divides landslides into specific and distinct areas of potential and actual degrees in terms of risk, this process is based on recognizing the qualitative ...
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Landslides claim the lives of thousands of people around the world each year, causing enormous damage to people and governments. Landslide risk zoning divides landslides into specific and distinct areas of potential and actual degrees in terms of risk, this process is based on recognizing the qualitative characteristics of the area and quantitative modeling based on the data of the study area. This can be the basis for long-term planning at the regional and local levels.The purpose of this study is to investigate and zoning landslide risk in the Yellow River Basin located in the east of Khuzestan province using fuzzy logic method; For this purpose, first through field visits, geological maps and topography and by reviewing previous sources and reviewing the conditions of the region; Nine factors: elevation, slope, direction of slope, distance from fault, distance from river, distance from road, precipitation, lithology and land use were considered and selected as effective factors on landslide occurrence. Landslide hazard zoning maps were prepared using fuzzy gamma operator with values of 0.7, 0.8, 0.9. Then, the obtained maps were classified into 5 classes: very high, high, medium, low and very low.The results of the qualitative sum showed that the 0.9 fuzzy gamma operator is more suitable than other fuzzy operators. The results of the classified maps showed that 21.56% of the area in the high-risk zone and 43.24% of the area The area is located in a low risk zone.
Ahmad, Najafi Eigdir; Shahram Roostaei; Asadollah, Hejazi; Masomeh, Rajabi; nader Jalali
Abstract
1-Introduction Landslides are influential factors in human life that are not well-known. Several factors have contributed to the occurrence of landslide that could increase the risk of landslide in any area. Identifying these factors and their value can help to appropriate landslide zonation. The classification ...
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1-Introduction Landslides are influential factors in human life that are not well-known. Several factors have contributed to the occurrence of landslide that could increase the risk of landslide in any area. Identifying these factors and their value can help to appropriate landslide zonation. The classification of areas susceptible to sliding and hazard zoning is an important step in assessing environmental hazards and plays an indelible role in the management of catchment areas (Sakar, 1995). Therefore, knowing the most important factors affecting slip instability and slipping will help us to make developmental plans using appropriate methods. Therefore, by using statistical models, their vulnerability to landslide is identified and zoned by assessing and validating them. Landslide inventory map is the best method for designing a landslide hazard map based on aerial photo interpretation, field surveys, and historic landslides. Then, the spatial distribution of mass movements is presented as a point or polygon on the map. The purpose of this research is to investigate various and effective factors in the occurrence of landslides, as well as to evaluate and compare the effectiveness of statistical models in landslide hazard zonation in Nazlochai basin and introducing the most appropriate methods. 2-Methodology In order to investigate the landslide susceptibility zonation, the provision of a landslide inventory map is the most important part of the work, which can be done by using of geographic information systems with high accuracy. The accuracy of landslide zonation is largely dependent on this stage. So, at first, the existing landslides were identified by using various tools including aerial photos, satellite imagery (Google Earth), existing information, GPS, and in particular field surveys. In the present study, ten factors affecting the occurrence of landslides were considered: elevation, slope, gradient direction, distance from the waterway, distance from the road, distance from the faults, lithology, land use, rainfall and vegetation index .For landslide zonation, bivariate statistical models, including Gupta-Joshi model with its correction method, information value method, and surface density method have been used. 3-Results and Discussion For landslide hazard zonation using the Bivariate Statistical Models, various factors including elevation, slope, gradient direction, distance from the waterway, distance from the road, distance from fault, lithology, landuse, rainfall and vegetation index were studied. Existence and density of landslides in the western slopes show the role of geological formations, the distance from the waterway and precipitation in the occurrence of landslide. To evaluate the accuracy of the Bivariate Statistical Models, the density ratio index and the quality sum index were used. The more distinction between risk classes is, the model is more capable, and the quality sum index is used to compare the performance of different models. Finally, with respect to the resulting values, the zoning with the information value and surface density models were found to be desirable for the studied area. 4-Conclusion According to the results of zoning (using the Bivariate Statistical Models), lithology, distance from the waterways and precipitation are the most important factors controlling the landslide occurrence in the studied area. Particularly lithologic factors are of great importance. Most of the landslides in the study area occurred on limestone and conglomerate, which are similar to the results of the research Amir Ahmadi who worked for Iran, while these formations do not have enough area in the basin. Limestone and a small amount of dolomitic limestone with an occupancy level of 15.5% of the basin, contain more than 30% of landslides. More importantly, limestone is coinciding with north orientation that confirms the role of gradient direction in occurrence of landslides. Although some scholars ignore the role of gradient direction (A. Gemitzi, 2011), other researchers (Carrara et al., 1991; Roostaei et al., 2017) have taken it into account in their research. The impact of the human factor mainly depends on changing environmental conditions, such as road construction, inappropriate plowing, excessive grazing and water diversion for agricultural use. Therefore, by studying the researches in Iran and in different parts of the world, the slipping factors in different basins and regions are not the same and in fact, different slip conditions are present in different regions.
fatemeh parhizkar; Masume Rajabi; Mojtaba Yamani; Davoud Mokhtari
Abstract
1-Introduction For thousands of years, mangrove forests have played a significant role in the economy and sustainable livelihoods of human societies. Therefore, identifying and measuring changes in the boundaries of mangroves over time can play an important role in planning and conducting effective protection ...
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1-Introduction For thousands of years, mangrove forests have played a significant role in the economy and sustainable livelihoods of human societies. Therefore, identifying and measuring changes in the boundaries of mangroves over time can play an important role in planning and conducting effective protection measures and reducing the vulnerability of mangroves to natural and human hazards. This study aimed to investigate changes in mangrove forests and the relationship between these changes and marine hydrodynamics and coastal morphology in parts of the north and east of the Strait of Hormuz for 47 years. 2-Methodology In this study, Landsat satellite images, MSS, TM, ETM +, OLI sensors from 1972 to 2019 were used to monitoring mangrove forest changes in the west of the Hormuz Strait. In the next step, the necessary preprocesses (radiometric and atmospheric corrections) were applied to the images in ENVI 5.3 software. And the classification of images was done by SVM, MLC, and ANN methods, and considering that to finalize the land use map, all classification accuracy indicators should be adjusted with one or more valid statistical indicators. The kappa index and general accuracy are among the statistical methods used. Post-processing operations also included the integration of classes that were applied to make the land use map more eloquent and eliminate single pixels on different classes. In the next step, the Change Detection method was used to detect changes and tell the results of the classifications. The next step is to convert the classified image to polygon and transfer it to the Arc GIS environment to manage the classes. Of course, the class that is most important to us here is the Mangrove Forest class, which was examined in the period 1972-2019. After the changes in the mangrove forests were identified, with the help of 1: 25000 topographic maps, contours of 2 meters of the range were prepared and the slope map was prepared using DEM images of the area. Also, using the half-hour tide data, the minimum, maximum, and average tide rates of Jask, Shahid Rajaee, Hormoz, and Sirik stations were calculated and finally, these data and maps were prepared to examine the development potential of mangrove forests. 3-Results and Discussion Land use maps were developed using Landsat images using three pixel-based classification algorithms (MLC, SVM, ANN) and the accuracy of the results was assessed using random points. The results showed that the highest overall accuracy and kappa coefficient were 99.44 and 0.99 for region A, and 98.41, 0.97, for region B, for SVM, respectively. Our study showed that SVM could be the most appropriate classification method for this study area. Therefore, SVM land use maps were prepared for the study area for 1972, 1987, 2002, and 2019. After preparing the land-use change map, it was stated that mangrove forests in region A accounted for 55.84% and in region B for 36.18%, tidal areas in region A accounted for 27.63%, and in Area B is 36.58 percent, Water Areas A is 3.04 percent, Area B is 1.78 percent, dry land is 15.37 percent and region B is 99.99. 7% have changed over the past 47 years. To explore the potential for the expansion of mangrove forests, we examined the slope of the region and its relationship with the average tide in the region. Comparing the results of the increasing and decreasing trend of mangrove forests with curves corresponding to the average tidal level and morphological features of the region, we conclude that the study area is about the hydrodynamic characteristics of the sea such as the average tidal area and extent. The catchment area, the height of the waves, and the coastal morphology such as slope and sediments and the water entering the areas from the Hasanlangi River and the Gaz and Hivi rivers have a very high potential for further development of mangrove forests. 4-Conclusion The results show that in the northern part of the Strait of Hormuz, the area of mangrove forests has increased in all the years, but in the eastern part of the study, we have always faced a decreasing and increasing trend and we don't see this part significant development during these 47 years in mangroves. However, according to the study of the geomorphic features of the region such as slope, topography, and the presence of Sabkha and Firth and sediments from the rivers of Hassan Langi, Gaz, and Hivi, as well as the average tide of the region and the vast area it covers, The study has the potential to develop mangrove forests. The results of this study can provide significant information about the progress or regression of mangroves in different coastal areas, can significantly help to implement protection measures and rehabilitate Iranian mangroves.
Masoumeh Rajabi; Shahram Roostaei; Bahareh Akbari
Volume 6, Issue 20 , December 2019, , Pages 21-40
Abstract
1- IntroductionRiver morphology is the science of knowing the river system regarding general shape and form, dimensions and hydraulic geometry, direction and longitudinal profile of the bed, and the process and quality of its changes. The river plan is divided into three classes of direct, braided (multi-branch) ...
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1- IntroductionRiver morphology is the science of knowing the river system regarding general shape and form, dimensions and hydraulic geometry, direction and longitudinal profile of the bed, and the process and quality of its changes. The river plan is divided into three classes of direct, braided (multi-branch) and meandering river in terms of the morphological structure of the river, among which the meandering pattern has attracted the most attention due to its abundance in nature. In order to describe the pattern of the meandering streams, a number of geometric parameters related to the river plan have been defined. By analyzing the frequency and magnitude of these characteristics along the river and at different times, the river changes in the temporal and spatial dimension can be examined. These parameters Such as the length of the pontoon, the width of the pontoon, the width of the river and the length of the river. The purpose of this study is to examine the characteristics and patterns of the Aji Chai River. These parameters are such as the length of meander, the width of meander, river width, and the length of the river. The purpose of this study is to examine the characteristics and pattern of the Aji Chai Rivers’ meanders. 2- MethodologyThe study area was part of Aji-Chay River (Bakhshayesh to Khajeh) with an approximate length of 50 km, located in the northeast of Tabriz. The following materials are used in this study:1) Topographic map of 1:50000 and 1:250000 scales were used to examine the morphology of the study area,2)Geological maps of 1:250000 and 1:100000 scales for the analysis of geological and tectonic characteristics of the study area and 3)Using Landsat-8 and Google Earth satellite images and the ArcGIS, Excel, Autocad softwares.The study area was divided into three reaches. Some circles fitted to the meanders in the AutoCAD environment and the geometric characteristics such as wavelength, arc length, and radius of curvature of the circle, which is tangent to the river path, were measured to calculate the curvature coefficient (S = c / v) and the central angle (c/Rπ = ϴ 180). Then specification of each of the circles of the same samples was obtained and then in the EXCEL software, a plot of the samples was drawn. 3- ResultsDue to the long-range of the study area, the intended path was divided into three reaches. In terms of the central angle index in the first reach, the most frequent central angle was 62.5%, which is related to developed meander pattern. In the second reach, the highest frequency of central angle with 56% was related to the developed meandered pattern. In the third reach also the most frequent central angle was related to the developed meander pattern with a frequency of 57.5%. By comparing the three studied reaches in terms of the central angle index in general, it is concluded that all three reaches have a meandering pattern, in particular, a developed one, so that the average of all three reaches (the first reach 110.2, the second 118.2, and the third 123.1, respectively) are in the developed meandering pattern category (85-158). In each of three reaches, the most frequent central angle belongs to the developed meandering pattern.The average curvature coefficient of the reaches, calculated by dividing the sum of frequencies in each reach by the total number of samples of each reach, is as follows: in the first reach, the average curvature coefficient was 1.18 which is in the range of 1-06 – 1.25 showing a sinusoidal pattern. In the second reach, the average curvature coefficient is 1.30, which is in 1.25-2 range, also has a meandering pattern. In the third reach, the average is 1.26, which is the same as the second average in the range 1.25-2 and the pattern is meandering. In general, the pattern of flow in the first reach was sinusoidal and with the increase of arches in the second reach, it changed to the meandering pattern. In the third reach, although, there was a minor reduction trend was, it retained the meandering pattern. 4- Discussion and conclusionBased on the results from the morphometric indices, including the central angle and curvature coefficient in the studied area, the total mean of the central angle in the three reaches is 126.1 degrees, which is in the range of 85-158, showing the developed meandering pattern in the river morphology.The mean curvature coefficient in the three studied reaches is 1.25, which is in range 1.25-2, takes the meandering pattern in terms of curvature coefficient, so the studied river has a meandering to developed meandering patterns.The findings of the study indicate that the study area has a nearly uniform and smooth slope, and considering the fact that the existence of a gradient is a significant factor affecting the development of the developed arcs and meander formation, as a result, in determining the river pattern and morphology of the study area, the topography factor had the first priority.Due to the fact that erodible formations cover most of the area, the factor of lateral erosion in low-slope areas has been effective in the warping of the river path due to the presence of loose and erodible sediments.
