علوم غیرزیستی دریا
Shiva Mohammadi Shamsabadi; Hakimeh Amanipoor; Sedigheh Battaleb-Looie; Sayed Hussein Roshun
Abstract
In this study, to investigate the hydrological regime and determine the environmental flow requirement of Beshar River at the Pataveh hydrometric station, hydrological methods (Tennant, Tessman, flow duration curve shifting) and hydraulic methods (wetted area) were used. For this purpose, the river flow ...
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In this study, to investigate the hydrological regime and determine the environmental flow requirement of Beshar River at the Pataveh hydrometric station, hydrological methods (Tennant, Tessman, flow duration curve shifting) and hydraulic methods (wetted area) were used. For this purpose, the river flow data were used in the statistical period of 1998-2020. First, the homogeneity and normality of the data were checked with the Run and Klomogrov-Smirnov tests. Then the hydrological characteristics of the stream were calculated in the IHA software. Finally, the environmental flow (EF) for the desired station was obtained with the above-mentioned methods. The results of this research showed that the flow rate has decreased for at least one to 90 days and the continuous period for the minimum annual flow has increased, which can be a threat to the life of plants and animals of the Beshar river ecosystem if the increasing trend continues. The environmental flow for semi-saturated and dehydrated periods by using Tennant's method were determined at 3.99 and 11.97 m3/s, respectively. Also, the environmental flow by the Tessman method indicated that the environmental demand is particularly important in the low water season and the first half of the full water period, and this amount of flow should be maintained to prevent the destruction of the river ecosystem. In the FDC-Shifting method, the environmental flow requirement (EFR) in Class A (normal), 69.60%, in class B (slightly changed) 50.10%, in class C (relatively changed) 37.80%, in Class D (largely changed) was 29.70%, in class E (severely changed) 24.20% and in class F (critically changed) 20.10%. Based on this, the FDC-Shifting class C method with an EF of about 72.54 cubic meters per second was selected as an environmental component. The environmental flow series in class C showed a decrease in flow rate over time. Based on the hydraulic method of the wet environment, the amount of environmental flow required was found to be about 20.6% of MAR.
علوم غیرزیستی دریا
Mohammadali Roshani; Mehdi Mumipour; Hakimeh Amanipour
Abstract
Landslides are a kind of mass movement that has significant human, financial and environmental damage. Due to the destructive effects of this phenomenon on socio-economic and natural systems, it is essential to identify areas prone to mass movement and landslides throughout the country for use in land ...
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Landslides are a kind of mass movement that has significant human, financial and environmental damage. Due to the destructive effects of this phenomenon on socio-economic and natural systems, it is essential to identify areas prone to mass movement and landslides throughout the country for use in land use planning. Sadat Hosseini region is sensitive to landslides due to its lithological, climatic and land use location, young roughness with high altitude differences and steep slopes. human activities Therefore, further studies in the region seem necessary. Three models have been used for landslide sensitivity zoning in the study area including Anbalagan, Haeri-Samiei method and AHP. In this study, lithology criteria, slope, type of land use and vegetation, slope direction, river length and seismic path and altitude classes have been used to identify landslide sensitivity. Effective factor maps were prepared in GIS environment and using GIS tools and statistical analysis, landslide sensitivity zoning map was obtained. The results of the output of the models showed that in landslide sensitivity zoning using the Anbalagan model, 0.01, 33.26, 48.20, 25.35, 90.17% of the area in the sensitivity classes are very low, respectively. , Low, medium, high, very high. Adaptation of landslide sensitivity zoning maps in the study area based on the three models as well as the current status of landslides shows that most landslides are seen in young alluviums consisting of barracks and young alluvial fans. Also, the results of the Anbalagan model in the region are more in line with the existing reality.
علوم غیرزیستی دریا
Heeva Elmizadeh; Hadi Mahdipour
Abstract
The purpose of this research is the automatic recognition of morphic patterns of drainage network in the center of Lahijan River using High Resolution Panchromatic Remotely Sensed (HR-PRS) and fuzzy clustering algorithms. It also investigates the efficiency of these methods in the GeoEye-1 satellite ...
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The purpose of this research is the automatic recognition of morphic patterns of drainage network in the center of Lahijan River using High Resolution Panchromatic Remotely Sensed (HR-PRS) and fuzzy clustering algorithms. It also investigates the efficiency of these methods in the GeoEye-1 satellite imagery segmentation of the study area in order to detect geomorphic features. In this regard, fuzzy segmentation of HR-PRS panchromatic images of the study area, after radiometric and geometric preprocessing using FWS, MSA, IDF and CFM algorithms, was performed in MATLAB software. Finally, the studied fuzzy clustering algorithms with fuzzy parameters are applied to the input HR-PRS images and the results are discussed. The results show that the Classical Fusion Method and FCM (CFM) clustering algorithm has the best performance in the field of fuzzy segmentation and detection of the studied indices. This algorithm can also reduce and improve segmentation problems due to the overlap of spectral features between classes of clustering results and well identify spatial phenomena and clusters with different sizes, shapes and densities. As a result, the image borders are well defined. The reason for this is the use of fuzzy numbers as well as efficient clustering methods in this method. These results also show that remote sensing technology, by providing multi-time images, can be a very good basis for monitoring and detecting environmental changes, detecting effects and accurately extracting information from images. Also, the use of clustering algorithms and fuzzy features is a suitable and optimal method for integrating HR-PRS satellite image information from a geographical area with the aim of segmentation.
علوم غیرزیستی دریا
Siavosh Shayan; Zahra Dadashzade; Mojtaba Yamani; r l
Abstract
The importance of scale issues in geomorphic studies is the definition of wide variables in the analysis of levels with different scales that are projected according to goals and abilities. Considering that in sedimentary cell systems, there are processes that operate on a wide range of scales, it is ...
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The importance of scale issues in geomorphic studies is the definition of wide variables in the analysis of levels with different scales that are projected according to goals and abilities. Considering that in sedimentary cell systems, there are processes that operate on a wide range of scales, it is important to determine the appropriate scale for studying these processes and their forms. In this study the coasts of Hormozgan province due to the diversity of landforms and coastal processes in its western and eastern parts was investigated. This coastal is divided into 6 cells and 17 sub cells based on geomorphologic unit and wave and currents pattern. 1: 25000 topographic map, 1: 100000 geology map, LandSat 5 satellite images, hydrodynamic data, wind, hydrology and large port dredging and sedimentology data were used for this purpose. This data was analyzed in ArcGIS 10.2 and coastal environment were classified based on common features of the form and process. Also an appropriate scale was determined for studying littoral cells based on our aim. The results indicated that all of these scales should be considered to determine management strategies. Studies have shown that scales used for coastal study include system scale (large scale), subsystem scale (moderate scale) and landform scale (small scale). temporal and spatial scales in the form of a littoral cell are in a moderate scale. It can be concluded the medium scales are usually of greatest interest for coastal management.
مهندسی دریا
maryam yaghoubzadeh; Afshin Danehkar; Bahman jabbarian amiri; Sohrab ashrafi
Abstract
We used 6 criteria and 29 indicators for determination environmental sensitivity of geomorphologic aspects of the coastal area in Hormozgan. Identification and determination of the important coefficient showed exclusivity and wilderness are the most important coefficients and industrial dependency had ...
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We used 6 criteria and 29 indicators for determination environmental sensitivity of geomorphologic aspects of the coastal area in Hormozgan. Identification and determination of the important coefficient showed exclusivity and wilderness are the most important coefficients and industrial dependency had the lowest priority for determination of the environmental sensitivity in this regard.Moreover, in order to, determine importance and priority of sensitivity of ecosystems in the study area 9 physical structure were studied in both shore and coastal zone (include: 4 structure in coastal area and 5 structure in shore area). According to the results, Inundated mudflat and in shore area and Low flat land in coastal area are of the most important sensitivity .After reviewing the physical structure and preparation map of overlaying this structure, sensitivity zoning was developed coastline in Hormozgan province on 5 class of sensitivity, Very low sensitivity, low sensitivity, moderate sensitivity, high sensitivity and very high sensitivity. Zoning of sensitive physical structure in coastal zone shows the lowest extent areas are in Low sensitive degree and the most extent areas are in moderate sensitive degree in physical sensitivity classes.According to the results, shore area in Hormozgan province that includes 11.35% of coastal zone has high physical sensitivity. In shore area Inundated Mudflat, Rocky shore and Inundate beach have most physical sensitivity and inundated process is the most important phenomena on the structures mentioned the shores. The most sensitive of coastal area is Low flat land.
علوم غیرزیستی دریا
Siavosh Shayan; Mohammad Akbarian; Mojtaba Yamani; Mohammad Sharifikia; Mehran Maghsoudi
Abstract
The instability and mobility of sand dunes is a major concern of planning and management in arid coastal plain. Usually, the dune systems are created based on several factors and elements. In order for environmental planning and management in coastal zone, the study of their formation and development ...
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The instability and mobility of sand dunes is a major concern of planning and management in arid coastal plain. Usually, the dune systems are created based on several factors and elements. In order for environmental planning and management in coastal zone, the study of their formation and development process has a major task. The present study is dale with factors identify for sand masses main processes and formed in western part of Makran coastal plain. Data set consist of spatial map of landforms distributions, winds velocities and directions, fetch length as well as dynamic waves were collected and processed. These data along with thematic maps of geology and topography as well as remotely sensed data (satellite images and aerial photographs) were used for further processing and analysis. The Geomorphologic units map was generated as first step. Next wind and wave rose's diagrams were provided. Furthermore, elongation and direction of sand masses movements was extraction form multi-temporal and multisensory data. Main rivers monthly discharges were analysis related to their hydrometric water stations and previous studies. Results indicate that location and distribution of coastal sand masses isn’t functioned by wind; it's more affected by the geomorphologic characteristics of foreshore and coastal hydrodynamics. Also distribution of internal sand masses on coastal plain is more affected by the plain stretches relative to the prevailing wind direction and to the extent of the old beds and floodplain that are exposed along to the prevailing wind nether than wind function.
علوم زیستی دریا
m h; i gh
Abstract
به منظور پایش زمین شیمی پهنه کارون-اروند و بررسی پیامدهای زیستی ناهنجاریهای احتمالی به ویژه در خلیج فارس، فراوانی شاخصهای فیزیکوشیمیایی، عناصر اصلی و برخی آنیونهای ...
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به منظور پایش زمین شیمی پهنه کارون-اروند و بررسی پیامدهای زیستی ناهنجاریهای احتمالی به ویژه در خلیج فارس، فراوانی شاخصهای فیزیکوشیمیایی، عناصر اصلی و برخی آنیونهای فرعی 33 نمونه گردآوری شده از 6 مقطع حوضه کاون-اروند با بهرهگیری از روشهای تیتراسیون و فتومتر شعلهای تعیین گردید. بر اساس دادههای حاصل کمترین و بیشترین فراوانی T.D.S و سختی کل به ترتیب در مقاطع ایذه-باغملک ( 66/355 و 239 ppm) و آبادان (5/2867 و 825 ppm) مشاهده میگردد. PH رودخانه نیز در تمامی طول مسیر، تغییر شاخصی نشان نمیدهد. میانگین سالانه فراوانی عناصر مختلف نیز عبارتند از: Cl=507.92 > Na=324.72 > S=323.3 > Ca=122.86 > K=3.75. بررسی شاخصهای محیطی تأیید می-کند که شرایط اقلیمی و زمینشناسی به ویژه در نواحی مرکزی و جنوبی، سهم به سزایی در افزایش حجم ذرات معلق، سختی کل و فراوانی Na، Ca و S دارد. فعالیت های انسانزاد به خصوص پساب کارخانه صابونسازی خرمشهر را می توان مؤثرترین عامل افزایش غلظت Cl در مقاطع خرمشهر و آبادان برشمرد. ضریب بالای همبستگی (>9/0) عناصر قلیایی با سختی کل، نشان از رژیم کربناته آب پهنه کارون-اروند در بسیاری از مقاطع دارد که این امر نیز از بستر آهکی-تبخیری آن ناشی می شود. با وجود افینیتهی قوی فلزات قلیایی نظیر سدیم و پتاسیم به فسفات، .