آرشیو

آرشیو شماره ها:
۴۹

چکیده

چکیده طرح مسئله: امروزه افزایش جمعیت انسانی ضرورت روزافزونی برای اشغال زمین های پیرامون مناطق سکونتگاهی را به وجود آورده است که این نیاز با شاخص های ژئومورفیک هر منطقه ارتباط تنگاتنگی دارد. اگر روند ایجاد سکونتگاه های جدید بدون تناسب با ظرفیت ها و امکانات طبیعی شکل بگیرد، آثار و نتایج نامناسبی در فضای کالبدی-زیستی درون شهری از قبیل بروز مخاطرات طبیعی، برهم زدن تعادل محیط زیست و اختلال در امر خدمت رسانی را به وجود می آورد. براساس مطالعات مختلف، بین مؤلفه های ژئومورفولوژی و سکونتگاه های انسانی ارتباط نزدیکی وجود دارد. این مؤلفه ها گاهی سبب رشد و تبلور کانون های مدنی و پیدایش و گسترش سکونتگاه ها شده و گاهی نیز برای این کانون ها پرمخاطره جلوه و دافعه ایجاد کرده اند؛ بنابراین شناخت ویژگی های محیط طبیعی و توانمندی های لندفرم هایی سطح زمین برای تمیز و تشخیص نقاط مناسب و پایدار به منظور ایجاد و توسعه استقرارگاه انسانی اهمیت و ضرورت دارد. هدف: هدف پژوهش حاضر، بررسی و تحلیل نقش عوامل و مؤلفه های ژئومورفیک در شکل گیری، توسعه، تحول و الگوی استقرار سکونتگاه های پیرامون کوه بزرگ شیرکوه در منطقه خشک و گرم ایران مرکزی است. روش: برای انجام این پژوهش از نقشه های توپوگرافی و زمین شناسی، تصاویر گوگل ارث و مهم تر از همه مطالعات و مشاهدات میدانی بهره گرفته شد. روش انجام کار نیز پدیدارشناسی توصیفی بوده است. نتایج: نتایج این پژوهش، حاکی از الگوی متفاوت سکونتگاه ها در دامنه های شمالی و جنوبی و همچنین غربی و شرقی شیرکوه است به گونه ای که اغلب سکونتگاه های واقع در ارتفاعات بالای دامنه های جنوبی در خط تعادل آب و یخ، در محدوده ارتفاعی 2450-2550 متر و در دامنه های شمالی، این محدوده ارتفاعی بین 1700 تا 1650 متر متغیر است. تحلیل ها نشان دهنده آن بود که مهم ترین عامل ایجاد سکونتگاه ها در وهله نخست، لندفرم های یخچالی و در وهله بعد دریاچه های کواترنری (چاله های کویری کنونی) و سواحل آنها بوده است؛ در حالی که لندفرم های جریانی ازجمله تراس های رودخانه ای، مخروط های افکنه و دشت سرها، حتی با داشتن منابع آب به نسبت خوب، برخلاف اغلب مناطق دیگر ایران و جهان، نقشی در به وجود آمدن این سکونتگاه ها نداشته اند. استقرار بر روی لندفرم های یخچالی در ارتفاعات بالای 2000 متر به احتمال به دوره های بسیار خشک و گرم و استقرار در حاشیه چاله های کویری کنونی به دوره های سرد کواترنر پایانی برمی گردد. نوآوری: این پژوهش نشان دهنده آن بود که اگرچه براساس مطالعات قبلی اغلب مراکز سکونتگاهی ایران اعم از شهری یا روستایی، به ویژه در بخش های مرکزی و شرقی بر روی مخروط افکنه ها استقرار یافته اند (حتی برای سکونتگاه های پیش از تاریخ)، مخروط افکنه ها به دلیل بارش های شدید رگباری و شدت سیلاب ها در هیچ جای منطقه موردمطالعه، تا قبل از سه دهه گذشته، هرگز مورداستفاده برای ایجاد سکونتگاه قرار نگرفته است؛ همچنین مطالعه نشان دهنده آن بود که لندفرم های یخچالی ارتفاعات بالا، بنا بر دلایل خاص اقلیمی، مطلوب ترین مکان برای ایجاد و تحول سکونتگاه بوده است.

The Roles of Geomorphological Factors and Change of Morphoclimatic Systems in the Formation and Evolution of Human Settlements in Central Iran (Around Shirkuh, Yazd City)

Abstract: Problem definition: Geomorphic phenomena have a primary impact on the locations, dispersions, spheres of influence, physical developments, and morphologies of settlements. In other words, geomorphic units and topographic elements are very important in physical development of settlemenets and play a significant role in the spatial distribution patterns of cities, as well as influencing the morphologies, constructions, and textures of them. Accordingly, location, orientation of mountains, and the type of landform have an undeniable role in issues such as urban construction and urban population movement. Nowadays, the increase in human population has created an increasing need to land occupation around residential areas; this is closely related to the geomorphic indicators of each area. Then, if the process of creating new settlements is formed with no proportion to natural capacities and facilities, it will create adverse effects and results in the physical-biological problems of cities, such as natural hazards, which cause disturbing the balance of the environment and disrupting services. Evidence of hazards in recent years show that most developing countries, especially in their rural areas, have high-risk physical structures that are often vulnerable to hazards. Therefore, based on various studies, there is a close relationship between geomorphological components and human settlements. These components have sometimes caused the growths and developments or emergence and expansions of settlement centers, which have sometimes appeared to be dangerous and repulsive. Therefore, recognizing the natural environment characteristics and the features and capabilities of landforms is important and necessary for identifying suitable and sustainable points for the creation and development of human settlements. Purpose: The purpose of this study was to investigate and analyze the roles of geomorphic features and components in the formations, developments, evolution, and patterns of settlements around Shirkuh Mountain in the arid and warm region of Central Iran. Methodology: To do this research, topographic and geological maps, Google Earth images, and, most importantly, field studies and observations were used. This study was based on descriptive phenomenological method. Accordingly, geomorphological factors, including altitude, direction, and lithology, geomorphic features, including fluvial landforms, such as alluvial plains, alluvial fans, plains, lake and river terraces, and glacial landforms like cirques, valleys, and glacial terraces were surveyed and analyzed. Then the role of each factor in the creation, development, and transformation of the settlements was studied and evaluated. Results: The results showed a different settlement pattern on the northern and southern slopes, as well as the western and eastern slopes of Shirkouh. Most of the settlements of the southern slopes were located at high altitudes between 2450-2550 m along the ice-water equilibrium line. However, the settlement range elevation on the northern slopes varied between 1700 and 1650 m, while fluvial landforms, such as river terraces, alluvial fans, and pediments, had not played a role in the formations of these settlements even with relatively good water resources unlike most other parts of Iran and the world. The settlement on glacial landforms at altitudes above 2000 m probably dated back to very dry and hot periods and the settlement on the edge of the current playa depression referred to the Late Quaternary cold periods. The formations and developments of settlements in the two completely different environments and climatic conditions, namely the high altitudes and the margins of the downstream depressions, indicated a climate change and consequently vertical displacements of the settlements along the Holocene. The results also revealed that other factors, such as geographical direction, altitude, slope, and lithology, had played an effective role in the densities and developments of these settlements. Innovation: This study showed that the alluvial fans had never been used to build a settlement anywhere in the study area until the last 3 decades due to heavy rainfall and heavy flooding. Although according to previous studied, most of the settlements in Iran, whether urban or rural settlements, especially in the central and eastern parts, have been located on alluvial fans, even the prehistoric settlements. Also, this study showed that glacial landforms located at the high altitudes had been the most desirable place for the creation and transformation of settlements due to specific climatic reasons.   Introduction  Geomorphic phenomena have a primary impact on the locations, dispersions, spheres of influence, physical developments, and morphologies of settlements. In other words, geomorphic units and topographic elements are very important in physical developments and play a significant in the spatial distribution patterns of cities, as well as influencing the morphologies, constructions, and textures of settlements. Accordingly, location, orientation of mountains, and the type of landform have an undeniable role in issues such as urban construction or population movement. Nowadays, the increase in human population has created an increasing need for land occupation around residential areas. This issue is closely related to the geomorphic indicators of each area. If the process of creating new settlements is formed with no proportion to natural capacities and facilities, it will create adverse effects and results in the problems of physical-biological spaces of cities, such as natural hazards, disturbing the balance of the environment, and disrupting services. Evidence from the hazards in recent years shows that most developing countries, especially their rural areas, have high-risk physical structures that are often vulnerable to hazards. Therefore, based on various studies, there is a close relationship between geomorphological components and human settlements. These components have sometimes caused the growths and developments or emergence and expansions of settlement centers, which have sometimes appeared to be dangerous and repulsive. Therefore, recognizing the natural environment characteristics and the features and capabilities of landforms is important and necessary for identifying suitable and sustainable points for the creation and development of human settlements. The purpose of this study was to investigate and analyze the roles of geomorphic features and components in the formations, developments, evolution, and patterns of settlements around Shirkuh Mountain in the arid and warm region of Central Iran.   Material and Methods  To do this research, topographic and geological maps, Google Earth images, and, most importantly, field studies and observations were used. The method of research was descriptive phenomenology. Based on this, geomorphological factors, including altitude, direction, and lithology, geomorphic features, including flow landforms, such as alluvial plains, alluvial fans, plains, lake and river terraces, and glacial landforms, such as cirques, valleys, and glacial terraces, were surveyed and analyzed and the role of each factor in the creation, developments, and transformations of the settlements was studied and evaluated.   Results The results showed a different settlement pattern on the northern and southern slopes, as well as the western and eastern slopes of Shirkouh. Most of the settlements of the southern slopes were located at high altitudes between 2450 and 2550 m along the ice-water equilibrium line. Nevertheless, the settlement range elevation on the northern slopes varied between 1700 and 1650 m, while fluvial landforms, such as river terraces, alluvial fans, and pediments, had not played a role in the formations of these settlements even with relatively good water resources unlike most other parts of Iran and the world. The settlement on glacial landforms at altitudes above 2000 m probably dated back to very dry and hot periods and the settlement on the edge of the current playa depression referred to the Late Quaternary cold periods. The formations and developments of settlements in the two completely different environments and climatic conditions, namely the high altitudes and the margins of the downstream depressions, indicated a climate change and consequently vertical displacements of the settlements during the Holocene. The results also showed that other factors, such as geographical direction, altitude, slope, and lithology, had played an effective role in the densities and developments of these settlements.   Conclusion This study revealed that the alluvial fans had never been used to build a settlement anywhere in the study area until the last 3 decades due to heavy rainfall and heavy flooding. Although, according to previous studies most of the settlements in Iran, whether urban or rural settlements, especially in the central and eastern parts, have been located on alluvial fans even the prehistoric settlements. Also, this study showed that glacial landforms located at high altitudes, had been the most desirable place for the creation and transformations of settlements due to specific climatic reasons.   Keywords: settlement, geomorphology, glacial landform, Shirkouh, Yazd City   References - Aucelli, P. P., Valente, E., Di Paola, G., Amato, V., Cesarano, M., Cozzolino, M., ..., & Rosskopf, C. M. 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In Existential-Phenomenological Perspectives in Psychology (pp. 41-60), Springer, Boston, MA. - Sharifi Paichoon, M. and Shirani, M. (2017). The effect of the geographical direction on alluvial fan dimensions (Case study: Shirkouh-Yazd). <em>Journal of Arid Regions Geographics Studies</em>, Vol. 7(28), 105-122. - Sharifi Paichoon, M. (2020). Analysis of the origin, formation, and development of sand ramps on the eastern slopes of Shirkouh, Yazd, Central Iran. <em>Geomorphology</em>, 351, 106-891. - Sharifi Paichoon, M. (2021). Tectonic geomorphology and Quaternary evolution of playas: A case study of Ernan Playa, central Iran<em>. Arabian Journal of Geosciences</em>, 14(13).  

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