فهرست مطالب

پژوهش های دانش زمین - پیاپی 39 (پاییز 1398)
  • پیاپی 39 (پاییز 1398)
  • تاریخ انتشار: 1398/06/01
  • تعداد عناوین: 14
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  • روح الله آدینه وند*، جابر مظفری زاده، زهرا سجادی، عبدالحمید انصاری صفحات 1-14
    با توجه به ارتباط منابع آب با محیط اطراف، شناخت برهمکنش این دو عامل می تواند دید مناسبی را جهت مدیریت بهینه منابع در اختیار قرار دهد. محدوده گله دار یکی از دشت های مهم صنعتی و کشاورزی در جنوب استان فارس می باشد که چه از لحاظ کمی و چه کیفی متاثر از این فرایند می باشد. در این تحقیق، عوامل کیفیت آب زیرزمینی دشت گله دار با تجزیه و تحلیل داده های کیفی چاه های بهره برداری انتخابی مورد بررسی قرار گرفت. از دیاگرام پایپر، نمودارهای ترکیبی، آنالیز آماری، تحلیل عاملی و بررسی نمایه های اشباع برای شناسایی منشا شوری و شناسایی عوامل تاثیرگذار بر روی کیفیت آب آبخوان دشت گله‌دار استفاده شد. آب زیرزمینی دشت گله دار دارای تیپ کلروره-سدیک و سولفاته-کلسیک می باشد، همچنین نمودارهای ترکیبی نشان می دهند که یک روند خطی واضحی بین سدیم و کلر و همچنین کلسیم و سولفات وجود دارد که حاکی از ورود آب های حاوی املاح هالیت و ژیپس ناشی از انحلال سازندهای اطراف و زمین های شور و نمکزارها منطقه می باشد. نتایج نشان می دهد که دلایل تخریب کیفیت آب های زیرزمینی در این دشت متعدد و ناشی از ورود آب های عبوری از نمکزارها، پساب‌های کشاورزی، آب شور رودخانه‌ها، و انحلال هالیت و ژیپس توسط رواناب های حاصل از سازندهای گچی اطراف دشت می باشد.
    کلیدواژگان: کیفیت منابع آب زیرزمینی، آنالیزهای آماری، نمودارهای ترکیبی، منشا شوری، دشت گله دار
  • علی بهرامی*، مهدی یزدی، حسین وزیری مقدم، عبداله قبادی، مارتین کوندرات صفحات 15-44
    در این پژوهش زیست چینه نگاری و سیستماتیک افق های حاوی مهره دار نهشته های کرتاسه پیشین (سازند داریان) در منطقه سیوند، واقع در 80 کیلومتری شمال شرق شهر شیراز مطالعه شده است. در مطالعه انجام شده، 5 راسته از ماهی ها (Aspidorhynchiformes, Clupeiformes, Ichthyectiformes, Pycnodontioformes and Semionotiformes) و یک جنس لاک پشت دریایی (Toxochelys) به همراه 9 جنس و 14 گونه از فرامینیفرها در قالب 4 زون زیستی شناسایی گردید که معرف سن آپتین پیشین (Bedoulian) تا ابتدای آپتین پسین (Early Gargasian) برای بخش های مورد مطالعه سازند داریان در برش سیوند می باشد: تجمع فسیلی 1: این تجمع در ابتدای سازند داریان در برش سیوند از قاعده تا ضخامت 16 متر این برش مشاهده می شود و شامل فونای Choffatella decipiens, textularids, و خرده های فراوان نرم تنان می باشد. این ضخامت احتمالا معادل زون 16 وایند (Wynd, 1965) (Hensonella-Orbitolina-Choffatella Ass. Zone) می باشد که از سازند داریان معرفی کرده و سن آپتین را برای آن در نظر گرفته است. تجمع فسیلی 2: این تجمع از ضخامت 16 تا 40 متر برش مذکور را حضور دارد. شامل فونای Radiolaria, Hedbergella sp., Globiogerinelloides sp., و اسپیکول اسفنج می باشد. این زون معادل زون 12 وایند (Wynd, 1965) (Radiolaria flood Zone) می باشد که وایند سن نئوکومین تا آلبین را برای آن در نظر گرفته است. تجمع فسیلی 3: این تجمع از ضخامت 40 الی 50 متر در برش مذکور مشاهده می شود. فونای این تجمع شامل: Hedbergella ruka, Hedbergella aptiana, Hedbergella roblesae, Hedbergella sigali, Hedbergella infracretacea, Globgerinelloides cf. trilobatus, H. luterbacheri, Globgerinelloides ferreolensis, Globgrinelloides paragottisi, Glogerinelloides aptiensis می باشد. سن این مجموعه فونی آپتین پیشین پیشنهاد می گردد. تجمع فسیلی 4: این تجمع زون از ضخامت 50 الی 60 متری برش ذکر شده مشاهده می‌شود. فونای این بیوزون شامل: Mesorbitolina parva, Orbitolina sp. Nodosaria sp. Nezzazata sp. miliolids, textularidsمی باشد. این تجمع می تواند معادل زون Mesorbitolina parva Zone (Schroeder et al. 2010) باشد که سن ابتدای آپسین پسین را برای آن در نظر گرفته است.
    کلیدواژگان: سازند داریان، زیست چینه نگاری، پالئواکولوژی، مهره داران دریایی، آپتین، ریز رخساره و حوضه شلف داخلی
  • حبیب بیابانگرد*، علی احمدی، شهناز ریماز صفحات 45-65
    سنگ های آتشفشانی ابارق- حرمک در کمربند آتشفشانی ارومیه- دختر و نوار ماگمایی دهج- ساردوئیه قرار گرفته اند. این مجموعه به سن ائوسن شامل بازالت، تراکی بازالت، آندزیت بازالت، آندزیت، تراکی آندزیت، ایگنمبریت، داسیت، ریولیت و سنگ‌های آذرآواری از قبیل لیتیک توف و توف های آندزیتی و داسیتی است. کانی‌های اصلی سازنده این سنگ‌ها پلاژیوکلاز، اوژیت، هورنبلند و مقدار کمی الیوین می باشد. داده‌های ژئوشیمیایی این سنگ‌ها نشان می دهد که آن‌ها متعلق به سری ماگمایی کالک آلکالن هستند و در عناصر خاکی سبک (LREE) غنی‌شدگی بیشتری نسبت به عناصر نادر خاکی سنگین (HREE) نسبت به مرجع کندریت دارند. نسبت های 5/34 تا 76/5 Ce/Yb=، Zr/Y بالا (4 تا 14)، غنی‌شدگی LILE و آنومالی Eu در گدازه‌های مورد مطالعه بیانگر ماگماتیسم کالک آلکالن وابسته به فرورانش است. از سوی دیگر ویژگی های ژئوشیمیایی نظیر نسبت 5/18-78/1 La/Yb=، محتوای پایین Rb به همراه نمودارهای تمایز محیط زمین ساختی وابستگی آن‌ها را به محیط‌های فرورانش نشان می‌دهد. بررسی شیمی کانی های کلینوپیروکسن و پلاژیوکلاز در سنگ های بازالتی منطقه نشان می دهد که ترکیب آن ها به ترتیب اوژیت و لابرادوریت است. دما- فشار سنجی کلینوپیروکسن ها در مرحله تبلور (مرحله اینتراتلوریک) گستره دمایی بین 950 تا 1200 درجه سانتی‌گراد و فشار 2 تا 5 کیلوبار را نشان می دهد. شیمی کانی کلینوپیروکسن نشان می دهد که سنگ های آتشفشانی ابارق-حرمک دارای ماهیت کالک آلکالن و در ارتباط با محیط های کوه زایی هستند. همچنین میزان آهن فریک آن‌ها نشان دهنده فوگاسیته بالای اکسیژن ماگماست.
    کلیدواژگان: ابارق، حرمک، ارومیه، دخت، بم، دما، فشارسنجی، گدازه های بازالتی
  • علی محمد رجبی، مهدی خداپرست*، مجتبی علیزاده صفحات 65-76
    امروزه استفاده از نقشه های پهنه بندی به عنوان سند اصلی هدایت و کنترل تحولات کالبدی و نظارت بر ساخت و ساز در عرصه های شهری مورد توجه قرار گرفته است. کاربرد این نقشه ها به منظور جلوگیری از تداخل غیرضروری و نامناسب کاربری ها و ارتقاء کیفیت و کارایی محیط شهری اهمیت زیادی دارد. کوشش های فراوانی به منظور تدوین نقشه های پهنه بندی و تعیین محدوده های وقوع پدیده های مخاطره آمیز ناشی از زلزله با میزان احتمالات مختلف مانند نقشه های پهنه بندی خطر زمین لغزش های ناشی از زلزله و خطر روانگرایی و نقشه های پهنه بندی پارامترهای مختلف ژئوتکنیکی انجام شده است. با استفاده از این نقشه ها، با توجه به نوع و اهدافشان بر مبنای استاندارد های موجود و بانک های اطلاعاتی گسترده، می توان هزینه ها را کاهش و سرعت تصمیم گیری در قضاوت های مهندسی را افزایش داد. شهر قم به عنوان یک از شهرهای پرجمعیت کشور، به دلیل توسعه و گسترش روز افزون و افزایش فعالیت های عمرانی از یک طرف و وجود منابع خطر از جمله گسل های خضر و قیزقلعه، بی شک در معرض مخاطرات زمین شناسی نظیر زلزله است. در این تحقیق با استفاده از اطلاعات ژئوتکنیکی به دست آمده و داده های مربوط به تعداد 3500 آزمایش نفوذ سنجی دینامیکی حاصل از بررسی 650 گمانه در 250 محل مختلف شهر قم و همچنین با بهره گیری از رابطه مربوط به محاسبه سرعت موج برشی از نتایج آزمایش نفوذ سنجی دینامیکی، نقشه پهنه بندی تیپ زمین بر مبنای ویرایش چهارم استاندارد 2800 ایران، در گستره آبرفت های شهر قم تهیه شده است.
    کلیدواژگان: پهنه بندی، سرعت موج برشی، آبرفت، نفوذسنج دینامیکی، نوع زمین
  • ابوالضل سلطانی* صفحات 77-93
    منطقه تنبو در بخش سندرک واقع در جنوب شهرستان میناب قرار دارد. این منطقه در نقشه زمین‌شناسی 1:250.000 طاهرویی در غربی‌ترین قسمت زون افیولیتی مکران واقع می شود. در این تحقیق کانی‌های فیبری برای اولین بار در شمال روستای تنبو معرفی و رخداد آن مورد بررسی قرار می گیرد. مطالعات اولیه این تحقیق با هدف تاثیرات زیست محیطی سنگ های افیولیتی در این منطقه انجام شد. سپس شناسایی کانی های فیبری براساس مشاهدات صحرایی، مطالعات میکروسکپی و انجام آنالیزهای شیمیایی (XRD و XRF) صورت گرفت. نتایج آنالیز شیمیایی XRD و مطالعات میکروسکپی نشان می دهد که کانی‌های فیبری نوعی کانی رسی به نام "سپیولیت" هستند. طول الیاف سپیولیت های شناخته شده در این منطقه گاهی به حدود 60 سانتی متر می رسد و نسبت طول به عرض آنها بیش از 1200 است. مقایسه اکسیدهای اصلی حاصل از آنالیزهای شیمیایی XRF بر روی کانی های فیبری روستای تنبو با نمونه های شناخته شده در ایران و دیگر کشورها، وجود کانی سپیولیت را در این منطقه تایید می کند. ساختار تشکیل سپیولیت منطقه تنبو به صورت ثانویه است زیرا به صورت پوششی بر روی سنگ های کربناته قرار گرفته است. با توجه به شواهد سنگ شناسی و اطلاعات ژئوشیمیایی، سپیولیت های منطقه تنبو، حاصل واکنش های شیمیایی محلول های هیدروترمالی با سنگ های هارزبورژیتی غنی از آهن و منیزیم هستند که تحت اثر دما و فشار بخار آب بالا دگرسان شده اند، به طوری که انحلال آهن، کلسیم و منیزیم در حضور دی اکسید کربن صورت گرفته است. طی این فرایندها، تغییرات شیمیایی کریزوتیل در حضور محلول های گرم که غنی از CO2، H2O و SiO2 هستند، به تولید مجموعه ای از کانی های کلسیت، مگنزیت و سپیولیت آهندار منجر شده است.
    کلیدواژگان: تنبو، سپیولیت، مکران باختری، میناب، هارزبورژیت
  • شهریار کشتگر، محمد بومری*، ساسان باقری صفحات 94-107
    کمپلکس ولکانو-پلوتونیک ماهیرود (چشمه استاد) که در شرق ایران قرار دارد، از لحاظ تکتونیکی بخشی از پهنه زمین درز سیستان محسوب می شود. براساس مطالعات پتروگرافی و ژئوشیمی، کمپلکس ماهیرود طیفی از سنگ های آندزیت بازالت، آندزیت، دیاباز و میکروگابرو را نشان می دهد که توسط یک استوک تونالیتی با سن کرتاسه فوقانی قطع شده اند. براساس تحقیقات قبلی، سنگ های ولکانیکی کمپلکس ماهیرود از دیدگاه ژئوشیمی خصوصیات سری های ماگمایی کالک آلکالن و تولئیتی دارند. نمودارهای عنکبوتی به هنجار شده عناصر فرعی و REE نسبت به MORB و کندریت، الگوهایی شبیه سنگ های متعلق به محیط های بالای منطقه فرورانش (SSZ) و خصوصا جزایر قوسی امروزی (IAT) نشان می دهند همان طور که مطالعات شیمی کانی های کلیدی موجود در این سنگ ها خصوصیات مشابهی را دارا می باشند. استوک تونالیتی ماهیرود دارای کانی های اصلی پلاژیوکلاز، کوارتز و هورنبلند و بیوتیت می باشد. براساس مطالعات شیمی کانی، پلاژیوکلازها ساخت منطقه ای عادی دارند و از نوع بیتونیت تا آلبیت هستند و روند نرمال تفریق بلورین را نشان می دهند. آمفیبول تونالیت ها از نوع مگنزیو-هورنبلند کلسیک و وابسته به محیط فرورانش می باشند. براساس مقدار آلومینیوم در آمفیبول فشار و دمای تبلور به ترتیب حدود 1 تا 2 کیلوبار و 700 تا 750 درجه ی سانتی گراد و مقادیر فوگاسیته اکسیژن بالا است. این یافته ها با نتایج حاصل از مطالعات جدید تکتونوماگمایی انجام شده بر روی کمپلکس ماهیرود مطابقت دارد.
    کلیدواژگان: آمفیبول، پهنه جوش خورده سیستان، تونالیت، چشمه استاد، شرق ایران
  • فرشته رنجبرمقدم*، فریبرز مسعودی، مسعود همام، محمد محجل صفحات 108-123
    گستره دگرگونی فریمان درجنوب شرق مشهد واقع شده است و شامل شیست‌های آندالوزیت‌دار با میان لایه‌هایی از آهک‌های تبلور مجدد یافته و کوارتزیت می‌باشد. واحدهای لیتولوژیکی مجاور این دگرگونی‌ها شامل مجموعه دگرگون شده کمپلکس سیبک می‌باشد. هدف از این مطالعه درک فرایند‌های دگرگونی و سرگذشت و تحولات دگرگونی در منطقه می‌باشد زیرا این منطقه یکی از شاخص‌ترین دگرگونی‌های نوع فشار پایین–حرارت بالا در ایران قلمداد می‌شود. با توجه به شواهد صحرایی و میکروسکوپی نظیر شیستوزیته و خطواره‌ها و ریزساختارهای موجود, دو مرحله دگرشکلی D1 و D2 طی رویدادهای دگرگونی اتفاق افتاده است. این شیست‌ها متحمل یک مرحله دگرگونی ناحیه‌ای دما بالا – فشار پایین در حد رخساره آمفیبولیت بالایی شده‌اند و سپس یک مرحله دگرگونی دما پایین دیناموترمال همراه با دگرشکلی در اثر جایگیری و بالا آمدن پوسته پایینی در شیست‌ها وکمپلکس مجاور آنها اتفاق افتاده است. به علاوه از شواهد چنین برمی‌آیدکه بعد از وقوع این رخداد شرایط تکتونیکی بسیار فعالی (نظیر زون‌های برشی) در منطقه حاکم شده و باعث دگرشکلی در این شیست‌ها و مجموعه سنگ‌های آذرین مجاور آن‌ها شده است. زمان بالا آمدگی و جایگیری نپ احتمالا بعد از کرتاسه بوده است. حرکات تکنونیکی گفته شده احتمالا با زمین درز سبزوار در ارتباط می‌باشد.
    کلیدواژگان: فریمان، جنوب شرق مشهد، شیست های آندالوزیت دار، دگرگونی ناحیه ای، دگرگونی دیناموترمال
  • فرزاد مرادی، عباس صادقی*، محمد حسین آدابی، علیرضا طهماسبی سروستانی صفحات 124-140
    به منظور مطالعه سازند آسماری در تاقدیس کبیر کوه یک برش چینه شناسی در جهانگیرآباد انتخاب و مورد نمونه برداری قرار گرفت. ضخامت سازند آسماری در این برش 179 متر و منطبق است با بخش تبخیری کلهر متشکل از سه واحد ژیپس پایینی، طبقات داخلی کلهر و سنگ آهک های آسماری میانی و بالایی. در مطالعات زیست چینه نگاری ضمن تشخیص 30 جنس و 29 گونه از فرامینیفرها یک زون زیستی در راس سازند پابده و سه زون زیستی به همراه یک زون تهی (Not zoned) در سازند آسماری به شرح زیر شناسایی و معرفی گردید. Borelis melo curdica – Borelis melo melo Assemblage zone Miogypsina – Elphidium sp.14 – Peneroplis farsensis Assemblage zone Globigerinoides subquadratus Assemblage zone Not Zoned Subbotina gortanii Assemblage zone (راس سازند پابده) براساس زون های زیستی و میکروفسیل های شناسایی شده سن سازند آسماری در برش مورد مطالعه شاتین پسین– بوردیگالین تعیین شده است.
    کلیدواژگان: سنگ چینه نگاری، زیست چینه نگاری، سازند آسماری، تاقدیس کبیرکوه، جهانگیرآباد
  • رضا اسماعیلی*، راحیل دلیری صفحات 141-153
    رودخانه‌های مئاندری دینامیک فعالی داشته و دائما در حال تغییر و دگرگونی هستند. اما فعالیت‌های انسان تغییراتی را در این فرایندها ایجاد می نماید. در این تحقیق روند تغییرات مورفولوژیکی رودخانه شلمان رود (شرق گیلان) در طی یک دوره 51 ساله بین سال 1346 تا 1397 مورد تحلیل و بررسی قرار گرفته است. برای انجام این کار از عکس‌های هوایی سال های 1346 و 1373 و همچنین تصاویر گوگل ارث سال های 1382 و 1397 استفاده شد. پارامترهای هندسی رودخانه (مورفومتری) شامل طول کانال، طول موج، زاویه مرکزی، دامنه موج و شعاع قوس اندازه‌گیری شدند. پارامترهای مورفودینامیک شامل مهاجرت جانبی کانال، میزان فعالیت کانال و میزان همپوشانی کانال مورد بررسی قرار گرفتند و سپس مورفولوژی کانال و مدل‌های مختلف مهاجرت کانال مورد ارزیابی قرار گرفتند. نتایج نشان داد میانگین مقادیر پارامترهای هندسی پیچانرودها طی دوره 51 ساله تفاوت مشخصی نداشته‌اند. پارامترهای مورفودینامیک تغییرات کاهشی مشخصی را تجربه کرده‌اند. میزان مهاجرت جانبی کانال در دوره 73- 1346 بسیار زیاد بوده اما در دوره های بعد شدیدا کاهش یافته و میزان همپوشانی کانال افزایش یافته است. مورفولوژی تغییرات مئاندر هم در دوره اول تغییرات محسوسی داشته و در دوره‌های دوم و سوم تغییرات ناچیزی داشته و الگوی کلی مهاجرت تغییر کرده است. این قسمت از رودخانه شلمان رود در طی دوره‌های مورد بررسی از تعادل دینامیک به تعادل استاتیک تغییر یافته است.
    کلیدواژگان: شلمان رود، پیچان رود، مورفودینامیک رود، گیلان
  • سمیه رفعتی*، مصطفی کریمی صفحات 154-173
    تغییر پارامترهای محیطی می‌تواند ویژگی‌های باد را به شدت تحت تاثیر قرار دهد، بنابراین برای تعیین پتانسیل باد در مکان‌ها و ارتفاعاتی غیر از نقطه‌ی اندازه‌گیری، تعیین اثر پارامترهای محیطی بر داده‌های اندازه‌گیری شده بسیار حائز اهمیت است. هدف از این مطالعه بررسی میزان تاثیر پارامترهای محیطی مثل زبری سطح و موانع اطراف ایستگاه بر ویژگی‌های باد بوده است. برای این منظور از داده‌های سرعت و جهت باد ایستگاه‌های سینوپتیک استان کرمانشاه (دوره آماری 2013-2009)، مدل رقومی ارتفاع و نقشه کاربری زمین استفاده شد. همچنین نقشه موانع در اطراف ایستگاه‌های سینوپتیک با استفاده از تصاویر ماهواره‌ای گوگل ارث (لندست و کوپرنیک) تهیه گردید و برای برآورد ویژگی‌های باد در شرایط محیطی متفاوت با شرایط ایستگاه نرم‌افزار WAsP به کار گرفته شد. براساس نتایج به دست آمده، تغییر میانگین سرعت باد بسته به ویژگی‌های محیطی ایستگاه‌ها از %40 در ایستگاه اسلام‌آباد تا %9 در ایستگاه هرسین و تغییر چگالی توان باد نیز از بیش از %81 در روانسر و اسلام‌آباد غرب تا حدود %27 در هرسین متغیر بوده است. تعدد موانع در جهت باد غالب در ایستگاه‌های روانسر و سرپل‌ذهاب و ارتفاع زیاد موانع در ایستگاه‌های کرمانشاه و اسلام‌آباد و همچنین زبری زیاد در ایستگاه‌های کرمانشاه، روانسر، اسلام‌آباد غرب، جوانرود و گیلان‌غرب تاثیر بسزایی در کاهش میانگین سرعت باد تا بیش از 26 درصد و همچنین چگالی توان باد تا بیش از 62 درصد داشته است. بنابراین نادیده گرفتن اثر پارامترهای محیطی به طور ویژه در مطالعات مربوط به تعیین پتانسیل باد می‌تواند الویت‌های معرفی مناسب‌ترین مکان برای تولید انرژی را تغییر دهد.
    کلیدواژگان: استان کرمانشاه، پارامترهای محیطی، سرعت باد، نرم افزار WAsP
  • منصور پروین* صفحات 174-190
    سیل به عنوان یکی از مهم ترین مخاطرات طبیعی هر ساله زیان های بسیاری به جوامع انسانی مناطق مختلف دنیا وارد می کند. پارامترهای مورفومتری به علت کنترل پاسخ هیدرولوژیکی، نقش مهمی در هیدرولوژی حوضه ها دارند. بنابراین تحلیل پارامترهای مورفومتریک یک ابزار مناسب برای ارزیابی پتانسیل سیل خیزی حوضه های آبخیز است. حوضه ی سرپل ذهاب به علت واقع شدن در دامنه های غربی زاگرس، دارای بارش های سنگین بوده و به علت شرایط ژئومورفولوژیکی مستعد رخ داد مخاطره سیل می باشد. هدف این پژوهش پهنه بندی پتانسیل خطر سیل خیزی حوضه سرپل ذهاب و زیرحوضه های آن می باشد. ابتدا شبکه ی زهکشی و زیرحوضه های، حوضه مورد مطالعه از DEM ده متر منطقه استخراج گردید. در روش اول با استفاده از 9 پارامتر مورفومتری تاثیرگذار بر سیل، درجه خطر سیل خیزی برای حوضه سرپل ذهاب و زیرحوضه های آن محاسبه گردید. در روش دوم مقادیر 12 پارامتر مورفومتری و شاخص (Cv) محاسبه شده و حوضه سرپل ذهاب و زیر حوضه های آن از نظر پتانسیل سیل خیزی پهنه بندی گردید. نتایج نشان داد، که روش دوم به علت به کارگیری تعداد بیشتر پارامترهای مورفومتری و تاکید بر پارامترهای مرتبط با شکل حوضه از کارایی مطلوبتری نسبت به روش اول برخوردار می باشد. به طوری که 67/32 % مساحت حوضه سرپل ذهاب منطبق بر حوضه ریجاب دارای پتانسیل خطر زیاد، 05/57 % منطبق بر زیرحوضه های قلعه شاهین و پاتاق دارای پتانسیل خطر متوسط و 27/10 % منطبق بر زیرحوضه های سرابگرام و قلاویز دارای پتانسیل خطر کم سیل خیزی می باشند.
    کلیدواژگان: پارامترهای مورفومتری، زیرحوضه، پتانسیل سیل خیزی، درجه خطرپذیری، حوضه سرپل ذهاب
  • محمدامین هونکزهی، زهره فنی* صفحات 191-213
    مخاطرات طبیعی در سده های متمادی، مشکلات و گره‌های گسترده‌ای در ارتباط با توسعه جوامع انسانی ایجاد کرده است. طبق بررسی‌ها، عواملی چون وجود گسل‌ها در اطراف شهر، تراکم جمعیتی، حاشیه‌نشینی بالا و در نتیجه مساکن غیر استاندارد و کمبود فضاهای باز و سبز، شهر زاهدان را در مقابل مخاطرات طبیعی آسیب‌پذیر نموده است. ظرفیت‌سازی نهادی، رویکردی برای ارتقاء فرصت‌های مشارکت عمومی و دستیابی به نتایج موفقی برای توسعه‌ی پایدار از راه آموزش و مشارکت مردم و نهادهای شهر، شرایط جغرافیایی و اکولوژیکی آن است. این پژوهش با هدف تحلیل کاهش اثرات مخاطرات طبیعی (زلزله) بر محیط‌زیست شهری با تاکید بر ظرفیت‌سازی، انجام ‌شده است. جهت گردآوری اطلاعات پژوهش از مشاهده، پرسشنامه، توزیع نرمال داده‌ها از آزمون کلموگروف-اسمیرنوف و بررسی تفاوت مقادیر متغیرها از رتبه‌بندی و آزمون T استفاده ‌شده است. نتایج پژوهش حاکی از آن است که براساس نتایج آزمون T، در بعد نهادی زیر معیار «میزان دسترسی به مکان‌های امن در صورت وقوع زلزله احتمالی در سطح 05/0 و دیگر زیر معیارها در سطح کمتر از 001/0 معنی‌دار می‌باشند. در بعد کالبدی– فضایی مولفه‌های «دسترسی به معابر اصلی و شریانی و میزان فرسودگی منازل مسکونی محله‌ی شما در سطح 05/0 و مولفه‌های اعتماد به واحد مسکونی از نظر معماری و مهندسی در سطح 01/0 و دیگر زیر تفاوت معنی‌داری خاصی وجود نداشت؛ و در بعد اجتماعی-اقتصادی غیرمعیارهای «میزان اطلاع‌رسانی عمومی به ساکنان هنگام وقوع زلزله و مشورت با افراد آگاه در راستای کاهش آسیب‌پذیری در سطح 05/0 و زیر معیار پوشش بیمه‌ای مسکن شما در سطح 01/0 معنی‌دار است، از لحاظ آسیب‌پذیری در نواحی مرکزی و حاشیه‌ای بیشترین دسترسی به فضاهای آزاد و کمترین آسیب‌پذیری وجود دارد.
    کلیدواژگان: مخاطرات طبیعی، محیط زیست شهری، ظرفیت سازی، زاهدان
  • محمد پروین، محمد تقی رضویان*، جمیله توکلی نیا صفحات 214-230
    توسعه صنعت گردشگری و بهره گیری از ظرفیت های آن یکی از گام های مهم در راستای رونق اقتصادی به شمار می آید. در این میان توجه جدی و هدفمند به گردشگری شهری به ویژه در کلانشهرهایی مثل تهران که از ظرفیت های بالایی در این زمینه برخوردار هستند می تواند به رونق اقتصادی شهر و افزایش درآمد برای بخش های دولتی و خصوصی و ارتقاء سطح معیشتی شهروندان منجر شود. برای دستیابی به این هدف ارزیابی شرایط فعلی و شناخت چالش های پیش رو اجتناب ناپذیر است. هدف این پژوهش تحلیل و ارزیابی تاثیر گردشگری در توسعه اقتصادی شهر تهران است. تحقیق حاضر از نظر هدف کاربردی و از نظر روش انجام پژوهش، توصیفی- استنباطی بوده و گردآوری داده ها با استفاده از روش کتابخانه ای و پرسشنامه صورت گرفته است. جامعه آماری پژوهش شهروندان ساکن در شهر تهران می باشند که پرسشنامه ای محقق ساخته بین آنها توزیع و جمع آوری شده است. با بهره گیری از فرمول کوکران تعداد افراد جامعه آماری 384 نفر به عنوان نمونه انتخاب گردیده و تجزیه و تحلیل داده ها و به کارگیری آزمون های آماری با استفاده از نرم افزار spss انجام شده است. براساس نتایج، رشد گردشگری و منابع درآمدی حاصل از این صنعت می تواند یکی از عوامل مهم و تاثیرگذار در توسعه اقتصادی و پایداری درآمدی شهر تهران باشد. همچنین توسعه صنعت گردشگری متاثر از عواملی نظیر زیرساخت ها و تسهیلات، اطلاع رسانی و تبلیغات می باشد.
    کلیدواژگان: اقتصاد، توسعه اقتصادی، تهران، درآمد، گردشگری
  • فرشته رضایی*، محمود احمدی، علیرضا شکیبا صفحات 231-247
    امواج گرمایی به عنوان یک پدیده حدی همراه با گرمایش جهانی می تواند بخش‌های مختلف را متاثر سازد. ضرورت شناسایی این پدیده در شرایط تغییر اقلیم باعث شد که در این مقاله به شبیه سازی آستانه دمایی منجر به موج گرما در مناطق مختلف کشور پرداخته شود. جهت رسیدن به این هدف ابتدا دمای حداکثر روزانه 90 ایستگاه در دوره گرم سال برای 30 سال آینده (2045- 2016) از طریق مدل گردش عمومی جو CanEsm2 تحت 3 سناریوی RCP 2.6، RCP 4.5 و RCP 8.5 و مدل ریزمقیاس نمایی آماری SDSM شبیه سازی شد. سپس براساس 3 شاخص جهانی (صدک 95، بالدی، سازمان هواشناسی جهانی (WMO)) آستانه دمایی موج گرما در مناطق مختلف تعیین گردید. نتایج نشان داد که مقادیر آستانه دمایی در زمان ها و مکان های مختلف کشور یکسان نمی باشد و از دامنه های متفاوتی برخوردار است. براساس سناریوی مختلف RCP 2.6، RCP 4.5 و RCP 8.5 طی سال های آتی، حد پایین آستانه دمایی در فصل بهار نسبت به وضع موجود تقریبا 5 درجه افزایش یافته است. علاوه بر این مرز پهنه های آستانه دمایی نیز تغییر محسوسی می یابد. به طوری که پهنه های دارای آستانه بالا به سمت عرض های متوسط و بالا پیشروی می کنند. در فصل تابستان نیز هر چند حد بالا و پایین آستانه دمایی نسبت به شرایط موجود تغییر نمی کند. اما نکته ی قابل توجه این است که در شرایط حاضر در تابستان قسمت زیادی از کشور دارای آستانه بین °40-°35 سلسیوس است ولی در 30 ساله آینده با توجه به افزایش دما، این رنج به °45 –°40 سلسیوس می رسد و تقریبا 70 درصد کشور آستانه بالای 40 درجه را تجربه می کند. از لحاظ مکانی نیز آستانه دمایی در فصل بهار از تفاوت مکانی بیشتر و در تابستان تقریبا از یکنواختی نسبی برخوردار است که علت این یکنواختی را می توان به وجود پرفشار جنب حاره ای آزور نسبت داد. همچنین نتایج نشان می دهد که از میان مناطق مختلف کشور، استان خوزستان در دوره گرم سال بالاترین آستانه دمایی را به خود اختصاص داده است. بررسی تغییرات آستانه دمایی نیز نشان داد که عرض های متوسط و بالا در دوره گرم سال در سال های آتی نسبت به وضع موجود، بالاترین تغییرات و افزایش را در مقدار آستانه دمایی خواهند داشت.
    کلیدواژگان: آستانه دمایی، سناریوهای تغییر اقلیم، موج گرما، CanEsm2-SDSM
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  • Rouhollah Adinehvand*, Jaber mozaffarizadeh, Zahra Sajadi, Abdolhamid Ansari Pages 1-14
    Introduction
    Nowadays, the quality of water resource and recognition of the effective factors in it is one of the most important issues in the world regarding consideration of water shortage. The interaction between water resources and porous and environmental media plays the important role to control of groundwater quality. Moreover, identification of this interaction can be helpful for optimal water management. Because of its agricultural and industrial importance, the groundwater quality assessment of these interaction affects the Galehdar plain which is located in the south of Fars province, Iran, is necessary.
    Materials and methods
    In this study, geological and anthropogenic factors affecting the groundwater quality of Galedar plain were investigated using analyses and interpretation of pumping-well quality data of 20 water well samples in March 2011. Piper charts, composition diagrams, statistical analyses, factor analysis, saturation indices, and maps of the hydrogeochemical parameters were used to in determination of the salinity sources and effective processes affecting the quality water of the aquifer.
    Results and discussion
    Water type changes from carbonate and sulfate to sodium-magnesium chloride in the direction of groundwater flow which is being consistence with Chebotarev ionic evolution and higher residence time. Based on piper diagram, groundwater of Galehdar is Cl-Na and SO4-Ca type. The composition diagrams show a clear linear trend between Na and Cl and also between Ca and SO4. This implied the arrival of waters originating from halite and gypsiferous formations and salty soils. Statistical and factor analyses demonstrate three effective groundwater quality-control factors. The first factor which is the most effective groundwater quality control-factor, explaining 51.9 percent variance of data and shows halite dissolution. Assessment of saturation indices demonstrates that total trend of hydrogeochemical processes of Galehdar plain is halite and gypsum dissolution and sedimentation of calcite and dolomite.
    Conclusion
    Surface waters recharging the aquifer where passed through the unsaturated aquifer media is the most probable of deterioration of water quality and chloride ion concentration increasing. The results show that the main groundwater quality degradation reasons are waters passes over salty soils, agricultural wastewaters, salt-water rivers, dissolution of gypsum and halite, and runoff originating from Gachsaran and Aghajari formations which is the most effective factor in the Calendar groundwater quality deterioration.
    Keywords: Groundwater quality, Statistical analysis, Composition diagrams, Salinity sources, Galehdar plain
  • Ali Bahrami*, Mehdi Yazdi, Hossein Vaziri Moghaddam, Abdollah Ghobadi, Martin Kundrat Pages 15-44
    Introduction
    Fossil vertebrates were first reported from Iran by Priem (1908), who reported on the fossil fishes from the Pabdeh Formation east of Ilam, in southwestern Iran. At the time, Priem (1908) considered these deposits to be Lower Cretaceous, but they are now known to be Eocene (Afsari et al. 2014). Several decades later, fish material from the same deposits was studied by Arambourg (1967), who had attributed the beds to the Oligocene. Since those studies, additional fish from the Pabdeh Formation have been described or revised (e.g. Haghipour and Brants 1971; Jafarian et al. 1999; Afsari et al. 2014; Davesne 2017) including members of the Scombridae, Carangidae, and Labridae. These support the revised Eocene age of the sediments. Recently, Mirzaei et al. (2016) reported a Pycnodontiform (a Neopterygian bony fish) tooth plate from the Albian–Cenomanian Sarvak Formation at Lorestan, southwest Iran. To our knowledge, this is the only Cretaceous vertebrate fossil from Iran, excluding the material we report here. The objectives of this paper are to describe and interpret the vertebrate-bearing horizons of the Dariyan Formation in order to determine the age of the vertebrate-bearing beds and to provide a preliminary report on the vertebrate assemblage present in this locality.
    Materials and Method
    The Sivand Section is located 80 km northeast of Shiraz, on the eastern flank of the Sivand Anticline at E 52° 51´ 27.70´´ and N 30° 4´ 54.88´´. The Fahlian, Gadvan, Dariyan, Kazhdumi, and Sarvak formations are exposed in this area. The thickness of the Dariyan Formation in the Sivand Section locality is about 287 ms. Dariyan Formation is mainly composed of cherty limestone, radiolaria-bearing limestones, Hedbergella-bearing marls, and thin-bedded micritic limestone layers. Vertebrates and ammonites occur mainly in the lower part of the Dariyan Formation. Among the bioclasts, fragments of bivalves, gastropods, and ammonites, Orbitalina foraminifera, and marine vertebrate debris can be observed. A section of sixty-five meters of the lower deposits of the Dariyan Formation was measured in detail in this region.
    Result and Discussion
    The samples, mainly slabs of micritic limestone with vertebrate fossils were collected, wrapped, packed and safely transferred to the Department of Geology lab., at University of Isfahan. Extra samples were systematically obtained from the special horizons for thin sections also a few washing samples in order to determine the precise age of the fossil bearing horizons of the Lower Dariyan Formation. Slabs of the vertebrate fossils were cleaned by special pneumatic air pen tool, photographed and studied in details for anatomical characteristics. Based on the succession of microfossil assemblages (Choffatella decipiens Range Zone, Radiolaria flood Range Zone, Globiogerinelloides blowi Range Zone, Mesorbitolina parva Range Zone), we propose that the Sivand fossiliferous deposits are Early Aptian (Bedoulian) through early Late Aptian (Early Gargasian) in age. Fossil vertebrates are preserved in the lower part of the formation.
    Conclusions
    Laboratorial studies, Microscopic characteristics and the thin sections led to discrimination of five orders of fish fossils (Aspidorhynchiformes, Clupeiformes, Ichthyectiformes, Pycnodontioformes, and Semionotiformes) and a marine turtle fossil of genus Toxochelys, accompanied with 9 genera and 14 species of foraminifera were identified that represents early Aptian (Bedoulian) to the beginning of late Aptian (Early Gargasian) ages for the studied parts of the Dariyan Formation in Sivand section. The Sivand locality preserves the first known Early Cretaceous assemblage of marine vertebrates from southwestern Asia. The obtained samples of marine vertebrates also introduced from other regions of the world, including North America, Europe, Australia, Africa, China and Lebanon. The preservation of a diverse assemblage of fossil vertebrates, makes the Sivand locality of special significance for understanding the diversity of vertebrates in lower Cretaceous of South Asia.
    Keywords: Dariyan Formation, Biostratigraphy, Paleoecology, Marine vertebrates, Aptian, Microfacies, Internal shelf basin
  • Habib Biabangard*, ali ahmadi, shahnaz rimaz Pages 45-65
    Introduction
    Abraq-Harmak area is located 40 Km northwest of Bam (southeast of Kerman province). Based on structural geology of Iran, this area is placed in the central Iranian zone, Urmieh-Dokhtar volcanic and Dehaj – Sarduyeh magmatic belt. The major units of the area are basaltic to dacitic lava flows with their pyroclastic rocks. Previous studies have done on these rocks by Dimeterich et al., 1973, Hosseini et al., 1993, Girou and Conrad, 1976, Zahedi, 2005, Alidadi Soleimani, 1394 and Mirali, 1392. In this paper, we are attempted to identify petrography, mineral chemistry, and the conditions of formation rocks in the Abraq-Harmak area.
    Materials and methods
    We have taken 150 samples rocks from of Abraq-Harmak area, and then prepared 110 thin sections. Petrographic studies were done and 9 samples select for analyzes. These samples are sending to Iranian Mineral Processing Center (IMIDRO) and determine amounts of major, minor and trace elements by XRF and ICPMS methods, respectively. The chemical analysis of pyroxene and plagioclase minerals was done on 35 points by EPMA-SX100 type electron micro probe with 15 Kv accelerator voltage, 15 nA current intensity and 5-micron beam size. Data was processed and interpreted using the usual geological software and related graphs.
    Results and Discussion
    Calc-alkaline basaltic flow that belonging to active continental subduction region show usually "zigzag", pattern of accessory and rare earth elemental and they are more enrichment in light rare earth elements than heavy earth elements (Gil, 2010, Wilson, 1980). The whole rocks and mineral geochemical studies on the Abraq-Harmak lavas shows that they are belong to the calc-alkaline basalts of the subduction areas. Also, accessory and rare elements normalized to Chondrite (Boynton, 1984) show similar patterns and similar to the basalts of the subduction regions. Pb, Ta and Cs elements have positive anomalies and Ti and P elements have negative anomalies, which are usually due to crustal contamination and magmatic differentiation (Reichew et al., 2004; Kurkcuoglu et al., 2008). Calc-alkaline basaltic lava is usually formed in the high oxygen fugacity (Gil, 2010). Thermo-barometry of plagioclase and pyroxene minerals in the Abraq-Harmak lavas indicate that the magma forming this lava are stopping at the sub surface and crystallization of them within magma chamber (less than 23 Km) and High oxygen fugacity.
    Conclusions
    Whole rock chemistry, minor and rare earth elements spider diagrams and other tectonomagmatic diagrams indicate Abraq-Harmak volcanic rocks are belonging to subduction zones. The chemistry of clinopyroxene mineral shows that Abraq-Harmak volcanic rocks are Calc-alkaline and related to subduction environments. Aluminum distribution of these minerals structure of indicates that they are crystallize from a hydrous magma with a 10 percent vapor pressure and with high oxygen fugacity. Temperature of clinopyroxenes formation (range from 950 to 1200 C) and pressure (2 to 5 Kb) indicate their crystallization happen during ascent magma and in shallow magmatic chamber. It seems that the magma formed these rocks, is formed from subduction of Arabian plate under the Iranian plate in the Urumieh-Dokhtar area
    Keywords: Abareq, Hormak, Bam, Basaltic lavas, Thermobarometry, Urmieh Dokhtar
  • Ali Mohammad Rajabi, mahdi khodaparast*, Mojtaba Alizadeh Pages 65-76
    Introduction
    Nowadays, Zonation Maps can be used as a main guiding document, control and supervision of construction and building in urban areas. Using these maps prevents the unnecessary interference and inappropriate land uses and improving the quality and efficiency of the urban Areas. Great efforts are done to develop zonation maps such as earthquake hazard zoning, determining the occurrence of earthquake hazard with different probabilities including landslide and liquefaction hazard zoning. Using these maps, depending on the type and objectives based on existing standards and extensive data bases, we can reduce costs and increase the speed of decision-making engineering judgments.
    Material and methods
    Qom as a populated city of the country, due to the extending and increasing of development activities on the one hand and the sources of risk, including Khedher and Qizqaleh faults undoubtedly is subject to geological hazards such as earthquakes.
    In seismic microzonation studies, estimating the velocity of seismic waves in soil layers is very important to be evaluated directly and indirectly. Dynamic probing test is one of the indirect methods for evaluating shear wave velocity.
    Since the relationship between the shear wave velocity and the experimental results of the dynamic probing test has not been used to compile zoning maps, so far, in this study, the results of the dynamic probing experiments have been used to estimate the wave velocities of soil layers in some areas of the city. Using geotechnical data and 3500 dynamic probing tests from 650 boreholes in 250 different locations in Qom and also using the relationship between calculating shear wave velocity and dynamic probing test results, shear wave velocity profiles at depths up to 30 meters was produced, and development of land zoning map based on the 2800 standard in the range of Qom, is considered.
    Results and Discussion
    The results of this research indicate that most of the soils of the Qom area up to a depth of 30 meters are silty fine grains. Except for the part of the northern and southern regions of the study area, soil type is type 3 with a mean shear velocity of 375-500 m/s.
    Conclusions
    The proposed zoning map with acceptable accuracy in order to reduce costs and increase the speed of decision making in engineering judgments for site classification, seismic analysis and seismic design of structures of medium importance in alluvial zone The city of Qom is widely used. It should be noted that site specific studies should be carried out separately for sensitive buildings such as hospitals and medical centers, and the cases mentioned in part 5-4-2 of Iran's 2800 Code, fourth edition.
    Keywords: Seismic zonation, Shear wave velocity, Alluvium, Dynamic probing, Ground type
  • Abolfazl Soltani* Pages 77-93
    Introduction
    The Tanbo Village is located in the Senderk region, south of Minab, Iran .Based on the Geological map of Taheruie (scale: 1/250,000), rocks of the study area are cropped out in the most western parts of Makran Ophiolite Zone where it crosses Zagros Fold Belt. Serpentinite, talc, harzborgite, conglomerate and calcareous Al-silicate rocks are the most Miocene exposed rocks occurring in Tanbo region. A harzborgite conglomeratic rock sequence exposed in light green color and includes long fibrous secondary minerals. The main scope and interest of this work is to characterize the fibrous minerals properties and their genetic relation. In the preliminary studies of this research, the fibrous minerals were assumed to be as “white asbestos group” belonging to the fibrous serpentinite (chrysotile). However, until now there is not any publication/information available about the lengthy fibrous minerals of this part of Iran. Based on the field observations, thin section studies, XRD and XRF analyses the fibrous silicate minerals are type of clay, namely “sepiolite”. Petrological and geochemical data indicate that the Tanbo sepiolite developed through hydrothermal fluids which strongly affected harzborgite. The dissolution of Fe2+, Ca2+ and Mg2+ cations at high fCO2 resulted in carbonation of chrysotile in the presence of fluids rich in CO2, H2O and SiO2. Carbonation of chrysotile at lower Al-activities and chemical reactions of the above mentioned fluids with high Fe-Mg rocks provided conditions to perform calcite, dolomite and Fe-sepiolite assemblage. The length of fibers in sepiolite sometimes reaches 60 cm and the ratio of the length to width is more than 1200. According to the XRF analyses on fibrous minerals of Tanbo Village and comparing data with published paper for sepiolite from NE Iran and international countries, the presence of sepiolite in Tanbo Village is confirmed. The formation of Tanbo sepiolite seems to be secondary because it has been developed during and after crystallization of carbonaceous minerals.
    Materials and Method
    This study is organized by three stages including literature review, field geology and experimental laboratory works. The literature studies indicate that there is not any published data regarding to mineralization and the presence of sepiolite in the region. After careful interpretation of field evidence, 10 microscopic thin sections from main rock assemblage and 10 thin sections from co-genetic minerals were prepared and studied by polarized microscope Leitz Laborlux in Shahid Rajaee Teacher Training University (SRTTU). The impurities were removed for all hand specimens, then samples were prepared for XRD and XRF analyses, undertaken by Geological Survey of Iran and Binalood Kansars Lab.
    Results and Discussion
    Microscopic studies reveal two groups of phyllosilicates including fine fibrous serpentinite, talc, calcite and dolomite. into the ultramafic rocks; and long fibers (up to 60 cm in length) of sepiolite into veins in contact with carbonates and harzborgitic rocks. The formation of sepiolite in veins hosted by carbonates (mostly calcite and dolomite). The selected objective is x100 and the light is XPL (and PPL ). The XRD patterns distinguished mineral peak intensities at 7-9º, 11-12º and 29-30º positions (º2 Theta) for sepiolite. For all analyzed samples, the patterns confirm distinct sepiolite mineral with chemical formula of Mg4Si6O15(OH)2.6H2O which is the major mineral component among hydrous fiber minerals. Minor mineral components recognized by XRF include montmorillonite, talc, calcite, aragonite, dolomite, antigorite, clinocrysotile and tremolite, all were identified by microscopic studies. According to XRF analyses the average chemical composition of selected hand-purified sepiolite includes SiO2 (52.6 wt%), MgO (19.3 wt%), LOI (18.2 wt%) and Fe2O3 (4.9 wt%), representing Fe-sepiolite which is a new composition compared with analogous sepiolite distinguished in Iran and global countries. The high content of LOI indicates a very hydrous structure as for the para genetic clay minerals.
    Conclusion
    For the first time, this work identified a secondary mineral namely ‘Fe-sepiolite’ in Tanbo village according to systematic field and laboratory experiments. It is found in Eocene ultramafic rocks (rich in Fe, Mg and Ca elements) belonging to Makran ophiolite, mainly serpentinite and harzborgite. It occurs within conglomerate and carbonate rocks which have undergone intense hydrothermal alteration in the presence of liquids rich in Ca++, Mg++ and Fe++ solutions.
    Keywords: Eastern Makran, Harzborgite, Minab, Sepiolite, Tanbo
  • shahriar keshtgar, Mohammad Boomeri*, Sasan Bagheri Pages 94-107
    Introduction
    The Mahirud volcano-plutonic complex (Cheshme-Ostad Group) in east of Iran is tectonically situated in the north-eastern part of the Sistan suture zone near to the boundary with the Afghan block. This tectonic zone includes the Retuk complex in the west and the Neh complex in the east. These two accretionary-prism-ophiolitic assemblages underlie the Sefidabeh forearc sedimentary basin. The Mahirud complex consists of the Upper Cretaceous volcano-sedimentary sequence which is structurally overlain by the Paleogene sediments. The Upper Cretaceous-Lower Tertiary stratigraphical formations in this area are subdivided into two distinct groups: 1-The upper group includes the Paleocene-Early Eocene volcano-sedimentary succession; 2- The lower group Includes the Cretaceous flysch-type sediments. These units construct the Lahno anticline. The most important igneous constituents of the Mahirud volcano-plutonic complex comprises in a younger part including the acidic intrusions and an earlier part including intermediate to basic extrusions. Acidic rocks injected as intrusive bodies contain tonalite, granodiorites, quartz diorite and rare leuco-plagioclase tonalite and tronhjemite. The basic to intermediate rocks appeared as pillow to flow volcanic and sub-volcanic rocks including of basalts, basaltic andesite, andesite, tuff, and dacitic dikes. Field observation clearly suggests that the tonalitic stocks injected after the extrusion of the lavas, and enclosed, assimilated, and altered the basaltic pillow lavas.
    Method and Material
    The prepared thin-polished sections were studied by polarized microscope for petrographic descriptions in University of Sistan and Baluchistan. Electron probe micro analysis (EPMA) of minerals was conducted in wavelength-dispersion mode on a JEOL JXA-8600 super probe at Yamagata University of Japan with accelerating voltage of 15 kV, a beam current of 20 nA, a beam diameter of about 5 μm, detection limits of 0.05 wt. %, and maximum 40 s counting interval.
    Result and discussion
    According to the results of the previous research, volcanic rocks have the characteristics of the calc-alkaline to tholeiitic magmatic series and have been attributed to a rift tectonic setting. However, the results of recent work based on the spider diagram patterns normalized to N-MORB and Chondrite show the magmatic rocks are similar to the ones belong to the supra-subduction zone (SSZ) and especially recent Island arcs ( IAT) setting. The studying of the EPMA on the key minerals provides the same results. Plagioclase, hornblende, quartz, and biotite are the main minerals of the tonalitic stocks.
    Conclusion
    According to EPMA, the chemical composition of plagioclase illustrates ranging from bytownitein the core to albite in the rim documenting a normal zoning resulted by a normal differential crystallization. Amphibole is a calcic magnesio-hornblende and could crystalize by a magma originated in a subduction zone. According to Aluminum content in amphibole, the crystallization characters such as pressure, temperature, and oxygen fugacity are respectively between 1 and 2 kb, 700 and750°C, and a high fO2. These results confirm the consequence of our other studies which assumed the Mahirud volcano-plutonic complex was formed in an intra oceanic subduction zone.
    Keywords: Amphibole, Cheshmeh Ostad Group, Island-arc, Sistan suture zone, Tonalite
  • fereshteh Ranjbarmoghadam*, Fariborz Masoudi, Masoud Homam, Mohammad Mohajel Pages 108-123
    Introduction
    Fariman metamorphic complex located in Northeast of Iran and indicative different metamorphism and deformation phases. This area is similar to many others Precambrian metamorphic rocks in central Iran that metamorphed in upper amphibolite facies and Sillimanite zone. In this research microfabric of andalusite schists and magmatic rocks investigated in order to constrain P-T path during metamorphic events.
    Materials and methods
    Studied metamorphic complex contain metasandstone (metapsemites), metagraywack and metacarbonates are as interlayered with metapelitic rocks that are major part of metamorphic rocks in study area. The metamorphic volcanic rocks also are seen that named Sibac complex and are in contact with granitic and gabbroic rocks. For petrography and microfabric studies, 80 oriented samples selected from andalusite schists and igneous rocks from Sibac complex. The samples cut and thin sections prepared.
    Results and Discussion
    Metamorphic rocks of Fariman have effected by two deformation phases, D1 and D2. D1 phase related to M1 that is a regional metamorphism event and D2 as an active deformation is related to dynamothermal metamorphism of M2. M2 reveals emplacement of nap and outcropping of lower crust and present an erosion window of neoprotrozoic rocks that are appeared as an uplift formation from central Iran basement that emplaced close to Paleozoic-Cenozoic sedimentation. The retrograde event has affected metamorphic rocks after M2. Evidences of this retrograde metamorphism are change andalusite to chlorite and muscovite or sericite and muscovite, growth of chlorite and talc in rim or on the other mineral, forming of tourmaline in rim of andalusite or in the veins. The D1 phase created schistosity S1, D2 has folded S1 and has formed S2 schistosite. Microstructure evidence, mineral paragenises and estimated Pressure and temperature show an anticlockwise P-T path that involving advective heating in result of intrusive abundant magma into lower- middle crust. The peak of Metamorphism followed by isobaric cooling. The affect of shearing motion is not equal in throughout of study area and in different rocks. Microtectonic evidences indicate a deformation in both ductile and brittle conditions with dextral component. Shear zones spatially can be observed in south and southwest of study area and has been made mylonites and phylonite type rocks.
    Conclusion
    In Fariman area, first high T-low P metamorphism occurred, and followed by dynamothermal metamorphism with shear zones.
    Keywords: Deformation phases D1 & D2, Regional metamorphism, Dynamothermal metamorphism, P-T path
  • Abbas Sadeghi* Pages 124-140
    Introduction
    In order to study the lithostratigraphy and biostratigraphy of the Asmari Formation in Kabir Kuh Anticline in Ilam area, one outcrop section in Jahangirabad, southwest of Darreh shahr with geological coordination of 33°06'45"N , 47°21'19"E with a total thickness of 179 m were selected and sampled.
    Methods & Materials
    Samples of the Asmari Formation were collected systematically (~2m) and about 180 samples were prepared in the laboratory.
    Discussion
    The Asmari Foramtion in mentioned section of Kalhur Evaporite consists of 3 units, Lower Kalhur Gypsum with 9 m, Inter Kalhur with 35.5 m and Middle & Upper Asmari Limstone with 134.5 m. The Upper Kalhur Gypsum unit and Transition Beds are not present in this section. In terms of lithology, Lower Kalhur Gypsum unit mainly composed of white thick gypsum contaminated with hydrocarbon materials, Inter Kalhur Beds with limestone and gray marlstone with pelagic facies and Middle & Upper Asmari Limestone with thick, medium to thin limestones with benthic facies. The lower and upper boundaries of the Asmrai Formation in this section are conformable with Pabdeh and Gachsaran formations respectively with sharp lithological changes. Thus, the marly limestone of upper part of the Pabdeh Formation changes to gypsum of Lower Kalhur Gypsum and limestone of upper part of the Upper & Middle Asmari Limestone changes to gypsum of the Lower part of the Gachsaran Formation. In biostratigraphic study of the Asmari Formation in this section 9 species belong to 6 genera of planktonic foraminifera and 10 species belong to 21 genera of benthic foraminifera have been identified and a not-zone in Lower Kalhur Gypsum, one biozone based on planktonic foraminifera in Inter Kalhur Beds and two biozones benthic forminifera and biozonation, based on Laursen et al., 2009, in the Middle & Upper Asmari Limestone in the Asmari Formation were recognized as follows:Borelis melo curdica – Borelis melo melo Assemblage zone Miogypsina – Elphidium sp.14 – Peneroplis farsensis Assemblage zone Globigerinoides subquadratus Assemblage zone
    Not Zoned Furthermore, one biozone based on planktonic foraminifera in the upper part of the Pabdeh Formation were identified as follows
    Subbotina gortanii Assemblage zone
    Conclusion
    According to location of Lower Kalhur Gypsum unit between upper part of the Pabdeh Formation with Late Chattian age and lower part of Inter Kalhur Beds unit with Aquitanian age, and also by considering isotope strontium studies in Lower Kalhur Gypsum (by Van Buchem at al., 2010), the age of the Lower Kalhur Gypsum late Chattian were identified. Also, for Inter Kalhur Gypsum consisting biozone of “Globigerinoides subquadratus Assemblage zone” and 82 m of the Lower part of Middle & Upper Asmari limestone unit consisting biozone of “Miogypsina Elphidium sp.14 peneroplis farsensis Assemblage zone” with the age of Aquitanian and 50 m of upper part of Middle & Upper Asmari limestone consisting of biozone of “Borelis melo curdica Borelis mel melo Assemblage zone” with the age of Bourdigalian were determined. Totally based on biozones and planktonic and benthic foraminifera that were recognized in the Asmari Formation in jahangirabad section, Late Chattian to Bourdigalian age were suggested.
    Keywords: Lithostratigraphy, Biostratigraphy, Asmari Formation, Kabir Kuh Anticline, Jahangir Abad
  • Reza Esmaili* Pages 141-153
    Introduction
    Meanders have active dynamic and are constantly changing. Morphodynamics of meanders are important in sediment patterns and processes and hydrological and ecological processes of flood plains. But human activities create changes in these processes. Hence, knowledge and understanding of the morphological changes of meanders and the natural dynamics of river systems are essential for the planning, conservation and reconstruction of river channels. In this research, the morphological changes of the Shalmanrood River (East Gilan) have been analyzed during a period of 51 years between 1967 and 2018.
    Material and method
    Changes in Shalmanrood meanders were evaluated for three periods of 1967-1994, 1994-2003 and 2003-2018. To do this, the aerial photos of the years 1967 and 1994 as well as the images of Google Earth in the years 2003 and 2018 were used. For each of these years, the river route was mapped and digitized. Changes in Shlmanrood meanders were analyzed with morphometric, morphodynamic and morphological indices. River geometric properties (morphometry) were measured with parameters including channel length, wavelength, amplitude channel, radius and central angle of curvature. Morphodynamic characteristics were examined with lateral channel migration, area occupied the active channel and channel activity rate and then, channel morphology and different channel migration models were evaluated.
    Results and discussion
    The mean values of the geometric parameters of Shalmanrood meanders were not significantly different at a significant level of 0.05 in the studied periods (51 years). Most of the Shalmanrood river arches have been developed meanders and it included 79, 81, 62 and 81 percent of the total arches in the years 1967, 1994, 2003 and 2019. Extremely developed arches have included 11 and 7 percent meanders in the years 2003 and 1397, which indicates changes in the forms of the arches in recent years.
    The channel activity was measured at 1967-1994, 1994-2003, 2003-2018, respectively, 2.77, 1.22, and 0.48 meters per year, indicating a decreasing trend in this parameter. The amount of overlap of the river channel in the period from 1967 to 1994 was 13 percent but they have increased in period 1994-2003 and 2003-2018 to 78 and 86 percent respectively. This trend represents a decrease in the channel's morphodynamics over the past 25 years. The morphology of Meanders' changes in the first period (1967-1994) has changed dramatically and has changed slightly in the second and third periods, and has changed the general pattern of immigration. Accordingly, during the period of 1967-94, the complex changes and the growth of Meander with a value of 67% were the largest channel of immigration pattern. Approximately 81% of the channel was unchanged during the period 1994-2003, and the remaining 19% related to migration patterns, meandering growth and lobbing. In the period of 2003-2018, the patterns of change were almost the same as in the previous period.
    Conclusion
    Reducing lateral channel migration and increasing the overlap rate of the channel, especially during the 2003-2018 periods, indicates a decrease in the geomorphic activity of river. The occupation of the surrounding areas of the river with agricultural and residential landuses, the construction of dikes and the consolidation of the banks in different parts of the river are among the factors influencing the reduction of geomorphic channel activities in the meander belt zone in Shalmanrood. In the current situation, the removal of sand and gravel from the channel bed and flood plain, the upstream parts of the study area, the bed lowering (incision), the presence of fine-grained and loose sediments in the size of the silt and sand in the bed and the bank and formation of developed meanders can increase the occurrence of channel interruption (cutoff) in the middle reaches and cause instability in the balance of the river. The results of this study show that geomorphologic study of meandering rivers using a total of morphometric, morphodynamic and morphological indices provides a more comprehensive and deeper understanding for the analysis of this type of rivers.
    Keywords: Shalmanrood, Meander, River morphodynamic, River morphometry, Gilan
  • Somayeh Rafati* Pages 154-173
    Introduction
    An important step in the implementation of wind turbines is an assessment of the wind energy potential for relevant locations. This can be challenging because of the nature of the resource. The characteristics of wind energy, in terms of speed and direction, exhibit a high degree of temporal and spatial variability. The variability could lead probabilistic uncertainties, and these uncertainties might affect system operation significantly. The change in environmental parameters can greatly affect the wind characteristics. Therefore, determining the effect of environmental parameters on measured data is very important for determining the wind potential in locations and heights other than the point of measurement. However, in many studies, wind potential has been evaluated solely on the basis of data measured at synoptic stations and has been generalized to the surrounding area.
    Materials and methods
    This research aimed to assess environmental parameters effects such as roughness and obstacles on wind properties. To do this we used 3-hour wind speed and wind direction data acquired from synoptic stations, Digital Elevation Model, and land use map of Kermanshah province. Also the obstacles map has been prepared around every synoptic station using satellite imagery. WAsP software was used for estimation of wind properties in given conditions (0.03 m roughness and remove obstacles). In this way, wind properties from measured data in stations was compared with estimated wind properties for given conditions in 10 m AGL and so environmental parameters effects on wind properties was evaluated in all stations.
    Results and Discussion
    Obstacles were identified around the all studied stations except for Tazehabad. Many obstacles were identified in the direction of the second prevailing winds (western winds) at Sarpol Zahab and Ravansar stations and in the direction of the north of the station at Javanrood and Sararood stations. The highest obstacles (with an average elevation of more than 10 meters) are also observed at in Kermanshah (northwest and north-east), Eslamabad-Qarb (west and southwest), Kangvar (south, southeast) and Harsin (east) stations. The result showed that the most induced environmental parameters effects change in mean wind speed occurred in Eslamabad-Qarb, Ravansar, Sarpol-Zahab, Kermanshah (30% to 40% respectively) and the least change of it was occurred in Harsin, Tazeabad and Somar (9% to 15%). The percentage of change in wind speed at other stations is equal to 28% at Gilanqarb, 26% at Sararood, 26% at Javanrood, 20% at Sonqor, 18% at Qashisharin, and 16% at Kangavar. Mean wind power density was changed between more than 81% in Ravansar and Eslamabad-Qarb to 27% in Harsin. The percentage of change in mean wind power density at other stations is equal to 66% at Sarpol-Zahab, 65% at Kermanshah, 64% at Sararood, 63% at Javanrood, 62% at Gilanqarb, 49% at Qashisharin, 48% at Sonqor, 38% at Tazeabad, 37% at Somar and 33% at Kangavar.
    Conclusion
    Thus many obstacles in wind dominates direction in Ravansar, Sarpol-Zahab, and high obstacles in Eslamabad-Qarb and Kermanshah and also high roughness value in Kermanshah, Ravansar, Eslamabad-Qarb, Javanrood and Gilanqarb has great impact on wind speed decrease to more than 26% and wind power density to more than 62%. As a result, it can change priority of suitable places for using wind energy if we ignore environmental parameters effects on wind measured data.
    Keywords: Environmental parameters, Kermanshah province, WAsP software, Wind speed
  • Parvin Mansor* Pages 174-190
    Introduction
    Flood is a stream that is larger than the average volume of water along the river (Wool, 2000). Bowell (2007) estimated flood damage in the 2000s by about $ 21 billion. In Iran, floods are one of the most important natural hazards in most parts of the country. The study of natural features of the catchment area helps to understand hydrological and geomorphic issues such as flood, erosion and mass movement (Isa and Afyang, 2011).One of the most important tools in hydraulic analysis is the study of morphometric parameters of the basin, which makes it possible to assess the behavior of the hydrological systems of the basin (Anjeliliri, 2008).The hydrological response of the river basin is related to the physiographic characteristics of the drainage basin, such as size, shape, slope, drainage density and flow lengths (Kumar et al., 2000). Morphometric analysis and prioritization of basins are essential parameters for managing and evaluating flood risk (Yusuf et al., 2011). Sarpol Zahab Basin has heavy rainfall and its geological and geomorphological conditions are favorable for the formation of flood. Due to the passage of the Alvand River through the city of Sarpul Zahab and the location of the village and agricultural land and human facilities along the river's outskirts, flood risk zoning is necessary and necessary. The aim of this study is to zonate the potential of flood discharge of Sarpul Zahab basin and its sub-basins using morphometric parameters.
    Materials and methods
    In the first method, 9 parameters of morphometry area, Slope index, Relief ratio, Weighted mean bifurcation ratio, Stream frequency, Drainage density, Basin shape index, Ruggedness numberand Texture Ratio Basin of Sarpul Zahab and its sub-basins were calculated. The degree of risk of the parameters was calculated according to equations (1) and (2).
    equations (1) HD =
    equations (2) HD =
    The zoning of sub-basins is based on the sum total of nine parameters in terms of flood risk. The risk of flooding is divided into five areas of low risk, medium risk, high risk, very high risk and severe risk (Table 2), and each zone has a score of 1 to 5 (Fahan and Ayat, 2017).In the second method, 12 parameters Bifurcation ratio, Drainage texture, Compactness index, Form factor, Circularity ratio, Elongation ratio, Lemniscates ratio, Relief, Stream frequency, Drainage density, Ruggedness number and Relief ratio Which have a direct runoff ratio, were calculated for the Sarapul Zahab basin and its five sub-basins. For the values derived from each of the twelve parameters in each sub-area, the rank (rank) is allocated from 1 to 6 (Altaf et al., 2014). The higher values have the greatest impact on flooding and have the highest score (Batt et al., 2019).The index (Cv) is an average of 12 morphometric parameters (Batt et al., 2019, 53), and the sub-basins are zoned in terms of the potential of flood landslides.
    Discussion and
    Results
    The studied basin has five sub-basins, Rijab, Pathagh, Ghaleh Shahin, Sarabgarm and Qarawiz. The drainage network pattern in the Sarpul Zahab Basin and its sub-basins is dendritic and the main drainage of Sarpul Zahab basin is 6. Total sum of the degree of risk of nine morphometric parameters in the catchment area 27.21, which indicates the potential for severe flood risk in this basin. The submarine Rijab with a degree of risk of 26.65 has a very high potential flood risk potential. The sub-basins of the castle and Shahin castle with a hazard degree of 28.26 and 27.12 have a high risk, the sub-basin of the 22.03 range with a medium risk potential and a sub-basin of 20.87 degrees with a low risk of flood risk. Indicator values (Cv) for the Sulfol Basin 4.75, which has a high potential for flood risk. The 4.27 Ridge submarine has a high potential flood hazard potential. The sub-basins of the castle and Shahin Castle are respectively 3.08 and 3.16, respectively, with a medium-risk flood hazard potential, respectively. The sub-basins of Qarawis and Sarabag with 2.83 and 2.91 values, respectively, have a potential flood hazard potential.
    Conclusion
    In the first method, 57.05% of the area of the Sarapul Zahab basin has a high risk, 32.67% has a potential hazard, 3.86% has a moderate risk potential and 6.41% has a low potential hazard. In fact, 89.72% of the area of the Sarpol Zahab Basin has a high and severe flood risk potential. The second method, 32.67% of the area of Sarpul-Zahab Basin has a high potential hazard, 57.05% has a moderate risk potential and 10.27% has a low potential hazard. The comparison of the results of the two methods with each other and the morphometric and geomorphological conditions of the Sarpol Zahab basin and its sub-basins indicate which results from the second method, which is based on 12 morphometric parameters, is more adapted to the natural conditions of the basin. The two small, fairly smooth slabs and low-slope sub-basins, which have low topographic slopes and are limited to the limited permeability of quaternary deposits, have low potential potentials. Submerged and long castles and castle fortifications, most of whose area is in the range of permeable quantum deposits, with low slope, has a medium risk potential. The Rijab sub-basin has sloping ranges because of its high ruggedness and is close to the circle, with a high potential hazard. The Sarpul Zahab basin is also high due to mountainous conditions and the presence of steep slopes in more than 65% of its area and the shape close to the circle has a high risk of flooding. The application of 12 morphometric parameters to 9 parameters of morphometry and more emphasis on parameters related to basin shape have made the second method more effective in potential flood hazard potential in Sarpul Zahab basin and its sub-basins.
    Keywords: Morphometric parameters, Sub-basin, Flood potential, Degree of risk, Sarpol Zahab basin
  • Zohre Fanni* Pages 191-213
    Introduction
    Natural hazards have created widespread problems and nodes in many centuries in relation to the development of human societies. According to the study, factors such as the presence of faults around the city, demographic density, high marginalization and, consequently, non-standard housing and lack of open and green spaces, have made Zahedan to be vulnerable to natural hazards. Among the examples of people's participation is capacity building, capacity building led by local institutions and organizations, provides a way to enhance public participation opportunities and achieve successful outcomes for sustainable development and, on the other hand, make progress in sustainable development dependent on social capacity building.
    Materials and methods
    Descriptive-analytic method has been used to investigate the reduction of natural hazards (earthquakes) on urban environment with emphasis on capacity building. In order to collect information from research, a questionnaire was used to survey the reliability of questionnaires using the Kronbach Alpha method and the coefficient 845 / ; Their validity was determined on the basis of Delphi technique and the expert judgment of the bachelor's degree. For more certainty, the CVI and CVR indices were used to determine the accuracy of the content validity because the coefficient above 70 /. , A desirable validity was obtained. To evaluate the normal distribution of data, the Kolmogorov-Smirnov test and the differences in the values of the variables were used for ranking and T test.
    Results and Discussion
    Based on the results of the T test, in the institutional dimension, the "access to safe places in the event of a possible earthquake in the level of 0.05 and other sub-criteria is less than 0.001 in the level. In the physical-spatial dimension, the components of "access to the main and arterial passages and the level of exhaustion of the residential houses in your neighborhood, at the level of 0/05 and the components of trust in the residential unit in terms of architecture and engineering at 01/0 and other sub-criteria", has a significant difference And in the socioeconomic dimension, the sub-criteria "The amount of general information to the residents in the event of an earthquake and consultation with the informed people in order to reduce the vulnerability at the level of 0.05 and below the level of coverage of your housing insurance at the level of 0.01 is significant.
    Conclusion
    According to the geographic conditions of the region and the existence of various faults, there is a probability of earthquake occurrence in the city. In terms of access to open and green spaces, vulnerability and resilience are different in different regions, so that the central, southeastern and marginal areas of access In the open spaces and the least vulnerable, the eastern parts of the city, due to the use of such as airports and military sites and the northern areas of the city, are exposed to the mountains with the lowest level of access to green space and open space, less resilience and more vulnerability. Based on the results of the research, capacity building in the institutional dimension is in a rather desirable situation. However, in socio-economic and spatial -physical dimensions, in the unfavorable situation, the need for more authorities to strengthen these dimensions is necessary.
    Keywords: Zahedan, Capacity building, Urban environment, Natural hazards
  • Mohammad Taghi Razavian* Pages 214-230
    Introduction
    Tourism development and enjoyment of its capacities is an important step in economic flourish. In this regard, serious and purposeful attention to the urban tourism especially in metropolitans such as Tehran which has high capacity in this case can lead the economic flourish of city and increase of income for public and private sectors, and promotion of living level of citizens. The existence of historical, natural, commercial, religious, therapeutic, sporting, and important scientific, cultural, social and political attractions have special capabilities that can play an important role in the development of tourism in Tehran. However, so far, little has been done regarding the optimal use of these capabilities. Considering the existing capacities in this metropolis, in the event of proper planning and management of urban tourism, Tehran becomes one of the most important tourist centers of the world, as a result of economic growth and attracting vast financial resources, creating employment and raising the level of income of citizens The inhabitants of this city are far from waiting. To meet this goal, it is unavoidable to evaluate the current conditions and recognize the foregoing challenges. The purpose of this research is to analyze and evaluate the effect of tourism on economic development of Tehran.
    Materials and Methods
    This research is practical in goals, descriptive- surveying in terms of research methodology, and the data was collected using the library and questionnaire method. After collecting the factors, a preliminary questionnaire containing a number of specific factors was provided to 15 experts of the tourism industry in Tehran including academic professors, researchers and experienced experts of this industry. The purpose of this work was to verify The factors are the completion and addition of new factors to the opinion of the experts of the field of tourism. After completing the final questionnaire and performing the validity and reliability test, a questionnaire was provided to the sample group for response. In order to measure the validity of the questionnaire, the opinions of the professors and experts in the fields of geography and tourism management were used and for the reliability evaluation, the Kronbach Alfa method was used. Statistical population of research is the inhabitants in Tehran among which the researcher- prepared questionnaire was distributed and collected. Enjoying Cochran formula, 384 persons were chosen as the sample of statistical population, data analysis and use of statistical tests were carried out using SPSS software.
    Results and Discussion
    The development of urban tourism in Tehran, which is the source of new developments in the field of economy, increasing the influx of international and domestic tourists and injecting new currency into the commercial and commercial cycle of Tehran, increasing the production of goods and services and increasing the level of citizens' income and creating Job opportunities and new investment in tourism will result in tax revenues from activities related to the tourism industry. Based on the results, growth of tourism and income resources of this industry may be an effective and important factor on economic development and income stability of Tehran. Also, tourism development is impressed by some factors such as infrastructures and facilities, information and advertisement.
    Conclusion
    If the conditions are met for the development of urban tourism in Tehran, the attraction of international and domestic tourists to the city will increase and as a result new money will be injected into the urban economy. Activities and investments in the tourism sector will expand and produce goods and services. For many unemployed youth, employment will be directly and indirectly created, and the income and quality of life of households in the city will be somewhat improved. To achieve this goal, the government should play a policy and purely sovereign role and delegate the role of the executive to the private sector with the necessary support and supervision.
    Keywords: Economy, Economic Development, Tehran, Income, Tourism
  • Freshteh Riazi* Pages 231-247
    Introduction
    Heat Waves as a climatic extreme phenomenon had more occurrence in recent years which this case is an evidence of earth climate change. The heat wave is generally defined as a period of consecutive days with the unusual high temperatures which has become as a common risk in the world due to the effects it has on the nature and human beings including health, hygiene, water resources and agriculture. The identification of these effects requires recognizing the heat wave and determining its thresholds, we have tried to determine the temperature threshold of the heat wave in different regions of the country during the warm period of the year.
    Materials and methods
    To fulfill this purpose, the statistics of daily maximum temperature of the 90 synoptic stations during the statistical period of 1986-2015 from April to September was received from the country's meteorological organization. Then after the primary processing of raw data, the temperature threshold of the heat wave during the warm period of the year wase determined based on three global indexes (Percentile 95, Baldy, World Meteorological Organization). Baldy indicator: Tmax daily ≥ Tmean max daily + 1.5sdmax daily Percentile 95 index: when the daily maximum temperature of each station is equal and larger than percentile 95 of that daily data’s station and continue at least 2 day, named as a heat wave. Global meteorological organization index: define the heat wave based on which daily maximum temperature of a station is 5 degree centigrade more than a long term mean for 5 day consecutive. Then in ArcGIS environment and by using a hybrid method of IDW and regression the temperature threshold was interpolated for the whole country, considering the latitude and altitude (as the 2 important and effective factors in the amount of the temperature threshold of the heat wave). the research is about simulation of temperatures threshold that leading to heat waves in different parts of the country.At first, the temperature maximum of 90 stations in the warm spell of the year for 30 years (2016-2045) by General Circulation models CanEsm2 under 3 scenarios RCP 2.6, RCP 4.5 and RCP 8.5 and statistical downscaling of SDSM simulated. Then base on 3 global indices determined temperature threshold heat wave in different country.
    Results and Discussion
    The results showed that the temperature thresholds in the country's different times and places are not the same in the warm period of the year, and they have different ranges. In April the temperature threshold ranged from 15 - 40 ,in May from 21-46 ,in June between 25-50, in July between 29- 49 ,in August between 32- 52 , and in September between 27- 47 degrees Celsius . In the months of April, May and September, the temperature threshold is higher from the local differences and in the months of June and July and August it has almost the relative uniformity, which is because of the presence of Azores subtropical high pressure which dominates all parts of Iran from the south of Alborz Mountains. On the other hand, the presence of this phenomenon makes the role of local factors such as altitude, latitude in the value of temperature threshold in these months not that much tangible, and the temperature threshold has the relative integration.
    Conclusion
    Also, the results show that the highest temperature threshold of the heat wave in the warm period of the year is related to Khozestan province and the lowest temperature threshold of the heat wave is related to the parts of the North and North West of the country. Based on different scenarios RCP 2.6, RCP 4.5 and RCP 8.5 in future, low-temperature threshold in the spring almost 5 degrees will be increased. In addition, the boundary of classification of temperature have a sensible change. Classification with high threshold movement toward high-latitude and middle- latitude. In summer high threshold and low threshold don’t change than present. It is remarkable that in current, large part of country have threshold 35-40 degree of Celsius, but in future will be 40-45c.In the other hand, almost, 70 percent of country experiment threshold more than 40c spatially in high-latitude and middle- latitude and in warm spell, temperature threshold have most changes and increase in future than past. The results of this research indicate this scientific truth that in order to obtain accurate temperature threshold for different regions of the country, different indices should be used because these indicators complete each other, and we cannot achieve the accurate results in this field by using just one index.
    Keywords: Heat wave, Temperature threshold parameters, Climate change scenarios, CanEsm2, SDSM