فهرست مطالب

  • پیاپی 110 (زمستان 1398)
  • تاریخ انتشار: 1398/10/01
  • تعداد عناوین: 11
|
  • مصطفی کریمی احمدآباد*، مهناز جعفری، فرامرز خوش اخلاق، سعید بازگیر صفحات 545-562

    در این پژوهش به‏ منظور بررسی نقش میزان شار رطوبت در نوسانات بارش ایران از داده ‏های دوباره واکاوی‏ شده ERA Interim مرکز پیش ‏بینی‏ های میان ‏مدت اروپا با قدرت تفکیک مکانی 1 در 1 درجه در دوره آماری 1981-2011 بهره گرفته شده است. نخست، به‏ منظور استخراج الگوهای مرطوب و خشک ایران، از شاخص استانداردشده z استفاده شد و سالی که درصد مساحت رخداد دوره ‏های فوق در آن‏ها بیشینه بود انتخاب گردید و محاسبات مجموع قائم واگرایی شار رطوبت در چهار لایه جوی در سطح و مرزهای ایران و همچنین سطوح آبی اطراف در دوره ‏های منتخب اجرا و مقادیر رطوبت ورودی به ایران محاسبه و استخراج شد. طبق نتایج حاصله، مشخص شد که الگوی جریان حاکم در منطقه و سطوح آبی نقش قابل‏ ملاحظه‏ ای در تغییرات رطوبت جو ایران داشته است؛ به ‏طوری‏که مقدار شار رطوبت جوی در همه لایه ‏ها در سال آبی مرطوب بیشتر از سال خشک است. با توجه به الگوی جریان در لایه‏های مورد بررسی، دریای عرب در تراز زیرین و دریای مدیترانه در ترازهای میانی و بالایی جو در سال مرطوب بیشترین سهم را در انتقال رطوبت به ایران دارا می‏باشند. همچنین، مرزهای جنوبی در سه لایه زیرین، میانی، و بالایی جو در مرتبه اول و مرزهای غربی در مرتبه بعدی اهمیت به لحاظ مسیر ورود رطوبت به ایران قرار دارند.

    کلیدواژگان: ایران، ترسالی، خشک‏سالی، شاخص استانداردشده z، واگرایی شار رطوبت
  • کبری زارعی، حسین محمدی*، سعید بازگیر صفحات 563-579

    هدف از این پژوهش پیش‏بینی مقادیر‏ عناصر اقلیمی دما و بارش ایستگاه سینوپتیک گرگان با مدل ریز‏مقیاس‏نمایی SDSM و با استفاده از خروجی مدل تغییر اقلیم CanESM2 بر پایه سناریوهای تغییر اقلیم  RCP 2.6, 4.5, 8.5 برای دوره ‏های آینده 2011- 2040، 2041- 20701، و 2071- 2100 و نیز بررسی روند سالانه این تغییرات با استفاده از آزمون من- کندال است. نتایج خروجی مدل در دوره آینده نزدیک و میانی از ماه فوریه تا آگوست و در آینده دور از ماه دسامبر تا آگوست کاهش میزان بارش تا 47.15 میلی‏متر در ایستگاه سینوپتیک گرگان را نشان می‏دهد. همچنین، میزان دمای بیشینه از 4/0 تا 33/1 درجه سانتی‏گراد، دمای کمینه از 15/0 تا 8/0 درجه سانتی‏گراد و دمای میانگین بین 18/0 تا 89/0 درجه سانتی‏گراد در هر سه سناریو رو به افزایش خواهد بود. از نظر روند سالانه بارش در سناریو‏های RCP 4.5 و RCP 8.5 معنادار و کاهشی و در مورد عنصر‏های دما این روند معنادار و افزایشی خواهد بود.

    کلیدواژگان: بارش، تغییر اقلیم، دما، ریز‏مقیاس‏ نمایی، سناریو‏های RCP‏، گرگان
  • منصور پروین* صفحات 581-595

    شهر کرمانشاه، به‏ عنوان بزرگ‏ترین شهر غرب کشور، در پهنه‏ های دشت پرمخاطره کرمانشاه واقع شده و در بازه زمانی 46 ساله مساحت آن حدود 7 برابر شده و حدود 87 کیلومترمربع به تصرف شهر درآمده است. این توسعه فیزیکی بدون اجرای مطالعات ژئومورفولوژیکی و درنظرگرفتن محدودیت ‏ها و مخاطرات ناشی از آن بوده است. ازاین‏رو، شناسایی مناطق مستعد توسعه فیزیکی با درنظرگرفتن محدودیت‏ها و مخاطرات ژئومورفولوژیکی امری لازم در توسعه شهری کرمانشاه است. هدف از پژوهش حاضر شناسایی مناطق مناسب برای توسعه فیزیکی شهر کرمانشاه براساس شرایط ژئومورفولوژیکی منطقه است. در این پژوهش با استفاده از مدل فازی نقشه پهنه ‏بندی نهایی توسعه شهری براساس نه پارامتر موثر تهیه شد. سپس، این نقشه‏ براساس شرایط ژئومورفولوژیکی و کاربری اراضی دشت کرمانشاه ارزیابی و مناطق مستعد توسعه شهری پیشنهاد ‏شد. نتایج نشان می‏دهد توسعه فیزیکی شهر کرمانشاه در طی چهار دهه گذشته تابع شرایط توپوگرافی بوده و مخاطرات و محدودیت‏های ژئومورفولوژیکی بسیار زیادی در محدوده مورد مطالعه وجود دارد؛ به ‏طوری‏که 65 درصد مساحت منطقه برای توسعه شهری مناسب نیست. مناطق مساعد با حدود 50 کیلومتر مربع در دشت آبرفتی در غرب و شرق شهر کرمانشاه واقع شده‏اند.

    کلیدواژگان: پهنه‏ بندی، توسعه شهری، شهر کرمانشاه، مخاطرات ژئومورفولوژیکی، مدل فازی
  • رضا اسماعیلی*، مریم صالحی صفحات 597-611

    نیمرخ طولی رود یکی از مولفه ‏های اساسی سیستم رودخانه‏ای است. در این تحقیق نیمرخ طولی 15 رودخانه در البرز شمالی، که بخشی از حوضه آبریز دریای خزر هستند، بررسی شده‏اند. نخست، با استفاده از مدل ارتفاعی رقومی، با قدرت تفکیک 12.5 متر شبکه‏ های رودخانه‏ ای شناسایی و نیمرخ طولی آن‏ها ترسیم شد. شکل نیمرخ طولی رود با شاخص تقعر (CI) و شاخص SLK اندازه‏گیری شد. سپس، شاخص گرادیان طولی رود (SL) برای هر قطعه از نیمرخ طولی محاسبه شد و با استفاده از نقشه‏ های سنگ ‏شناسی و گسل‏ها تفسیر شد. نتایج نشان می‏دهد که شکل نیمرخ طولی رودخانه‏ های البرز شمالی در دره‏ های عرضی به‏ صورت مقعر با چندین شکستگی است که بیانگر غلبه فرسایش در بلندمدت است. در دره ‏های طولی البرز شمالی، نیمرخ طولی رودخانه ‏ها به‏ صورت محدب است که ناشی از ساختار چین‏خوردگی و بالاآمدگی سنگ‏هاست. بررسی شاخص SL نشان می‏دهد که عامل سنگ ‏شناسی و گسل‏ها به‏ ترتیب 53 و 45 درصد در ایجاد شکستگی در نیمرخ طولی این رودها نقش داشته ‏اند. از مجموع 98 خط گسلی، که به‏صورت عرضی رودخانه ‏ها را قطع کرده ‏اند، فقط بیست‏ درصد آن‏ها موجب شکستگی در نیمرخ طولی رود شده ‏اند. اثر گسل در نیمرخ طولی رودخانه‏ های غرب و شرق استان مازندران به ‏ترتیب 70 و 30درصد بوده است.

    کلیدواژگان: البرز شمالی، شاخص تقعر، مازندران، نیمرخ طولی رود
  • ملیحه سادات حمصی، داریوش یاراحمدی*، مجید اونق، علی اکبر شمسی پور صفحات 613-632

    هدف از این مطالعه بررسی پدیده تغییراقلیم در حوضه دشت کاشان و ارزیابی اثرهای این پدیده و کاربری اراضی بر خشک‏سالی است. به‏ منظور شناسایی روند تغییرات در سیمای این حوضه از تصاویر ماهواره لندست در یک دوره سی‏ودوساله استفاده شد. در طبقه ‏بندی تصاویر از روش نظارت‏شده و الگوریتم حداکثر احتمال استفاده شد. پردازش اطلاعات در این دوره زمانی حاکی از افزایش سطح اراضی کشاورزی، مسکونی، و صنعتی در دوره 1985-2000 به میزان 5.7 و 0.32درصد و کاهش اراضی مرتع و کشاورزی به میزان 5.6 و 4.7درصد و افزایش اراضی شوره‏زار به مقدار 20درصد در دوره 2000-2017 است. با هدف پیش ‏بینی آینده، داده ‏های بارش با مدل آماری SDSM برای دوره 2050-2011 محاسبه شد. همچنین، با مدل من‏- کندال روند تغییرات بارش در دوره 1966 تا 2017 بررسی شد. خشک‏سالی از طریق شاخص SPI به‏دست آمد. مطالعه هم‏زمان تغییر کاربری و اقلیم با توجه به خشک‏سالی طولانی‏ مدت، آسیب‏ پذیربودن، و خش ک‏بودن حاکی از تحمیل فشارهای زیاد بر محیط زیست منطقه است. در صورت ادامه روند فعلی حوضه دشت کاشان با خسارت جبران‏ناپذیری روبه‏ رو می‏شود. ازاین‏رو، این تحقیق راهبرد آمایش سبز (کم کربن) را برای کاهش خطرهای محیط زیستی و خسارات خشک‏سالی در منطقه پیشنهاد می‏کند.

    کلیدواژگان: آمایش سبز (کم کربن)، تغییر اقلیم، تغییر کاربری زمین، حوضه دشت کاشان
  • فاطمه ارسلانی، بهلول علیجانی، مهری اکبری، شیرین محمدخان* صفحات 633-649

    هدف از پژوهش حاضر اندازه‏ گیری و پهنه ‏بندی غبار ریزشی شهر تهران در دوره آماری یک‏ساله (1/10/1396-30/9/1397) است. بدین‏ منظور، غبار ریزشی شهر تهران جمع‏آوری شد. وزن غبار ریزشی در زمستان معادل با 18943.5 تن، در بهار معادل با 27119.5 تن، در تابستان معادل با 17111.2 تن، و در پاییز معادل با 23002.3 تن است. نقشه تحلیل فضایی گردوغبار ریزشی شهر تهران حاصل ترکیب نه لایه بر اساس وزن تعیین‏شده برای هر لایه ترسیم شد. بیشترین میزان گردوغبار ریزشی در زمستان 1396 در غرب تهران و در بهار، تابستان، و پاییز 1397 در جنوب غرب تهران بوده است. بررسی‏های میدانی ثابت کرد گردوغبار ریزشی در ارتباط مستقیم با ساخت‏ و ساز شهری قرار دارد. این افزایش با pm10، تراکم کارخانه ‏ها، تراکم پوشش گیاهی، رطوبت نسبی، بارش بالای 5 میلی‏متر، دما و سرعت و جهت باد نیز در ارتباط است. باد غالب تهران جهت غرب دارد که از معادن شن و ماسه می‏گذرد. باد غالب در تابستان جنوب شرقی است. باد جنوب شرقی از معادن شن و ماسه، کارخانه ‏های سیمان عبور می‏کند و در مسیر خود گردوغبار این مناطق را وارد تهران می‏کند.

    کلیدواژگان: تحلیل فضایی، تله رسوب‏گیر MDCO، شهر تهران، گردوغبار ریزشی
  • بهروز ساری صراف*، حبیبه نقی زاده، علی اکبر رسولی، سعید جهانبخش، ایمان بابائیان صفحات 651-671

    تغییرات عمق برف، به‏‏سبب تاثیرگذاری در شار انرژی سطحی و شرایط هیدرولوژیکی، در تحولات آب و هوای محلی و جهانی نقش درخور ‏توجهی دارد. هدف از این مطالعه مدل‏سازی و تحلیل فضایی عمق برف با استفاده از پایگاه ECMWF نسخه ERA Interim برای دوره زمانی 1980-2016 با تفکیک مکانی 125/0×125/0 درجه قوسی است. در این راستا داده‏های ارتفاع، طول و عرض جغرافیایی، و شاخص پوشش گیاهی NDVI سنجنده MODIS با استفاده از روش‏های GWR و OLS ارزیابی شد. ارزیابی خودهبستگی فضایی عمق برف با دو شاخص Moran’s I و Geary's C نشان داد عمق برف در پهنه شمالی ایران دارای الگوی خوشه‏ای ساخت‏یافته است. بیشینه متوسط عمق برف در ماه فوریه به ‏دست آمده است. شمال غرب ایران همراه علم‏کوه در رشته‏ کوه البرز بیشترین ‏عمق برف را نشان داده‏ است. نتایج نشان داد روش GWR برآوردهای دقیق‏تری در مقایسه با روش OLS ارائه می‏دهد. براساس خروجی ‏های به ‏د‏ست‏ آمده از روش GWR، عمق برف با ارتفاع رابطه خطی را نشان نمی‏دهد، بلکه این رابطه بسته به تغییرات پوشش گیاهی، دمای هوا، و جهت شیب در منطقه مورد مطالعه متفاوت است.

    کلیدواژگان: پهنه شمالی ایران، روش GWR، عمق برف، مدل‏سازی فضایی، ERA Interim
  • وحید صفریان زنگیر، بهروز سبحانی*، صیاد اصغری صفحات 673-692

    خشک سالی یکی از مخاطرات طبیعی و تاثیرگذار در همه فعالیت‏های موجودات زنده است. هدف از پژوهش حاضر مدل‏سازی و تحلیل خشک سالی در جنوب ‏غرب ایران است. برای این کار، نخست از پارامترهای اقلیمی بارش، دما، ساعات آفتابی، حداقل رطوبت نسبی، و سرعت باد در بازه زمانی 32 ساله (1987-2018) در 15 ایستگاه جنوب ‏غرب ایران استفاده شد. برای مدل‏سازی شاخص فازی T.I.B.I، نخست چهار شاخص (SET, SPI, SEB, MCZI) با استفاده از منطق فازی در نرم ‏افزار Matlab فازی‏سازی شدند. سپس، شاخص ‏ها با هم مقایسه شدند و در نهایت از مدل تصمیم‏گیری چند متغیره SAW برای اولویت سنجی مناطق درگیر با خشک سالی استفاده شد. یافته‏ های پژوهش نشان داد بیشترین درصد فراوانی وقوع خشک سالی در مقیاس 6 و 12ماهه در ایستگاه اسلام ‏آباد غرب و کمترین آن در مقیاس شش ماهه در همدان فرودگاه و در مقیاس دوازده ماهه در ایستگاه خرم آباد رخ داده است. مدل T.I.B.I طبقات خشک سالی چهار شاخص یادشده را با سطح اطمینان بالا در خود منعکس کرد. براساس مدل‏سازی انجام گرفته، شاخص فازی T.I.B.I نسبت به شاخص فازی SPEI برتری نسبی نشان داد. در نهایت، براساس مدل تصمیم ‏گیری چندمتغیره SAW، ایستگاه اسلام‏آباد غرب با مقدار امتیاز 1 در اولویت بیشتر در معرض درگیری خشک سالی قرار گرفت.

    کلیدواژگان: شاخص T.I.B.I، مدل SAW، مدل‏سازی، منطق فازی، MATLAB
  • نسرین حسین آبادی، تقی طاوسی*، عباس مفیدی، محمود خسروی صفحات 693-713

    هدف از این پژوهش بررسی روند وارونگی دمای لایه مرزی کلان‏شهرهای تهران، مشهد، و تبریز است. در این راستا، از داده‏های پیمایش قائم جو سال‏های 2007- 2017 ساعت صفر (00) ایستگاه‏های هواشناسی تهران، مشهد، و تبریز از پایگاه داده‏ های اقلیمی وایومینگ استفاده شد. برای تعیین انواع وارونگی دما، نمودارهای تفی‏گرام داده‎های جو بالا با استفاده از نرم ‏افزار RAOB ترسیم شد. سه نوع وارونگی تابشی، فرونشستی و جبه ه‏ای به‏عنوان سه تیپ اصلی و چهار نوع دیگر به ‏عنوان تیپ ‏های ترکیبی متشکل از این سه نوع وارونگی مشخص و توزیع زمانی فراوانی و درصد هر یک از 7 تیپ وارونگی در هر ماه محاسبه شد. روند یازده ‏ساله هر یک از تیپ‏ های وارونگی با استفاده از روش ناپارامتریک من- کندال و تخمینگر شیب سن تعیین و مقایسه شد. نتایج نشان داد تیپ وارونگی تابشی در همه ایستگاه‏ها کاهش معنادار در سطح اطمینان 01/0 (Z>2.58) و برعکس وارونگی فرونشستی روند افزایشی معناداری در سطح اطمینان 05/0 (z>1.96) نشان داده است. از میان تیپ‏های ترکیبی، تیپ تابشی- فرونشستی روند افزایشی معنادار داشت. در مجموع، نوع تیپ ‏های وارونگی در دوره 2007-2017 از تیپ ‏های وارونگی خالص به تیپ‏ های ترکیبی و چندلایه و به ‏طور شاخص تیپ تابشی- فرونشستی تغییر یافته است.

    کلیدواژگان: آزمون من- کندال، شدت وارونگی، شیب سن استیمیتور، وارونگی دما
  • محمدرضا سلیمی سبحان، زهرا حجازی زاده*، فریبا صیادی، فاطمه قادری صفحات 715-731

    هدف از این پژوهش طبقه ‏بندی مناسب الگوهای جوی مرتبط با وقایع تگرگ و ویژگی‏های اقلیم ‏شناختی مسبب آن‏ها در حوضه زاب است. بنابراین، از داده‏های ایستگاهی (کدهای 27-87-96 الی 99 از 100 کد مربوط به هوای حاضر) بارش تگرگ سه ایستگاه همدید حوضه زاب طی دوره 24ساله (2016-1992) استفاده شد. همچنین، با استفاده از داده‏های پایگاه NCEP/NCAR، به واکاوی الگوهای گردشی مقارن با این رخدادها اقدام شد. با تحلیل خوشه ‏ای داده ‏های فشار تراز دریا و ارتفاع ژئوپتانسیل (500 هکتوپاسکال)، سه الگوی گردشی مرتبط با بارش تگرگ شناسایی شد؛ از جمله 1. تقویت سامانه کم‏فشار سودان؛ 2. تقویت پرفشارهای اروپایی و سیبری؛ 3. قرارگیری منطقه بر روی شرق ناوه مدیترانه. سپس، با اجرای همبستگی درون‏گروهی بین هر خوشه روزی که بیشترین همبستگی را با سایر روزها داشت روز نماینده الگوی گردشی آن خوشه انتخاب شد و مبنای واکاوی پژوهش واقع گردید.

    کلیدواژگان: بارش تگرگ، پرفشارهای شمالی، تحلیل همدید، حوضه زاب، ناوه مدیترانه
  • محمد راهدان مفرد، محمدحسین رامشت*، امیر صفاری صفحات 733-760

    رابطه‏ انسان و محیط در سال‏های اخیر معطوف به تغییرات محیطی و تعریف توسعه پایدار بوده است. اکنون باید دید سهم ژئومورفولوژیست‏ها در بحث تغییرات محیطی و انسان چقدر بوده است. برای تحقق این هدف، با تشکیل جامعه آماری مرکب از 456 مقاله از پایگاه استنادی WOS، طی سال‏های 1970 تا 2018، به تجزیه و تحلیل کتاب ‏شناختی با هدف علم‏سنجی دانش ژئومورفولوژی با کمک نرم‏افزار Citespace مبادرت شد. نتایج به‏ دست‏ آمده نشان می‏دهد که فلیپس، شوم، گوودی، و گریگوری هسته مرکزی محققان را شکل داده و کلیدواژه ‏های «ژئومورفولوژی، تغییرات اقلیمی، و هولوسن» بیشترین تکرار، «ژئومورفولوژی و پوشش گیاهی» بیشترین پایایی، و «تغییر محیطی، تغییرات اقلیمی، و اثر انسان» دارای بیشترین مقدار شاخص شکوفایی هستند. همچنین، خوشه ‏بندی روند فکری ژئومورفولوژیست‏ها از تحلیل شاخص مرکزیت نشان می‏دهد که آن‏ها هفت مرحله فکری را پشت سر گذارده‏اند. این مراحل عبارت است از گرایش کلی ‏‏پژوهش‏ها به علوم محیطی؛ به‏ کارگیری دیدگاه سیستمی در ارائه راه‏ حل‏ها؛ تمرکز بر ژئواکولوژی؛ گرایش به ژئومورفولوژی رودخانه‏ای؛ چرخش مطالعات به زمین‏باستان‏شناسی؛ تخصصی‏ ترشدن متدولوژی‏های تحقیق؛ مبنا قرارگرفتن تغییرات محیطی به ‏ویژه در نه سال منتهی به 2018 به‏ عنوان موضوع مورد توافق بیشتر ‏‏‏‏پژوهش‏های مرتبط با انسان و محیط.

    کلیدواژگان: انسان، ژئومورفولوژی، محیط، Citespace، WOS
|
  • Mostafa Karimi *, Mahnaz Jafari, Faramarz Khoshakhlagh, Sayeed Bazgir Pages 545-562

    Introduction :

    Atmospheric moisture resources which affect rainfall in a region are one of the most important issues in atmospheric sciences. In addition, understanding the mechanism of origin and transfer of atmospheric moisture causes the knowing of water cycle in a region. The main components of water cycle are the evaporation from land surface and oceans, transfer of water from ocean to land, precipitation over oceans and lands and the recurrence of water from land to the ocean. Consequently, the percentage of moisture flow of a region and amount of evaporated water could be evaluated using atmospheric moisture flow and observed precipitation. Therefore, the effect of evaporation from water bodies and transfer of atmospheric moisture on precipitation could be determined by calculating them. The spatio-temporal variations of precipitation could be investigated by study of moisture fluctuation due to variations in atmospheric circulation in dry and wet patterns conditions. Therefore in recent study the difference in atmospheric patterns of drought and wetness conditions, moisture flux and water resources which affect the transfer of moisture over Iran in various atmospheric levels.

     Materials and Methods:

    In this study, re-analysis data of the ERA interim center of Europe medium-term forecasts (ECMWF). With a spatial resolution of 1 ° * 1 ° of geographical latitude and longitude for a 1981-2011 period were used. In order to find the wet and dry patterns in Iran, precipitation data were used. Moreover, geo-potential height, specific humidity, zonal and Meridional components of wind in 00 and 12 UTC of 1000, 850, 700, 500 and 300 hPa for analysis of atmospheric moisture source were used. Standardized Z-Index was used for determining dry and wet patterns over Iran and the percentage of occurrence of the patterns worked out yearly and the year with maximum percentage of area of occurrence of dry and wet periods were selected for further analysis. In next step, precipitation periods of selected years with precipitation of more than 1 mm and minimum 30 percent of affected area were determined for estimating contribution of water bodies in the periods. The total vertical divergence of moisture flux were calculated in 1 ° * 1 ° of geographical latitude and longitude networks in lower, middle and upper and total atmospheric thickness over Iran for selected years. In the next step, the positive and negative values of moisture flux of each network were derived for Iran and water bodies out of Iran, respectively. In the last step, atmospheric circular and specific humidity maps of precipitation periods of wet and dry years were prepared and analyzed for 850, 700 and 500 hPa as a indicator of lower, middle and upper levels, respectively.

     Results and Discussion:

    The results of calculation of Z-Index showed that the 1995-96 and 1999-2000 were determined as wet and dry years with 87.3 and 98.7 percents, respectively. The humidity flux and percentage of variations for all layers were more in wet year as compared to the dry year. The most contribution in transfer of moisture in wet and dry periods was related to Arabian Sea over Iran. The Mediterranean and red seas were in the second order, Persian Gulf was in the third order, and black Oman and Caspian seas were in the next orders in both wet and dry periods. The Arabian and Caspian seas had no impact on moisture due to the flow patterns in middle atmospheric levels. Therefore, the Mediterranean Sea had the most contribution for transfer of moisture over Iran. In upper levels, the contribution of water resources in transferring the moisture was the same as the middle levels. Although, the amount of moisture flux was changed. The results also revealed that the southern border of the country are the most important direction for the entering moisture, especially at atmospheric lower levels. It might be due to the fact that the southern water bodies and Arabian Sea are the main moisture sources at atmospheric lower levels. In overall, the atmospheric low levels had a significant role in transferring moisture in Iran at all directions and the atmospheric upper levels had lesser task in this regard and the southern and western directions had more contribution as compared to other directions. 

    Conclusion:

     The results showed that the flow pattern of the region and water bodies had a remarkable role for imported moisture variations over Iran. The moisture flux at wet period was more at all levels in wet year. In addition, Arabian Sea at atmospheric low level and Mediterranean Sea at medium and upper levels had more contribution for transferring moisture content in Iran. Moreover, the results showed that southern border were in first priority and western borders in second priority for importing moisture at atmospheric lower, medium and upper levels over Iran.

    Keywords: Drought, Humidity, Divergence of Humidity Flux, Standardized Z Index, Iran
  • Kobra Zarei, Hosein Mohammadi *, Saeid Bazgeer Pages 563-579

    Introduction:

     The planet's climate has been constantly changing throughout Earth history, but with the onset of the industrial revolution and human intervention on the environment in recent years, special conditions for rising global temperature have been created. Increase in Earth's temperature has modified the climatic balance and widespread climate changes have been occurred on the Earth's surface, which is referred to as "climate change". To study the effects of climate change on different systems in future, the climate variables should be initially simulated in the future. There are various methods for simulating climatic variables; the most prudent of them is the use of the outputs of atmosphere-ocean general circulation models (AO-. GCMs). Since these models simulate climatic variables in large spatial and temporal scales, to use these simulated variables in smaller scales, the output of these models should be scaled down by various techniques. The microscopic statistical method has more advantages, especially when it comes to lower costs and quicker assessment of the factors which affect climate change, including the SDSM model. Method and

    methods

    The purpose of this study was to predict climate change by the SDSM model using the CanESM2 Climate Change Output based on RCP8.5, RCP4.5, RCP2.6 climate change scenarios for the coming periods of 2040-2011, 2070-2041, and 2100- 2071, as well as study the annual trend of these changes using the Man-Kendall test and the age-related slope estimator. For this purpose, daily data of rainfall and temperature parameters during the statistical period (1981-2010) were collected from the Meteorological Organization. Then, using statistical downscaling model (SDSM), these climatic parameters were simulated in a monthly scale and compared with the base period (1981-2010).In the SDSM model, for the microscopic metering, three types of data are used. The stages of working with this model are briefly summarized as follows: 1. Preparing predictive data and large scale predictors 2. Quality control of data and data conversion (for precipitation data) 3. Choosing the best predictor variables 4. Calibrating the model 5. Production of weather forecasting using observational predictors 6. Statistical analysis 7. Graphical output of model 8. Production of climate scenarios using model climate predictors.

    Results and discussion

    According to the results, it was found that during the 21st century the temperature in the station of Gorgan is increasing and precipitation is decreasing. In three scenarios RCP8.5, RCP4.5, RCP2.6 in the two periods of near future (2040-2011), and the middle (2041-2070) from February to August and in the distant future period (2071-2100) from December to August there is a decrease in rainfall. The highest precipitation decline is in the near future period in June, July and August, with 19.1, 20.9, and 20 mm, and in the middle and the distant future period in each of the three scenarios belongs to May from 28.8 till 47.15 mm. Generally, in all scenarios, as we move towards the end of the 21st century, the average rainfall will be reduced, and the decrease in the RCP 8.5 scenario is more than the other two scenarios. Regarding temperature variables, the general trend of temperature variables in future periods is consistent with the trend of these variables in the base period, with the difference that the temperature will increase slightly in the winter and spring until mid-summer, but from late summer to late fall it will decrease. In the upcoming period, at first the temperatures will be higher in June and in the upcoming mid and later periods it will be higher in May than in other months. Moreover, the more moving from the near future towards the end of the century, the temperature will increase. The augmentation in the RCP 8.5 scenario is more than two other scenarios. However, Regarding the annual precipitation rate, RCP 4.5 and RCP 8.5 scenarios are meaningful and decreasing, and in the case of maximum, minimum and mean temperature variations, there is a significant increase. Also, the precipitation drop and temperature rise in the end of the century and in the RCP 8.5 scenario are more than RCP 2.6 and RCP 4.5 scenarios. According to the

    Conclusion

    In this research, the simulation of climatic parameters of temperature and precipitation was carried out using several linear models of SDSM and general atmospheric circulation models in Gorgan. The output of the CanESM2 model was simulated under RCP8.5, RCP4.5, RCP2.6 scenarios for subsequent periods in 21 steps. The results showed that temperature data, better correlation with observation data (compared with rainfall data). According to the results, it was found that during the 21st century the temperature was increasing and the precipitation was decreasing. At Gorgan Station, in three scenarios RCP8.5, RCP4.5, RCP2.6, in the two near future (2040-2011) and mid-term (2041-2070) from February to August and in the distant future period (2071-2100) between December and August we see a decline in rainfall. The highest precipitation falls in the period in June, July and August, at 19.1, 20.9, and 20 mm, and in the middle and long distances in each of the three scenarios it is from May 28.8 to 47.15 mm .In general, in all scenarios, as we move towards the end of the 21st century, the average rainfall will be reduced, and this decrease in the RCP scenario of 8.5 is more than the other two scenarios. Regarding temperature variables, the general trend of temperature variables in future periods is consistent with the trend of these variables in the base period, with the difference that the temperature increased slightly in the winter and spring until mid-summer,but from late summer to late The fall will decrease. In the upcoming period, the higher temperatures will be higher in June and in the upcoming mid and later periods in May than in other months. Also, the more coming the near future towards the end of the century, the higher the temperature will increase. This increase in the RCP 8.5 scenario is more than two other scenarios. overall result of this study, the increase in temperature and precipitation in the spring and summer and the rising rainfall and the cooling of the autumn season seems to be in the planning of water resources, and in particular, the planning of the agricultural sector This should be taken into account in order to minimize the potential negative effects of climate change in the targeted area.

    Keywords: Precipitation, climate change, temperature, SDSM, RCP Senarios
  • Mansor Parvin * Pages 581-595
    Introduction

    Urbanization and urban development are one of the most important aspects of human ivilization, which leads to the transformation of the environment (Ronald, 1973, 5). Urban development has occurred in the context of geomorphologic landforms, which has the effect of geomorphologic hazards and restrictions on the urban development process and, if not carefully studied, would have harmful financial and financial consequences on human societies. Cities in the developing world have grown dramatically in the past several decades, with the size of the city of Kermanshah rising sevenfold over the course of four decades. In terms of geomorphology of the Navidisi Plain of Kermanshah, Kermanshah City has serious geomorphological limitations for urban physical development. Therefore, zoning and recognizing the areas susceptible to physical development with a geomorphological approach can be the basis for the preparation of urban development plans and lead to proper planning of civil engineering and scientific management of the city.The purpose of this research is to identify areas susceptible to physical development in Kermanshah city in the future. 

    materials and methods:

     In this research, at first, the amount of physical development in Kermanshah city over 4 decades was determined with the use of MSS and OLI satellite images of Landsat by using the supervised classification method. The map of zoning of areas susceptible to physical development in Kermanshah city using fuzzy model based on topographic slope parameters, altitude, distance from main faults, distance from sub faults, distance from main waterway, distance The submarine, lithology, geomorphologic landforms and distance from the city center were prepared.The final map of the zoning of areas susceptible to physical development in Kermanshah city has been investigated based on land use restrictions and ultimately areas susceptible to the city's physical development in the future.

    Findings:

     Determining the districts of Kermanshah during the years 1977 and 2017 shows that physical development occurred in all directions and the most physical development in the northern part of the city was the boundary between the Ghareh Souz and the highlands of Ankhebahestan. The physical development of Kermanshah city in the last four decades was subject to topographic conditions and only rugged areas in the southern, southwest, and southeastern directions have limited the physical development of Kermanshah to other areas, and the physical development of the city over the past 40 years has not followed a particular order. After preparing the fuzzy layers, the nine parameters using the gamma operator 0.8 were used as the best fitting coefficient and a map was developed of the physical development of Kermanshah . The map was divided into five classes using natural fractures. The floor with a very low proportion represents more than half the area of the study area and the appropriate classes include about 26% of the area. 

    Conclusion:

     Inappropriate areas include the highlands of Prao-Bisotun in the north of the city, the White Mountain peaks in the south of the city and the area around the Qara-Ansu River in the Kermanshah plain. The inappropriateness of mountainous regions due to the outcrops of limestone formations, slopes and altitudes, the presence of the main and secondary faults, and the activation of forming processes such as the fall of parts and blocks of lime. The limits of the Qar-e-Sou river due to the loose river sediments, the risk of flooding and the existence of the original Qara-Sos fault is inappropriate. The mountainous hill areas are also not suitable for physical development due to the presence of topographical, lithological and limiting limitations. Suitable and suitable areas are suitable for alluvial plain with appropriate topographic conditions and outcrops of quaternary deposits and a suitable distance from faults and drainage networks. The area of the zones suitable for urban development after land use interference and the distance from the city is about 50 square kilometers. Considering the appropriate distance from faults and waterways in suitable topographic areas and mainly on deposits Quaternary is located in the Alluvand plain in the west and east of Kermanshah. Finally, it can be said that the current range of the city of Kermanshah, as well as the surrounding area due to geomorphologic conditions, has severe hazards and limitations And over the past few decades, the physical development of Kermanshah has been made without regard to these restrictions. Therefore, it is suggested that A comprehensive plan for the high risk areas of Kermanshah city has been developed and in the next stage, considering the socio-economic conditions of proposed areas for the development of city physics, is selected.Also due to the constraints of the vertical and massive structures and planning with exact planning in the appropriate areas to be considered.

    Keywords: zoning, urban development, geomorphologic hazards, Kermanshah City, fuzzy model
  • Reza Esmaili *, Maryam Salehi Pages 597-611

    Introduction:

     The longitudinal profile of river is one of the main components of the fluvial system, which is result from the interaction between lithology, tectonics, fluvial incision and base level change. The longitudinal profile of the rivers that are in a Equilibrium state have concave form, but several factors cause changes to the longitudinal profile of the river, including, lowering base level, rock resistance, structural control, sediment input, non-fluvial processes, bed load effects, human changes and insufficient time. Alborz Mountains are considered as one of the geomorphological zone of Iran, which geological, climatological and vegetation characteristics have created a special geographic landscape. In this study, longitudinal profiles of the northern Alborz rivers (Mazandaran province), which are part of the Caspian Sea basin, have been investigated. The aim of this research is to quantitatively analyze the longitudinal profile of the rivers in the region.

     Methods and Material:

     The longitudinal profile of 15 rivers in the northern Alborz were investigated. The drainage network was extracted by the 12.5-m DEM and Longitudinal profiles of the fifteen trunk channels were extracted using the ArcGIS 10.3. Geological maps were used to interpret lithology and fault distribution. The form of longitudinal profile was measured by the concavity index (CI) and SLK index. The longitudinal gradient index (SL) was calculated for each segment of longitudinal profile. concavity index was computed based on deviations from a straight line profile (Philips and Lutz, 2008). The SL Index analysis was performed with Hack's (1973) method.The SLK index for the longitudinal profile of the river was calculated by normalizing the distances in the horizontal axis and the elevation in the vertical axis. To normalize values (SLK), in the horizontal axis of the graph, the normalized distances are represented as (d / D), where d is the distance between the specific points along the longitudinal profile and D is the total length of the profile. In the vertical axis of normalized height (e / E) it is shown that e is the height of specific points along the longitudinal profile and E is the height difference between the beginning and the end of the longitudinal profile (Vojtco et al., 2012). The maximum amount of concavity along the SLK profile was determined as Zmax. 

    Results and Discussion:

     The northern Alborz rivers are not smoothly concave profiles and there are numerous knickpoints in their longitudinal profiles. In all cases, the best fit (R2) of regression has been matched with polynomial equations of degrees 2, 3 and 4. the coefficient of determination of these regression equations was very high (>0.96). Some of rivers such as Kheyrood, Kojur and Noor have a convex profile with concavity index of -4, -4, and -11respectively. A number of other rivers such as Tajen, Babol, Sardabrood and Chalakrood with CI 8, 7.5, 9 and 8 respectively have more concavity than other rivers. Based on the relative concavity index (CIrel), 20% of the longitudinal profile of the North Alborz in the convex form (CIrel <0), 53% had a relatively straight or very low concave (0 Regarding the good correlation coefficient (0.73) between the SLK index and the CI index, the SLK index is used for clustering. The studied rivers were classified into three groups based on concavity of longitudinal profile and the position of maximum concavity. The first group includes rivers with a concavity of between 0.13 and 0.47 and the maximum concavity is in the second quartile of the profile. In this group, 80% of the North Alborz rivers are located and they are all in the transverse valleys. In the second group, the amount of concavity index of longitudinal profile was negative, that is, they have a convex shape and maximum convexity is in the third quartile. The rivers in the longitudinal valley are in this group. In the third group, the concavity is less than 0.1 and the maximum concavity is in the second quartile of the profile. The analysis of longitudinal gradient index (SL) in the northern Alborz rivers shows that 53% of knickpoints are due to lithologic changes, 45% due to the activity of faults and 2% due to dam construction. Of the 98 fault lines that crossing rivers, only 20% of them have broken the longitudinal profile. The effects of lithology on longitudinal profile were analyzed by statistical test.The results show that the sig value is less than 0.05 and the rejected zero hypothesis in the Safarood, Cheshmeh Kileh, Sardabrood, Chalous, Noor, Heraz, Talar and Nekah catchments, That is, the type of lithology has a significant difference in longitudinal profile formation. The effect of faults in the longitudinal profile of the rivers west and east of Mazandaran province was 70% and 30%, respectively. Conclusion In the longitudinal valleys, the rivers have a convex profile, where uplift (active tectonics) is dominant. In these valleys, the rate of uplift is greater than the amount of river incision and the river can not create a equilibrium profile.The longitudinal profile of the rivers in the transverse valleys is Concave–convex with erosion steps that indicate long-term predominance of erosional processes. Their profile is due to the high altitude difference, short distance to the base level (Caspian Sea) and lithological resistance. It seems that river icision has overcome the tectonics and the lithological factor has more effect on the longitudinal profile of the Northen Alborz rivers.

    Keywords: : river lonitudinal profile, Cancavity Index, Northen Alborz, Mazandaran
  • Maliheh Sadat Hemmesy, Daryush Yarahmadi *, Majid Ownegh, Aliakbar Shamsipour Pages 613-632

    Introduction:

     Land use is generally referred to as the use of land in the present state.Land cover and its changes can cause greenhouse gas emissions Which causes climate change.climate change and land use interact with each other.This matter is of great importance in sensitive areas especially in arid and desert areas. These areas are sensitive to climate change and land use. In the case of climate change detection, the drought study has been very much considered in recent years. Iran is one of the countries that has suffered heavy damage from this natural threat because of being in the dry and desert region of the world. Various researchers have pointed to the relationship between land and climate change around the world.The purpose of this study was to investigate the relationship between land use and land use planningin in relation to climate change. This research proposes the new Land Use Planning approach in relation to land use as a management tool for climate change mitigation and carbon footprint reduction. Introduction Land use is generally referred to as the use of land in the present state. Land cover and its changes can cause greenhouse gas emissions Which causes climate change. climate change and land use interact with each other. This matter is of great importance in sensitive areas especially in arid and desert areas. These areas are sensitive to climate change and land use. In the case of climate change detection, the drought study has been very much considered in recent years. Iran is one of the countries that has suffered heavy damage from this natural threat because of being in the dry and desert region of the world. Various researchers have pointed to the relationship between land and climate change around the world( Cuo, Zhang, Gao, Hao, Cairang ,2013; Delgado, Gaspari, Kruse, 2015).The purpose of this study was to investigate the relationship between land use and land use planningin in relation to climate change. This research proposes the new Land Use Planning approach in relation to land use as a management tool for climate change mitigation and carbon footprint reduction. Material and methodes Introducing the study area Kashan watershed covers about 5574 square kilometers and Located in the north of Isfahan province and southwest of Tehran. The climaye of the study area is classified in dry or desert climate In the plain areas and it is classified in the semi-arid climate ,in the mountainous regions according to Domartan method The tools and methods in this research include: A.Land use: In order to study land use changes, Landsat5 MSS images,1985; Landsat-7 ETM+ images,2000 and Landsat 8 OLI,2017 were used. B.Climate change weather data available over the 30 year period from 1988 until 2017 at 7 meteorological stations: Kashan, Isfahan, Golpaiegan, Natanz, Meime, Ardestan, Najafabad(table1). This historical, data were obtained from the Islamic Republic of Iran Meteorological Organization (IRIMO) The model was validated using three

    methods

    1. Coefficient of Determination(R^2), 2. root-mean-square error (RMSE), 3. Mean Squared Error )MAE) C. Low Carbon Land Use Planning(Green land use planning) Green land use planning(GLUP) is to determine the suitable use of each region based on its potential ,so that a land use with lower carbon levels be selected in place of more carbon levels. C1. Standardization of constraints and limitations C2. Weighing the constraints and limitations C3. Multi-criteria evaluation by weighted linear combination (WLC) Research findings Classification of images The results of the changes shown tha t Agricultural land use area increased by 5.7%, Bare land area by 0.61%, and Residental area by 0.32% of the total study area during the period (1985-2000). Range land, Sanddune,Salt land, Garden have decreased by 5.05, 0.92, 0.57 and 0.1% respectively. The results of Investigating the changes during the time period (2000-2017) show that Salt land, Residental and garden area increased by 12.20, 1.07 and 0.28 percent, respectively, and Range land, agriculture, Bare land and Sanddune area were 5.62, 4.69, 2.52 and 0.73 percent, respectively. Validation of downscaling model The results of the indicators indicate that the SDSM model has a more accuracy than the daily scale in the monthly and seasonal and annual scales for the downscaling of the precipitation parameter in the studied watershed. And in general, this model has a good performance in downscaling region precipitation. The results of Validation of downscaling model Based on the results of the SDSM, RCP4.5 predicts the lowest average rainfall of 0.2 in December and the highest average rainfall of .08 in May. Drought assessment The results of 12month spI index for overall study period during 1950-2050 show that in 1985 there was a drought in the range from 1.5 to 1.99, which indicates the sever drought on the studied area, In 2000 , the drought is located in the 0.99-99 range, which represents a near-normal drought. In 2017, the average 12-month SPI is reduced, and drought is in the 1.99-to-1.5- range, which indicates hard drought. Based on the SPI index for the next years 2030 (2011-2050), under the 4.5 scenario, the drought is reduced compared to the baseline and is located on the range of -2 and less range, which indicates an sever drought, indicating that the monthly precipitation Will decrease in 2030 during the climate change. Evaluation of ecological land capability Ecological capability was evaluated for 8 land uses ( Agriculture, range land , forestry, conservation, Extensive and intensive tourism and urban and rural development. Green Land Use Planning (Low Carbon Land Use Planning) The green land use planning map was created with priority for land uses with less water consumption and less carbon, to reduce the impact on climate change for the Kashan plain watershed. 

    Reasults:

     The trend of change in Kashan plain watershed shows that at the same time as the study began, the trend of climate change (1985) has increased the agricultural and residential and industrial land araes. In general, these applications have the greatest impact on the rate of evapotranspiration and reduction of water resources and increased greenhouse gas emissions. With the continuation of the climate change trend and the negative trend of drought , the agricultural land and Range land areas have decreased and increased against the salt land areas. This situation is due to the reduction of agricultural land efficiency due to soil salinity and drying of irrigation wells and the abandonment of these lands, especially in the salt lake and the northern lands of Aran, Bidgol, Abu Zayedabad and Nasr Abad.

    Keywords: Land Use Change, climate change, Green land use planning (Low carbon land use), Kashan plain watershed
  • Fatemeh Arsalani, Bohlol Alijani, Mehri Akbari, Shirin Mohammadkhan * Pages 633-649

    Introduction :

    Dusts are referred to as aerosol particles that are made up of different sources of land and humanization, and after which time, again, they fall on the surface due to their size and density (Salman Zadeh et al., 2012). This phenomenon can damage infrastructures, telecommunications and agricultural products and affect transport through reduced visibility and cause a lot of economic damage. (Song et al 2007., Cao et al 2016). The purpose of this study is measuring and spatial analysis of the city of Tehran in a one-year statistical period. 

    Materials and methods:

     In this research, we used the laboratory method to measure falling dust, collecting dust using Marble Dust Collector. For this purpose, the falling dust was collected using a Marble Dust Collector in 28 stations in Tehran during the statistical period. In order to analyze the spatial distribution of dust, dust was collected from 28 dust collecting stations, and Tehran PM10 data taken from the air quality control company, the number of construction urban under construction in Tehran were obtained from Tehran Municipality Organization, mean maximum wind speed parameters, average relative humidity,days of rainfall above 5 mm,the average temperature of Tehran taken from the country's meteorological organization in the one-year statistical period (1/10/96 - 30/9/97) to enter the Arc Map10.5 environment and preparing the desired layers Were prepared. Statistical analysis of the data showed that Dust collected, pm10 and the number of running construction projects have regional (trend) behavior. Therefore, Universal trend is better suited. Due to the high preconditions for stagnation use of Universal trend In the area with fewer meteorological stations (Chitgar, Geophysics, Mehrabad and Shemiran) Universal trend is not applicable, Therefore, the IDW method was selected for climatic parameters. Also, the vegetation cover and factories file Shapes were taken and by analyzing Euclidean distance of each of these complications in GIS for Tehran, there impact on the dust in each area were considered. Then all the layers were weighed to determine the weights using the Reclassify tool. Then, using Expert Choice software, we compared all the layers two by two till estimate the value of each layer relative to the other layer. We multiplied the values obtained at each level. We transferred all layers to the Fuzzy Overlay tool. And draw up the final map of the spatial analysis of falling dust in Tehran city using the Gama 0.9 function. Also, daily speed and wind direction data were received from the Meteorological Organization of the country during the one-year statistical period, (30/9/97- 1/10/96). And with the help of the WRPLOT software for statistical analysis and the location of the wind, the windrose was drawn. Results and discussion The results of computations performed on the data obtained from the collecting of falling dust in Tehran showed that the weight of falling dust in the winter of 1396 is 18943.5 tons, in the spring of 1397 it is equivalent to 27119.5 tons, in the summer of 1397 it is equivalent to 17111.2 tons and in the fall of 1397 it is equivalent to 23002.3 tons. Also, the results showed that the highest falling dust was collected in spring, autumn, winter and summer, respectively. The spatial analysis map of Tehran's falling dust is a combination of 9 layers, based on the weight assigned to each layer. The results showed that the highest amount of dust in the winter of 1396 was found in west of Tehran. We had the lowest amount of falling dust in the north and northeast (regions 1 and 4). In the spring, summer and autumn of 1397, the halo of the most falling dust was displaced slightly eastward and settled in the southwest. The lowest amount of dusts in these seasons was located in the north and northeast. The halo with the lowest amount of dust falling has expanded further in the autumn than spring and summer.

     Conclusion:

     The results of this study showed that the spatial distribution of falling dust varies in different seasons. Which shows that the source of falling dust in the city of Tehran is not uniform throughout the year. Field precise surveys have shown that the increase in falling dust in different parts of Tehran is directly related to urban construction. So that in the statistical year of the study, construction and subsequent falling dust has been less in eastern Tehran than its west and this increase is also associated with pm10. The largest amount of pm10 was reported from the west and southwest, which simultaneously collected the highest amount of falling dust. The highest density of factories and the lowest vegetation density are in these areas. The climatic factors also contributed to these conditions. So that, It was reported that the highest number of rainy days to exceed 5 mm was reported in north and north east of Tehran, where the lowest amount of dust was collected. And the highest average temperature in different seasons is reported from Southwest of Tehran, which has the highest amount of falling dust in spring, summer and autumn. But in winter climate conditions were slightly different from other seasons. So that, the highest relative humidity reported in other seasons from the West has been reported from north and northeast this season. The dust collected in winter is higher in the west than in the southwest. But the average maximum wind speed, which is in the west and south, is in the winter, spring and autumn to the west and southwest Which is from sand quarts of Quds, Shahriar, and Malard cities, especially the sandy-sand dune areas and abandoned agricultural land in Baharestan, Islam-Shahr and Robat-Karim, then dust from these areas enters Tehran west. In addition, the wind disperses the dusts generated by construction around the city. In the summer, in addition to the west and southwest, there is wind for north and south east. The northern wind comes from Shemiranat, bringing fresh air to the north and north-east of Tehran. The southeast wind passes from the Pakdasht sand and cement factories in Tehran and the abandoned agricultural land of Varamin and contains dust. The low wind speed in these areas gives more time to hangs off more particles. And of course, climatic conditions with the lowest relative humidity, the highest temperature, and a lack of rainfall above 5 mm also help to pollute the southern part of Tehran. Keywords Spatial analysis, Sediment trap, Tehran City, falling dust

    Keywords: Spatial Analysis, Sediment trap, Tehran city, Falling dust
  • Behroz Sari Saraf *, Habibeh Naghizadeh, Aliakbar Rasouly, Saeid Jahanbakhsh, Iman Babaeian Pages 651-671

    Introduction:

     Snow is an important component of the climate system over the mid- and high-latitude regions of the Earth. Its high shortwave albedo and low heat conductivity modulate heat and radiation fluxes at the Earth’s surface and thus directly modulates regional temperature evolution and ultimately atmospheric circulation patterns. Moreover, because snow acts as a temporary water reservoir, snow variability impacts soil moisture, evaporation and ultimately precipitation processes). As a result, snow cover has an essential influence on ecological) and economical systems. Vice versa, snow cover itself is determined by climate variations. Recent Arctic warming has severely impacted spring snow cover. This study aimed to evaluate the snow depth it the north of Iran. The results of this study can be used in the field of water resources, flooding and climate change will be useful. 

    Materials and methods:

    The present study aimed at evaluating Modeling and spatial analysis of snow depth of the European Centre for Medium-Range Weather Forecasts (ECMWF) of the ERA-Interim version with a 0.125 × 0.125 arc-spatial resolution in a survey has been designed and implemented. In this regard, the temporal and temporal changes of the snow depth of the North Country were also evaluated. This study, the monthly data of the 6-level 3 product (MYD08_M3_6), Normalized Difference Vegetation Index (NDVI) of the ،Terra Satellite were used. Modeling of spatial relationships between snow depth and Geographic Parameters and NDVI index was obtained by using OLS and GWR models. The coefficients of regression equations obtained for the relationships were used in the area studied after calculation. Several criteria have been proposed for selecting the appropriate bandwidth. In this study, the Akaike information criterion (AIC), was used to select the core bandwidth.

    Results and discussion:

     studied after calculation. Several criteria have been proposed for selecting the appropriate bandwidth. In this study, the Akaike information criterion (AIC), was used to select the core bandwidth. Results and discussion The average depth of snow in the northern zone of Iran ranges from 0.006 to 1. 748 cm for winter, April and autumn, respectively. The northern area of Iran in this season is 1.34 cm. In winter, the maximum average snow depth in the northern zone of Iran in February is 1.748 cm. The maximum amount of standard deviation occurred in the same season. In general, in winter and year, the maximum snow depth in the northern zone of Iran is more than in the other months of the year. The third quartile can be considered as the maximum snowfall and the first quartile is the northern border of the northern northwest of Iran, which can then be classified as the northern part of Iran's snowfall. In winter one-fourth of the year, the northern zone of Iran has a snow depth of more than 1.98 cm. The significant difference between Moran's I and Geary's c expected and Moran's I and Geary's c measured has shown that the spatial autocorrelation values calculated for each month really fluctuate and the value cannot be due to the magnitude of the data and changes caused by around the mean.

     Conclusion:

     The results showed that the winter season with mantle cubes is 1.34 cm maximum snow depth during the seasons. Winter also has the highest snow depth variability. The highest snow depth was obtained with an average of 1.74 cm in February. Based on the results of the study, using quartz statistics, in winter one-quarter of the northern zone of Iran has a snow depth of more than 1.98 cm, which is the maximum value among seasons. The spatial dependence of the depth of snow on universal Moran methods has been rejected by the hypothesis that there is no relation between the depth of snow in the northern zone of Iran, and the Geary's c method has also shown that snowfall areas with high snow depth are relatively relative in terms of geographic patterns and a behavior They show clusters of their own. Correlations obtained with snow depth with longitude and vegetation index of NDVI have a significant reverse relationship and its relationship with latitude and elevation is a significant direct relationship. Modeling with GWR and OLS has also shown that the GWR method has a higher ability to justify the spatial association of snow depth with geographic parameters. The results of the GWR model show that the relationship between snow depth and geographic parameters, especially elevation, does not follow a linear model. Altitude in the mountain range of Alborz and northwestern Iran is mountainous areas that have shown significant snow depth. 

    Conclusion:

     The results showed that the winter season with mantle cubes is 1.34 cm maximum snow depth during the seasons. Winter also has the highest snow depth variability. The highest snow depth was obtained with an average of 1.74 cm in February. Based on the results of the study, using quartz statistics, in winter one-quarter of the northern zone of Iran has a snow depth of more than 1.98 cm, which is the maximum value among seasons. The spatial dependence of the depth of snow on universal Moran methods has been rejected by the hypothesis that there is no relation between the depth of snow in the northern zone of Iran, and the Geary's c method has also shown that snowfall areas with high snow depth are relatively relative in terms of geographic patterns and a behavior They show clusters of their own. Correlations obtained with snow depth with longitude and vegetation index of NDVI have a significant reverse relationship and its relationship with latitude and elevation is a significant direct relationship. Modeling with GWR and OLS has also shown that the GWR method has a higher ability to justify the spatial association of snow depth with geographic parameters. The results of the GWR model show that the relationship between snow depth and geographic parameters, especially elevation, does not follow a linear model. Altitude in the mountain range of Alborz and northwestern Iran is mountainous areas that have shown significant snow depth.

    Keywords: Snow depth, Space Modeling, GWR Method, ERA Interim, Northern Zone of Iran
  • Vahid Safarian Zengir, Behroz Sobhani *, Sayyad Asghare Saraskanrod Pages 673-692

     Introduction:

     Drought is one of the natural hazards, which during its occurrence has damages and effects of irreparable damage in various sectors of agriculture, economics, and so on. In recent years, different regions of the world have experienced more severe drought (Mirzai et al., 2015: 98). Also, drought is one of the most important natural disasters affecting agriculture and water resources, which is abundant especially in arid and semi-arid regions (Shamsenya et al., 2008: 165).Drought changes are well-suited for optimal management of water resources utilization (Alizadeh, 2017: 169). Drought is also referred to as a climate phenomenon with a lack of humidity and rainfall relative to normal conditions. This phenomenon strongly affects all aspects of human activity (Zeinali and Safarian Zangier, 2017). Regarding the studies done inside and outside of the country, this study attempted to model and monitor the drought phenomenon in southwest of Iran using a new index. 

    Material and method:

     In this study, drought modeling in southwest of Iran was carried out using climatic data of rainfall, temperature, sunshine, minimum relative humidity and wind speed monthly (6 and 12 months scale) for the period of 31 years (1987 - 2018) in five provinces of Khuzestan, Lorestan, Ilam, Kermanshah and Hamedan in 15 stations using a new index modeling called the TIBI Architectural Index, fuzzyized from four indices (SET, SPI, SEB, MCZI) The World Meteorological Organization was used. Fuzzy index T.I.B.I The fuzzy index (T.I.B.I) is presented to resolve some of the disadvantages of the SPEI index. The index T.I.B.I was derived from the integration of the indicators (SET, SPI, SEB, MCZI), which is the result of drought fuzzy modeling architecture that is designed using fuzzy logic in a fuzzy inference system. 

    Conclusion:

     Monitoring of drought fluctuations based on four integrated indicators in T.I.B.I In order to investigate the effect of drought fluctuations in drought conditions of stations, it is possible to find changes in the parameters (SET, SPI, SEB, MCZI) in the TIBI index, Checked. Considering the large number of stations studied, for the sake of better understanding, only the drought series chart, East Islamabad station at two 6 and 12-month scale was presented in Figures 7 and 8 (Figures 7 and 8). The above-mentioned red dot indicates a 6-month drought margin with a value of 0.44 and more, and represents a 0.44 and a magnitude 12-month scale. The analysis of these forms shows that at Islamabad-West station at 6 and 12-month scale, the temperature was different in the drought environment, which was decreasing in the 6-month scale from April 1994 to August 1997, and after This month has been gaining momentum, from July 1996 through 2003, an incremental increase. If the impact of rainfall on a 12-month scale is weaker than the 6-month scale. Between May 1994 and November 1997, the declining trend followed by a 12-month-long drought after June 1997 to December 2002, followed by a similar pattern. And the indicators (SET, SPI, SEB, MCZI) affect the TIBI index and show some trends, indicating that the new TIBI fuzzy index reflects the four indicators well and the scale Drought classes were presented in Table 5. The T.I.B.I index on a 12-month scale shows a sharper shape than scale 6.

    Results:

    One of the natural hazards that has affected the country in recent years is the dangers of drought. One of these areas affected by drought was the southeastern part of Iran, where researchers conducted many studies to monitor drought in Southwest Iran with different models but did not adequately address the issue. Is The purpose of this study is to model and monitor the drought phenomenon in southwest of Iran using a new fuzzy index in the 6 and 12-month scale. In the study area, the intensity and frequency of drought are more than 6 months on a 12-month scale. Drought persistence is more than 12 months old. Short-term droughts were less sustained and affected by rainfall and temperature parameters. While the severity of drought in the long periods of time was less responsive to temperature and precipitation variations.The trend of drought in the south-west of Iran was increasing and the temperature trend was more rapid, increasing and increasing trend. The highest frequency of drought occurrence was at the 6th and 12th month scale, Islamabad-West station and the lowest rate was 6 Hamadan airport scale and 12-month scale Khorram Abad station. The percentage of drought frequency in Hamedan Nogheh, Islamabad and Zarapulzahab stations was higher than the 6-month scale in the 12-month scale.

    Keywords: T.I.B.I index, SAW Model, Fuzzy logic, MATLAB, modeling
  • Nsrin Hosian, Taghi Tavousi *, Abbas Mofidi, M. Khosravi Pages 693-713

    Introduction :

    The temperature in the troposphere usually decreases with increasing height, therefore, with increasing distance from the ground, the air temperature will be lower (roughly 0.6 degrees Celsius per 100 meters. However daily atmosphere evaluation shows unlike the above description, in many cases the opposite is seen to be called inversion. The purpose of this study was to investigate the adaptive trend of inversion of the temperature of the boundary layer of Tehran, Mashhad and Tabriz metropolis in 2007-2017 on the daily, monthly and annual time scale. 

    Materials and methods:

     The atmospheric sounding data from the Meteorological stations of Tehran, Mashhad and Tabriz for the years 2007-2017 were extracted from the Wyoming climate database at 0 o'clock. In order to determine the types of temperature inversion in each metropolis, the graphs of the atmospheric data of each station were mapped using RAOB software and the total number of days with temperature inversion was extracted at the stations. Three types of radiation, superstructure and frontal inversion were identified as three main types and four other types as combinational types of these three types of inversion. Then the frequency distribution and percent of each of the seven inversion types were calculated for each station in the 12 months of the year. The eleven-year process of each inversion type was determined using the non-parametric Man-Kendall method and the estimator of the Estimator slope and compared with each other. 

    Results and discussion:

     Results analysis indicated that from the seven inversion types, the inversion type of radiation in the three stations under study in all months of the year has been quite decreasing and significant trend at 95% and 99% levels. The subsurface inversion type at all three stations showed a positive and significant trend at 95% and 99% levels in the most months of the year. The trend of forward inversions in the stations under study has been decreasing for the most months (the Z score and Sen’s Estimator Slope is negative). Radiation-submerged-frontal combined type inversion in the study period in all studied stations in most months has no significant trend. Among the seven types of inversion observed at the studied stations, the combination of radiation-subsidence type has the most significant and incremental trend in all three stations. In all three stations, for 6 months of the year, the increasing frequency of radiation-subsidence type at 95% and 99% confidence levels was significant and the most frequent increase in this type of inversion occurred in the winter and autumn seasons. The combined type of radial-frontal inversion and the Subsidence- frontal type at all stations in Tehran, Mashhad and Tabriz have not been significantly trendy for most of the months. The investigation results of the number of inversion layers in the stations showed that in all three stations in all months of the year, the number of inversion layers increased significantly at 99% and 95% confidence levels. An annual review of the frequency of inversion days in all three stations showed a significant increase in the annual scale. In this study, using the inversion layer temperature difference, the thickness of the inversion layer and the station height were used to calculate the intensity of the inversions. Formula (1) I=((Δθ)2)/(3+Z(Δz)) The inversions were calculated only for inversions of the surface of the earth up to the surface of 500 hPa, then by applying the two conditions of the Haffter ((Δθ / (Δz)> 0/005 km ^ (-1) and θ_"t" -θ_"b" >2( Critical inversion was investigated by the total inversion occurred and the severity of the inversions trends. The results of applying the Mann-Kendall test and the Sen’s Estimator Slope on the data of the severity of critical inversions in different months of the year showed that except for the months of October, November and December at the Mehrabad station, the rate of critical invertebrates was significant at 95 % level. For the rest of the months, the trend of severity of critical inversions has been increasing, but they are not significant at all levels of confidence. In February, the trend of inversion was decreasing in all three stations. Conclusion The results showed that the radiation type inversion occurred in the period 2007-2017 at all three stations decreased significantly, conversely, the subsidence inversion type showed a significant increase in all three stations. Radiation- Subsidence combined type had a significant increase in all three stations. It can be concluded that the types of inversion in the period of 2007-2017 have changed from pure inversion types to combine and multi-layer types and, specifically, to the Radiation- Subsidence type. The significance of the increasing trend of inversion layers was also confirmed by statistical tests. Despite the increasing trend of the inversions occurring during the statistical period, this trend has not been significant at any level of confidence. However, the intensity of inversions other than the fall of Tehran station at other stations did not have a significant trend, although they have experienced a positive slope for many months. Several factors, including the release of high heat energy, the increase of greenhouse gases, as well as the increase in population and land use change, the change in surface evolution from heat transfer, pollutant emissions, evapotranspiration and land cover due to the impact of wind currents considered to be reasons of this increased air stability in the boundary layer and the local climate change of these metropolises.Despite the increasing trend of the inversions occurring during the statistical period, this trend has not been significant at any level of confidence. However, the intensity of inversions other than the fall of Tehran station at other stations did not have a significant trend, although they have experienced a positive slope for many months. Several factors, including the release of high heat energy, the increase of greenhouse gases, as well as the increase in population and land use change, the change in surface evolution from heat transfer, pollutant emissions, evapotranspiration and land cover due to the impact of wind currents considered to be reasons of this increased air stability in the boundary layer and the local climate change of these metropolises.

    Keywords: Tehran, Mashhad, Tabriz, inversion
  • Mohammad Reza Salimi Sobhan, Zahra Hejazizadeh *, Fariba Sayadi, Fateme Ghaderi Pages 715-731

    The purpose of this study is to establish a proper classification of atmospheric patterns related to hail events and their climatic characteristics in the Zab Basin. Therefore, station data (27-87-96-99 to 100 present weather codes) were used to capture hail from the 3 synoptic stations of the Zab basin over a 24year period (1992-2016). The NCEP / NCAR database data was also analyzed to analyze the circulation patterns of these events. Cluster analysis on sea level pressure data and geopotential height (500 hpa) identified three circulation patterns associated with hail precipitation. Including: 1. Strengthening Sudan's low-pressure system 2. Strengthening European and Siberian high-pressure systems 3. Locating the area east of the Mediterranean Sea. Then, by performing intra-group correlations between each day cluster that was most correlated with other days, it was selected as the day to represent the circulation pattern of that cluster and the basis of the research was analyzed. Keywords: Synoptic analysis, Northern Highlands, Mediterranean Nave, Hail precipitation, Zab Basin. Introduction Hail is considered one of the most important atmospheric hazards as a consequence of a thunderstorm that damages the environment every year . Hailstorms usually occur from the clouds of cumulonimbus and are often thunderstorms and generally accompanied by thunderstorms, especially in spring. In general, hail is the product of intense convection found in a thunderstorm. To analyze and predict the mechanisms of each climatic phenomenon, one needs to have a detailed understanding of the main components of its climatic systems. Compared to other countries in the world, Iran has a high rank in the crisis due to natural disasters due to its environmental diversity. As a result, of the 7 natural disasters in the world, 7 have occurred in Iran. According to the FAO (World Food Organization) report, Iran ranks 10th in the world in terms of potential and disaster potential. Given the varied weather conditions in Iran, hailstorms are common. The occurrence of destructive and severe hailstorms as one of the major natural disasters has been reported in many parts of this vast country, with damages in various aspects of economic, agricultural, transport, infrastructure and so on and so on. Hail damages are sometimes greater than hurricanes and hurricanes. Since hail in the Zab basin annually causes significant damages, especially in agriculture and livestock, the aim of this study was to investigate the synoptic patterns of hail in the Zab basin in order to reduce the damaging effects of this. The climatic phenomenon is on different parts Area of study The Zab Minor catchment in the southwestern province of northwestern and northwest of Kurdistan province consists of Piranshahr, Sardasht and Baneh counties and is about 2 km 2 Material and method In this study, an environmental circulation approach was used to identify the circulation patterns of the days associated with hail in the west of the country. In this study, the code of days associated with the hail of Sardasht, Piranshahr and Baneh synoptic stations (with the longest statistical period between provincial stations) was obtained from the establishment (1992) up to year 2016 from the Meteorological Organization of Iran and then according to the code. The intensity of days associated with the hail event was identified during the study period. To identify large-scale synoptic patterns of day-event hail phenomena, hectopascal altitude and sea-level pressure data from open NCEP / NCAR analysis data on daytime events ranging from 0 ° C to 120 ° C and 0 ° C to 90 ° N They were prepared. Also, to determine the moisture flux of hail event days, Schulz and Benacus moisture flux equation was used. Discussion and Conclusion The purpose of this study is to establish an appropriate classification of atmospheric patterns in relation to hail events and the climatic characteristics that cause them in the Zab Basin. Therefore, station data (27-87-96-99 to 100 present weather codes) were used to capture hail from the 3 synoptic stations of the Zab basin over a 24year period (1992-2016). Using the NCEP / NCAR Center data, it is possible to analyze synoptically and identify the circulation patterns that coincide with these events. Cluster analysis of sea level pressure and geopotential height data revealed three weak, moderate and severe circulation patterns associated with hail precipitation. Finally, in order to identify the most important systems, intra-group correlation was performed between each cluster, and the day that had the highest correlation with other days in one cluster was selected as the representative day of the circulation pattern of the cluster and the basis of this study was analyzed. In the study of the synoptic patterns of hail precipitation according to the obtained results, the model best justified the hail precipitation in the Zab basin. In the first model, which included low hail precipitation, we observed a contrast between warm and humid low-pressure Sudan systems and high-pressure European cold tabs on the study area. In the second pattern at sea level with the formation of a low pressure center on Iraq, this low pressure is reinforced by the development of warm and humid air through the Sudanese system and the formation of a high-pressure belt across the northern Iranian strip, which, with its rotation and rotation, drives cold air. The study area has provided conditions for frontalisation in the area In the third model, Sudan's low sea level is strengthened so that its tongues stretch to the northwest and northwest of Iran, which inject hot and humid air and create convergence conditions over the study area. The Siberian high pressure on the north of Iran is also at its peak, and its tabs and motions cause very cold air to fall over the study area, and in this case the very cold northern and warm southern humid conditions make for the front. The region has created instability and instability Previous research on hail precipitation or only the role of Sudanese high or low pressure northern Sudan in hail precipitation events has shown that hail precipitation in western Iran necessitates confrontation of air masses. The cold north is warm and humid south and the strongest hailstorms occurred when these air masses penetrated the study area at peak times and created conditions for overburden and instability with the help of high-level currents. They cause severe vertical motions in the atmosphere and, as a result, hail..

    Keywords: synoptic analysis, northern high pressures, Mediterranean Trough, hail fall, Zab catchment
  • Mohammad Rahdan Mofrad, M.H Ramesht *, Amir Safari Pages 733-760

     Introduction :

    Geography has always been based on the three basic elements of human, the environment and the relationship between them and depending on what the concept of man has been in different eras, it has led to the formation of numerous approaches such as classical geography, regional, spatial and phenomenological. However, the introduction of a systematic approach into geography had many implications, including the formation of the human ideal which is called "sustainable development", and led to the participation of different branches of environmental science in sharing and providing solutions for achieving sustainable development. A review of past research shows that Geomorphology has a closer look at the relationship between humans and the environment. It should therefore be examined that what has Geomorphology to offer the global environmental change debate and how might this contribution be framed? To answer this question, the views of scientists must be examined through the process of research related to the relationship between man and the environment during the short life of geomorphological knowledge and this is exactly what was used in this study with the help of CiteSpace software for citation analysis. Using this method, we can examine the relationships between the factors influencing the production of a particular research along with its historical trends in explaining the intellectual structures of knowledge. The purpose of the present study is to use the data available in the Web Of Science database and CiteSpace software to analyze researchers spatially and temporally; Clustering strategic keywords with the help of indicators such as centrality and finally, examining the thoughts of influential researchers in each cluster in order to understand the scientific structure of knowledge in the field of human-environment relationship in Geomorphology 

     Material and Methods:

     In this study, CiteSpace software was used for statistical analysis of scientific citation data. So, in the first step, all the researches between 1970 to 2018 were extracted through web filtering (CiteSpace raw data provider) and after monitoring, a set of 456 articles was obtained. After entering this data into the software, charts of the number of articles and citations, journals and active countries/institutes, burst-detection, country/institute co-citation maps and co-author map were prepared. Then, the present research period was categorized into seven clusters by calculating the centrality of keywords and using the year of production of each word. Each cluster that encompasses a specific time period was analyzed with the help of parameters such as the number of research and citations, the most strategic keywords, the most cited and most famous authors, the external scientific influencers factors, the relationship of other keywords to the strategic word in the tf-idf chart. It was also tried to study the trends of geomorphological knowledge in each of the clusters according to the domestic writers' research and comparing with the results obtained from CiteSpace software.  

    Results and Discussion:

     According to co-citation analyzes, the leading Geomorphology journal in terms of number of research and citation indexes among all the journals indexed in the WOS database indicates the importance of geomorphological knowledge in addressing the issue of human-environment communication among the various branches of environmental science. The analysis of the distribution of countries and institutes in relation to the research shows that the results are consistent with the Pareto law. It can also be pointed out that countries' backgrounds influence their ranking as top countries in terms of number of studies although the results show that the research topic is more important for countries. According to the authors' co-citation map, the core of the researchers is made up of authors such as Phillips, Schumm, Goudie and Gregory. The results of comparing the Burst-detection and the In-network citation indicate a low citation among authors with high Burst-detection. Violation of this rule in the case of Schumm shows that in addition to presenting a new idea, he has remained an important citation index throughout the entire period studied. Keyword analysis shows that "Geomorphology, climate change and Holocene" have the highest frequency, "Geomorphology and vegetation" have the highest sustainability and "environmental change, climate change and human impact" have the most Burst-detection. The centrality index also identified the most strategic words that resulted in the clustering of the entire research period into seven clusters to identify the scientific structure of knowledge in the present study.

    Conclusion:

     According to information obtained until 2000, most geomorphologists' focus on Geomorphology knowledge was a general trend of environmental science research that was most influenced by global conferences on climate and human environment. The geomorphologists' systematic view is quite evident in order to provide a solution to the issues between the landscape and human impact in the second period between 2000-2002. Co-citation studies from 2002-2003 suggest a new approach to solving problems in human-environment interactions under the heading of combined geo-ecological research in geomorphological knowledge. In the fourth period, between 2003-2005, geomorphologists have used the fluvial Geomorphology-related topics to better illustrate human impacts on the environment. In the next period (2005-2008) was made a rethinking of the geo-archeological studies of ancient times and early humans. Also a common point of most research in this period is the use of river/sedimentary Geomorphology and vegetation data which includes the strategic keywords of the previous period (2005-2003) and the next period (2009-2008) respectively. Because of the use of the sediment keyword and thus a more specialized perspective at environmental protection, the sixth period can be cited as a turning point in determining the extent of geomorphologists' involvement in human-environment research. In the last period, the 'Environmental Change' strategic keyword, remained unchanged for 9 years (unlike all six previous periods in the 17 years ending 2009 with 35 strategic keywords) which shows that geomorphologists have reached an agreement in human and environmental research. And more importantly, it may be the answer to the basic question in the introduction to this study; what has Geomorphology to offer the global environmental change debate and how might this contribution be framed? 

    Keywords: Human, geomorphology, environment, Citespace, WOS