فهرست مطالب

پژوهش های ژئومورفولوژی کمی - سال هفتم شماره 1 (تابستان 1397)
  • سال هفتم شماره 1 (تابستان 1397)
  • تاریخ انتشار: 1397/06/20
  • تعداد عناوین: 15
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  • مهران مقصودی *، مجتبی یمانی، ابراهیم مقیمی، محمدرضا رضوانی، مهدی بهاروند صفحات 1-12
    ژئوسایت های کارستی از جمله لندفرم هایی هستند که در جذب گردشگر تاثیر بسزایی دارند. این لندفرم ها علاوه بر ویژگی جذابیت، دارای ارزش های علمی - آموزشی هستند. پلدختر یکی از شهرستان های جنوبی استان لرستان است که دارای ژئومورفوسایت های کارستی و غیر کارستی متنوعی است. در این تحقیق ژئومورفوسایت های کارستی شهرستان شناسایی و با استفاده از مدل تلفیقی کوبالیکوا و کرچنر مورد ارزیابی قرار گرفتند. غار کلماکره، غار کوگان، دره خزینه، تنگ ملاوی، تنگ پاعلم، تنگ هلت، دره های تیپیک، آبشار افرینه، غار طلسم، تنگ گاوزرده، آبشار آب تاف، منطقه گول چپ و آبشار چشمه گوش به عنوان ژئومورفوسایت های مطالعاتی انتخاب شدند. ارزیابی ها نشان داد که ارزش های حفاظتی و اقتصادی آن ها در وضعیت مطلوبی نیستند و نتایج نهایی نشانگر این است که غار کلماکره، غار کوگان و منطقه کول چپ بیشترین امتیاز را کسب نموده و مهمترین ژئومورفوسایت های کارستی شهرستان پلدختر محسوب می شوند.
    کلیدواژگان: کارست، ژئومورفوسایت، ارزیابی، معیار، شهرستان پلدختر
  • سامان نادی زاده شورابه، عطا الله عبدالهی کاکرودی، نجمه نیسانی سامانی، فاطمه مرادی پور صفحات 13-29
    به دلیل ماهیت دینامیکی خطوط ساحلی تهیه نقشه این مناطق و میزان تغییرات آن جهت برنامه ریزی و دستیابی به توسعه پایدار امری بسیار ضروری می باشد. بنابراین هدف از این پژوهش بررسی تغییرات خطوط ساحلی و نمکزار دریاچه ارومیه با استفاده از داده های سنجش از دور ماهواره لندست بین سال های 1976 تا 2015 می باشد. از داده های ترازسنجی ماهواره ای از سال 1371 تا 1389 برای بررسی نوسانات سطح تراز آب دریاچه استفاده شده است که بر اساس آن تراز آب دریاچه حدود 8 متر افت داشته است. برای استخراج خطوط ساحلی از شاخص NDWI با دقت کلی 97/0 و برای استخراج نمکزار از شاخص SI2 با دقت کلی 0. 98 استفاده شده است. نتایج حاصل از این مطالعه نشان می دهد مساحت قابل توجهی از سطح آب دریاچه ارومیه در طول 39 سال مورد مطالعه به ویژه در دهه ای اخیر کاهش یافته و بر مساحت نمکزار اطراف دریاچه افزوده شده است. به طوری که از مساحت5216،30 کیلومترمربع آب و 18/106 کیلومتر مربع تمکزار در سال 1976 به ترتیب به 12/1519 کیلومتر مربع و 50/3777 کیلومتر مربع در سال 2015 رسیده است. همچنین بیشترین تغییرات مساحت مربوط به نمکزار و خط ساحل به ترییب 45/1286 و 97/1310 کیلومترمربع مربوط به دوره زمانی 2006 تا 2011 می باشد. قسمت های جنوب شرقی و جنوب به دلیل عمق کم دارای بیشترین تغییرات می باشند اما در جهت های شمالی این تغییرات کمتر بوده است.
    کلیدواژگان: تغییرات خط ساحل، تغییرات نمکزار، سنجش از دور، GIS، دریاچه ارومیه
  • فریبا کرمی *، معصومه رجبی، کلثوم اباذری صفحات 30-47
    شبکه های زهکشی فعال ترین و حساس ترین عناصری هستند که می توانند به عنوان ابزاری قدرتمند برای درک فعالیت های نئوتکتونیکی در یک منطقه مورد استفاده قرار گیرند. به منظور تحلیل اثرات تکتونیک فعال در حوضه های زهکشی از تحلیل های مورفومتری که ابزار مفیدی در مطالعات تکتونیکی محسوب می شوند، استفاده می شود. در این پژوهش تاثیر فعالیت های تکتونیکی گسل تبریز بر حوضه های آبریز ورکش چای، گمانج چای، نهند چای و سرند چای واقع در شمال تبریز با استفاده از شاخص های تراکم زهکشی (Dd) ، فرکانس زهکشی (Df) ، ضریب گردواری (CR) ، نسبت طول آبراهه اصلی به متوسط عرض حوضه (LSBW) ، حجم به سطح حوضه (VA) ، نسبت کشیدگی (Re) ، شاخص انشعاب (R) ، شاخص عدم تقارن حوضه زهکشی (AF) ، نسبت شکل حوضه (BS) و شاخص تعقر لانگبین (IC) ، شاخص ناهنجاری های سلسله مراتبی (Da) و شاخص تراکم ناهنجاری های سلسله مراتبی (ga) بررسی شدند. بین شاخص های مذکور رابطه همبستگی پیرسون برقرار شد و ضریب تببین بدست آمد. نتایج نشان داد که ضریب همبستگی بین پارامتر هایDa-Re، Da-CR، Da-Bs، Da-LSBW، Da-R، Da-IC، به ترتیب 99/0، 91/0، 69/0، 87/0- ،85/0-، 55/0 است و بین پارامترهای ga-Re ga-CR، ga-Bs ،ga-LSBW، ga-R، ga-IC، ضریب همبستگی به ترتیب 95/0، 93/0، 83/0، 94/0-،80/0- ، 65/0 برقرار است. نتیجه تحلیل ها نشان می دهد که شاخص های Da وga کاملا تحت تاثیر کشیدگی حوضه ها که ناشی از اثر تکتونیک فعال می باشد قرار دارند. در ضمن ناهنجاری های شبکه زهکشی تمامی حوضه های شمال تبریز از شاخص تقعر نیمرخ رودخانه نیز متاثر می شوند.
    کلیدواژگان: ناهنجاری های سلسه مراتبی شبکه زهکشی، پارامترهای مورفومتری، شاخص های ژئومورفیک، تکتونیک فعال، حوضه های شمال تبریز
  • محسن رنجبران*، فرزاد ستوهیان صفحات 48-60
    روستای کندوان، در استان آذربایجان شرقی از نظر تقسیمات ژئومورفولوزیکی جزء واحد آذربایجان محسوب می شود. رخساره های سنگی در ناحیه مورد مطالعه شامل سنگ های آتش فشانی، سنگ های آذرآواری و نهشته های لاهار و اپی کلاستیک می باشد. در تحقیق حاضر سعی گردید با بررسی های دقیق میدانی و اندازه گیری های به عمل آمده و نیز مطالعه مقاطع نازک میکروسکوپی تغییرات بافتی و کانی شناسی واحد های سنگی مذکور مورد بررسی دقیق قرار گیرند. بر اساس ترکیب کانی شناسی سنگ های ولکانیکی ترکیبی در حد آندزیت و تراکی- آندزیت دارند، کانی های پلاژیوکلاز و آمفیبول موجود در آنها بسیار مستعد هوازدگی شیمیایی می باشد. سنگ های آذرآواری که بیشتر ایگنمبریت ها را شامل می شود از نظر لیتولوژی تغییر قابل توجهی را نشان نداده و کانی های تشکیل دهنده آن تقریبا سالم بوده و شکل اولیه خود را حفظ نموده اند. شرایط فیزیکی و خصوصیات خاکسترهای داغ آتش فشانی که در طی فوران های متعدد به یکدیگر جوش خورده و باعث بوجود آمدن حجم زیادی رخساره ایگنمبریتی شده است که بستر مناسبی را برای مردم و ساکنین اولیه در خصوص حفاری و شکل گیری روستا فراهم نموده است. همین ویژگی سبب گردیده که روستاییان از این سنگ ها برای محل سکونت خود استفاده نمایند. در بخش هایی که نهشته های لاهار رخساره غالب منطقه را تشکیل می دهد به دلیل داشتن بافت سست و عدم استحکام ، مانع از حفاری و سکونت روستاییان در این نهشته های آواری شده است.
    کلیدواژگان: روستای کندوان، ولکانوکلاستیک، سهند، لاهار، ایگنمبریت
  • علی مهرابی، محسن پورخسروانی * صفحات 61-73
    در تاریخ 4 اسفند 1383 زمین لرزه ای به بزرگی 4/6 ریشتر شرق شهر زرند در استان کرمان را لرزاند. در ابتدا عامل این زلزله گسل کوهبنان پنداشته شد، ولیکن مطالعات بیشتر نشان می دهد که یکی از گسله های فرعی باعث این زلزله بوده است. در این تحقیق بر آن شدیم تا با استفاده از تصاویر راداری به بررسی و مدل سازی میزان تغییرات و جابجایی های رخداده در سطح زمین بر اثر این زلزله پرداخته و گسله عامل زمین لرزه را شناسایی کنیم. بدین منظور دو تصویر راداری ASAR از ماهواره ENVISAT یکی مربوط به قبل و یکی مربوط به بعد از تاریخ رخداد زلزله به سازمان فضایی اروپا سفارش و در اختیار قرار گرفت. ابتدا با اعمال فیلتر خطاهای احتمالی از جمله خطاهای اسپکل و نویز، را رفع نموده و سپس با انجام عملیات رفع ابهام فاز عملیات تهیه نقشه جابجایی انجام می گیرد. آنالیز تداخل سنجی بر روی تصویر بالارو ماهواره Envisat نشان می دهد که بر اثر شدت ناشی از زلزله منطقه ای در بخش شمالی بلافصل کانون سطحی زلزله به مساحت 100 کیلومتر مربع دچار بالا آمدگی شده و حداکثر میزان برازش آن به 34 سانتی متر نیز می رسد. همچنین محدوده ای در حدود 150 کیلومتر مربع در بخش جنوبی کانون سطحی، به میزان 24 سانتیمتر دچار فرو افتادگی شده است. بر اساس نتایج به دست آمده گسل مسبب زلزله، گسلی با روند شرقی- غربی با مولفه راندگی و طول 20 کیلومتر می باشد.
    کلیدواژگان: تداخل سنجی راداری، جابجایی، گسل کوهبنان، زلزله داهوئیه، تصاویر ماهواره Envisat
  • فریبا همتی*، داود مختاری صفحات 74-89
    ناپایداری های دامنه ای یکی از خطرات طبیعی است که همه ساله خسارات جانی و مالی فراوانی را به همراه دارد. بنابراین باید مناطق حساس را شناسایی و با اولویت بندی این مناطق، سیاست و برنامه های مدیریت ناپایداری دامنه ای را ارائه نمود و تا حدی از خطر وقوع خسارات ناپایداری ها کاست. رشته کوه بزغوش در شمال غرب ایران و بین استان آذربایجان شرقی و اردبیل با روند شرقی- غربی در مختصات بین 00 °48 تا 30 °47 درجه طول شرقی و 00 °38 تا 30 °37 درجه عرض شمالی قرار دارد. گسل بناروان با طول بیش از 20 کیلومتر یکی از مهمترین گسلهای موجود در دامنه جنوبی بزغوش آذربایجان است. در این پژوهش محدوده گسل بناروان مورد بررسی قرار می گیرد بنابراین هدف از تحقیق حاضر، مشخص کردن نقاط حساس به حرکت های توده ای و تهیه نقشه پهنه بندی خطر به منظور پیش بینی خطر در آینده با استفاده از مدل رگرسیون لجستیک می باشد. به منظور به دست آوردن اطلاعات از طریق بازدید میدانی، نقشه های زمین شناسی و توپوگرافی و با مرور منابع قبلی و بررسی شرایط منطقه 9 عامل به عنوان عوامل موثر بر وقوع ناپایداری های دامنه ای شناسایی شد و سپس با استفاده از مدل پرسپترون چند لایه در نرم افزار IDRISI بررسی شد. نتایج به دست آمده نشان می دهد که 81/5، 95/12، 38/19، 06/27، 78/34 درصد از مساحت منطقه به ترتیب در کلاس های خطر بسیار بالا، بالا، متوسط، پایین و بسیار پایین قرار گرفته است. نقشه پهنه بندی خطر ناپایداری دامنه ای نشان می دهد که مناطق داری خطر زیاد و بسیار زیاد حدود 76/18 درصد محدوده مورد مطالعه را در بر می گیرد، که بیشتر منطبق بر ارتفاعات بالا، پهنه گسلی و شیب زیاد منطقه می باشد. با توجه به نقشه نهایی به دست آمده از پهنه بندی خطر زمین لغزش و در راستای توسعه و امنیت شهری باید از ساخت و ساز در محدوده با خطر بسیار زیاد و زیاد و آبخیزهای دارای دامنه های پرشیب و دارای پتانسیل زمین لغزش و همچنین حریم رودها در منطقه یک ممانعت به عمل آید و بایستی همه کاربری های مختلف شهری از جمله کاربری های مسکونی با استفاده از روش ها و تکنیک های مهندسی پایدار شوند.
    کلیدواژگان: ناپایداری های دامنه ای، پهنه بندی خطر، گسل بناروان، IDRISI، مدل MLP
  • مجتبی یمانی، مهران مقصودی، هادی نیری *، خبات امانی صفحات 90-105
    تغییرکاربری اراضی بدون توجه به قابلیت های آن از معمول ترین دخالت های انسان در طبیعت بوده و همواره پدیده هایی از قبیل سیلاب و فرسایش خاک را به دنبال دارد. از آنجا که رودخانه ها از مهم ترین شریان های حیاتی شهرها و به عنوان هسته تجمع و استقرار بشر به شمار می روند پژوهش حاضر به شناخت مخاطرات ناشی از توسعه بدون ضابطه در پیرامون چنین محیطی در رودخانه قشلاق پرداخته است و بر اساس متغیرهای تاثیرگذار و از طریق روش فازی اقدام به پهنه بندی توسعه کاربری ها در این محدوده نموده است. بازه مورد بررسی از سد وحدت در 12 کیلومتری شمال شرق شهر سنندج شروع شده و به طول 55 کیلومتر تا سد ژاوه ادامه می یابد. پژوهش حاضر از نوع کاربردی بوده و روش آن توصیفی- تحلیلی می باشد. ابزارهای پژوهش را نقشه های توپوگرافی و زمین شناسی، تصاویر ماهواره ای و نرم افزارهای تحلیلی تشکیل داده اند. یافته ها به مطالعات پیشین، گزارش های موجود و سایر داده های آماری و میدانی مستند شده اند. جهت دست یابی به اهداف پس از شناخت تهدیدهای موجود، لایه ها در نرم افزار Arc GIS وزن دهی و هم پوشانی شده و با استفاده از روش فازی اقدام به پهنه بندی محدوده برای کاربری های مورد نیاز شده است. سپس ارتباط بین کاربری های موجود با کاربری های پیش بینی شده بررسی شده است. نتایج نشان می دهد که حدود 30 درصد از محدوده مورد بررسی برای کاربری مسکونی و تجاری مطلوب است. شیب کم، فاصله زیاد از خطوط گسلی فعال و امکان برنامه ریزی و تعیین حدود اصولی برای آبراهه رودخانه در این محدوده از مهمترین دلایل این پیشنهاد است. اما ابتدا و انتهای محدوده مورد مطالعه به دلیل وجود گسل های فراوان و شیب زیاد، فضای بسیار کمی برای گسترش کاربری هایی که تراکم بالای انسانی را می طلبد در نظر گرفته شده است.
    کلیدواژگان: سنندج، پهنه بندی، مدل فازی، رود قشلاق
  • زهرا فاتحی، لیلا گلی مختاری*، شهرام بهرامی صفحات 105-123
    تنوع خاک های موجود در سطح زمین، نتیجه عکس العمل عوامل پنج گانه خاکسازی می باشد و شدت و ضعف هر یک از این عوامل یعنی آب و هوا، موجودات زنده، مواد مادری، پستی بلندی و زمان سبب تشکیل خاکهای متفاوت با خصوصیات و افق های مختلف می گرد. پژوهش حاضر در پی بررسی تشکیل خاک در روی سطوح مختلف ژئومورفیک و تکامل آن در منطقه می باشد. برای دستیابی به این هدف اقدام به برداشت 26 نمونه خاک از بخشهای مختلف دامنه بر طبق مدل 9 واحدی کاتنا گردید. برای تعیین بافت و ویژگی های خاک آزمایشات هیدرومتری و گرانولومتری روی نمونه های برداشت شده صورت گرفت و نتایج نشان داد که در هر بخش از ناهمواری نوع خاک متفاوتی تشکیل می شود و این خاکها از نظر بافت کاملا متمایزند. همچنین با اندازه گیری عمق خاک در واحد های مختلف ژئومورفیک تغییرات عمق نیز مورد بررسی قرار گرفت. نتایج بدست آمده بخوبی نقش عوامل توپوگرافی ژئومورفولوژی و نیز هیدرولوژی را در تشکیل و تکامل خاک منطقه نشان داد. به منظور تعیین نقش عوامل مختلف خاکزا در تشکیل خاک منطقه از تحلیل رگرسیون حداقل مربعات جزئی استفاده شد. مدل تهیه شده حاصل از تحلیل رگرسیون حداقل مربعات جزئی، پس از اثبات برازش مناسب مدل، نشان داد که مهمترین عاملی که در تشکیل خاک منطقه نقش داشته عامل شیب بوده است. با توجه به نتایج به دست آمده به نظر می رسد در نظر گرفتن ابعاد چندگانه و پیچیده اثراتی که هر یک از گروه های مربوط به عوامل موثر در تشکیل خاک دارند و مدلسازی برهم کنشهای احتمالی آنها می تواند راهگشای بسیاری از مسائل موجود در رابطه با فرسایش و تنزل کیفیت و کمیت خاکها در سطح کشور باشد.
    کلیدواژگان: تکامل خاک، تشکیل خاک، لندفرمهای ژئومورفولوژیکی، تحلیل PLS، شهرستان جغتای
  • مرتضی پورزارع، عبدالله سیف*، حبیب الله سیاری، سیروس فخری صفحات 124-145
    شناخت ویژگی های ژئومورفولوژیکی و اقلیمی نقاط مختلف کشور یک اصل مهم و ضروری به حساب می آید و عدم شناخت آنها جز ارتکاب به اشتباهات خطرناک، کاردیگری انجام نخواهد شد. این مقاله به بررسی ویژگی های جغرافیایی و به ویژه ارتباط و پیوند میان عوامل ژئومورفوکلیمایی بر مکان گزینی مطلوب مراکز حیاتی، حساس و مهم منطقه سواحل مکران از جاسک تا خلیج گواتر با رویکرد دفاع غیرعامل می پردازد. با توجه به ضرورت مکان گزینی مراکز و تاسیسات حیاتی، مهم و حساس با رویکرد دفاع غیر عامل بصورت موثر و هوشمندانه با ارزیابی شاخص های ژئومورفولوژیکی و اقلیمی سواحل مکران (بندرجاسک تا خلیج گواتر) به منظور دست یابی به پایداری امنیتی در این ناحیه از کشور ایران بر اساس نقشه طرح توسعه سواحل مکران ترسیم شده توسط دبیرخانه توسعه سواحل مکران، دراین پژوهش متناسب با تفکیک واحدهای ژئومورفولوژی منطقه مکران، خط ساحلی و جلگه ساحلی تا شعاع 50 کیلومتر را به عنوان منطقه عملیاتی ودشت های پایکوهی وکوهستان تا شعاع 200 کیلومتر درعمق را منطقه راهبردی در نظر گرفته شده است. ابزارهای تحقیق پژوهش را نقشه های توپوگرافی، زمین شناسی و تصاویر هوایی و ماهواره ای منطقه تشکیل داده است. همچنین با ارائه و تنظیم پرسشنامه ها، مصاحبه با افراد کارشناس به شناسایی عوامل موثر اعم از طبیعی و انسانی در مکان یابی مراکز حیاتی، حساس و مهم با تاکید بر دفاع غیرعامل پرداخته و پس از مشخص شدن آنها، داده های عوامل ژئومورفولوژیکی و عناصر اقلیمی را با استفاده از روش تحلیلی بهترین- بدترین (BWM) به منظور انجام مقایسه معیارها به صورت بهترین و بدترین مورد تجزیه و تحلیل قرار گرفته و عوامل و عناصر تاثیرگذار در مکان گزینی با رویکرد دفاع غیرعامل رتبه بندی و وزن دهی نهایی گردید که از بین شاخص ها، میزان شیب با وزن نهایی (257/0) و رطوبت نسبی با وزن نهایی (030/0) به ترتیب مهمترین و کم اهمیت ترین شاخص ها مشخص شدند. در نهایت در محیط نرم افزار Arc GIS با هم پوشانی لایه ها، نقشه ای که در آن مناطق مناسب برای احداث مراکز حساس و مهم در آن مشخص شده اند را بدست آوردیم. نتایج نشان می دهد که مناطق شرقی ساحلی منطقه مورد مطالعه برای مکان یابی شرایط مناسب تری را نسبت به مناطق غربی دارد. همچنین با توجه به نقشه نهایی که بر اساس عوامل ژئومورفولوژیکی در محیط سیستم اطلاعات جغرافیایی تهیه شده است، مساحت پهنه های مطلوب برای مکان گزینی مراکز حساس و مهم در بخش شمالی نسبت به مناطق جنوبی بیشتر است، به عبارت دیگر می توان گفت که ویژگی های ژئومورفولوژیکی از جمله شرایط توپوگرافی، فیزیوگرافی رودخانه ها و... منطقه در بخش شمالی شرایط مطلوبتری نسبت به مناطق جنوبی و نیز در ناحیه جلگه ساحلی در بخش شرقی نسبت به بخش غربی برای انتخاب مکان بهینه مراکز حساس و مهم برخوردار هستند.
    کلیدواژگان: شاخص های ژئومورفوکلیمایی، مکان گزینی، دفاع غیرعامل، واحدهای مورفولوژی مکران، روش تحلیلی بهترین - بدترین
  • رسول صمدزاده *، پریسا صمیمی هشتجین صفحات 146-161
    حوضه آبخیز گزازچای به عنوان یکی از زیرحوضه های رودخانه قزل اوزن در ارتفاعات تالش شامل مجموعه ای از نهشته ها و لندفرم های با ماهیت، سن و موقعیت های متفاوت است. این حوضه بخشی از تاریخ طبیعی کواترنر ارتفاعات یاد شده را در خود جای داده است. بازشناسی این تاریخ و اشکال و لندفرم های دیرینه شکل گرفته در بستر زمانی و مکانی آن هدف اصلی پژوهش حاضر را تشکیل می دهد. این پژوهش از لحاظ روش از نوع بنیادی است که تجزیه و تحلیل آن بر پایه روش تحلیلی استوار بوده و طی آن عوامل و متغیرهایی مورد پژوهش قرار گرفته اند که حداقل از کواترنر تا عصر حاضر به ویژه در طول هولوسن در شکل زایی حوضه تاثیرگذار بوده اند. تراس های زمین ساختی در طبقات متفاوت ارتفاعی، نهشته های دریاچه ای سدی هولوسن با تناوب دوره های آب وهوایی خشک و نیمه خشک تا مرطوب، توالی عمودی نهشته های رودخانه ای در لابلای نهشته های دریاچه ای و نمود آن ها به صورت یک سطح بازمانده، نهشته های پوششی و قرارگیری آن ها بر روی نهشته های دریاچه ای و زمین لغزش دیرینه مهم ترین اشکال و لندفرم های موروثی در سطح حوضه هستند. شکل گیری این اشکال و لندفرم های موروثی ارتباط مستقیمی با فرارفت سطح حوضه و فرونشست سطح اساس ناحیه ای آن یعنی حوضه کاسپین جنوبی دارد. مهم ترین تاثیر این فرارفت متروک ماندن تراس های زمین ساختی به عنوان بخشی از سیسم گزازچای و اختلاف ارتفاع زیاد آن ها با بستر کنونی رودخانه است. بدین ترتیب در طول تکوین حوضه برتری با فازهای کاوشی بوده است.
    کلیدواژگان: دیرینه ژئومرفولوژیک، کواترنری، لندفرم های موروثی، حوضه گزازچای، خلخال
  • موسی عابدینی*، ابراهیم بهشتی جاوید صفحات 162-179
    امروزه سیل به عنوان یکی از مهم ترین مخاطرات محیطی شناخته شده در طبیعت است. کشور ایران به دلیل برخورداری از شرایط طبیعی مساعد برای سیل خیزی در زمره کشورهای حادثه خیز از نظر وقوع این مخاطره است. هدف اصلی این پژوهش تعیین پهنه های سیل خیز و سیل گیر حوضه لیقوان چای تبریز است. جهت انجام این کار از مدل ترکیبی فرآیند تحلیل شبکه و منطق فازی به همراه 12 پارامتر طبیعی استفاده شده است. بر اساس مدل فرآیند تحلیل شبکه برای سیل خیزی، معیارهای شیب (187/0) ، جنس سازند (125/0) و برای سیل گیری نیز پارامترهای شیب (229/0) ، انحنای پلان (2/0) بیشترین ضریب تاثیر را داشته اند. بر اساس نتایج، بخش های جنوبی حوضه با قرارگیری در پهنه هایی با پتانسیل خیلی زیاد و زیاد، به عنوان سیل خیزترین بخش های حوضه معرفی شده اند. این مناطق به خاطر سنگ بستر آتشفشانی، نفوذپذیری پایین، شیب زیاد، دریافت بارش بیشتر و تراکم شبکه آبراهه بالا قابلیت تولید روآناب بالایی را دارا هستند و از این نظر در کلاس طبقات با پتانسیل خیلی زیاد و زیاد قرار گرفته اند. از نظر سیل گیری نیمه شمالی حوضه بیشترین پتانسیل سیل گیری را دارد. این مناطق عمدتا زمین های اطراف رودخانه های اصلی، زمین های پست و هموار بخش خروجی حوضه را در بر می گیرند. از نظر تقسیمات واحدهای اراضی این مناطق عمدتا به عنوان زمین هایی با پستی و بلندی کم و شیب نسبی کمتر از 10 درصد می باشند که اغلب نواحی حاشیه ای رودخانه ها، تراس های قدیمی و جدید را در بر می گیرند. این مناطق با ویژگی هایی همچون شیب کم، ارتفاع نسبی پایین، فاصله کم از رودخانه و انحنای پلان و پروفیل مقعر مشخص شده اند.
    کلیدواژگان: پتانسیل سیل خیزی، پهنه بندی، ANP، منطق فازی، لیقوان چای
  • علی احمدآبادی*، محمد فتح الله زاده صفحات 180-192
    یخچال های طبیعی جزء میراث طبیعی زمین محسوب می شوند که با پیشروی و عقب نشینی خود پاسخ های متناسبی به تغییرات اقلیمی کره زمین نشان می دهند به طوری که در چند دهه اخیر و با توجه به افزایش انتشار گازهای گلخانه ای در جو و به تبع آن گرمایش جهانی، ذوب یخچال های طبیعی افزایش یافته و از حجم آنها به میزان زیادی کاسته شده است. بررسی وضعیت یخچال های طبیعی به دلیل قرارگیری در پناه کوهستان های بلند با سختی و دشواری هایی روبروست از این رو مزایای کاربرد تکنیک های سنجش از دور برای این مناطق به خوبی آشکار می شود. NDSI یا شاخص سطح نرمال شده پوشش برف معیاری برای تعیین سطوح برفی می باشد و مبنای تعیین این شاخص بازتابندگی بالای برف در ناحیه مرئی و بازتابندگی پایین در محدوده فروسرخ میانی می باشد. در این پژوهش جهت شناسایی و تعیین تغییرات برف مرز در اشترانکوه، ابتدا سیرک های یخچالی منطقه تعیین و موقعیت یابی شدند. پس از آن توسط مدل رقومی ارتفاعی و با استفاده از روش ارتفاع کف سیرک پورتر و روش رایت، حد برف مرز دائم در دوره کواترنر پسین به ترتیب 2505 و 2549 متر تعیین شد. سپس به کمک تصاویر ماهواره ای لندست 8، شاخص سطح نرمال شده پوشش برف محاسبه و سطوح برفی برای دو دامنه جنوب غربی و شمال شرقی برای 4 سال پیاپی (سال های 2013 تا 2016) تعیین و نهایتا ارتفاع قرارگیری سطوح برفی در حال حاضر برابر 3346 متر برآورد شد. براین اساس ارتفاع قرارگیری سطوح برفی در حال حاضر نسبت به کواترنر پسین افزایش 841 متری با در نظر گرفتن روش ارتفاع کف سیرک پورتر و 797 متری با در نظر گرفتن روش رایت نسبت به ارتفاع برف مرز در کواترنر پسین را نشان می دهد که خود بیانگیر افزایش میانگین دما در این منطقه نسبت به دوره کواترنر پسین می باشد.
    کلیدواژگان: یخچال های طبیعی، اشترانکوه، برف مرز، NDSI
  • زرین فروغی*، سیاوش شایان، پرویز کردوانی صفحات 193-210
    مطالعه تغییرات زمانی و مکانی کاربری اراضی، اطلاعات مهمی در زمینه تغییرات ژئومورفولوژی مجرای رودخانه فراهم می کند؛ لذا در این تحقیق نقش مداخلات انسانی و بخصوص تغییرات کاربری اراضی در وضعیت ژئومورفولوژیکی رودخانه کر (بالادست سد درودزن- استان فارس) به عنوان یکی از مهمترین مناطق کشاورزی و گردشگری و مهمترین منبع آبی شمال استان فارس مورد بررسی قرار گرفته است. مراحل انجام تحقیق بر مبنای آنالیز سنجش از دور تغییرات کاربری اراضی و بررسی اثر تغییرات کاربری اراضی بر منابع زیست محیطی و تغییرات ژئومورفولوژی رودخانه با استفاده از روش روزگن است. نتایج روش ارزیابی وضعیت ژئومورفولوژیکی روزگن نشان داد که در طی دوره زمانی مورد مطالعه حداکثر تغییرات ژئومورفولوژیکی در سطح یک و دو روش روزگن مربوط به بازه های مکانی شماره یک و دو بوده است و پس از آن به ترتیب بازه های شماره 4، 5 و 3 در اولویت قرار می گیرند. در تمامی بازه های مکانی مورد مطالعه به علت فرسایش پذیری کرانه ها، تغییراتی عرضی و طولی چشم گیری رخ داده است و حداکثر تغییرات به ترتیب مربوط به بازه های مکانی 2، 1، 3، 4 و 5 است. تغییرات عرضی به ترتیب به علت تغییر شیب، رژیم هیدرولوژیکی، بار معلق و بار بستر، تعرض به زمین های محدوده حریم رودخانه و وجود سد بوده است.
    کلیدواژگان: ژئومورفولوژی، کاربری اراضی، روزگن، طبقه بندی رودخانه، رود کر
  • مجید پیشنماز احمدی*، کیوان محمدزاده، مهدی ثقفی صفحات 211-225
    زمین لغزش ها یکی از بزرگ ترین مخاطرات محیطی هستند که خسارات اقتصادی، مالی، جانی، همراه با تخریب تاسیسات و افزایش هزینه ها را به دنبال دارند. پژوهش حاضر به منظور پهنه بندی خطر زمین لغزش و همچنین پهنه بندی آسیب پذیری روستاها در مقابل خطر زمین لغزش با استفاده از روش تحلیل شبکه (ANP) در یکی از زیر حوضه های سفیدرود واقع در شهرستان رودبار انجام گرفت. در این تحقیق برای پهنه بندی خطر زمین لغزش در منطقه موردمطالعه، 14 عامل تاثیرگذار شامل ارتفاع، شیب، جهت شیب، فاصله از جاده، فاصله از گسل، فاصله از رودخانه، زمین شناسی، نوع خاک، اقلیم، کاربری اراضی، بارندگی، شاخص رطوبت توپوگرافیک (TWI) ، شاخص طول شیب (LS) و شاخص قدرت آبراهه ای (SPI) مورد استفاده قرار گرفت. به همین منظور بعد از شناسایی فاکتورهای موثر در زمین لغزش، در محیط نرم افزار Super decision وزن هرکدام از فاکتورها مشخص گردید، سپس وزن های به دست آمده در محیط نرم افزار Arc GIS اعمال شده و نقشه نهایی پهنه بندی زمین لغزش به دست آمد. در این تحقیق فاصله از گسل، جهت شیب، فاصله از آبراهه ها و شیب به ترتیب بیشترین اهمیت را به خود اختصاص دادند. بررسی نتایج نشان داد که بیش از 50 درصد منطقه موردمطالعه دارای خطر متوسط به بالا بوده و از طرفی پهنه بندی آسیب پذیری روستاها در مقابل خطر زمین لغزش نشان داد که از مجموع 188 روستا، تعداد 49 روستا (53/25 درصد) در پهنه های با خطر زیاد و خیلی زیاد قرار گرفت. و این تهدیدی جدی برای ساکنان این نواحی تلقی می شود.
    کلیدواژگان: پهنه بندی، زمین لغزش، آسیب پذیری، تحلیل شبکه (ANP)، حوضه رودبار
  • میر اسدالله حجازی، معصومه رجبی، جواد وروانی، آتنا عسگری * صفحات 226-240
    بخش هایی از پوسته زمین در عهد حاضر دارای حرکات زمین ساختی هستند و در آینده نیز مستعد بروز خطر خواهند بود. از این رو، اشکال ژئومورفولوژیکی در برابر فعالیت های زمین ساختی بسیار حساس بوده و در اثر این حرکات تغییر می کنند. حوضه آبریز میقان یکی از حوضه های مرکزی کشور در شمال شرقی استان مرکزی واقع شده است. وجود دو سیستم گسلی اصلی تبرته - تلخاب با روند جنوب شرقی ? شمال غربی و گسل های فرعی متعدد نشان دهنده ظهور پدیده های مهم زمین ساختی در این منطقه است. ارزیابی فعالیت های زمین ساختی با استفاده از برخی از شاخص های کمی، نقش مهمی را در شناخت این فعالیت ها داشته و به تفسیر وضعیت زمین ساختی مناطق کمک می نماید. هدف از این پژوهش بررسی وضعیت نو زمین ساخت با استفاده از داده های ژئومورفولوژیکی است. برای دستیابی به این هدف از هفت شاخص ژئومورفولوژیکی: شاخص های شیب طولی رودخانه (SL) ، نسبت پهنای کف دره به ارتفاع آن (VF) ، عدم تقارن حوضه زهکشی (AF) ، تقارن توپوگرافی عرضی (T) ، نسبت شکل حوضه (BS) ، منحنی هیپسومتری حوضه (HC) و پیچ و خم رودخانه (S) ،به عنوان ابزارهای اصلی این پژوهش بهره گرفته شده است. روش تحقیق بر پایه روش تحلیلی استوار است. ابزارهای مورد استفاده در این پژوهش شامل نقشه های توپوگرافی و زمین شناسی منطقه مورد مطالعه، تصویر ماهواره ای و سامانه اطلاعات جغرافیایی در قالب نرم افزار ArcGIS 10 می باشد. همچنین، نتایج کمی بدست آمده طی چندین مرحله کار میدانی مورد ارزیابی قرار گرفتند. نتایج بدست آمده از این پژوهش نشان می دهد که منطقه مورد مطالعه براساس شاخص های شیب طولی رودخانه که مقدار آن برابر (4/353) ، عدم تقارن حوضه زهکشی (6/47) ، تقارن توپوگرافی عرضی (24/0) ،منحنی هیپسومتری حوضه ،و پیچ و خم رود که (21/1) می باشند از لحاظ زمین ساختی در وضعیت فعال و تنها بر اساس شاخص، نسبت پهنای کف دره به ارتفاع آن که برابر (24/2) و نسبت شکل حوضه که (5/3) می باشد در حالت نیمه فعال قرار دارد. در نتیجه می توان گفت شاخص BS که بیانگر شکل حوضه است در حوضه های کشیده تر مقدار آن بالاتر است و از آنجا که بیشتر زیرحوضه های مطالعاتی نیز کشیده بودند بیانگر فعالیتهای تکتونیکی بالا می باشد.
    کلیدواژگان: زمین ساخت، حوضه میقان، شاخص های ژئومورفیک، سیستم اطلاعات جغرافیایی
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  • Mehran Maghsoudi * Pages 1-12
    Karstic geomorphosites are some of the landforms that have an impact on attracting tourists. In addition to attractive, these landforms have scientific-educational values. Poldokht is one of Lorestan city which has various karst and non-karst geomorphosites.
    The variation of geotouristic forms in Poldokhtar city is such that one can distinguish karst and non-karst geomorphocytes from each other and evaluate them in a specialized way. The dynamic and variable structure of karst in the city of Poldokhtar, in addition to creating geomorphosites, has caused the development and expansion of them over time. Therefore, in this research, the final goal is to collect general information about karst geomorphosites and introduce them as a specialized part of the city's attractions along with other natural and historical attractions.
    In this research, 13 geomorphosites named Kelmakrah Cave, Cogan Cave, Khazine Valley, Tang e Malawi, Tang Palelam, Tang-Halt, Typical Valleyed, Afrineh Waterfall, Telesm Cave, Tang-e-Gav zarddeh, Abtaf Waterfall, kiil chap region and Cheshmeh Gosh Waterfall They were selected as study geomorphosites. Karst geomorphosites were identified in the study area using field studies and data card design. Use of written resources, field surveys, GPS, GIS, laser meters and questionnaires are methods and tools for collecting information. There are several models for assessing geomorphocytes. In this study, a combination Kubalikova& Kirchner)2016(was used to evaluate the geomorphocyte's ability.
    The final results indicate that Kalmakere Cave, Cogan Cave and Cole Left Region are the most important karst geomorphosites in the city. The evaluations showed that their conservation and economic values are not in a favorable situation. Developing geotourism within the case study requires the coordination of various components, including scientific, educational, economic, conservation and value added. Attracting popular contributions, developing educational affairs, placing the city's geomorphosites in conservation areas and creating care bases by public or private organizations, guiding tourism tours and conducting scientific and academic trips to geosites and ... It should be seriously pursued within the scope of the study.
    Keywords: Karst, geomorphous, evaluation, criterion, Poldokhtar city
  • Saman Nadizadeh * Pages 13-29
    Introduction; Of important geomorphological characteristics of Uremia Lake is instability coastline. The salinity Phenomenon and Genesis crust of salt in the coastal lands is of the manifestations of this is the use, season. Monitoring the coastal areas and Extraction the water level changes in, different time, considered as fundamental research, because nature of coastline is dynamic and the management of such Sensitive ecological environments needs to earn detailed information in Different time intervals. For this purpose, Remote Sensing Technology has unique application uses information from these phenomena. Because multispectral satellite images have benefits and advantages that availability and this Digital interpretation is their most important. The overall objective of this study, was to evaluate the processes The governing on Dry environment and the hydrodynamic evaluate of lake in determining lake shoreline changes using the Landsat satellite images MSS, TM5, ETM 7 and OLI in period of 39 years (1976- 2015) and then is evaluate the effect these changes on amount of salt deposits around the lake.
    Methodology
    In this study, to investigate the changes in Coastline and salt marsh Uremia Lake is used of Landsat satellite images (MSS-TM5-ETM -OIL) that have been downloaded of USGS. To prepare satellite images in during processing, have been done pre-processing steps down: geometric correction, atmospheric correction, mosaic and Resample. Considering the importance of accuracy geometric correction on accuracy of the results of detection of changes Because of pixel by pixel comparison of satellite images together, these images must have coincided perfectly geometrically. So images using the 1:25000 Topographic Maps With the image registration to map method in WGS84 coordinate system and projection UTM Zone 38 with RMSE errors less than 5.0 were corrected. Initially the digital value of each pixel (DN) was Conversion to the Spectral radiation in sensor (Radiance) and then obtained Radiance was Conversion to reflection on the sensor (reflectivity), for atmospheric correction has been used of FLAASH method. After performing these steps, because this area is not within a Landsat image, for coverage of the full study area were mosaic images of each year. Finally all of images were re-sampling with method nearest neighbor. In this study, is used of six Salinity Index (NDSI, SI1, SI2, SI3, SI9, SI14). In order to changes evaluate Water Levels Uremia Lake do this in the period of 1976 to 2015 the water level in each image extracted from each image individually. To, various indices including normalized indices water, the normalized index humidity, corrected water normalized index, the index water ratio, normalized vegetation index, is used the index automatic extraction of water. After applying of indices on images, accuracy of the results of the index using the samples point that Lifted from the Google Earth was assessed. Eventually has been selected Suitable index for extract the shoreline and salt marsh and in in order to the separate of shoreline and salt marsh desired using the Model Maker extension in the ERDAS software was binary by taking considering threshold. Then been done with convert raster to vector maps and analyzes of Intended changes in the GIS10.3 software.
    Discussion &
    Results
    According to obtained results for the study area NDWI index is the strongest index for Water extraction, So that properly extracted 191 water sample point and of 218 sample points of salinity have put Only 7 samples in Water class. To extract Salt marsh strongest indicator, is the SI2 so that 214 sample points of salinity extracted correctly and of 195 samples points of water, only 12 samples out of put in salinity class and The weakest index, is NDSI indicator. According to the analysis of satellite images surface area of ​​Lake Uremia is reducing and the salt marsh is increase. So that the water level of the lake and salt marsh reached respectively of ​​5216.30 and 106.18 square kilometers in 1976 to 1519.12 and 3777.50 square kilometers in 2015. The results of surveys show that have area of water the negative trend and salt marsh have increased trend. So that the water level Declined 72.76 square kilometers between the years of 1976 to 1985 to 1262.03 square kilometers between the years of 2011 to 2015 but Area of salt marsh have increasing trend so that increased the 59.53 square kilometer between the years of 1976 to 1985 to 1247.82 square kilometers between years of 2011 to 2015. According to the extraction of shoreline using the satellite imaging greatest change has happened in the direction of East and Southeast (estuary of river Permanent and full water of Zarinehrood) lake.
    Conclusion
    the main objective of this research because of the importance and special Status Lake in Ecosystems, is detect of changes of shoreline and salt marsh Uremia Lake during the period of 39 years. Check fluctuations level of lake using the data of satellite Level gauge of 1992 to 2018 showed that level of the lake has about 8 meters dropped. Results of the accuracy of the Accuracy of various indices for extract the shores of Lake Uremia Revealed that The strongest and the weakest index respectively, NDWI and NDMI index and The strongest and the weakest index for extract of salt marsh is SI2 and NDSI index. Analysis of satellite images shows that area of ​​the lake water and salt marsh respectively reached from 5216.30 and 106.18 square kilometers in 1976 to 1519.12 and 3777.50 square kilometers in 2015. These results it shows reduction of 70.87 percent area of Water Lake and increase in 3457.63 percent of the land of salt marsh of ​​ the study area during the past 39 years. Most of changes of area are related to ​​salt marsh and shoreline respectively 1286.45 and 1310.97 square kilometers Related to the period 2006 to 2011. Comparison of changes the coastline and depth of the lake showed that greatest of changes in parts of southeast and south due to the shallow depth of these Regions happened.
    Keywords: changes of the coastline, changes of salt marsh, Uremia Lake, remote sensing, GIS
  • Fariba Karami * Pages 30-47
    Introduction
    Tectonic activity plays an important role in the development of drainage basin morphology. Drainage networks are the most active and sensitive elements which can be used as a powerful tool to understand the neotectonic activities of an area (Ahmed and Rao, 2016). The geomorphic indices are a tool for analyzing the landforms and evaluating the degree of tectonic activity in a given area (Keller, 1986; Guarnieri and Pirrotta, 2008). Calculation of parameters of the hierarchy of the hydrographic network such as bifurcation index (R), bifurcation ratio (Rb), hierarchical anomaly number (Ha),hierarchical anomaly index (Δa), drainage density (Dd) and drainage frequency (Df), allows us to define the influence of tectonics on the hydrographic network evolution (Guarnieri and Pirrotta, 2008). Several studies show that rivers necessarily flow from high to low elevations parallel to the maximum regional slope (regional topographic gradient). All deviations of stream flow direction from the regional topographic gradient Considered as anomalies related either to structural or lithological discontinuities (Deffonataines, 1990; Sedrette et al, 2016). Iran is located in an active tectonic zone due to its location in the belt of the Alp-Himalayan. Arabia and Eurasia shells convergence is the cause of active tectonic in Iran. There is a special complication of structure process on northwest of Iran. One of Azarbijan important faults that plays basic role in its structure evolution is Tabriz fault. It crosses the north of Tabriz city . North of Tabriz Fault (NTF) is collection of fault branches. This fault affects upon geology and geomorphology processes on region basins. Since drainage networks patterns present useful information about past and present region tectonic, so one of sensitive landforms to tectonic activities are rivers. In this way, the present study studies the effect of active tectonics of Tabriz fault on the hierarchical anomalies of the drainage network Varkesh Chay basin, Gamanaj Chay basin, Nahand Chay basin and Sarand Chay basin that located on north of Tabriz.
    Methodology
    In this research for recognizing study region we have used from topography maps, geology maps 1:100000 ( Tabriz and Khoja) and DEM image with resolution of 30 meter. Also ARC GIS, EXCEL and SPSS soft wares were used for drawing region maps and parameter analysis. In this research studied Varkesh Chay basin, Gamanaj Chay basin, Nahand Chay basin and Sarand Chay basin that located on north of Tabriz. In this study used a quantitative method for calculation of stream's hierarchical anomaly number. Morphometric parameters to be used are hierarchal anomaly index (Δa), Density hierarchical anomaly index (ga), asymmetry factor (Af), basin Shape (Bs), basin length to mean width ratio (Bl/Bmw), bifurcation index (R), drainage density (Dd), drainage frequency (Df), Basin volume / Area index (VA), Basin elongation ratio index (Re), Circulatory ratio (CR) and Langbin Concavity index (IC).
    Results And Discussion
    Results show that the strong correlations exist between pairs Da-Re (R=0.99), Da-IC(R=0.91), Da-LSBW (R=-0.87), Da-BS (R=-0.87), Da-R(R=0.69), Da-CR (R=0.55). also the strong correlations exist between pairs ga-IC(R=0.95), ga-Re (R=0.93), ga-R(R=0.83), ga-LSBW(R=-0.94), ga-CR(R=0.65), ga-BS (R=-0.8). The results of the analyzes indicate that the indices Δa and ga are completely affected by the basins elongation caused by the active tectonic effect. In addition, Anomalies in drainage network of all northern basin of Tabriz are affected by the Langbin Concavity index (table1).
    Table 1: Coefficients Pearson Correlation between morphometric index in study basins
    IC Df Dd R VA LSBW CR Af BS Re
    0.91 0.06 0.02 0.69 0.08- -0.87 0.55 0.33 0.85- o.99 Da
    0.93 0.27 0.14 0.83 -0.27 -0.94 0.65 0.25 -0.80 0.95 ga
    Conclusion
    In this study used a quantitative method for calculation of stream's hierarchical anomaly number. Morphometric parameters to be used are hierarchal anomaly index (Δa), Density hierarchical anomaly index (ga), asymmetry factor (Af), basin Shape (Bs), basin length to mean width ratio (Bl/Bmw), bifurcation index (R), drainage density (Dd), drainage frequency (Df), Basin voulume / Area index (VA), Basin elongation ratio index (Re), Circulatory ratio (CR) and Langbin Concavity index (IC) . Results show that the strong correlations exist between pairs Da-Re (R=0.99), Da-IC(R=0.91), Da-LSBW (R=-0.87), Da-BS(R=-0.87), Da-R(R=0.69), Da-CR (R=0.55). also the strongcorrelations exist between pairs ga-IC(R=0.95), ga-Re (R=0.93), ga-R(R=0.83), ga-LSBW(R=-0.94), ga-CR(R=0.65), ga-BS(R=-08). The results of the analyzes indicate that the indices Δa and ga are completely affected by the basins elongation caused by the active tectonic effect. In addition, Anomalies in drainage network of all northern basin of Tabriz are affected by the Langbin Concavity index.
    Keywords: Hierarchal Anomaly, Drainage Networks, Morphometric Parameters, Geomorphic index, Active Tectonic, North of Tabriz Basins, North of Tabriz Fault (NTF)
  • Mohsen Ranjbaran * Pages 48-60
    Kandovan village is situated 58 kilometers from the southwest of Tabriz and 20 kilometers southeast of Oskou East Azerbaijan Province, Iran. The village of Candovan is structurally located in the geological zone of Central Iran and within the range of igneous rocks of the Osku. This village is one of the rare examples of rocky architecture. The Kandovan is a historic village of considered as one of the most beautiful landscapes of the country, with dug houses inside the cone-shaped rocks. Sahand Mountain is an important dormant massive, heavily eroded stratovolcano in East Azerbaijan Province, directly south of Tabriz northwestern Iran. These cone shaped structures (Karans) were shaped by ash and debris from a volcano eruption of now-dormant Sahand Mountain. During the activity, volcanic Sahand diagnosed three stages: the first stage of andesitic lava flows Secondly, intermittent release of ignimbrite (containing fragments of pumice, etc.) dacite and dacite lava flows of the third stage.
    After the eruption of Sahand these materials were naturally welded and formed the rocks of Kandovan.
    In the Kandovan area, there are three lithological facies. These lithological facies include lava flows or volcanic rocks, ignimbrites, and Lahar and epicclastic deposits. The lava flows mostly have porphyritic texture and their chemical composition is more andesitic and dacitic. These volcanic rocks are usually very fine-grained or aphanitic texture. These rocks often contain phenocrysts. The phenocrysts are feldspar and quartz crystals that are larger than the matrix and are identifiable with the unaided eye. The dominant minerals in these rocks are plagioclase, hornblende, biotite, quartz. The minerals that appear in the form of large crystals and porphyry texture are from feldspar minerals. Textural zoning patterns preserved in plagioclase phenocrysts provide useful information about magmatic evolutions.
    According to the welding range of ignimbrite can be divided into three classes in the field (partially welded with pumice, partially welded with fiamme and densely welded). The strength of the resulting ignimberite tuff would depend on how hot the tephra was when it was deposited. Very hot tephra can 'weld' together and not crumble easily. Ignimbrite deposits, which are dig up in the Kandovan village houses, have explosive texture. Their composition and mineralogy those are rock fragments, pumice pieces, volcanic glass and fragments of feldspar and quartz minerals. All ignimbrites are rhyolitic-rhyodacitic in composition.
    The welding of clast of volcanic pyroclastic Ignimbrite deposits involves of pumice pieces and rock fragments occurred during explosive eruptions in acidic magma occurs under a compactional load at temperatures above the glass transition temperatures. The welding of pyroclastic materials during Sahand explosions causes the formation of porous, light weight deposit those are susceptible to to excavating.
    Over the period of thousands of year’s ash and debris from volcano eruption were hardened, shaped and sculptured by natural elements such as wind, rain, snow and so on. Morphologic change in the area produced present landscape occurred in a semi-arid climate mainly during Quaternary.
    Consequently this cone-shaped landforms which originated by tuff erosion were excavated by humans and utilized as dwelling and similar to dwellings in the Turkish region of Cappadocia, are locally called “Karans ".
    Around the village the thickness of this formation exceeds 100 m and with time due to water erosion the cone shaped cliffs were formed. The maximum height of the Cone-Shaped is about 60 m. Ignimbrites deposits along the Kandovan valley are under the influence of current water irrigation and atmospheric precipitation, and the shape of the conical hill has formed. Lahar deposits have soft texture and very poorly sorted particles from of clay to gravel size. The Lahara, due to its physical nature, which has a very poorly maturity range from clay to gravel size, is not suitable for digging. Therefore, the conical houses in this group of rocks are not created. Lava flow and Lahar deposit are not suitable for diggings up according to their texture. Lava flows cannot be break down due to its high strength and hardness; therefore, cone-shaped houses cannot be created them.
    The most important destructive factors on the Kandovan village are the cases of topography, the physical and chemical properties of the rock, the climate conditions, and, consequently, the biological activities. The effect of physical weathering on the destruction of conical houses in the Kandovan village is more effective than chemical weathering. With the absorbed water causes loss and decomposition of the cement connecting the rock and species damage such as crusting, crushing and alteration Minerals also cause the crystallization of salts as well as the cause of the growth of biological pests in different types. The boundaries of the entrance section of the Kandovan village have been more damaged due to the excessive winds and rains of the western-eastern part of the eastern part, due to the presence of higher hills and higher ranges.
    Keywords: ignimberite, lahar, Kandovan Village, Sahand Mountain
  • Mohsen Pourkhosravani * Pages 61-73
    Introduction
    The use of satellite imagery processing to fault lines extraction and faults identification is very common (Yassaghi, 2006: 35; Mehrabi et al. 2016: 45). However, the use of radar imagery in the field of faults is an emerging phenomenon, and so far, less work has been done. The radar images, in addition to measuring the intensity of the signal, also have phase information, therefore, that can be used in fault studies and earthquakes with using phase information and interferometry technique (Wright et al. 1999: 213; Simons et al. 2002: 145; Qu et al. 2017: 78). The subject of this study is to Measurement of surface displacement caused by the 2004 Dahuieh (Zarand) earthquake in Kerman province and identification of the operating fault using the radar interferometry method.
    Materials And Methods
    Initially, the focal mechanisms of earthquake information in 2004 were obtained from the site of the International Institute of Earthquake Engineering and seismology (IIEES). Then, two ASAR radar images of ENVISAT satellite were ordered from the ESA, one related to before the earthquake, and one related to after the earthquake event. The image that is related to before the earthquake is called the master image and the image associated with it later is a slave image. Also, a topographic map of 25000/1 was used to provide a digital elevation model (DEM). The processes and interferometric techniques were made using the Envi software via the Sarscape 4.3 plugin.
    Results and Discussion
    Two ASAR radar images, due to the fact that one was taken before the earthquake and one after the earthquake, can show the changes and effects of the earthquake on the surface as a phase of displacement. As shown in Fig. 4, in the image of the interferometric map that created at the earthquake surface center, numbers of fringes were created. Since the used satellite (Envisat) works in the C band, and each fringe obtained is 2.2 λ equal to 8.2 centimeters, the amount of displacement in the direction of the satellite's view is given by counting the number of fringes. Depending on how the color cycles are observed, the displacement rate also varies, so that if the cycle is yellow-blue-red, moving away from the radar and if the cycle is yellow-red-blue, the shift to the radar has occurred. As shown in Fig. 3, the northern and southern fringes both collide and disappear in both eastern and western parts, Just like the two poles of a magnetic field, if we connect these two poles with a single line, the upper part of the line has an uplift and its lower part has fallen, and almost the same line can be assumed as the fault of the earthquake. Before the interferometric map can provide a surface displacement, with the Goldstein filters must eliminate possible errors, such as the speckle and noise error. Since interferometric phase information is on the 2π scale, there is an ambiguous problem in calculating the correct number of phase currents, so that the interval to the phase observations must be added to obtain the distances. Eventually, the map of displacement created by performing and applying the filter and solving the ambiguity of the phase (Fig. 5). As shown in this figure, the difference in displacement exactly is started from the point of the earthquake surface. The north of this point has a high elevation, and the lower part is drooping. An area of 100 square kilometers has risen with maximum values of 34 cm. An area about 150 square kilometers in the southern part of surface focal has dropped by 24 cm. In Figure 6, the position of the aftershocks occurred one year after the earthquake was also included in the area. As seen, the post-shaking distribution follows the specified fault line. If the stone layers of the area are also examined (Fig. 7), evidence of the breakdown and displacement of these layers is observed exactly along the known fault line.
    Conclution: An earthquake of seismic moment magnitude (Mw) 6.4 occurred in eastern Zarand city in Kerman province on February 22th, 2005. At first, the Kuhbanan fault was considered to be the cause of this earthquake. However, further studies of (Nemati and Gheitanchi, 2011: 3) show that One of the secondary faults that caused this earthquake. In this research, we decided to use radar images to investigate and model the changes and displacements occurring on Earth's surface due to this earthquake, and identify the caused fault. On the basis of ascending data, InSAR analysis reveals due to intensity of earthquake in the northern part of surface focal an area of 100 square kilometers has risen with maximum values of 34 cm. Also, an area about 150 square kilometers in the southern part of surface focal has dropped by 24 cm. Based on the results, the causative fault of the earthquake is the east-west fault with a reverse component and a length of 20 km.
    Keywords: Radar interferometry, Displacement, Kuhbanan Fault, Dahuieh earthquake, Envisat satellite images
  • Fariba Hemati * Pages 74-89
    Introduction
    Faults are among the most common geological conditions in rock masses, which are considered as one of the most significant examples of rock discontinuity. The earth’s instability is often due to the presence of faults in or near them. Bozqush Mountains are the most important landscapes in southern Azerbaijan, including the south-western border of Tabriz fault’s extension, and south-eastern border of Mianeh-Ardebil fault. Benaravan fault in the eastern part of this mountain range is part of the Mianeh-Ardabil fault. In the present study, a study was conducted titled as Zoning the Risk of Hillside Instability Using Artificial Neural Network with MLP Model. This was the purpose of selecting this model to investigate areas with the potential of hillside instability occurrence.
    Data and Methodology: In this study, aerial photos and ETM satellite images of the region, topographic maps with a scale of 25000/1, and geological map with a scale of 100000/1 were used. There were also several field visits to the area.
    Artificial Neural Networks Model: Neural network models are a kind of simplistic modeling of real neural systems that are used extensively in solving various problems in science. The best way to solve complex problems is to break it down into a simpler sub-question, and each of these sub-sections can be easily understood and described. In fact, the network is a collection of these simple structures that together describe the ultimate complex system. It must be pointed out that in this study, a variety of multilayer perceptron networks were used.
    Data Analysis: To investigate the relationship between the factors affecting the occurrence of hillside instabilities in the studied area, after providing dispersion map of instability points, the dispersion of these points to nine factors affecting the occurrence of hillside instabilities was investigated. Each information layer was classified into five classes, and based on the degree of sensitivity to hillside instabilities, each of the rating classes was given a score between 1 to 5. 5 was given to a class that had the greatest hillside instability.
    The Argument and the Findings: The maps of the factors affecting the hillside instability, which are independent variables in the instability occurrence, were entered into IDRISI software and were processed. In constructing an artificial neural network, the first task is to determine the type of the network. In this study, an artificial neural network with a multi-layer perceptron structure (MLP) with 1 input layer, including 9 neurons, and a hidden layer with 16 neurons, and an outlet layer were used. The algorithm used in this network was the same after error algorithm, and the sigmoid function was used as an activity function. In order to achieve better zoning and proper output with high precision, a different structure of the neural network was tested by changing the number of neurons and other parameters. This optimal number was achieved at 20000th recurrence with a training error of 440/0 and a test error of 0.0622. As stated, the best way for an appropriate network architecture is achieved through trial and error. In this study, using the trial and error method, the best architecture was selected with 1 input layer including 9 neurons, a hidden layer including 16 neurons, and an output layer (9,16,1). The study used 3181 sliding pixels data for network training and testing. Of these pixels, 2544 pixels were used for training and 636 pixels for network testing. Multiple training rates and momentum factors were tested, and finally, the training rates between 0.014-0.01 with amounts and momentum factors of 0.5 were selected. After performing the above steps, using neural network method, the zoning map of hillside instabilities occurrence risk was prepared,
    Conclusion
    When a hillside is liable to instability, the occurrence of instability at its surface will be inevitable. Theoretically, if steep hillsides that are formed by loose and detached materials, get adequate moisture or water, they are prone to instability. Then, if one or more secondary factors interfere, the instability will occur. Heavy rainfall, movement of faults, earthquake, Earth’s roughness and so on are among such factors. Given these cases, the likelihood of hillside instabilities occurrence in an area, in case of occurrence conditions, is expected. For zoning hillside instabilities occurrence risk using artificial neural network, first at the testing stage, in order to avoid error increase and over-training of the network, each of the parameters of the artificial neural network was determined by trial and error. In this study, a network with an architecture of an input layer with 9 neurons including categories as altitude, gradient, gradient direction, lithology, distance from fault, distance from canal, distance from road, land use, vegetation, and an intermediate layer with 16 neurons and an output layer (9,16,1) that shows areas with potential for the occurrence of hillside instability, was used. The results showed that 81.5%, 95.12%, 38.19%, 06.27%, and 78.34% of the area were located in very high, high, medium, low and very low risk groups, respectively. The zoning map of hillside instability risk shows that areas with high and very high risk, cover about 76.18% of the study area, which are more consistent with the high altitudes, fault zone, and high gradient of the area.
    Keywords: slope instability, risk zoning, IDRISI, MLP model
  • Hadi Nayyeri * Pages 90-105
    Introduction
    Switch land regardless of its inherent talents of the most common human interference in nature is and always phenomena such as floods and soil erosion to follow. Because of the Lifeline Rivers and cities as the core and aggregation deployments are human so are of particular importance. The river bed can be as effective to deploy a range of applications to be considered commensurate with its potentialities. In terms of land use, including the most important issues that the region has suffered in recent years, Integration of heterogeneous and unplanned growth of urban space and surrounding villages such as Naysar, Hassan Abad, is Gerizeh and Doushan. No doubt such cases contradictory to the riverbed and despite changes in its morphology, Increased threats such as flooding and flooding in the future. Present study is the first to identify hazards at the sides of the river bed in Gheshlagh and went on zoning the area for different uses.
    Area of study: Gheshlagh located in the West River flows from the mountains north of Sanandaj stems. About 17 small river in Gheshlagh from a merger between 10 and 25 km in length is formed. Land along the river in most studied gender differences in Sanandaj shale flow And 6 fault line cut perpendicular to the river. But the study area study, a range of 55 km from dam wall Unity (Gheshlagh) started in 12 km from the city of Sanandaj And to continue Zhavh dam under construction. In this study, the zoning Gheshlagh river bed in the study area to a distance of 3000 meters above the right and left banks of the river will be discussed.
    Data and
    Methods
    Digital topographic maps and geological research tools as well as application of GIS and fuzzy logic models have formed. The data consists mainly of previous reports and resources, climate and hydrological data and field data have been. The research and its applications, and cross-reference data through the software Arc GIS, Excel, Google Earth has been analyzed. To analyze the roughness of the Cross in four selected points during the period studied was collected through surveys and ground control. Then-related features are line-water flood, distance from the river, faults, slope and harvested in the form of separate layers were grouped in Arc GIS software. In the next step in the application data through weighting method served, as well as experts, have given weight. The most appropriate weight for residential and commercial applications and then depending on the human density to less important applications has been allocated barren land. Finally, using the left and right banks of the river zoning gamma fuzzy model to a distance of 3000 meters from the main stream has been paid. The results obtained are presented in the form of use maps for different purposes and as well as existing land use map applications also predicted by the findings of the study have been compared and analyzed table.
    Result and
    Discussion
    For the zone of Gheshlagh river bed of the 5 parameters, slope and distance from the river, faults and away from line-water flood For residential and commercial applications, services, municipal sites, agriculture and farming, green space and parks and other areas have been selected. In many mountain areas, as the slope is the most important limiting factor. The maximum slope that the city is suitable for deployment should not exceed 11 percent. Slope gradient of 15% as the upper limit applicable for urban construction will be considered. In areas of low slope gradient map layer Fuzzy high points and low points Pass mark for steep areas are included. Establishment of human society, regardless of the distance from the river always has great human and financial losses. In the present study suitable location for residential and commercial applications such as rivers, dense 900 meters away. For the establishment of low-density closer distances than marked. Since the seismic potential latent faults and seismic are Distance from the fault must also land use planning as an important factor to be considered the map faults, fuzzy function is defined in such a way that the distance of the pixel values is greater fault lines. Given that much of the area investigated in this study are located in the metropolitan area surrounding the city of Sanandaj, Due to overcrowding the space for concrete to be felt. As a result, around bed for residential and commercial applications, municipal services sites, agricultural lands and agricultural and green spaces and parks are considered And very steep area near the intersection of faults and rivers are known for wasteland.
    Conclusion
    The results show that in areas close to the metropolitan area of Sanandaj, space for commercial and residential use is widespread enough about 30 percent of the total area allocated to the range. Low slope, distance from active fault lines and possibility of planning and demarcation principles for river channel in the area of the main reasons for the proposal. At the beginning and end of the study area due to frequent faults and steep, Very little space to expand the use of the high density of human needs have been considered Since that within the context of the presence of thick alluvium, relatively flat slope, topography and access to water resources River Gheshlagh conditions favorable for agricultural land is arable and The result left the shores of the river lands have been appropriate for this function. But the right bank of the substrate is intended for green space and parks. Because these users require less energy than agriculture As a result, the range is covered more area behind the sun. Finally, parts of the area that was not suitable for any of the applications were identified as other an area is 22/75% of the study area. This range is recommended for the protection of soil and limit erosion.
    Keywords: Zonation, hazard, fuzzy, Gheshlagh, Sanandaj
  • Leyla Goolimokhtari * Pages 105-123
    Soil is one of the most important elements of the universe, substrate production; food security and self-sufficiency are directly related to soil conditions. Soils are formed on geomorphologic surfaces. These surfaces have certain age, aspects and slopes and also specific position. Time dependent soil formation generally occurs in regions with certain age land­­forms such as river terraces debris fans or slide masses and mud flows. This may leads to soil diversity in different geomorphological environments. Therefore geomorphological studies, due to different physical and human factors, could have an important role in identification of agricultural prone areas and planning for soil conservation and preventing from soil losses. This research uses a comprehensive procedure and soil lithological and geomorphological data in order to assess the effects of geomorphology on rate of soil forming process in Joghatay County.
    Methodology
    In this study, after preparing the required maps of physical characteristics, layers were incorporated and then locations of sampling were determined. These points were located in different elevation, different slopes, certain plan and profile curvature and lithological features. Partial Least Square Regression method was used to analysis and determining the important factors in soil forming process in studied area. PLS path modeling is primarily used to develop theories in exploratory research. It does this by focusing on explaining the variance in the dependent variables when examin­ing the model.
    Results And Discussion
    Using 9-unit model of catena, 7 units were identified in studied area and from these units soil samples were prepared.
    Most of samples in unit 4 have large to medium grain size. Except in sample 5, 6 (because of convex slops). In unit 5 amount of sand in comparison with silt and clay is higher. Also, soil depth in this unit is low and minimum soil depth is l0 cm. Gravel size in this unit is medium. In the middle of this unit formation of some geomorphic factures such as alluvial fans is common. Hydrometric analysis of this unit samples (3, 4, 8, 12, 14) show that in sample 3 that is located in upper part of the fan, amount of sand is more than silt and clay. Results from sieve analysis show that the percent of coarse grain size in sample 3 is more than sample 2 and 4. The reason is that in an alluvial fan from higher elevation to flatter areas, coarser grain sizes changed to finer grain sizes. Sample 4 is located between 2 alluvial fans. In this area the percent of sand is more than two others. Samples 12, 8, 14 have large amount of sands since they are located in upper part of alluvial fan. In location of sample 14, the slope has a special from. The plan curvature in this point is convex and profile curvature is concave therefore there is a high convergence in this location, therefore gravels are not enable to persist here. In units 6, 7 that are concave parts of slope and receive large amounts of sediments and solutions in overland or underground flows and deposited in foot slope. In sample 2 that is located in lower part of alluvial fan, sand has the first rank in soil components (84%) but the amount of silt and clay is less than sample 3. Sample 1 that is located in flattest part of the area has a fine grain soil and the least amount of sand and gravels are in minimum ranges. Also, locating of sample 1 in the end part of alluvial fan and near the Jovein river, resulted in increasing soil depth.
    Part 2 of investigation, begins with preparing of a model to investigate the role of each soil forming factor on soil formation and development in study area. This model as mentioned before is in the form of structural equations and PLS procedure. In this case, latent variables are divided in 2 forms reflective and formative variables. Fitting of this model was performed in 3 parts. 1- Fit of measurement model 2- Fit of structural model 3- Fit of general model. In designed model, four models related to hydrological, topographical and geomorphological, geological and soil formation variables were created. The results are shown in table 1. The results show that all of models have proper design and are suitable for our study.
    Conclusion
    Each unit of catena in slope extent is affected by special process and drainage condition and show different soil properties, therefore, slopes are the best areas for soil geomorphological studies. In unstable areas such as slope shoulder, weathered materials transfer to down slope and deposit in more stable area. In studied area slope gradient and aspect are of important factors in soil formation. Especially southward slopes have an important effect on soils. Elevation is another factor that shows direct effects on soil formation that leads to very thick soil layers in flat areas and very thin layer in high gradient slopes and slope shoulders. Also hydrological factors such as soil moisture and order of river are effective factors on soil genesis and development. Results from PLS analysis show that among all investigated factors, slope is the most important one that has critical effect on soil formation. Regarding these results it is clear that geomorphology could have an important role in soil conservation planning because in each unit of slope concerning its influence on soil formation we can present suitable strategies for soil conservation and maintenance.
    Keywords: Soil Evolution, Soil Genesis, Geomorphological landforms, Joghatay County
  • Abdolah Seif * Pages 124-145
    Recognizing the geomorphologic and climatic features of different parts of the country is an important and essential principle, without which dangerous mistakes will not be made. this paper examines the geographical features, especially the relationship between Geomorphoclastic factors with the optimal locating of critical, sensitive, and important centers of Makran coastal area from Jask to Gowatre Bay with Passive Defensive Approach.
    Considering the necessity of locating critical, sensitive, and important centers and facilities with Defensive Passive approach effectively and cleverly and evaluation Characteristics Of geomorphological and climatic of Makran coastal (from Jask to Gowatre Bay), the map of the development plan of Makran Coastal was drawn by the secretariat of the development of Makran Coastal achieve security stability in this area of Iran country. In the current study, according to the separation of the geomorphologic units of the Makran region, the coastline and coastal plain up to 50 km radius and hills and mountains up to 200 km in depth were considered as operational and strategic areas, respectively.
    The research instruments were topographic and geology maps and aerial and satellite images of the region. Furthermore, we identified the effective factors, both natural and human, in locating critical, sensitive, and important centers with an emphasis on Defensive Passive approach, using questionnaires and interviewing with experts. Identifying the factors, the geomorphologic and climatic elements were analyzed using BWM analytical method for comparing the criteria in the best and worst case; the effective factors and elements in locating with Passive Defensive approach underwent final ranking and weighing. Among the indices, slope with final weight (0.257) and relative humidity with final weight (0.030) were the most and the least important indices, respectively. Finally, in Arc GIS software environment, we obtained a map in which the areas suitable for the construction of sensitive and important centers were identified.
    The results indicate that the eastern coastal regions of the concerned area are in more suitable conditions for locating compared to the western ones. In addition, according to the final map based on geomorphologic factors in the GIS environment, the area of ​​optimal zones for the locating of sensitive and important centers is more in the northern part, compared to the southern regions. In other words, it can be said that the geomorphologic features such as topographic and physiography conditions of rivers and… of the region are more favorable in the northern part compared to the southern regions and in the coastal plain area in the eastern part compared to the western part for the selection of an optimal locating for sensitive and important centers.
    Keywords: Characteristics Of Geomorphoclimaei, locating, Passive Defensive, Morphology Units Of Makran, Best -Worst Analytical Model
  • Rasool Samadzadeh * Pages 146-161
    Introduction
    From the Quaternary period to the Neolithic age of the West Asian Region, which covers a wide range of Iran, it has undergone numerous environmental changes. In general, with respect to the natural history and environmental changes of the Quaternary region of the Middle East, which includes Iran and West-Asian, some researchers believe in the theory of cold and dry phases during glacial and warm and humid periods in interglacial periods. What is important to day and almost universally agreed is the coincidence of cold and dry weather-phase phases, with glacier conditions and wet phases, with the interglacial periods of the northern hemisphere. The Gizaz-chay watershed as one of the sub-watersheds of the Gezelozan River and one of the subsystems of the Baghrodagh mountains comprises a assemblage of deposits and landforms of varying nature, age and position in the landscape. This watershed is home to a part of quaternary's natural history that has embraced Tallesh Mountains. Recognition of this history and palaeolandforms formed in its temporal and spatial context was the main purpose of this study.
    Methodology
    This research is empirical in terms of the method of analysis, which is based on the analytical method, in which factors and variables have been investigated which have influenced at least Quaternary up to the present time in the dynamics of the area surface. The physical instruments used include the topography map 1: 50000 and of geological map 1:100,000 kivi, aerial photographs 1: 550,000 satellite images taken from the Google Earth site. To determine the coordinates of identifiable forms and paleolandforms at the catchment area and transfer them to the map and the GIS environment, GPS has been used. In order to provide a chronological framework for reconstructing the history of long-term climate changes and evolution landscape of the basin during the Quaternary, the age-depth model presented for 13500 years of Neor lake (located 20 km north of the Gazakhshay Basin) Based on the core 7.5 meters from the southern lake peats.
    Results And Discussion
    Although the Gizaz-chay watershed is presently from semi-arid and semi-humid weather conditions, the evidence of clay and brown silt layers in the lava cuttings of the temporary lagoon sediments belong to the Holocene, almost wet conditions It shows the present climate. Salt and clay-green clay layers with sandy interlayers can be interpreted as an index of colder and wetter conditions by reducing evaporation and higher lake levels. These layers represent a low-energy sedimentary environment with colder and humid climate conditions. Vertical sequence of river deposits along the lake deposits can be attributed to the lake recurrence due to dry and semiarid climate conditions, along with reduced rainfall and increased runoff energy. In such a situation, coarse sediments are transported to distant distances and are located on small-scale lake deposits.
    Conclusion
    The most important palaeogeomorphic evidence in the Ghizaz-chay Khalkhal basin is the following: Tectoinical terraces on different altitudes, lake sediments with the periods of dry and semi-arid to humid, Vertical sequence of river deposits along the lake's deposits and their appearance as a residual surface, covering deposits and their placement on the lake's deposits and the paleolandslide of the Neyakhoram.The lack of deposits with the origin of the large flood stream at the bottom of the dam, the gorge form of the Gazakhach River, as well as the large width of the natural dam consisting of trachytic volcanic rocks, suddenly disrupts is reject. The formation of these forms and heritages landforms has a direct link with uplift movements and subsidence Caspian Sea. The contining drop in regional base level as a result of subsidence of the Caspian Sea has driven incision and aide in the retention of the terrace deposits as they have been abandoned as the Ghizaz-chay systems have eroded downward. This way during evolution of the watershed has been predominance with erosive phase.
    Keywords: Quaternary, Palaeogeomorphologic evolution, Gizaz-Chay Khalkhal Ghizaz-chay
  • Mosa Abedini * Pages 162-179
    Introduction
    Flood is largest and most important climate crisis that kills thousands of people every year. And causes many damages to human society and the environment. This phenomenon of the distant past has always been a fear in human society (Nasrin Nejad et all, 2014: 16). Flood is one of the three natural disasters and major events in Iran and to note that at least a year, a major flood occurred in the country. According to studies in each year number of 40 small and large floods occurs in parts of the country (Department of Planning And Strategic Supervision president, 2010). Today is considered Non-structural deal with floods in catchment. Accordingly, the first action that comes to reduce the threat of flooding is flood control in the upper basin (Abdi, 2006:200). One of the common methods in combating the floods is Identifying in terms of potential flooding in basin. zoning possibility of recognizing watershed Specifies in terms of the flood.
    Several studies have been conducted in the field of flood inside and outside the country that among these can be noted in research conducted by Thilagavathi et all(2011), Ozturk et all(2013), nasrin Nejad et all (2014), eskandary nejad et all (2015) and etc. Determination of flooding and flood-prone zoning Lighvan River is the main objective of this research. Lighvan River originates from the northern slopes of Sahand and after passing through the Tabriz and Basmenj cities eventually pours into Urmia Lake.
    Methodology
    Determination of flooding and flood-prone zoning Lighvan River is the main objective of this research. To do so has been used a combination of two Analytical Network Process and fuzzy logic models and along with 12 environmental parameters.
    Analytical Network Process: Analytical Network Process model is broad form of AHP model, Analytical Hierarchy Process is introduced by the Saaty (1980). The underlying assumption of this method is Existence of independent sub-criteria together (Saaty, 2006). Saaty In cases where this principle is violated, and structure of issue has become a network, introduces Analytical Network Process model (Amalnik et al, 2010:202). Analytical Network Process for each subject considers in the form of a network of criteria, sub-criteria and options that have been gathered together in clusters. This model has several steps, which are as follows: 1) build models and create a network structure 2) binary comparison and determine the priority vectors - create a unweight super matrix 4) Creating weighted super matrix 5) finally, create a Limit super matrix.
    Fuzzy logic model: Fuzzy logic model is a generalization of the classical set theory in mathematics, science, and every day is a new method to express uncertainty and ambiguity. Fuzzy sets are defined by membership functions. For each fuzzy set between zero and there is a lack of full membership and a full membership represents zero (Hosseini et al, 1390). Fuzzy modeling is done by using several operators. An important function of the fuzzy logic model can be fuzzy Algebraic multiplication operator (Fuzzy Product), sum Fuzzy (Fuzzy Sum) gamma phase and so on. This operator of multiplication by the algebraic sum of fuzzy based on the fuzzy relation (1) is defined. Equation (1)
    Discussion
    The parameters used in the modeling, due to the nature of their were categorized in four clusters such as: hydroclimate, geomorphology, geology and land cover for potential zoning for the flooding and two clusters of geomorphology and hydroclimate for zoning. Continue on with taking the network connection between the clusters and the parameters, established network structure between the parameters. By forming network structure between the clusters and the parameters arrives stage implementation of Analytical Network Process model, the formation of super matrix's and paired comparison. Due to the existence of two goals in the research (flood and flooding potential zoning) and impact of different parameters in them, Analytical Network Process model was conducted for each of the goals individually and in view of Effect In the flooding and flood risk and their relative weights Was obtained to each other.
    Based on Comparisons of currently criteria, slope (0.18), lithology (0.125), aspect (0.118) have highest impact factor in flooding and slope parameters (0.229), the plan curvature (0.2 ) and profile curvature (0.134) have the highest impact factor in the flood risk in the study basin.
    According to this research results, the southern part of the basin have been introduced as the prone to flooding areas with classifying in zones with high and very high potential. This area due to volcanic bedrock, Low permeability, High slope, more rainfall and high drainage density Have the ability to produce high runoff And that is why are located in these classes. In terms of flood risk the northern half of the basin's the greatest potential for flood risk. These areas mainly include land surrounding the main River, low and flat lands portion of the basin output. In terms of subdivisions land units these regions, mainly are known as the land with low roughness and relative slope less than 10% that included marginal areas of rivers, old and new terraces And have been characterized With features such as low slope, low relative height, low distance from river and the concave plan and profiles curvature.
    Keywords: flooding potential, Zoning, ANP, fuzzy logic, Lighvan River
  • Ali Ahmad Abadi * Pages 180-192
    The glaciers are among the phenomena on the Earth's surface that with the advance and retreat of the planet show an appropriate response to climate change so that in recent decades due to increased emissions of greenhouse gases in the atmosphere and consequently increasing global temperatures, melting glaciers increased the volume greatly reduced. Check the status of glaciers due to their placement in the shadow of high mountains with hardships and difficulties faced, as a result the advantages of using remote sensing techniques for these areas is obvious. NDSI or Normalized Difference Snow Index is the criterion to determine levels snow cover and the basis for determining the index above the snow reflectance in the visible region and low reflectance in the middle infrared range and used to identify clear snow and snow-free areas that considering the problems of access and impassable mountainous regions to identify areas covered with snow and snow levels are used to determine the exact area. In this study was to determine the changes snowline in Oshtorankuh region, the cirques glacier were designated area and positioning. After regional status the cirques by the digital elevation model and using the cirques floor height Porter and Wright, the permanent snowline at 2505 and 2549 meters, respectively Late Quaternary period was determined. Then with the help of satellite images Landsat 8, the Normalized Difference Snow Index(NDSI) calculation and determined Snow levels for both the southwest and northeast and range for four consecutive years(2013 to 2016). Eventually the height of 3346 meters was already wrapping Snow levels. Accordingly, taking into account the height of the Porter method snow levels are already rising to 841 meters of Late Quaternary and considering the Wright method shows rising 797 meters to the height of the snowline in the Late Quaternary.
    Introduction
    The glaciers are large masses of ice and snow which are formed in regions with cold climates with frost. In these areas snow is more than melting and evaporation, and the glacier feed is positive. Generally, the formation of natural glaciers are such that snow falls in the form of crystals of various shapes on the surface of the ground, accumulated in areas that are prone to the formation of a glacier due to the environmental and atmospheric conditions and the three factors The ambient temperature, sublimation, and the effect of increasing pressure are subject to complex transformation and during this process, ice frosts are formed(Vaziri, 2000). Snow reserves in the upstream mountains affect the downstream seasonal run off pattern, especially in areas with a dry summer season, where snow melt and glacier run off is a major source of water supply(Yang et al, 2005).
    Methodology
    To determine the extent of snow line changes in the Oshtorankuh region, we first determine the height of snow line of the region in the later quaternary. For this purpose, the glacier cirques of the region should be determined as the most prominent glacial landforms. After identification of the cirques of the Oshtorankuh region, by using Porter method and Wright method Snow lines of the Quaternary period were determined. Then, by using the Landsat images related to July from 2013 to 2016, the NDSI determined for each year, using the of these, the approximate snow line height of the region is now determined.
    Results And Discussion
    First, the glacier cirques of Oshtorankuh region were investigated and using the topographic map of 1/2500 and the digital model elevation of 10 meter, 33 the glacier cirques was determined and positioned. Then, with respect to the Oshtorankuh stretching northwest-southeastern, the cirques are divided into two hillside of northeastern cirques, which include 18 cirques and southwest hillside, consisting of 15 circuses. The difference between these two hillsides is the intensity of the radiation and the duration of the radiation received. The southwestern range of cirques are superior in terms of duration and intensity to the northeast due to solar radiation, which increases glacial melting in warm seasons, leaving no effect on snow line and glaciers in the late summer. Gets After determining the position of the cirques in the region, using Porter method and Wright method, the limit of permanent snow line in the quaternary period 2505 and 2549 meters was determined. Then, by calculating the NDSI value in late July 2013 through 2016, in the Erdas Emagine 2014 software and by using digital model elevation of 10 meter, the snow cover surface and snow line height region in now equal to 3346 meter was determined.
    Conclusion
    In this research, after determining the position of the cirques, by digital elevation model, using the Porter and Wright method, the limit of snow line in the quaternary period was 2505 and 2549 meters respectively. Then, using the NDSI, the altitude of snow line levels for the two southwest and northeastern regions was calculated for 2013-2016, and finally the altitude of the snowy surface is now equal to 3346 m. As a result, the height of snow levels is now higher than the quaternary elevation of 841 meters, taking into account the Porter's method and 797 meters, considering the Wright method relative to the snow line height in the later Quaternary, which expresses the increase in mean the temperature in this area is relative to the quaternary period. As a result of this rise in temperature, the occurrence of hydro geomorphological changes in the region is as a result of the change in the forces forming the surface of the glacier to run off at the height of the snow line, which is also evident in the region.
    Keywords: glacier, Oshtorankuh, snow line, NDSI
  • Zarrin Foroghi * Pages 193-210
    Background/goal: Study of temporal and spatial changes in land use, provides important information about changes in the river channel geomorphology. Therefore, in this research, the role of artificiality and especially land use change on geomorphologic state in the Kor River (Upstream of the Droodzan Dam - Fars Province) as one of the important agricultural and tourism region and the important water source in the north of Fars province have been investigated.
    Methodology/design: Remote sensing analysis, GIS tools, and environmental statistics and information also Rosgen morphological method were used to investigate the river morological changes.
    Findings: The results of Rosgen geomorphological assessment showed that during the study time, maximum geomorphologic changes in levels one and two of Rosgen morphological method were for reach number of 1 and 2 and then reach number of 4, 5 and 3 are priority in the Kor River, respectively. Because of the erosion of the bank in all the reaches, Significant lateral and longitudinal alteration occurred, and the maximum alteration are related to reach number 2, 1, 3, 4, and 5, respectively.
    Conclusion
    The alteration were due to slope change, hydrological regime, suspended and bed load, invasion to the boundaries of the river boundary and the presence of the dam.
    Keywords: Geomorphology, Land use, Rosgen, River classification, Kor River
  • Majid Ahmadi * Pages 211-225
    Introduction
    Landslides are one of the greatest environmental hazards that cause economic, financial, and life losses, along with the destruction of facilities and rising costs. Iran is considered as a high-risk country due to the favorable geographical conditions and the lack of comprehensive management and failure to observe environmental thresholds. So that is one of the 10 most hazardous countries in the world and every year landslides in most of the provinces cause economic damage to roads, railways, communications lines, irrigation and water supply channels, mineral installations, extraction facilities, oil and gas refinery, vital networks of cities, factories and industrial centers, artificial and natural dams and lakes, forests and pastures and natural resources, farms and residential areas and villages or threatening them. Therefore, identification of slopes instability and movements and landslides and their causing factors, and classification of villages in terms of vulnerability to landslide and determination of safe points for relief is essential. In order to reduce the damage caused by landslide, accurate understanding and full identification, the study of the aggravating factors, as well as the identification of susceptible areas and its prediction is necessary.
    Materials And Methods
    Rudbar basin with an area of 1550 square kilometers is located in the southwest of Gilan province. The basin is one of Sefidrud sub-basin. In this area, due to the type of formations, the high depth of sediments in the slopes and the average rainfall, a lot of landslides occur. In this research, using the network analysis method, the area is zoned in terms of landslide occurrence and then the rural areas are zoned in terms of vulnerability to landslide hazard. In terms of type, this research is of descriptive-analytical study, and in terms of methodology is a descriptive-analytical study. The method is based on the analysis of criteria in the Decision Super software, and then overlapping the information layers in the ARCGIS software environment and integration of weighing models such as analytic network process and overlapping index. In this research, the factors affecting the occurrence of landslide were first identified and the network structure was created, then the weight of each factor was obtained and the final map of landslide risk zonation was obtained. Finally, the rural settlements were zoned in terms of vulnerability to landslide hazard.
    Discussion and
    Results
    In this research, in order to zoning the risk of landslide, 14 effective factors including elevation, slope, slope direction, distance from the road, distance from fault, distance from the river, geology, soil type, climate, land use, rainfall, the topographic wetness index (TWI), length- slope index (LS), and stream power index (SPI) were used. In this research, in order to zoning the area in terms of the landslide hazard occurrence using the network analysis process, first, the weight of each factor was obtained in the Super decision software. Then the obtained weights were applied to the Arc GIS software and the final landslide zonation map was obtained. In the analytic network process, the incompatibility rate is calculated and presented by the Super Decisions software for each pairwise comparison matrix, that if it exceeds 0.1, then judgment is inconsistent and judgment should be reviewed. In this research, the rate of inconsistency was 0.06486 which is acceptable. In this study, geology, land use, distance from fault, distance from the waterways and slope were respectively the most important factors.
    Conclusion
    The present study was carried out in order to zoning the risk of landslide and also the zoning of vulnerability of villages against the landslide risk by analytic network process (ANP) in one of the Sefidroud sub-basins in Rudbar county. For this purpose, first, effective factors for landslide occurrence were identified, and the weight of each factor was determined in the Super decision software. Then the obtained weights in Arc GIS software were applied e and the final landslide zonation map was obtained. The evaluation of results showed that more than 50% of the study area has a medium to high risk. Of this amount, 14.57 percent are located in high and very high risk zones. Most of these areas are located in the southern parts of the basin and this is due to the existence of landslide-sensitive formations. A numerical value (0.914) obtained for the Roc curve also showed that the landslides in the study area has a strong relationship with the probability values derived from the analytic network process. According to the results, of total 188 villages, 49 villages (25.53%) are located in high and very high risk areas and this is a serious threat for the inhabitants of these areas.
    Keywords: zonation, landslide, vulnerability, analytic network process (ANP), Rudbar basin
  • Atena Asgari * Pages 226-240
    Parts of the earth's crust during the time of the present have land-based movements and will be susceptible to danger in the future. Therefore, geomorphologic forms are highly sensitive to tectonic activities and are subject to changes in these movements.Meghan is one of the central basins of the country in the northeast of Markazi province. The existence of two main tabarte-tealkhab systems with the southeast-northwest process and multiple sub-faults indicates the emergence of significant tectonic phenomena in the area. . The evaluation of tectonic activities, using some quantitative indicators, plays an important role in recognizing these activities and contributes to the interpretation of the tectonic condition of the areas. The purpose of this study is to investigate the state of the newly built land using geomorphological data. To achieve this goal, seven geomorphologic indices: Longitudinal slope indicators of the river, The width of the valley floor to its height, Asymmetry of drainage basin, Transverse topographic symmetry, Basin shape ratio, Basin Hypsometric Curve, River maze, As the main tools of this research has been used. The research method is based on the analytical method. he tools used in this research include topographic and geological maps of the study area, satellite image and geographic information system in the form of ARC GIS 10 software. Also, the quantitative results obtained during several stages of fieldwork were evaluated. The results of this study show that the study area based on the slope of the river, whose magnitude is (4/353), drainage basin asymmetry (6/47), transverse topographic symmetry (24/0), hypsometric curve basin, and the maze is that (21/1) are in tectonic active status and only based on the ratio of the width of the valley floor to a height equal to (24/2) and the shape of the basin (5/3) It is in semi-active state.. As a result, the BS index, which represents the shape of the basin, is higher in the taller basins, and since most of the study sub-basins are drawn, it indicates high tectonic activity.
    Keywords: Ground construction, Meghan basin, geomorphic indicators, Geographic information system