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پژوهش های ژئومورفولوژی کمی - سال ششم شماره 4 (بهار 1397)
  • سال ششم شماره 4 (بهار 1397)
  • تاریخ انتشار: 1397/04/04
  • تعداد عناوین: 12
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  • سیدمحمد زمان زاده، اسماعیل پاریزی، مهدی امینی صفحات 1-16
    دولین یکی از لندفرم های شاخص مناطق کارستی است که در اثر عوامل و فرآیندهای گوناگونی شکل می گیرد. مطالعه مورفومتریک این عوارض علاوه بر اینکه یک تحلیل کمی از محیط های کارستی را فراهم می کند، بلکه مقایسه پارامترهای متنوع دولین ها ممکن است منجر به طرح فرضیاتی در مورد نحوه تکامل آن ها شود. هدف از این پژوهش تجزیه وتحلیل کمی مولفه های مورفومتری دولین ها جهت مدل سازی و ارائه شاخص بعد فرکتال گسل ها برای ارزیابی فعالیت گسل ها در مناطق کارستی بین پرآو و شاهو است. در این راستا از روش های ژئومورفومتری، CCLs، شمارش جعبه ای هاسدورف و تکنیک های آنالیز رگرسیون استفاده شده است تا امکان تحلیل رگرسیون، مدل سازی و حل تابع لگاریتمی Number – Size فراهم شود. نتایج آنالیز رگرسیون خطی تک متغیره نشان دهنده این است که مولفه های محیط با قطر بزرگ، قطر کوچک با محیط، قطر بزرگ با مساحت، مساحت با محیط و عمق با مساحت به ترتیب با ضرایب تبیین 93/0، 86/0، 85/0، 83/0 و 668/0 از بیشترین میزان همبستگی معنی دار برخوردارند. همچنین حداکثر ارتباط معنی داری برای روابط درجه 2 و 3 در سطح معنی داری 99/0، بین مولفه های مساحت و محیط با ضرایب تبیین 940/0 و 945/0 و خطای برآورد 05/0 و 04/0 وجود دارد. نتایج رگرسیون چند متغیره خطی نیز موید ارتباط معنی دار عمق با پارامترهای شیب، قطر کوچک و مساحت با ضریب تبیین 834/0 و خطای برآورد 85/7 است. تخمین بعد فرکتال در مناطق مورد مطالعه موید آن است که منطقه شاهو و پرآو به ترتیب با مقادیر 24/1 و 15/1 دارای بیشینه و کمینه ابعاد فرکتالی گسل ها می باشند. در واقع ارزیابی میزان فعالیت گسل ها به وسیله هندسه فرکتال نشان داد که معادله Number – Size و شاخص بعد فرکتال روشی مناسب جهت ارزیابی گسل ها در مناطق کارستی می باشند.
    کلیدواژگان: دولین، مورفومتری، آنالیز رگرسیون، بعد فرکتال، معادله Number، Size
  • مرضیه مکرم، مهران شایگان صفحات 17-31
    تعیین مناطق مستعد وقوع زمین لغزش یکی از اقدامات اولیه در کاهش خسارات احتمالی و مدیریت حوضه های آبخیز کشور می باشد. با توجه به اهمین موضوع هدف از این تحقیق بررسی وضعیت زمین لغزش در شرق شهر کرمان و ارتباط آن با نوع لندفرم می باشد. برای این منظور از پارامترهایی مانند شیب، جهت، ارتفاع، فاصله از گسل، فاصله از رودخانه، کاربری اراضی، فاصله از جاده و زمین شناسی به عنوان لایه های ورودی برای تعیین خطر زمین لغزش استفاده شد. بعد از تهیه هر یک از این لایه ها با استفاده از روش فازی و تعریف تابع عضویت، نقشه فازی برای هر یک از پارامترها تهیه شد. در نهایت به منظور همپوشانی هر یک از نقشه های فازی و تهیه نقشه نهایی زمین لغزش، با توجه به اهمیتی که هر یک از لایه ها در خطر وقوع زمین لغزش دارند، با ایجاد ماتریس مقایسه زوجی در مدل تحلیل سلسله مراتی (AHP) نقشه نهایی تهیه شد. در ادامه برای تعیین ارتباط بین زمین لغزش و نوع لندفرم، با استفاده از شاخص موقعیت توپوگرافی (TPI) نقشه لندفرم منطقه تهیه شد. نتایج نشان داد که بیشترین احتمال رخداد زمین لغزش در غرب، شمال و جنوب غرب منطقه مورد مطالعه می باشد. نتایج حاصل از نقشه لندفرم های منطقه نشان داد که بیشترین درصد لندفرم در منطقه مربوط به آبراهه ها (دره ها) با حدود 31 درصد و قله ها با حدود 7/26 درصد می باشد. همچنین نتایج نشان داد که هر چه به لندفرم های مناطق کوهستانی مانند خط الراس ها، تپه ها و قله ها نزدیک می شویم احتمال خطر زمین لغزش بیشتر می شود. بنابراین با توجه به اینکه در این نوع لندفرم ها احتمال وجود اراضی باغی، کشاورزی، جاده ها و در بعضی مناطق روستاها وجود دارد، باید مدیریت بیشتری در این مناطق صورت گیرد.
    کلیدواژگان: زمین لغزش، روش فازی وAHP، شاخص موقعیت جغرافیایی (TPI)، لندفرم
  • مهدی ریاحی، غلامرضا روشن، عبدالعظیم قانقرمه صفحات 32-52
    بررسی هیدروژئومورفولوژی و پایش و پیش یابی بیلان آب در حوضه های آبخیز می تواند گامی مهم در آمایش سرزمین و دسترسی به توسعه ی پایدار باشد. لذا مطالعه ی حاضر با توجه به مدل بیلان آبی تورنت وایت، مازاد و کمبود آب در دسترس حوضه ی آبریز سد گلستان2 را برای دو دوره ی پایه(1350 تا 1390) و آینده(1391 تا 1428) با استفاده از نتایج مدل گردش عمومی GISS و دو سناریوی تغییر اقلیم RCP4.5 و RCP8.5مورد واکاوی قرار داده است. نتایج این تحقیق گویای میانگین دمای پایه ی حوضه به میزان 12.51 درجه سانتیگراد بوده که با توجه به سناریوهای RCP4.5 و RCP8.5 بترتیب میانگین سالانه ی دما به مقادیر 16.60 و 16.96 درجه سانتیگراد افزایش خواهد یافت. در ادامه خروجیها برای تغییرات مولفه ی بارش، گویای روند کاهشی آن برای هر دو دوره ی مطالعاتی پایه و شبیه سازی شده می باشد، بطوری که برای دوره ی پایه، شیب کاهشی بارش معادل 41- میلیمتر و برای RCP4.5 و RCP8.5 بترتیب شامل 9- و 18- میلیمتر در هر دهه خواهد بود. در نهایت خروجیهای تحقیق حاضر نشان می دهند که با توجه به میانگین درازمدت دوره ی پایه، میانگین کمبود آبی 505- میلیمتر و مازاد آبی 61 میلیمتر بوده، حال آنکه با توجه به گرمایش جهانی بر مبنای سناریوی RCP4.5، میانگین سالانه ی کمبود آبی 694- میلیمتر و مازاد آبی آن 2 میلیمتر می باشد. اما در خصوص واکاوی نتایج RCP8.5 بترتیب میانگین سالانه کمبود و مازاد آبی حوضه با مقادیر 715- و 1 میلیمتر شبیه سازی شده اند. بنابراین انتظار می رود که با توجه به تغییرات اقلیمی آینده، حوضه ی آبریز سد گلستان2 دچار تنش کم آبی شدید گردد که این نیازمند اعمال مدیریت ریسک در تخصیص منابع آبی برای فعالیتهای مختلف جامعه ی مورد نظر بوده تا چالشهای آبی پیش روی به بحران آبی مبدل نگردد.
    کلیدواژگان: تغییر اقلیم، عدم قطعیت، بیلان آبی، کمبود و مازاد آبی، حوزه ی آبریز سد 2 گلستان
  • سینا صلحی، عبدالله سیف صفحات 53-69
    مورفومتری رویکرد جدیدی در بررسی و تحلیل های کمی لندفرم های ژئومورفولوژیکی محسوب می گردد. مورفومتری پروفیل طولی دره های کوهستانی، نشان از رفتار فرمی و فرآیندهای حاکم بر آنها داشته و شاخص های کمی می تواند در جهت تحلیل های فرم- فرآیند و تفسیر وضعیت تکامل و تحول واحدهای ناهمواری مورد استفاده قرار گیرد. در این پژوهش از 13 دره کوهستانی سهند واقع در شمال غرب ایران استفاده شد که از نظر لیتولوژیکی شرایط همگن و متقارنی را دارا است. شاخص های مورفومتریکی در 3 سطح پائین، میانی و بالا(تخصصی) تبیین، و در محیط پایتون برنامه نویسی گردید. 5 شاخص مورفومتریکی سطح پائین (ژئومتریک، توپولوژیک)، 20 شاخص مورفومتریکی سطح میانی(آماری، توپوگرافیک) و 4 شاخص سطح بالا (نسبت طول دو بعدی به سه بعدی، شاخص درصد تقعر پروفیلی، شاخص تقعر و تحدب، شاخص نسبت برجستگی ارتفاعی) مورد استفاه قرار گرفت. نتایج نشان داد که دره های واقع بر دامنه های شمال و شمال شرقی سهند از تکامل پروفیل طولی متفاوتی نسبت به دامنه های جنوب تا جنوب غربی برخوردارند،که حاکی از تفاوت در سیستم های اقلیمی، فرسایشی و نیز رژیم های رطوبتی - حرارتی متفاوت در این دو جناح از ارتفاعات سهند است. در انتها تمامی شاخص های مورفومتریکی در محیط برنامه نویسی پایتون، برنامه نویسی و واسط گرافیکی کاربر با استفاده از کتابخانه Tkinter طراحی و نرم افزار گرافیکی Longi-Profile Analyzer V.1 تهیه و ارائه شد.
    کلیدواژگان: مدلسازی، مورفومتری، پروفیل طولی، شاخص تقعر پروفیلی، دره های یخچالی سهند
  • علیرضا ایلدرمی، مهدی سپهری صفحات 70-87
    سیستم شبکه هیدروگرافی تابعی از عوامل سنگ شناسی (سختی، نفوذپذیری، کیفیت و کمیت درزه ها و شکاف ها) و عوامل ساختمانی (وضعیت امتداد و شیب لایه ها، وجود یا عدم وجود گسل و...) است. بنابراین مشخصات آبراهه های (جهت جریان، تراکم، نوع و شکل) تابعی از وضعیت سنگ و ناهمواری های هر منطقه می باشد. در این بررسی ابتدا 4 سازند زمین شناسی شامل، گرانیت الوند، هورنفلس کلریت دار، سنگ آهک مارنی و شیست استرولیت دار انتخاب شد و در هر سازند یک پلات 2 در2 کیلومتری به صورت تصادفی - سیستماتیک در هر سازند نصب و جهت بررسی شبکه زهکشی از روش استرالر و مقایسه بهتر از بعد فرکتال نیز استفاده شده است. همچنین به منظور بررسی فرسایش پذیری سنگ ها و نقش آنها در تخریب سازند های دامنه شمالی توده کوهستانی الوند، مقاطع میکروسکپی با نمونه گیری از سنگ های گرانیت، شیست و هورنفلس انجام شد. نقشه فرسایش پذیری تهیه و با نتایج حاصل از بعد فرکتال و شبکه زهکشی مقایسه گردید. بررسی مقایسه ارقام فرکتال به دست آمده از پلات های 4 سازند نشان داد که بیشترین مقدار عدد بعد فرکتال معادل 33/1 و 31/1 به ترتیب مربوط به سازندهای هورنفلس کلریت دار و سنگ آهک مارنی می باشد که از تراکم زهکشی و همچنین توان فرسایشی بالاتری در منطقه برخوردار است. همچنین سازندهای شیست استرولیت دار با عدد فرکتال 27/1 در رتبه بعدی از نظر مقاومت به فرسایش قرار داشته و نهایتا سازندهای گرانیت الوند با کمترین مقدار عددی بعد فرکتال که معادل 22/1 و کمترین تراکم آبراهه به عنوان مقاوم ترین واحد سنگی یا سازند در منطقه همدان شناخته شده اند. به طور کلی نتایج نشان داد که با افزایش بعد فرکتال، همراه با پارامتر شبکه زهکشی، فرسایش پذیری سازند های زمین شناسی نیز افزایش می یابد. به علاوه نتایج حاصله از بررسی کانی شناسی مقاطع میکروسکپی نشان می دهد که سنگ های گرانیتی فرسایش پذیری کمتری نسبت به شیست، هورنفلس و آهک و مارن در مقابل فرسایش دارد.
    کلیدواژگان: تراکم زهکشی، سازند زمین شناسی، فرکتال، ژئومورفولوژی کمی، همدان
  • ابراهیم بهشتی جاوید، فریبا اسفندیاری صفحات 88-102
    طبقه بندی لندفرم در حقیقت یک موضوع پژوهشی اصلی در ژئومورفومتری و علومی است که تجزیه و تحلیل کمی از سطح زمین دارند. لندفرم ها کنترل کننده شرایط آستانه برای فراینده های ژئومورفولوژیک فعلی و دیگر فرایندهایی مثل میکروکلیما، اکولوژی و هیدرولوژی سطحی و غیره است. از این رو شناسایی دقیق آنها میتواند کمک زیادی در زمینه مدیریت و برنامه ریزی محیطی باشد. در این پژوهش با استفاده از روش شی گرا و سه لایه انحنای پلان، انحنای میانگین و انحنای پروفایل، لندفرم های یخچالی(سیرک ها) دامنه های شمالی سبلان مورد شناسایی قرار گرفته است. لایه مدل رقومی ارتفاعی زمین با قابلیت تفکیک زمینی 10 متر(تهیه شده از نقشه توپوگرافی 1:250000) به عنوان لایه پایه به منظور تهیه لایه های انحنا استفاده شد. برای تعیین مقیاس مناسب جهت قطعه بندی لایه ها از نرم افزار ESP و همچنین از ابزار الحاقی آن در نسخه 8 نرم افزار ecognition استفاده شد با توجه به نتایج بدست آمده مقیاس 44 برای قطعه بندی لابه ها انتخاب شد. در ادامه کار با در نظر گرفتن مدل مفهومی پژوهش و اجرای آن در نرم افزار ecognition سیرک های یخچالی منطقه به همراه لایه خط الراس ها شناسایی و استخراج شدند. مقایسه نتایج بدست آمده با بازدیدهای میدانی انجام شده و تصاویر ماهوار ه ای منطقه نشان می دهد که روش فوق توانسته تا درجه زیادی اهداف مورد نظر در پژوهش را برآورد سازد.
    کلیدواژگان: لندفرم های یخچالی، سیرک، روش شی گرا، دامنه های شمالی، سبلان
  • شهرام روستائی، اسدالله حجازی، معصومه رجبی، نادر جلالی، احمد نجفی ایگدیر صفحات 103-119
    زمین لغزش فرایندی است دامنه ای که تاثیر مخربی بر محیط زیست و زندگی انسانی داشته و نیازمند بررسی و اقدامات پیشگیرانه میباشد. شناسایی عوامل موثر در وقوع زمین لغزش و پهنه بندی خطر آن جهت انجام اقدامات کنترلی از اهداف تحقیق حاضر میباشد. بنابراین برای مدیریت خطر در حوضه نازلوچای در شمالغرب ایران، کارایی روش منطق فازی مورد ارزیابی قرار گرفته است. لذا از طریق بازدیدهای میدانی و استفاده از اطلاعات محلی و همچنین اداره آبخیزداری، عکسهای هوایی، تصاویر ماهواره ای Google Earth، نقشه پراکنش زمین لغزشها تهیه گردید. در ادامه عوامل موثر در زمین لغزش شامل شیب، جهت شیب، ارتفاع، بارش، پوشش گیاهی، زمین شناسی، کاربری اراضی، فاصله از گسل، فاصله ار رودخانه و فاصله ار جاده با استفاده از نقشه توپوگرافی، عکس هوایی و تصاویر ماهواره ای تهیه و وارد مدل گردیدند. بعد از مرحله فازی سازی، نقشه های پهنه بندی زمین لغزش با استفاده از عملگرهای جمع، ضرب و گامای فازی با مقادیر 0.7، 0.8 و 0.9 تهیه شد. نتایج حاصل از معادله Qs(شاخص جمع کیفیت برای مقایسه کارایی مدلها) نشان می دهد که عملگر گامای 0.7 در مقایسه با دیگر عملگرها ی فازی مناسبتر است ولی با توجه به انطباق توده های لغزشی با نقشه های گامای 0.8 و 0.9 می توان از نتایج آنها برای برنامه ریزیهای توسعه ای استفاده کرد. بیشتر عوامل نقش مهمی در ایجاد حساسیت به لغزش داشته و نقشه های خروجی با 5 کلاس(خیلی کم، کم، متوسط، زیاد و خیلی زیاد)، 5.4 درصد حوضه را (با گامای 0.7) در کلاس با حساسیت بالا و خیلی بالا و 62.5 درصد آن را در کلاس با حساسیت خیلی کم قرار داد. رطوبت زیاد دامنه های غربی، حساسیت بالای سازندهای زمین شناسی وتاثیر فعالیتهای تکتونیکی از عوامل مهم ایجاد زمین لغزش در این قسمت از حوضه می باشند.
    کلیدواژگان: سامانه اطلاعات جغرافیایی، منطق فازی، پهنه بندی زمین لغزش، نازلوچای
  • مجتبی دولت کردستانی، احمد نوحه گر، سعید جانی زاده صفحات 120-130
    مدلسازی و پیش بینی دقیق رسوب معلق در رودخانه عنصر کلیدی مدیریت منابع آب و سیاست های محیط زیستی می باشد. در این پژوهش کارایی مدل های شبکه عصبی مصنوعی و شبکه عصبی-فازی تطبیقی در پیش بینی بار رسوب معلق روزانه ایستگاه گرو واقع در حوضه آبخیز گرو مورد ارزیابی قرار گرفت. بدین منظور از آمار 782 نمونه (1380-1393) رسوب معلق برحسب میلی گرم بر لیتر و دبی جریان اندازه گیری شده متناظر با رسوب بر حسب متر مکعب بر ثانیه در سه الگوی ورودی مختلف استفاده شد. برای اجرای مدل های شبکه عصبی مصنوعی و شبکه عصبی-فازی تطبیقی داده ها به دو دسته آموزش و آزمون تقسیم به طوری که 80% داده ها برای آموزش و 20% برای آزمون در نظر گرفته شد. در شبکه عصبی مصنوعی از دو تابع سیگموئید و تابع تانژانت هیپربولیک در لایه میانی و از تابع خطی در لایه خروجی و برای انجام مدل شبکه عصبی فازی-تطبیقی از روش تفکیک شبکه ای با سه تابع عضویت (مثلثی، گوسی و زنگوله ای تعمیم یافته) با تعداد عضویت بهینه که با سعی و خطا تعیین شد استفاده گردید. نتایج حاصل از پیش بینی رسوب معلق نشان داد که بهترین پیش بینی با با ضریب همبستگی 96/0، ضریب کارایی 95/0 و میانگین مربعات خطای 12/4789 میلی گرم بر لیتر مربوط به الگوی ورودی 2 با متغیر های ورودی دبی جریان روز جاری (Qt) و تاخیر دبی جریان روزانه تا 1 روز قبل از مبدا زمانی پیش بینی (Qt-1) و تاخیر رسوب معلق روزانه تا 1 روز قبل از مبدا زمانی پیش بینی (St-1) می باشد. بررسی نتایج حاصل از مدل های شبکه عصبی-فازی تطبیقی و شبکه عصبی مصنوعی نشان داد که مدل شبکه عصبی-فازی تطبیقی در هر سه الگو عملکرد بهتری نسبت به شبکه عصبی مصنوعی در پیش بینی رسوب معلق روزانه داشته است.
    کلیدواژگان: حوضه آبخیز گرو، شبکه عصبی مصنوعی، شبکه عصبی، فازی تطبیقی، رسوب معلق روزانه
  • امجد ملکی، سارا محمدی، حاجی کریمی، علی اکبر زینتی زاده صفحات 131-146
    بررسی خصوصیات هیدروژئوشیمیایی چشمه ها در لندفرم های کارستی زاگرس می تواند راهنمای مناسبی برای تعیین میزان تکامل و توسعه ی کارست و مدیریت منابع آب این مناطق باشد. هدف این پژوهش مقایسه ی توسعه یافتگی کارست به کمک ویژگی های هیدروژئوشیمیایی چشمه های کارستی توده ی شاهو در زاگرس رورانده و آبخوان اسلام آباد در محدوده ی زاگرس چین خورده است. ابتدا با استفاده از نقشه های توپوگرافی، زمین شناسی، ژئومورفولوژی و مطالعات میدانی لندفرم های کارستی مناطق مورد مطالعه شناسایی شد. سپس 17 نمونه آب از چشمه های دائمی منطقه در فصل تر (اردیبهشت ماه 96) برداشت و در آزمایشگاه شیمی دانشگاه رازی تجزیه گردید. وضعیت هیدروژئوشیمیایی چشمه های فوق با استفاده از روش تحلیل مولفه های اصلی مورد بررسی قرار گرفت. به منظور شناسایی فرآیندهای ژئوشیمیایی حاکم بر آبخوان ها، نمودارهای ترکیبی، نسبت های یونی و اندیس های اشباع کلسیت، دولومیت و ژیپس نمونه ها مورد ارزیابی قرار گرفت و جهت صحت سنجی داده ها از نمودار MRDS استفاده شد. نتایج حاصل نشان داد که سیستم کارستی آبخوان شاهو نسبت به آبخوان اسلام آباد توسعه یافته تر است. رخساره ی کلسیتی، نسبت بالای Ca2+ به Mg2+ و پایین بودن شاخص اشباع دولومیت در شاهو که بیانگر خلوص بالای آهک است و بالا بودن نسبت دبی حداکثر به حداقل، که بیانگر تراکم بیشتر مجاری باز و وجود جریان مجرایی- انتشاری (آشفته- خطی) در آبخوان شاهو است نیز تایید کننده مطلب است. در مقابل، پایین بودن نسبت Ca2+ به Mg2+ در آبخوان اسلام آباد و بالا بودن شاخص اشباع دولومیت، مبین دولومیتی بودن کارست در این محدوده است. پایین بودن نسبت دبی حداکثر به حداقل در چشمه های محدوده ی اسلام آباد نیز نشان دهند ه ی وجود جریان انتشاری در آبخوان های این محدوده و عدم توسعه ی کامل کارست است.
    کلیدواژگان: کارست، هیدروشیمیایی، چشمه ی کارستی، کرمانشاه
  • هیوا علمیزاده، علیرضا عباسی صفحات 147-159
    کاهش تراز آب دریاچه ارومیه در سال های اخیر سبب شده که اراضی بخش هایی از بستر آن خشک شده و فرایندهای ژئومورفیکی به درون بستر آن گسترش یابد. در این پژوهش با هدف بررسی شبکه آبراهه های پدید آمده در بستر خشک شده دریاچه ارومیه، از مدل تحلیل رده-آرایه ای استفاده شده است. به این منظور داده های وکتوری شبکه آبراهه های به دست آمده از تصاویر ماهواره ای، در محیط نرم افزار MapViewer با استفاده از روش استرالر رده بندی شده و نمودار فراداده های رده و تعداد آبراهه های رده 1 تا 6 در نرم افزارهای Grapher و Curvexpert ترسیم گردید. با توجه به نتایج میان فراداده های رده و تعداد آبراهه های رده های 1 تا 6 همبستگی نمائی برقرار بوده و ضریب تعیین میان این دو متغیر در نیمه راست پهنه پژوهش برابر 982/0 و در نیمه چپ 975/0 است و با توجه به بیشتر بودن ضریب همبستگی و تعیین رده و تعداد آبراهه ها در نیمه راست، روند تکامل ریخت شناختی آبراهه ای تندتر از نیمه چپ است. همچنین همبستگی میان رده و میانگین درازای آبراهه های هر دو نیمه از نوع معکوس مربع است و ضریب تعیین میان رده و میانگین درازای آبراهه ها در دو نیمه تقریبا برابر بوده و حدود 98/0 می باشد. تفاوت میانگین درازای آبراهه ها در این دو نیمه در روند شتاب افزایشی-کاهشی آن است، به گونه ای که روند شتاب افزایش و کاهش میانگین درازای آبراهه ها در نیمه چپ شدیدتر از نیمه راست می باشد.
    کلیدواژگان: شبکه آبراهه، دریاچه ارومیه، تکامل، رده، آرایه ای، ژئومورفولوژی جریانی
  • محمدمهدی حسین زاده، سمیه خالقی، میلاد رستمی صفحات 160-171
    مدیریت و حفاظت از کرانه رودخانه ها از اهداف اساسی توسعه منابع آب بشمار می رود. در این میان مطالعه ناپایداری کرانه رودخانه جهت فعالیت مهندسی به منظور پایدارسازی کرانه در مقابل فرسایش از اقدامات لازم و ضروری است. لذا در این مقاله، ضریب ناپایداری رودخانه گلالی قروه و راهکار مهندسی جهت پایدار سازی کرانه آن با استفاده از روش تنش برشی لین مورد تحقیق قرار گرفت. بدین منظور کلیه پارامترهای مورد نیاز با استفاده از بررسی میدانی و تصاویرگوگل ارث اندازه گیری و در نهایت شیب، تنش برشی، زاویه شیب بدنه، ضریب پایداری ذره، زاویه انحراف خطوط جریان، عدد پایداری شیب بدنه ذره، زاویه حرکت ذره بستر، ضریب پایداری و سپس اندازه پاره سنگ موثر جهت سنگ چینی بدست آمد. بر این اساس مقاطع 1 و 5 دارای بیشترین و مقاطع 2، 4 و 3 به ترتیب دارای کمترین ضریب ناپایداری هستند و اندازه پاره سنگ موثر برای پایدارسازی مقاطع 1 تا 5 به ترتیب برابر با 42، 26، 20، 22 و 60 سانتی مترتخمین زده شد.
    کلیدواژگان: پایداری کرانه، تنش برشی، اندازه پاره سنگ، رابطه لین، رودخانه گلالی
  • سمیه عمادالدین، آیدین مرادی صفحات 172-190
    شناسائی پهنه های حساس متاثر از لغزش و ریزش مهم ترین بخش در تهیه نقشه زمین لغزش و ریزش می باشد. مطالعه حاضر در محور جاده هراز حدفاصل بین امامزاده هاشم و شهرستان آمل که از محور های پرتردد و پرخطر ایران می باشد انجام پذیرفت. در این پژوهش از دو مدل شبکه عصبی مصنوعی (ANN) و فرآیند سلسله مراتبی (AHP) به منظور ارزیابی و مقایسه با وضع موجود و معرفی مدل مناسب استفاده شده است. همچنین وضعیت موجود منطقه به صورت میدانی پایش شده و مناطق متاثر از پدیده های ریزش و لغزش ثبت گردیده است. سطح بندی نقاط از نظر میزان خطر، تعداد نقاط از نظر عوامل خطرآفرین و اشتراک عوامل مخاطره آمیز در نقاط ثبت شده، مرحله دیگری از مطالعه میدانی می باشد که با رویکرد کاهش ریسک انجام پذیرفت. از نقشه های رقومی ارتفاعی، شیب، جهت شیب، زمین شناسی، کاربری اراضی، فاصله از گسل، فاصله از راه به عنوان لایه های اطلاعاتی استفاده شد. در مطالعات میدانی 261 نقطه حادثه خیز متاثر از لغزش و ریزش ثبت گردید. با در نظر گرفتن تعداد نقاط برداشت شده و آمار اشتراک مخاطرات موجود در آن ها و همچنین سطح بندی نقاط این نتیجه بدست آمد که تمامی نقاط ثبت شده با خطر احتمالی ریزش مواجه است. لازم به ذکر است 191 مورد از نقاط ثبت شده با سطح پر خطر تشخیص داده شد. بیشترین خطر در رابطه با اشتراک مخاطرات مربوط به ریزش و روآناب بدست آمد. با توجه به این که 88 مورد از نقاط ثبت شده مرتبط با پدیده لغزش می باشد، در صورت رخداد، این مورد بیشترین تاثیر را از نظر میزان آسیب خواهد داشت. در نهایت نتایج حاصل از پژوهش نشان داد که روش شبکه عصبی مصنوعی با وضع موجود مطابقت بیشتری داشته است. خطای بدست آمده از روش شبکه عصبی مصنوعی 8 درصد بوده و این میزان، قابل قبول بودن تحلیل های انجام شده را نشان می دهد و این روش می تواند در مناطق مشابه مورد استفاده قرار گیرد.
    کلیدواژگان: لغزش، ریزش، مطالعه میدانی، روش تحلیل سلسله مراتبی، روش تحلیل شبکه عصبی مصنوعی، کاهش ریسک، جاده هراز
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  • Mohamad Zaman Zadeh, E. Parazi, M. Amini Pages 1-16
    Introduction Karst is a geomorphic and hydrologic system which is created due to the dissolution of soluble stones like lime, dolomite and Gypsum (Ozyurt et al., 2014). The development of a karstic system is dependent upon climactic, lithologic and structural (wrinkle, fault and gap) factors (Ford and Williams, 2013). The most important landforms in the created perspectives include carnic bands, dolines and swallowing gaps. These shapes are usually but not necessarily formed in the areas which suffer from a fracture or a gap (Kovacic & Ravbar, 2013). Nowadays the theory of fractal collections and multifractal measuring is extensively used in describing some natural processing like the activity of faults (Ayunova et al., 2007 & Feder, 1988). In fact the process of fault creation can be investigated through fractal concepts (Mandelbrot 1983 & Sarp 2014). As the behavior of the faults certainly nonlinear (Turcottee, 1990) and the fractal theory is a method for determining and predicting complex dynamic nonlinear behaviors (Yang et al., 2007) this method can be used to examine the behavior of faults (Torcotte, 1997).
    Materials and instrumentation Initially the dolines of the target areas were extracted on the basis of DEM10 meter and method CCLs. after extracting these dolines their morphometric factors which consisted of area, perimeter, depth, slope, large diameter and small diameter were calculated in GIS software. Following that the SPSS software was utilized for the descriptive and regressive analysis the morphometric parameters of dolines. To this end single and multivariable variable linear methods were employed and those models which were of more value were presented.
    1/100000 geological maps of Kermanshah, Kamiaran, Miyan Rahan and Paweh were used to determine the fault systems of the examined areas and extract their fault maps. Afterwards, since the faults followed a vector shape, the Number-Size equation was selected to calculate the fractal dimension of the faults. In this equation a self-similar exponential relationship exists which is affected by the number factors and the size of spatial quantities. Therefore, based on what was explained, Number-size equation can be explained according to equation 1 (Mehrnia, 2006).
    Equation 1): Log (Ns)= a K Log (s)
    In this equation Ns is the number of the phenomena (in this study the number of the faults), S is the size of the network, k is the coefficient of the line slope or the fractal dimension (Mandelbrot, 1983).
    Findings and discussion The results of the single variable linear regression shows that the relationships between perimeter with major diameter, area with perimeter, depth with area, minor diameter with perimeter and area with major diameter were statistically significant and the correlation coefficients were 0/93, 0.837, 0/668, 0/860, and 0/850. Moreover, the most degree of significant correlation for second and third degree equations was observed between perimeter and large diameter with correlation coefficients of 0/932 and 0/942 and the estimated error of 0/297 in the area has a possibility of error which is smaller than 0/01. The results of multiple regressions also revealed that the most significant correlation of the depth is with area, slope, and minor diameter with a correlation coefficient of 0/834 and estimated error of 7/85. The estimation of the fractal dimension in the investigated areas shows that Shahoo and Paraov areas have the maximum and minimum fractal fault dimensions which are 1/24 and 1/15 respectively.
    Conclusion This study was an attempt to analyze the dolines which exist between Shahoo and Paraov areas using quantitative geomorphology, statistic methods and fractal geometry. The existence of a high correlation between most of the morphometric factors of dolines indicates that that these landforms can be modelled with a high degree of accuracy provided that exact and sufficient data is existent. The employment of fractal geometry and Number-Size equation also showed that by estimating the fractal dimension through the above method the activity of the faults their relative effect on the solution of the soluble stones can be determined. As a matter of fact this method can be utilized as a new index in studying the faults of the karstic areas.
    Keywords: dolines, morphometry, regression analysis, fractal dimension, Number, Size equation
  • M. Mokaram, M. Shaygan Pages 17-31
    Introduction Using information about landslide occurrence can get accurate information about landslide hazard assessment (Dai et al., 2002). Dangerous effectives of landslides is in relation to the economic system of many countries (Nefeslioglu et al., 2008). There are different methods for landslide susceptibility mapping such as Malczewski 1996; Jankowski et al. 1997; Nyerges et al. 1997; Bennett et al. 1999; Feick and Hall 1999; Jankowski and Nyerges 2001a, b; Kyem 2004. Thus, the region was selected fuzzy-AHP method to investigate landslide susceptibility in east of Kerman province, Iran.
    Methodology
    TPI: Andrew Weiss presented a very interesting and useful poster at the 2001 ESRI International User Conference describing the concept of Topographic Position Index (TPI) and how it could be calculated (Weiss 2001). Using this TPI at different scales, plus slope, users can classify the landscape into both slope position (i.e. ridge top, valley bottom, mid-slope, etc.) and landform category (i.e. steep narrow canyons, gentle valleys, plains, open slopes, mesas, etc.). The algorithms are clever and fairly simple. The TPI is the basis of the classification system and is simply the difference between a cell elevation value and the average elevation of the neighborhood around that cell. Positive values mean the cell is higher than its surroundings while negative values mean it is lower. The degree to which it is higher or lower, plus the slope of the cell, can be used to classify the cell into slope position. If it is significantly higher than the surrounding neighborhood, then it is likely to be at or near the top of a hill or ridge. Significantly low values suggest the cell is at or near the bottom of a valley. TPI values near zero could mean either a flat area or a mid-slope area, so the cell slope can be used to distinguish the two. TPI is naturally very scale-dependent. The same point at the crest of a mountain range might be considered a ridgetop to a highway construction crew or a flat plain to a mouse. The classifications produced by this extension depend entirely on the scale you use to analyze the landscape. TPI (Eq. (1)) compares the elevation of each cell in a DEM to the mean elevation of a specified neighborhood around that cell. Mean elevation is subtracted from the elevation value at center. (1)
    where M0 = elevation of the model point under evaluation, Mn = elevation of grid, n = the total number of surrounding points employed in the evaluation.
    Fuzzy-AHP
    Method
    Fuzzy logic was initially developed by Lotfi Zadeh (1965) as a generalization of classic logic. Lotfi Zadeh (1965) defined a fuzzy set by memberships function from properties of objects. A membership function assigns to each object a grade ranging between 0 and 1. The value 0 means that x is not a member of the fuzzy set, while the value 1 means that x is a full member of the fuzzy set. Traditionally, thematic maps represent discrete attributes based on Boolean memberships, such as polygons, lines and points. Mathematically, a fuzzy set can be defined as following (Mc Bratney et al., 2000): (2)
    In order to define the fuzzy rules and fuzzy-AHP models, the critical level of each parameter for corn production was extracted using some references in the study area.
    AHP is a structured technique for organizing and analysing complex decisions. This method is based on a pair-wise comparison matrix. The matrix is called consistent if the transitivity Equation (5) and reciprocity (Equation (6) rules are respected.
    aij = aik · akj (3)
    a ij= 1/ a ji (4)
    where i, j and k are any alternatives of the matrix.
    Results and discussion The aim of this study was to determination of landslide susceptibility in the east of Kerman, Iran. Nine major properties were selected to landslide susceptibility including slope, aspect, elevation, distance from fault, land use, distance from road, geology, rainfall and distance from stream were evaluated. Then, raster map was prepared in ArcGIS for each of the parameters. Also, the fuzzy and AHP method used for predictive landslide susceptibility map. The results of the fuzzy and AHP method in this study show that the west of the study area was suitable for landslide. The relationship between landslide susceptibility and landform showed that the possibility of landslide on the peaks, ridges and hills is high.
    Conclusion Based on the different conditions of the study area, such as the financial condition of the people and government, age distribution of the population, etc., the landslide susceptibility map with the fuzzy-AHP method can be used.
    Keywords: landslide, fuzzy, AHP, Topography Position Index, landform
  • M. Riyahi, Gh Rooshan, A. Ghanghermeh Pages 32-52
    Introduction Natural and anthropogenic pressures on hydrological systems often coexist and mutually interact, contributing to deeply modify watershed hydrology and determining relevant alterations in many hydrological processes, which are commonly referred to as “hydrological changes. Natural pressures are essentially related to modifications induced by the intrinsic variability of the different natural processes involved in the water cycle. Anthropogenic pressures are related to all the human activities (e.g., pollution of streams and aquifers, agricultural and irrigation practices, overexploitation of water resources, runoff regimentation and regulation, etc.) and human-induced alterations on climate forcings (e.g., greenhouse gases emission in atmosphere, heat island effect, etc.) and basins’ characteristics (e.g., morphology, land cover and use, soil imperviousness degree, etc.) that may have a role in modifying the catchment scale hydrological dynamics(Pumo, et al.,2017). Iran is located in a dry and semi-arid region facing the water crisis. Therefore, predictions and monitoring the water balance in different water basins can be an important step in land-use planning and access to the sustainable development. Therefore, present study has investigated the surplus and scarcity of available water in drainage basin of Golestan II Dam based on Thornthwaite water balance model for two base (1971- 2011) and future (2012- 2048) period by using the results of two climate change scenarios of RCP8.5 and RCP4.5.
    Materials and Methods In this research, for evaluation of predictions and monitoring of water balance changes in drainage basin of Golestan II Dam, Thornthwaite water balance model has been used based on two different time series. In this research, base data has 40-year time series from 1971 to 2011 and the other one is simulated data from 2012 to 2048. Climate data which is used in this research is Thornthwaite water balance model consist of temperature and precipitation.
    Therefore, for base period, data is monthly available and for the simulated data of future temperature and precipitation, it is extracted from data output of prediction components of GISS large scale model from BCSD database (NASA affiliate) with resolution of 2.5 * 2.5. It has to be mentioned that predictions has been done by using two climate change scenarios of RCP8.5 and RCP4.5. Since the resolution of the GISS model is large in scale, so by using a multivariate regression method, output of temperature and precipitation in dimensions of 4000*4000 meters for 137 study pixels changed to Tiny Scale by using Matlab software. Also for locating and mapping of spatial-temporal distribution of water balance, the Arc GIS software and the Kriging interpolation method have been used.
    Findings: The results of this research indicate that the average temperature of the basin is 12.51 ° C, which respectively will increase to 16.60, and 16.96 ° C, according to RCP4.5 and RCP8.5 scenarios.
    The outputs for the variation of the precipitation component show the decreasing trend for both base and simulated study periods. The interesting point is that for base period slope of precipitation is -41 mm per decade, but for RCP4.5 and RCP8.5 and will be -9 and -18 mm per decade respectively. Finally, the outputs of the present research show that, based on the long-term average of the base period, the average of water scarcity was -505 mm and the surplus was 61 mm, while considering the global warming based on the RCP4.5 scenarios, the average annual water scarcity is -694 mm and surplus of 2 mm. But regarding the results analysis of RCP8.5, the average annual scarcity and surplus in the basin are respectively -715 and 1 mm.
    Conclusion
    Therefore, due to future climate change, the Golestan Dam drainage basin is expected to suffer from severe water scarcity. So the Risk management should be guided in allocation of water resources for various activities of the society that prevent water challenge to become water crisis and enable us for adapting to the future water conflicts and decreasing the negative effects by adopting various policies.
    Keywords: Climate change, uncertainty, Water balance, surplus, water scarcity, basin of Golestan II Dam
  • S. Solhi, A. Seyfi Pages 53-69
    Longitudinal profile morphometry of the mountain valleys, provide a numerical and quantitative indicators for researchers of geomorphology to draw form-processes conclusions from the morphological evolutionary state of mountainous units. Morphological Behavior of the valley’s longitudinal profile, could be a sign of predominant processes and their interactions with topography.13 valley’s basins in mountainous area of Sahand (Western Azarbayejan,Iran) were delimited with a homogenouse lithology.To homogenize criteria in different valleys, each basin outlet was bounded at the absolute height of 1800m. In each valley, main drainage paths, were drawn using Arc Hydro Model (V.2). Coordinates of the location of each point on these paths (Longitudinal profile) were extracted from digital elevation model and python programming languge was used to make it automate. In this research five Low-level (Geometric, Topologic), twenty Mid-level (Statistic, Topographic), and four High-level (2L-3L.R[1], P.C.I[2], C.C.I[3], E.R.R[4]) morphometrical indices were used and run.The Percent of profile concavity (P.C.I), shows that longitudinal sections which are located in the northeast hillside of Sahand mountain has a higher level so that is a sign of more concavity ratio and thus more profile evolution.The profile concavity index (C.C.I) has also similar trends. Elevation Relief Ratio (E.R.R) and 2D to 3D length ratio (2L-3L.R) shows a higher levels in the southwest hillside. Eventually, under consideration of these four morphometric models, it’s possible to observe clear differences in the evolution of longitudinal profiles which are located in the north to northeast hillsides of Sahand mountain in comparison with south to southwest part of this mountainous unit, which is corresponded perfectly with sunny hillside and slopes located in the shade.
    Introduction Geomorphometry is a scientific branch on the basis of measurements, computational geometry, topography and morphology of the earth's surface and their temporal deformation. Geomorphometry is a quantitative analysis of the earth's surface. Geomorphometry is a quantitative analysis of the earth's surface (Pike,1995,2000a: Rasemman et al., 2004). Digital Elevation Model (DEM) is used as an input for many geomorphometric models. Many researchers of geomorphology had studied in the field of morphometrical modeling of geomorphological features. Some of them had studied longitudinal and profile sections of mountainous valleys, until estimates glacial and fluvial valleys and the dominant conditions of their evolutionary phases. Several different morphometrical models have been employed in various field of geomorphology included deserts, mountains, plains and costal environments. Some of them had a tectonic or geologic approaches others have a morphogenic views. But in general, almost all of them are using mathematical, geometrical and physical equations and relations for investigating land surface phenomena.
    Methodology In recent study, Digital Surface Models(DSMs), published by the Japanese Space Agency in May and October 2015, in 30m spatial resolution were used. This data is extracted from ALOS satellite images. This data is based on global 3D topographic DSM data (5m grid version) which is the most accurate elevation data in the global scale (T. Tadono et.al,2014). For extracting rivers, valleys, rural and urban centers, topographic maps published by Iran National Cartographic Center (NCC) were used. Drainage basin of each valley were delimited from Digital Elevation Model (DEM), Topographic maps and Hillshade model with using Arc Hydrology model in the Arc GIS package. Then, the longest drainage path from the outlet to the highest tip of each valley’s basin was drawn in the form of vector-based geometry. Each of vector layer divided into the vertices with a high density. Each vertex has an xyz coordinate which is stored in the form of txt and ASCII file formats. Data stored in the txt and ASCII files imported into python environment and was prepared to programming with. Morphometrical modeling, measurements and progressive algorithms were automated using python, in order to morphometry of longitudinal profiles purposes. Morphometrical results are classified into three main classes: including low-level (or basic), mid-level (or prerequisite) and high-level (or advanced) morphometrical indices.
    Results and discussion Morphometrical indices shows that longitudinal profile concavity ratio is clearly different at north to northeast and south to southwest aspects in this mountainous unit. Numerical value of this index is maximum in northeast aspects and the rate is minimum at southwest part. Profile concavity and convexity index (C.C.I) has a similar trend and shows a clear difference between northeast and southwest slopes. Elevation Relief Ratio (E.R.R) has a completely different trend and reaches to the maximum and minimum values at southwest and northeast slopes respectively. The ratio between 2D and 3D longitudinal length shows a higher value in the northeast slopes or generally northern slopes.
    Conclusion In this paper, longitudinal profile of Sahand’s valleys were modeled using 4 morphometrical indices (Including: 2D to 3D length ratio, profile concavity, Concavity and Convexity Index, and Elevation Relief Ratio). Results gotten from Profile Concavity Ratio show higher values of longidudinal profiles located on the noertheast valleys of sahand mountain, which suggest more morphological profile evolution. Concavity Index shows similar trends. Both Elevation Relieaf Ratio and 2L-3L.R have a higher value in the southwest slopes. with taking into account these 4 advanced morphometrical models, recognizable differences in evolution of logtidunial profiles of north to northeast slopes in Sahand mountain were detected. With regard to the fact that quaternary glaciation played a major role in the main mountainous unit of Iran, glacial and subglacial process had played a recognizable change on mountainous area especially the height above 3000m and higher latitude bands. Because of high latitude (near 37 Degree) and elevation (more than 3600m), Sahand mountain was affected by glacial and subglacial erosion. In the higher latitude bands, because of more winter inclination angle, southern slopes recive sunlights in a wider angle and so there is a difference between northen and southern slopes from the view point of radiation energy absorbtion. Eastern slopes have a lower radiation energy campared with western one and thus leaded to the less energy balance. Furthermorem, north and northeast slopes of the Sahand mountain are in the vicinity of Caspien sea water body, so it had received more precipitation during glacial phase in relation to Siberian cold wind. Despite of being young and having igneous lithology, Sahand mountain shows morphological evidence of glacial and subglacial evolution of longitudinal profiles due to the favorable climatic condition such as enough winter snow. These morphometric indicators are perfectly adjusted to the slope aspects and morphological changes are synchronized with glacial and subglacial process. Finally all these morphometric indices programed and designed in python Tkinter GUI programming enviornment and a GIS toolkit named Longi-Profile Analyzer V.1 prepared fundamentally for longitudinal profile analizing.
    Keywords: Morphometry, Longitudinal Profile, Concavity, Concavity Index, Mountainous Valley, sahand Mountain
  • A. Ildermi, M. Sepehri Pages 70-87
    The Hydrographic network system is a function of lithological factors (hardness, permeability, quality and quantity of joints and gaps), and structural agents (the status of stretching and slope of the layers, the presence or absence of faults, etc.). Therefore, the characteristics of the waterways (flow, density, type and shape) are a function of the status of the rock and the roughness of each region. In this study, four geological formations including alvand granite, chlorite hornfels, marl limestone and screw styrite were selected. In each formation, a 2 km 2-kilometer plot was installed randomly-systematically in each formation, and to investigate the drainage network of The Australian method and a better comparison of the fractal dimension are also used. Also, in order to study the erosion of rocks and their role in damaging the northwestern formations of Alvand Mountain, microscopic sections were performed with sampling of granite, schist and hornfels rocks. The erodibility map was prepared and compared with the results of fractal dimension and drainage network. In this study, in first 4 geology formation that including Alvan granite, Cordierite hornfels, marly limestone and Staurolite schist was selected and then each zone of geology formation, set a plot with the size of 2*2 km as randomly and extract drainage network of each formation and then the fractal dimension of them were be calculated. Comparison of fractal dimension showed that maximum and minimum of fractal dimension related to Cordierite hornfels and Alvan granite with 1.33 and 1.22, respectively. On the other hand, the result showed that graphical and mathematical fractal dimension in 4 geology formation, have correlation coefficient upper 99 percent. The results showed that with increasing fractal dimension, with the parameter drainage, erosion of geological formations increases. The results from the mineralogical study of microscopic sections show that granite rocks are less erodible than schist, hornfels and lime and marn against erosion.
    Keywords: Drainage network, Fractal, geology formation, Hamadan, quantitative Geomorphology
  • E. Beheshti, F. Esfandiyari Pages 88-102
    Introduction Semi-automated extraction of selected landform types from land-surface models such as digital elevation models (DEMs), curvatures, and slope gradients is of particular interest in geomorphology, hydrology and related fields(Eisank et al,2010:1). Geomorphometry is the science of quantitative land-surface analysis (Pike, 1995, 2000a; Rasemann et al., 2004). The morphometry of landforms perse, by or without the use of digital data, is more correctly considered part of quantitative geomorphology (Thorn, 1988; Scheidegger, 1991 Leopold et al., 1995; Rhoads and Thorn, 1996).
    Evans (1972) was the first person that divided Geomorphometry in two branches the general and special Geomorphometry, in special Geomorphometry More is be discussed landforms and geomorphic processes such as glaciers and runoff in geomorphometry terrain segmentation is an approach for structuring terrain data such as digital elevation model(DEM) via derived land-surface into spatially discrete plan-view areas known as terrain units(strobl,2008).The shape of terrain, i.e. landforms, influence the flow of surface water, transport of sediments, soil production, and determines climate on local and regional scales, furthermore, natural phenomena like vegetation are directly influenced by landform patterns and their relative position across the landscape Landforms although have different meaning to different disciplines, they reveal common physiological and morphological characteristics of terrain which may guide through understanding past and present processes acting on terrain and provide necessary information to related disciplines about land characteristics and potentials(Gerçek, 2010:9). In this study, using MRS algorithms and Ecognition software have been studied glacial landforms the northern slopes of Sabalan.
    Methodology In this study, the DEM and derivative of its, have been used in order to extract glacial landforms. To prepare the digital elevation model layer have been used of topographic maps with 1: 25000 scale. Profile curvature, plan curvature and mean curvature are three important layers used in this study.The semi-automated methods refer to the automatic procedures of extracting landform based-process. This is mainly relying on unsupervised isodata classification, pixel-based clasification (supervised /subpixel classifier based on training material), analysis of digital elevation models (DEM), algorithms, hydrological modelling and object oriented analysis (Nabil and Moawad, 2014:42). In this study object-oriented methods and Ecognition software is used for classification and extraction of landforms.
    Results and discussion In this study, we are looking for are extracted cirques the northern slopes of Sabalan. This area because of the high altitude receives high humidity this precipitation is mainly in the form of snow and is appropriate for the formation of glacier and for cirques. A cirque is one of the most prominent forms of glacial erosion (Embleton and Hamann, 1988). According to Evans (2004: 154) cirques are “hollows formed at glacial sources in mountains and partly enclosed by steep, arcuate slopes (headwalls)”. In general cirques exhibit concave shape in both plan and profile direction, with a size ranging from hundreds of metres to a few kilometers (Glasser and Bennett, 2004). They are typically composed of a cirque crest, a steep headwall, and a gentler cirque floor often filled by a cirque lake. For extraction of circus having profile curvature, plan curvature and mean curvature layers is necessary. With respect to this aforementioned layers were obtained in the SAGA software.
    Scale parameter is a crucial threshold that determines the maximum allowed heterogeneity for segmentation, which has a direct influence on the size of the objects to be obtained. Scale parameter is recognized after a trial and error process (Gerçek, 2010:115). In this study ultimately scale of 36 was selected for the segmentation.
    Extracting ridge line position is very important in determining and identifying the the cirque. According to the morphometry of this landforms for classification the ridge were used convex shapes in layers.
    In general, the convex shape of the ridge is determined by the positive values in mean and plan curvature. The Ecognition software and MRS algorithm was used for the execution of the model and Segmentation of the layers. Ridge layer was obtained by defining morphometriy characteristics of the ridge and comparing the results with field data. Finally, according to the semantic model of research, the relevant rules defined in Ecognition software and was extracted circus position.
    Conclusion In this study glacial landforms (circus) were extracted with semi-automatic approach and by using object-oriented approach in northern slopes of Sabalan. The Result of research were presented in the form of a map which shows the location circuses.
    Keywords: Circuses, glacial landforms, object, oriented, Ecognition
  • Sh Rosta, A. Hejazi, M. Rajabi, N. Jalali, A. Najafi Pages 103-119
    IntroductionLandslides are one of the most important natural threats in mountainous and sloping areas that are affected by various natural and human factors. Therefore, knowing the most important factors affecting sloping instability and landslide occurrence will help us to make developmental and infrastructural plans using appropriate methods. Therefore, using the fuzzy model, its evaluation and validation, sensitive zones of the basin should be identified and classified. The quality and quantity of existing data, the work scale, and the selection of appropriate analysis approach and modeling, guarantee the validity of landslide sensitivity maps. The process leading to such plans involves several qualitative and quantitative approaches (Ayalew & Yamagishi, 2005). Judging by experts is the criterion of qualitative approaches that do risk or sensitivity analysis (Aleotti& Chowdhury, 1999). Qualitative methods can be divided into two types: scatter analysis or inventory and exploration. Mass movement inventory maps are the basis of most methods for landslide hazard zonation (Van Westen & Soeters, 1998). Quantitative methods (quoted by Roostaei and colleagues) are based on the numerical expression of the relationship between controlling factors and landslides (Ayalew & Yamagishi, 2005) and are divided into two approaches: Statistical and algebraic analyzes. The fuzzy logic membership functions range from 0 to 1, with zero absent Statistical and algebraic analyzes. The fuzzy logic membership functions range from 0 to 1, means that 0 is not a member of the fuzzy set and 1 means full membership (Juang et al., 1992). Therefore, in this research, based on the effective factors in the establishment of landslide, the study area is classified by using fuzzy logic. The study area is located between 44 ° 24 'and 45 ° 53' E longitude and 37 ° 30' to 37 ° 58' N latitudes in the northwest of the country and in the political zone of the West Azerbaijan Province. The area of the catchment is 1518/8 km2.
    Research MethodologyIn order to investigate the landslide susceptibility zonation, the provision of a landslide inventory map is the most important part of the work, which can be done by using of geographic information systems with high accuracy. The accuracy of landslide zonation is largely dependent on this stage. So, at first, the existing landslides were identified by using various tools including aerial photos, satellite imagery (Google Earth), existing information, GPS, and in particular field surveys. In the present study, ten factors affecting the occurrence of landslides were considered: elevation, slope, gradient direction, distance from the waterway, distance from the road, distance from the faults, lithology, land use, rainfall and vegetation index. Landslide susceptibility zonation was done after determining fuzzy membership values for each of the thematic layer classes using different fuzzy operator functions (fuzzy OR, fuzzy AND, fuzzy algebraic product, fuzzy algebraic sum and fuzzy Gamma operators).
    Research FindingsFor landslide hazard zonation using fuzzy logic model, various factors including elevation, slope, gradient direction, distance from the waterway, distance from the road, distance from fault, lithology, landuse, rainfall and vegetation index were studied. Existence and density of landslides in the western slopes show the role of geological formations, the gradient direction, the distance from the waterway and precipitation in the occurrence of landslide. To evaluate the accuracy of the operators of the fuzzy logic model, the density ratio index and the quality sum index were used. Density ratio index was used to evaluate the model's ability in hazard classe's separation. The more distinction between risk classes is, the model is more capable, and the quality sum index is used to compare the performance of different models. Finally, with respect to the resulting values, the zoning with a 0.7-gamma operator was found to be desirable for the studied area.
    ConclusionAccording to the results of zoning (using fuzzy gamma methods), geology, gradient direction and distance from the waterways are the most important factors controlling the landslide occurrence in the studied area. Particularly geologic factors are of great importance. Most of the landslides in the study area occurred on limestone and conglomerate, which are similar to the results of the research by Mr. Tangestani in the southwest of Iran and Mr. Amir Ahmadi who worked for Iran, while these formations do not have much area in the basin. Limestone and a small amount of dolomitic limestone with an occupancy level of 15.5% of the basin, contain more than 30% of landslides. More importantly, limestone is coinciding with north orientation that confirms the role of gradient direction in occurrence of landslides. The impact of the human factor mainly depends on changing environmental conditions, such as road construction, inappropriate plowing, excessive grazing and water diversion for agricultural use. Therefore, by studying the researches in Iran and in different parts of the world, the slipping factors in different basins and regions are not the same and in fact, different slip conditions are present in different regions.
    Keywords: Geographical Information System, fuzzy logic, landslide zonation, Nazlo, Chay
  • ...
    M. Dolat Kordestani, A. Nohe Gara, S. Jani Zadeh Pages 120-130
    The precise modeling and prediction of suspended sediment in the river is a key element of water resources management and environmental policies. In this study, the efficiency of artificial neural network models and adaptive neuro-fuzzy network models were evaluated in prediction of daily suspended sediment load in Gero station located in Gero watershed. For this purpose, 782 samples (2001-2014) suspended sediment in milligrams per liter and flow rate measured corresponding to sediment in terms of cubic meters per second were used in three different input patterns. To implement artificial neural network and adaptive neuro-fuzzy network models, the data were divided into two groups of training and testing, in which 80% of the data were for training and 20% for the test. In the artificial neural network, there are two sigmoid functions and a hyperbolic tangent function in the middle layer and a linear function in the output layer, and to perform adaptive neuro-fuzzy network model, a network segmentation method with three membership functions (triangular, Gaussian, and generalized bells) was used with the optimal membership number, which was determined by trial and error. The results obtained from prediction of suspended sediment showed that the best prediction with correlation coefficient (0.96), coefficient of efficiency (0.95) and mean square error (4789.12 mg/l) related to the input pattern 2 with the input variables of current flow rate of current day (Qt), and the daily delayed daily flow rate to 1 day before the origin of prediction time (Q t-1) and the daily suspended sediment delays up to 1 day before the origin of the prediction time (St-1). The results of adaptive neuro-fuzzy network and artificial neural network models showed that the adaptive neuro-fuzzy network model had better performance than artificial neural network in predicting daily suspended sediment in all three patterns.
    Keywords: Gero Watershed, Artificial Neural Network, Adaptive Neuro, Fuzzy Network, Daily Suspended Sediment
  • A. Malaki, S. Mohamadi, H. Karimi, Aa Zinati Zadeh Pages 131-146
    Introduction Investigating the hydrogeochemical characteristics of springs in Zagros karstic landforms can be a useful guide to determine the extent of Karst development and management of water resources in these areas. The purpose of this research was to compare the development of karst with the help of hydro geochemical characteristics of Shahoo mass karstic springs having an area of 649 km2 in the thrust Zagros zone of the Kurdistan and Kermanshah Provinces, and Karstic aquifer of Islamabad with an area of 818 km2 in the simply folded zone of Zagros in Kermanshah Province. The most important carbonate formation in the Shahoo aquifer is Bisotun Limestone and in Islamabad aquifer is dolomitic limestone of Asmari and Telezang Formation. Therefore, due to the different dissolution capacities of various Zagros formations, this study investigates the dissolution of cations and anions, and in particular the rate of karstification of the two regions, by assessing the hydro geochemical characteristics of the karstic springs in the study areas.
    Methodology In order to evaluate the hydro geochemical characteristics of the karstic springs in the Shahoo and Islamabad aquifers, after field visits , the karst features and formations, faults and fractures were identified and their location was determined using GPS .Then, 17 water samples were taken from karst springs of the Shahoo and Islamabad aquifers in wet season (May 2017). Finally, using ionic ratios (calcium to magnesium ratio), combinational charts and Calcite and Dolomite saturation indices using R-software and PhreeQC software, different water characteristics of karstic aquifer and dissolution rate of anions, cations and karstification of the two regions were investigated.
    Results and discussion The results of quantitative water analysis helps to explain the karstic features of the areas. Generally speaking, the hydro chemical properties of water, along with geological formations, reflect the degree of dissolution of carbonate compounds and, in turn, the extent of karst development in the regions. Therefore, for the evaluation of hydro geochemical properties of karst springs, 17 water samples were collected from permanent springs in two Shahoo and Islamabad aquifers and the results were investigated by hydro geochemical methods. The results of the high calcium/magnesium ratio in Shahoo springs compared to the Islamabad aquifer clearly indicate the high purity of limestone and the presence of developed karst aquifers in the Shahoo area (Bisotun limestone) compared to the dolomite Karst of Islamabad aquifer (Asmari and Shahbazan Formations).This is confirmed by the high values ​​of the calcite saturation indices and the lower degree of dolomite saturation indices in the Shahoo compare to Islamabad aquifer. This indicates a large connection between groundwater and the lithology of the aquifer, impurities in the lime of the region, diffusion nature of Karst and a long residence time, all of which are indicative of lower Karst development in Islamabad area. The low discharge of the springs of this area along with low fluctuations in the discharge in dry and wet seasons as well as the high dissolved ions (water electrical conductivity and hardness) as well as the amount of bicarbonate and sulfate ions in the water confirm the lower karst development compare to Shahoo aquifer. Therefore, it can be concluded that the type of flow regime in the Shahoo aquifer is mainly conduit flow which the conduits are well developed, while the karst system in Islamabad aquifer is mainly diffuse.
    The results of the Ahmad Synthetic Chart (MRD) indicate that the type of water in most of the Shahoo massif is of bicarbonate calcium type (calcite bicarbonate) and water of most springs of the of the Islamabad aquifer is of the bicarbonate magnesium type. This diagram also confirms the lithology of Shahoo aquifer and Islamabad aquifers as limestone and dolomite respectively, and consequently indicating the greater dissolution potential and karst developmental within the Shahoo area (as calcite dissolves faster than dolomite) in contrast to the Islamabad aquifer.
    Conclusion The most important difference between the two Shahoo and the Islamabad aquifers are the difference in rainfall and temperature, the different effects of tectonics and different lithology, causing a difference in the solubility of the region which created springs with different discharges in the regions. High rainfall, snowiness, low temperature, which dissolves more carbon dioxide in water, and lithology and geomorphological features of Shahoo aquifer have led to the higher karst development in this area. Although Asmari lime in the Islamabad area is also susceptible to karstification, but it has youthfulness, purity and less thickness compared to the Bismuth lime, lower precipitation mainly in the rain form, higher temperature and the effect of geomorphologic factors such as aquifer shape, altitude and different effects of tectonic performance, have led to a lower degree of Karst development in Islamabad than Shahoo, which was examined and confirmed by hydro geochemical studies in this study. Considering the importance of the karstic territories of western Iran, and in particular the Kermanshah province and the vulnerability of karst aquifers, their vulnerability assessment is one of the most important management approaches to encounter potential risks, such as pollution, water supplies and the crisis of water resources. The study of karst development can provide a realistic view to investigate the karst system in such a way that with the help of these results, in addition to the accurate knowledge of the chemical and physical properties of these aquifers, we can better manage the amount and time of using of these aquifers that has to be taken into consideration by the relevant authorities.
    Keywords: karst development, Hydrogeochemical, Karstic spring, Shahoo, Islamabad aquifer
  • H. Almirzadeh, A. Abbasi Pages 147-159
    Introduction
    The network of streams is a blueprint for landing. In general, streams in nature have a tree pattern. Rivers are one of the most important geomorphic landscapes in which the connection between the system of forces and forms of landform is clearly understandable, because these factors are exclusively involved in the determination of the flow morphology. The dried bed of Urmia Lake is in the low slope with a gentle slope in which drainage networks are flowing. These rivers are formed on a short scale and have always been agents or factors that have changed the way and formed them. Reduce the water level of the urmia lake in recent years has caused the land portions of the dried bed and geomorphic processes that extend into the substrate. These Micro Drainage Network, despite the fact that they have a permanent and natural access to the final discharge of the stream into the Lake Urmia; from a longitudinal and transversal point of view, they are constantly changing and evolving and have a special dynamism; however, what is important is the way and the main factors of these developments. And the formation of streams that are not the same in all areas of the study and do not have a uniformity and this is the main objective of the research.
    Methodology
    Lake Urmia is located at four coordinates of 44 degrees &59 minutes to 45 degrees & 56 minutes east and 37 degrees & 4 minutes to 38 degrees & 16 minutes north latitude between the two provinces of East Azarbaijan and western. This study examined the drainage network emerged in the dried lake bed, the model order_matrix analysis is used. In this method, the network of channels of the basins is classified according to the Strahler model and then the network of drainage network is divided into three parts: right, center and left. The basin dividing line is the line of the drainage network that have the largest category. Continuing this stream, the main line between the two right and left sides of the basin divides the basin into two. Eventually The distribution of traces of streams is counted and written in the framework of a square array whose rows and columns are equal to the largest category of river basins. The infrastructure for data collection in this study is satellite imagery of 2015 available in the Google Earth software environment. For this purpose, the network vector data streams derived from satellite imagery, in MapViewer software using strahler methods stream classification and metadata graph lines and drainage network category 1 to 6 in Grapher software and Curvexpert were drawn. After acquire and storing the images, they are georeferencing with high-precision in the context of the Global Mapper software, and aligned all the existing streams on the captured images and taken in Shpefile format.
    Results And Discussion
    According to the results of metadata category and number of drainage network categories 1 to 6 exponential correlation has been established and according to the most correlation coefficient and determine the category and number of drainage in the right half morphological evolution drainage is steeper than the left half. The correlation between the class and the average length of streams both halves of the inverse square. The coefficient of determination between the two halves of the category and the average length is approximately equal drainage and is about 0/98. The mean length of drainage in the mid-additive process accelerated its decline, so that accelerated the process of increasing and decreasing the average length of drainage in the left half of the right half is more severe.
    Conclusion
    The results of the research show that although the correlation between the number and class of drainage in the study area is high, however, due to the higher correlation coefficient and the determination of the number and number of drainage in the right half of the morphological evolution of the shorter drainage than the left half. The trend of mean changes in the length of the right and left dividers of the channel network of the research area is different with the trend of changes in the category, number and length of its drainage. In such a way that in each right and left, the average length of the canals increases from 1 to 4 and then from grade 4 to grade 6 this mean decreases with a steep slope.
    Keywords: drainage, Urmia Lake, evolution, Order, matrix, Fluvial Geomorphology
  • Mm Hossein Zadeh, S. Khaleghi, M. Roostami Pages 160-171
    Introduction The river bank protection against the erosion is considered as one of the main objectives of river improvement in sustainable development of water resources. The erosion of the river banks is causing damage to agricultural land, damage to structures such as bridges and roads, widening stream channel and environmental issues considerably. Bank erosion is a major cause of non-point pollution of water resources and increased sediment load in many rivers. Increasing banks erosion not only increases the sediment load but also causes river instability and changing flow and channel pattern. Thus, during the recent decades, sediment load and river banks have been created a large concern in the world and the large sums have been spent to stabilize banks. One of the important characteristics of the river banks erosion is permanent and active in comparison to other forms of the erosion, while other forms of the erosion are activated only during or shortly after the start precipitation. Interaction active forces of the water flow and the resistance forces to the flow due to bed and bank material were eroding the bank of the channel. Thus numerous engineering solutions have been created to strengthen the banks against the erosion. By conventional methods, the rock riprap or large boulders that are on the bank are used for bank protection beacuse they are easy to pick up. If rock riprap with appropriate dimensions and affordable is available, it can be widely used to protect banks of the river. Two methods are provided for determining the size of cobble for rock riprap. 1- Shear stress method, 2- flow velocity method. Shear stress method is used in this study. In shear stress method, stability of rock riprap on slope side depend on the amount and the velocity of flow or shear stress at the banks, slope angle and rock properties such as size, density and angle.
    Methodology Gulalai catchment is located on 43 km from the Qorveh city, in the southeastern of Kurdistan province. Galali River is the main stream in this catchment. Length of the studied river reach in this paper is 3 km and from the bridge near the Shirvaneh village to the next bridge in the Gulalai village. In this reach, 5 cross sections were selected and the channel cross sections were measured using meter and survey indicator and parameters were measured such as bankfull width, average bankfull depth, banks and bed slope, bed and banks particle size, radius of curvature and flow velocity. Based on the measured data of the cross-sections, the required parameters in the measurement of shear stress were calculated. Shear stress is calculated based on Lane’s equation, upon effective size of rock for bank stability under shear force.
    Results and discussion Results show that cross-sections 1 and 5 have the highest and sections 2, 3 and 4 have the least important factor of instability and the effective rock size for stabilization of cross-sections 1 to 5 were estimated 42, 26, 20, 22 and 60 cm respectively and given that βθ is less than 90 in all of cross-sections, so particles move down the slope toward the thalweg. The size of the rocks and angle of repose in different cross-sections are vary, section 1 and 5 are the large gravel and sections 2,3 and 4 are large cobble. The size of the rocks obtained for the rock riprap have been predicted as too large cobble for cross-sections 3 and 4, small boulders for cross-sections 1 and 2 and medium boulders for cross-section 5.
    Conclusion Galali River has sinuses pattern in the most of its path and all its cross-sections are unstable so that providing management strategies is essential. Lanes shear stress method based on the effective size of rock riprap were used to estimate bank stable condition and given the constant stream flow, the most important influential factor of bank instability at different cross-sections is the particle size of the channel bank. Therefore after obtaining the required parameters, the safety factor of the bank, the size of rock riprap in moving threshold and the effective rock riprap were calculated for Galali river bank.
    Keywords: Bank stability, Shear stress, Size of rock, Lanes equation, Gulalai River
  • S. Emadoaldin, A. Moradi Pages 172-190
    Introduction Natural disasters management requires local information to make human societies ready against dangers and reduce the disaster procedure. Hence, evaluation of landslide occurrence in the areas prone to landslide due to geographical condition and human constructions is highly crucial. Identification of rockfall and landslide sensitive zones makes the most important part of preparing map for such areas. The present study is conducted on Haraz road, within the distance of Imamzade Hashem and city of Amol, which is a busy and hazardous road in Iran.
    Methodology Two models of Artificial Neural Network (ANN) and Analytic Hierarchy Process (AHP) is used to assess and make comparison with the present condition while a proper model is introduced. A field study is also conducted on current condition of the region and landslide sensitive areas are recorded. The next stage of the field study involved ranking parts of the road based on the amount of risk; number of these parts according to risk factors, as well as identifying the common risk factors in the parts recorded aiming for risk reduction. Using digital elevation maps, such layers of information on slope, slope direction, geology, land use and distance from a fault line and road were provided. 261 parts of the road were recorded as
    Results and discussion The road passes through areas that the points overlooking it often have a significant slope. The slope direction map also demonstrates that such zones overlook Haraz road. Geology of the region indicates frequency of Quaternary alluvium, basaltic tuffs and gray shales as well as sandstones in the middle third of the region. The most likely threat to the road with respect to frequency is related to rockfall. It should be noted that surface runoff produced in slopes overlooking the road during rainfall is both hazardous per se and directs the material down when the water runs. Potential Landslide other than those occurred before and fault are among the threats in the next stage. As the area is active tectonically, crushing of stones and other hard formations in fault zones is more observed and this may play a significant role in triggering slips and landslides.
    Conclusion Based on the number of detected points and common risks there as well as their ranking , it was concluded that all recorded points faced potential risk of rock fall. It is noteworthy that 191 of the recorded points were identified as hazardous. Most hazardous of all common risks was found as related to rock fall and surface runoff. As 88 cases were related to rock fall, it was found as the most effective factor to create harm. It was finally found that the Artificial Neural Network model is more compatible with the current condition. The error obtained from this method was 8 percent confirming that the analysis was acceptable and the method could be used to study similar areas.
    Keywords: landslide, slip, Analytic Hierarchy Process (AHP), Artificial Neural Network (ANN) method, risk reduction, Haraz road