فهرست مطالب
مجله پژوهش آب ایران
پیاپی 43 (زمستان 1400)
- تاریخ انتشار: 1400/12/09
- تعداد عناوین: 10
-
-
صفحات 1-10
انعقاد یکی از مهمترین فرآیندها در تصفیه آب است. نگرانی روزافزون جهانی در مورد مسایل زیست محیطی علاقه به تحقیق در مورد منعقدکننده های طبیعی را افزایش داده است. در حال حاضر ثابت شده است که منعقد کننده های طبیعی به دلیل در دسترس بودن ، مقرون به صرفه بودن، ماهیت غیرسمی و زیست تخریب پذیر بودن، جایگزین خوبی برای منعقد کننده های شیمیایی هستند. در این مطالعه پتانسیل، مناسب بودن ، اثربخشی و کارایی دانه بنه به عنوان منعقد کننده طبیعی برای تصفیه آب با کدورت اولیه NTU100 بررسی شد. از طرف دیگر ، روش سطح پاسخ (RSM) از نوع طراحی مرکب مرکزی (CCD) در 5 سطح برای ارزیابی و بهینه سازی شرایط واکنش فرآیند انعقاد-لخته سازی در تصفیه آب آشامیدنی به کار گرفته شد. از سه پارامتر غلظت منعقد کننده، pH و زمان تماس که از عوامل مهم و تاثیرگذار بر فرآیند انعقاد-لخته سازی هستند به عنوان متغیر در طراحی آزمایش استفاده شد. یک مدل چند جمله ای درجه دوم با مقدار0.9654=R2 (ضریب تشخیص) به داده ها ارایه شد. آزمایش های صحت مدل، مطابقت خوب بین مقادیر واقعی و مقادیر پیش بینی شده را نشان داد. در تصفیه آب آشامیدنی حاصل از نتایج تجربی، کاهش قابل ملاحظه کدورت یعنی 95.13 درصد با غلظت 53/90 میلی گرم در لیتر ، 9.79= pHو زمان تماس 44.86 دقیقه برای منعقدکننده بنه حاصل شد. با توجه به نتایج بهینه سازی، دانه بنه به عنوان منعقدکننده در تصفیه آب آشامیدنی پتانسیل بالایی را از خود به نمایش گذاشت.
کلیدواژگان: منعقدکننده طبیعی، بنه، حذف کدورت، بهینه سازی، انعقاد -
صفحات 11-20
مالکیت مجاری طبیعی آبی یکی از مسایل مهم حقوق آب کشور است از این رو سیر تحول و تطور مالکیت بستر مجاری مذکور از ابتدای دوره قانون گذاری تا کنون، با استناد به قانون مدنی به عنوان قانون مادر و بند 6 ماده 96 قانون شهرداری ها به عنوان نخستین قانون ناظر بر مالکیت بستر جاری در شهرها و ماده 2 از قانون آب و نحوه ملی شدن آن و تبصره های مربوطه و همچنین ماده 2 از قانون توزیع عادلانه آب و تبصره های ذیل آن به عنوان قوانین مخصوصه بخش آب مورد بررسی واقع، معیارهای قانونی تعیین و تشخیص بستر، نقد و آثار حقوقی آن بر مالکیت اراضی مجاور مجاری طبیعی آبی تبیین گردید. نتیجه این که بستر مجاری طبیعی آبی از مشترکات عمومی بوده و در اختیار حکومت اسلامی است و ملک دولت تلقی نمی گردد و اقدامات وزارت نیرو صرفا من باب تولیت بوده و اعمال ضوابط و معیارهای قانونی در تشخیص بستر مجاری طبیعی آبی و حد نهایی آن و همچنین تثبیت آن در طبیعت به منظور حفظ حقوق عامه و جلوگیری از ورود خسارت به مالکین اراضی مجاور و همچنین جلوگیری از ایجاد تزلزل و یا تحدید در مالکیت آنان مورد تاکید قرار گرفت.
کلیدواژگان: مجاری طبیعی آبی، قوانین مخصوصه ی آب، حکومت، دولت، معیار تشخیص بستر -
صفحات 21-33
تبخیر و تعرق به عنوان یکی از مولفه های کلیدی چرخه هیدرولوژیکی کره زمین می باشد و برآورد دقیق آن به عنوان یک عامل مهم در برنامه ریزی و مدیریت منابع آب در کشاورزی از اهمیت بسیار زیادی برخوردار می باشد. طی چند دهه گذشته، روش های مبتنی بر استفاده از تصاویر ماهواره ای مورد توجه پژوهشگران قرار گرفته است به طوریکه محققان انواع روش های سنجش از دور را برای برآورد تبخیر و تعرق توسعه داده اند. در پژوهش حاضر، امکان استفاده از دو مدل مبتنی بر سنجش از دور سبال (SEBAL) و متریک (EEFlux) و نیز مقایسه آنها در برآورد تبخیر و تعرق روزانه در مزرعه اوقاف اراک مورد بررسی قرار گرفت. با استفاده از مدل های SEBAL و EEFlux شارهای سطحی برای هر پیکسل تصویر ماهواره لندست 8 (برای هست تصویر در دوره فصل رویشی در مزرعه اوقاف اراک) محاسبه و مقدار تبخیر و تعرق واقعی به صورت باقی مانده معادله توازن انرژی در سطح برآورد شد. دقت نتایج الگوریتم های SEBAL و EEFlux با استفاده از داده های لایسیمتر (برداشت شده در 8 تاریخ منطبق با تاریخ تصاویر ماهواره لندست 8) با استفاده از معیارهای PBAIS، NSE، RMSE و R2 انجام شد. نتایج برآورد تبخیر و تعرق روزانه حاصل از الگوریتم های SEBAL و EEFLux به این صورت بود که با شروع فصل زراعی مقادیر تبخیر و تعرق روزانه کم بود و سپس با گذر زمان و رسیدن به میانه های فصل زراعی مقدار تبخیر و تعرق به اوج خود رسید و سپس بعد از آن مقادیر تبخیر و تعرق به علت کاهش دما و همچنین تغییرات پوشش ذرت در منطقه مورد مطالعه سیر نزولی به خود گرفت. مقایسه الگوریتم های SEBAL و EEFLux حاکی از آن بود که الگوریتم SEBAL حدود 7.71 درصد تبخیر و تعرق واقعی روزانه در محدوده مزرعه اوقاف اراک را بیشتر برآورد کرده است. نتایج ارزیابی عملکرد بیانگر این بود که RMSE، NSE، PBIAS و R2 بر اساس الگوریتم SEBAL به ترتیب برابر با 0.711، 0.807، 7.398 و 0.885 و برای الگوریتم EEFLux به ترتیب برابر با 1.046، 0.582، 15.080 و 0.793 بود. از این رو ارزیابی عملکرد الگوریتم های SEBAL و EEFLux با توجه به داده های لایسیمتر نشان داد که الگوریتم SEBAL دارای همبستگی بالاتر و و انحراف معیار کمتر نسبت به الگوریتم EEFLux می باشد. براین اساس، الگوریتم SEBAL نسبت به الگوریتم EEFLux نتایج بهتری را ارایه داده است و الگوریتم SEBAL دقت بالای تصاویر در برآورد تبخیر و تعرق را نشان داد
کلیدواژگان: تبخیر و تعرق روزانه، سنجش از دور، لندست 8، SEBAL و EEFLux -
صفحات 35-43
حوضچه های آرامش قسمت کوتاهی از یک کانال کف سازی شده اند که به صورت سازه ای خاص در انتهای سرریزها و هر سازه دیگری که جریان فوق بحرانی ایجاد می کند، برای کنترل پرش هیدرولیکی ساخته می شوند و هر چه طول آن ها کوتاه تر باشداز نظر اقتصادی مناسب تر خواهند بود. هدف از این تحقیق بررسی خصوصیات پرش هیدرولیکی در کانال با شیب معکوس و پله منفی ابتدایی می باشد. در این پژوهش اثر همزمان سه شیب معکوس و سه ارتفاع پله منفی ابتدایی بر اعماق مزدوج، طول پرش و افت انرژی در اعداد فرود 4.5 تا 9.5 بررسی شده است. نتایج نشان می دهد که با افزایش شیب معکوس کانال، مقدار نسبت اعماق مزدوج، طول پرش و افت انرژی به ترتیب 12.6، 13.9 و 16.8 درصد کاهش می دهد. در حالی افزایش که پله منفی نسبت اعماق مزدوج و طول پرش را به ترتیب 5.66 و 6.2 درصد افزایش و افت انرژی را 2.6 درصد کاهش می دهد. ترکیب دو عامل شیب معکوس و پله منفی نسبت اعماق مزدوج، طول پرش و افت انرژی را به ترتیب 12.42، 14.8 و 3 درصد کاهش می دهد و نیز تنش برشی 12.56 برابر شرایط بستر صاف به دست آمد. بنابراین نقش پله منفی در تثبیت پرش در محل حوضچه آرامش می باشد و شیب معکوس این تثبیت پرش را سخت تر می کند.
کلیدواژگان: پرش هیدرولیکی، شیب معکوس، پله منفی ابتدایی، عدد فرود، تنش برشی بستر -
صفحات 45-58
باتوجه به افزایش تولید محصولات کشاورزی و همچنین وقوع خشکسالی مکرر در بسیاری از مناطق جهان، نیاز شدید به برآورد دقیق تری از میزان آب مصرفی گیاهان و درنتیجه برآورد دقیق تبخیر و تعرق مرجع احساس می شود. معادله پنمن مانتیث فایو برای برآورد تبخیر و تعرق مرجع به عنوان روشی استاندارد در بسیاری از تحقیقات معرفی شده است. از معایب اصلی این روش به صورت نقطه ای و دردسترس بودن داده های هواشناسی در مکان های خاص می باشد. درحالی که با استفاده از داده های سنجش ازدور می توان این مشکل را برطرف نمود. در این پژوهش، هدف اصلی ترکیب داده های سنجش ازدور با مدل-های یادگیری ماشین برای برآورد تبخیر و تعرق مرجع است. با استفاده از مدل های یادگیری ماشین، چالش های انتخاب بهترین مدل ممکن، متغیرهای ورودی مدل و دردسترس بودن داده های موردنیاز ایجاد می شود؛ بنابراین در این پژوهش مدل-های مطرح RF، GBR و SVR انتخاب و از داده های تصاویر لندست و شاخص های پوشش گیاهی استفاده شد. منطقه موردمطالعه، دشت همدان بهار واقع در مناطق غربی کشور است. در این پژوهش برای برآورد تبخیر و تعرق مرجع، از دو رویکرد استفاده شد که در رویکرد اول، متغیرهای ورودی مدل ها با مقادیر همه باندهای تصاویر لندست، درحالی که در رویکرد دوم، شاخص های پوشش گیاهی به عنوان ورودی مدل معرفی و استفاده شد. مدل RF با شاخص های پوشش گیاهی، نتایج آماری برابر با (%14.1=RMSE و %76.4=R2) داشت، درحالی که با استفاده از همه باندهای لندست (%11.7=RMSE و %84.1=R2) و همچنین در مقایسه با الگوریتم های دیگر، با مقداری دقت بیشتر تبخیر و تعرق مرجع را برآورد کرد. نتایج، بیان کننده توانایی و پتانسیل شاخص های پوشش گیاهی به تنهایی و تصاویر لندست در تهیه اطلاعات لازم برای مدیریت آبیاری در کشاورزی و همچنین توانایی الگوریتم های یادگیری ماشین در برآورد پارامترهایی نظیر تبخیر و تعرق مرجع می-باشد.
کلیدواژگان: مدیریت آبیاری، یادگیری ماشین، شاخص های پوشش گیاهی، سنجش ازدور، تبخیر و تعرق -
صفحات 59-67
به دلیل محدود بودن منابع آب، استفاده از آب های نامتعارف در بخش کشاورزی امری اجتناب ناپذیر است که یک توجه جدی را به استفاده صحیح از آب های نامتعارف مانند آب شور، فاضلاب شهری و صنعتی می طلبد. در این راستا، آزمایشی به صورت فاکتوریل در قالب طرح پایه کامل تصادفی با 15 تیمار و چهار تکرار در گلخانه تحقیقاتی دانشکده کشاورزی دانشگاه فردوسی مشهد طی شش ماه بر روی گیاه گوجه فرنگی انجام شد. هدف از انجام این پژوهش مقایسه تاثیر پنج نوع کیفیت آب آبیاری (آب شهری (W)، فاضلاب خام (WS)، فاضلاب تصفیه شده (TWS)، مخلوط 50% آب شهری و 50% فاضلاب خام (W+WS)، مخلوط 50% آب شهری و 50% فاضلاب تصفیه شده (W+TWS)) به عنوان عامل اصلی و سه سطح آبیاری (40%، 70% و 100% نیاز آبی گیاه) به عنوان عامل فرعی بر برخی صفات بیوشیمیایی و مورفولوژی گیاه بوده است. نتایج حاصل از این آزمایش نشان داد که اثر کم آبیاری بر برخی صفات مورفولوژیکی و بیوشیمیایی گیاه تفاوت معنی دار داشته است به طوری که افزایش آبیاری باعث افزایش تعداد برگ، سطح برگ، کلروفیل a، کلروفیل b، کاروتنویید و پرولین گردیده است. همچنین نتایج نشان داد که اثر کیفیت آب آبیاری بر برخی صفات مورفولوژیکی و بیوشیمیایی دارای اختلاف معنی دار است اما بر میزان پرولین برگ تاثیری نداشته است.
کلیدواژگان: کلروفیل a، کلروفیل b، کارتنوئید، تعداد برگ، پرولین -
صفحات 69-82
توسعه روش هایی برای بهبود ظرفیت رطوبت خاک و افزایش عملکرد بیولوژیکی گیاهان در مناطق خشک و نیمه خشک ضروری است. این مطالعه برای ارزیابی تاثیر کمپوست نیشکر بر عملکرد ذرت تحت شرایط آب و هوایی دشت گتوند در استان خوزستان، جنوب غربی ایران انجام شده است. بنابراین یک آزمایش میدانی با سه تیمار کاربرد کمپوست نیشکر (0 ، 15 و 30 تن در هکتار) و چهار سطح تامین آب محصول (%50، %75، %100 و %125 کل آب موردنیاز) در سه تکرار انجام شد. این آزمایش ها برای دو فصل رشد (فصل رشد اول از فروردین تا تیرماه 1398 و فصل دوم رشد از مرداد تا آذرماه 1398) طراحی و اجرا شد. برنامه ریزی آبیاری، عملکرد بیولوژیکی، شاخص برداشت و پوشش تاج در دو فصل رشد اندازه گیری و برای شبیه-سازی رشد ذرت در سناریوهای مختلف کاربرد آب و کمپوست نیشکر با استفاده از نرمافزار AquaCrop بکار گرفته شد. نتایج نشان داد که سطح پوشش سایه انداز و طول دوره بلوغ تا آغاز پیری سطح سایه انداز در کشت بهاره بیش از کشت تابستانه بود. علاوه بر این آزمون حداقل خطا نشان داد که استفاده از کمپوست نیشکر عملکرد محصول را در سطح اطمینان یک درصد افزایش داد. عملکرد بیولوژیک ذرت در منطقه مورد مطالعه بین 13678 کیلوگرم در هکتار در تیمار کم آبیاری 50 درصد با کاربرد 30 تن در هکتار کمپوست تا 17344 کیلوگرم در هکتار در شرایط آبیاری کامل بدون کاربرد کمپوست در کشت تابستانه متغیر است. آنالیز اقتصادی کاربرد کمپوست افزایش حداقل 20 درصد درآمد خالص را نشان داد.
کلیدواژگان: شاخص برداشت، بهرهوری آب، پوشش سایه انداز، عملکرد محصول -
صفحات 83-96
امروزه به لطف داده های سنجش از دور ماهواره ای، مشاهدات فضایی برای نظارت و پایش دقیق و مداوم سطح و تراز دریاچه ارومیه فراهم شده است. با این وجود، هنوز مدل مناسبی جهت تعیین ارتباط بین مساحت و تراز دریاچه ارومیه که یک فاکتور مهم در تجزیه و تحلیل های مختلف هیدرولوژیکی و زیست محیطی است، پیشنهاد نشده است. هدف مقاله حاضر، استخراج خصوصیات تراز-سطح دریاچه ارومیه با استفاده از داده های سنجش از دور (فضایی)، مشاهدات زمینی و مدل های تحلیلی است. معادلات تراز-سطح دریاچه با استفاده از داده های تراز ایستگاه زمینی و داده های سطح مستخرج از تصاویر ماهواره ای همزمان آنها تعیین شده است. در تحقیق حاضر 6 مدل پیشنهادی شامل توابع پایه چندجمله ای، نمایی، فوریه، گوسین، کسری (گویا) و شبکه عصبی به همراه مدلهای موجود، شامل؛ آب منطقه ای آذربایجان غربی و مدل دانشگاه سهند با استفاده از داده های تعلیمی آموزش دیده و با استفاده از داده های اعتبارسنجی مورد ارزیابی قرار گرفته است. با مقایسه معیارهای ارزیابی RMSE، MAE، MAPE و NSE، مشخص گردید که تابع کسری به عنوان بهترین مدل پیشنهادی تراز-سطح دریاچه ارومیه، قادر است تنها با خطای RMSE=57.8 کیلومترمربع و با NSE=0.9958، مساحت دریاچه ارومیه را برآورد نماید. با لحاظ معیار RMSE، مشخص می شود که مدل تابع کسری پیشنهادی خطای تخمین سطح دریاچه را نسبت به بهترین مدل پیشین حدود 5 برابر کاهش داده است. با توجه به اندازه گیری روزانه تراز دریاچه در ایستگاه زمینی، مدل پیشنهادی تراز-سطح، می تواند مساحت روزانه دریاچه را بدون نیاز به مشاهدات فضایی (تصاویر ماهواره ای) برآورد نماید.
کلیدواژگان: تخمین مساحت، سنجش از دور، رگرسیون، تابع کسری، شبکه عصبی -
صفحات 97-105
افزایش جمعیت، نیاز به تولیدات کشاورزی و غذای بیشتر و محدودیت منابع آب، بشر را به سمت استفاده از آب های با کیفیت کم سوق داده است. به منظور بررسی تاثیر سطوح مختلف شوری بر عملکرد و بهره وری آب گیاه لوبیا، پژوهشی گلدانی در فضای آزاد، به صورت فاکتوریل در قالب طرح کاملا تصادفی با سه تکرار اجرا شد. فاکتور اول اعمال شوری در مرحله رشد رویشی در سه سطح 0.34 (شاهد)، 1.5 و 2 دسی زیمنس بر متر و فاکتور دوم اعمال شوری سه سطح فوق در مرحله رشد زایشی انجام شد. نتایج نشان داد تنش شوری در مرحله اول و دوم به طور معنی داری باعث کاهش عملکرد، اجزای عملکرد، میزان جذب آب و شاخص بهره وری آب و بیولوژیک در گیاه لوبیا شد. بیشترین مقدار شاخص بهره وری آب در تیمار شاهد و کمترین مقدار در تیمار با شوری 2 دسی زیمنس بر متر در دو مرحله رشد به ترتیب با میزان 0.67 و 0.39 کیلوگرم بر متر مکعب مشاهده شد. صرف نظر از سطح شوری، میانگین اثرات شوری در مرحله رشد رویشی و زایشی منجر به تولید 3067 و 2892 کیلوگرم در هکتار عملکرد دانه شد. نتیجه اینکه اثرات ناشی از تنش شوری بر عملکرد دانه و شاخص بهره وری آب در مرحله رشد زایشی محسوس تر است.
کلیدواژگان: آب های نامتعارف، تنش شوری، کیفیت آب، لوبیا رقم درخشان -
صفحات 107-120
پیش بینی بروز سیلاب یا رواناب بر پایه ریسک فرایندی است که به محققان اجازه می دهد عدم قطعیت های عامل بر فرایند تصمیم گیری را در نظر گرفته و سطح اعتمادپذیری رویدادهای هیدرولوژیکی را تعیین کنند. این تحقیق به منظور کاربرد عدم قطعیت های هیدرولوژیکی در برآورد احتمالاتی سیلاب های دشت بارز در استان خوزستان واقع در جنوب غربی ایران انجام شد. تاثیر منابع عدم قطعیت بر مشخصه های بارندگی و رواناب با استفاده از توسعه یک مدل احتمالاتی چندمتغیره بر پایه توابع توزیع کاپولا تعیین شد. برای دستیابی به این هدف، سری های زمانی اطلاعات شامل حداکثر دبی لحظه ای و حداکثر حجم سیلاب برای یک دوره 37 ساله گردآوری شد. در این راستا از توابع توزیع احتمالاتی تک متغیره برای متغیرهای بارندگی و رواناب و از توابع کاپولا برای برازش چندمتغیره اطلاعات هیدرولوژیکی استفاده گردید. در بخش بهینه سازی واکنش فازی دو تابع هدف متضاد شامل کمینه سازی و بیشینه سازی تابع پیش بینی رواناب در ساختار یک مدل شبیه سازی - بهینه سازی الگوریتم ژنتیک چندهدفه مبتنی بر رتبه بندی نامغلوب تعریف و برای رسیدن به بهترین مقادیر متغیرهای تصمیم اجرا شد. توابع توزیع گاما، لوگ نرمال، مقادیر حدی تعمیم یافته، لوگ پیرسون و تابع ارشمیدسی کلایتون گزینه های منتخب به ترتیب برای شدت بارندگی، عمق بارش، پیک جریان، حجم رواناب و محاسبه دوره بازگشت دومتغیره هستند. همچنین نتایج نشان داد که همبستگی بین مشخصه های بارندگی 73/0 و بین شدت بارندگی و رواناب 86/0 بر اساس شاخص پیرسون است.
کلیدواژگان: عدم قطعیت، رتبه بندی نامغلوب، بهینه سازی چندهدفه، تحلیل هیدرولوژیکی
-
Pages 1-10
Coagulation is one of the most important processes in water treatment. Water sources can be contaminated with pathogenic microorganisms, soluble and suspended solids, particles that change the taste, odor and color of water and make water unsafe for human consumption. The presence of such impurities and contaminants reduces water quality and must be effectively removed. Coagulation / flocculation is performed as the first step in water treatment processes to remove turbidity from suspended solids and colloidal particles. The materials used in this stage of water treatment can be inorganic coagulants, synthetic organic polymers or coagulants of natural origin. Aluminum sulfate (alum) is a common coagulant used worldwide in water treatment. Despite the high efficiency of alum in removing turbidity, the volume of sludge produced after the coagulation process is high, which raises concerns about its harmful environmental effects. The use of synthetic polymers and the presence of residual monomers is undesirable due to nerve toxicity and strong carcinogenicity. Therefore, the use of natural coagulants received more and more attention. In contrast to chemical coagulants, natural coagulants are safe, eco-friendly and generally toxic free. Natural coagulants have been found to generate not only a much smaller sludge volume of up to five times lower but also with a higher nutritional sludge value. As such, sludge treatment and handling costs are lowered making it a more sustainable option. The raw plant extracts are often available locally and hence, a low cost alternative to chemical coagulants. Since natural coagulants do not consume alkalinity unlike alum, pH adjustments can be omitted and this provides extra cost savings. Natural coagulants are also non-corrosive. In this study, Pistacia atlantica seeds was used as a natural coagulant. The seeds were obtained from coriander tree in the Zagros Mountains (Lordegan province, Rig region). These husks of the seeds were removed manually. This biomass was first subjected to coarse grinding using manually mill followed by Bosch electric mill for fine grinding. 5 g/l of seeds milled was mixed with distilled water and stirred at 500 rpm using electric stirrer for 10 min at room temperature. The filtered extract containing the active coagulant was then used in the coagulation process. Synthetic turbid water was prepared by adding kaolin a stock kaolin suspension to distilled water for all coagulation experiments. The stock kaolin suspension was prepared by dissolving 10 g of kaolin powder in 1 L of distilled water. The suspension was stirred at 20 rpm for 1 h to achieve uniform dispersion of the kaolin particles. The suspension was then permitted to stand for 24 h to allow for complete hydration of the kaolin. This suspension was used as a stock solution for the preparation of water samples of varying turbidity for the coagulations tests. 1 molar solution of HCl and NaOH were added into the synthetic turbid water to adjust the pH values. The coagulation activity of Pistacia atlantica extract was determined by Jar test 300 ml of Synthetic turbid water of different initial turbidities was filled into 600 ml beakers. Pistacia atlantica extracts with variable doses and densities were added to these beakers and mixed at 100 rpm for 4 min for rapid mixing using mechanical stirrer. The mixing speed was reduced to 40 rpm for another 25 min. The suspensions were then allowed to settle down. After 30 min of sedimentation, clarified samples from beakers were collected and their residual turbidities were measured using turbidity meter. The initial turbidity was studied 100 NTU and the solvent 0.5 M NaCl were employed. All the experiments were repeated at least twice for consistency and results averaged. On the other hand, the response surface methodology (RSM) of central composite design (CCD) at 5 levels was used to evaluate and optimize the reaction conditions of the coagulation-flocculation process in drinking water treatment. Three parameters of dose, pH and contact time, which are important and influential factors on the coagulation-flocculation process, were used as variables in the experimental design. A quadratic polynomials model with a value of R2 = 0.9654 (correlation coefficient) was presented to the data. Model accuracy tests showed a good correlation between actual and predicted values. In the treatment of drinking water obtained from experimental results, a significant reduction in turbidity, i.e. 95.13% with a dose of 90.53 mg / l, pH = 9.97 and a contact time of 44.86 minutes was obtained for Pistacia atlantica coagulant. According to the results of Pistacia atlantica seed as a coagulant in drinking water treatment showed high potential.
Keywords: Natural coagulant, Pistacia atlantica, turbidity removal, Optimization, coagulation -
Pages 11-20
Ownership of natural waterways is one of the most important issues in the country's water rights، which, unfortunately, along with other important issues, this fledgling field was not considered due to the lack of a comprehensive law in the country's water industry. The subject of that affects all stakeholders and stakeholders, including individuals, legal entities, managers, judges and lawyers. In this article, an attempt has been made to mention the evolutionary stages of channel bed ownership, the obvious and exclusive examples of which are: rivers, natural streams and canals, in the laws that have been approved by the legislator since the beginning of the legislative period in Iran (1285 AH), expressed. In this article, an attempt has been made to mention the evolutionary stages of channel bed ownership. Therefore, taking into account the various divisions that exist for property, ownership of water channels with the term "natural" or "public use" should be included in the category of public property. With this view, ownership of natural water channels in the civil law approved in 1307 AH as the mother law and paragraph 6 of Article 96 of the Municipalities Law approved in 1345 AH as the first law that ruled the ownership of the riverbeds in the cities was checked. Also, Article 2 of the Water Law and the manner of its nationalization approved in 1347 AH and it’s following notes and Article 2 of the Law on Fair Distribution of Water and related notes approved in 1361 AH were analyzed as special laws for the water sector. In examining the legal status of this category of property in the relevant laws from the beginning of the legislative period until now, it was found that the ownership of water channels from the perspective of the legislator does not have a single ruling. The evolution of the relevant laws indicates that the legislator had three different views on the ownership of this category of property and in accordance with the circumstances of the time of the adoption of the law; 1- A view that respects private property, 2- A view that declares it in government ownership 3- A view that considers this property as public wealth and commonalities and at the disposal of the Islamic government. Since each of the legislative periods had an impact on the ownership of individuals over waterways, and whether rightly or wrongly at some point in time, actions were taken by individuals that led to the issuance of a title deed to such property in the name of individuals. And also that in the current law, according to which the last will of the legislator, which is currently in an executive position, not only private property of individuals but also state ownership of such property was not accepted. And given that the title deed to waterways has faced dramatic tides due to its legal background, and is not very clear in terms of legal vacuum or ambiguity in existing laws, by studying the laws of the subject and its analytical review, necessary attempt to explain the ownership of natural waterways is the subject of research, which is still one of the main concerns of stakeholders, , individuals and communities, was done the results indicate that in the current legal system, water channels can be divided into two categories: "natural" and "construction", each of which has its own rule. With comparison Article 2 and its following notes on special water laws, criteria and legal criteria for determining and determining the bed of rivers, natural streams and canals were reviewed and legal effects of how to determine and identify the bed of such natural channels according to the number and size of these channels throughout the country, increasing economic value of land, especially in a situation where we are facing population growth and rising land prices and land use change it was stated about the ownership of the owners of the adjacent lands and it was emphasized in accordance with the legal standards regarding the stabilization of the bed of natural water channels and its marking in nature which is a social and public demand, to be acted upon in a timely manner by regulating property relations between individuals and the government to prevent any encroachment on the riverbed on the one hand, as well as destroying the lands of adjacent owners or creating instability and restriction in their ownership on the other hand. The role and position of the government (executive branch, especially the Ministry of Energy) and the Islamic government in relation to such channels, which appeared naturally in the geographical area of each water basin without human intervention and are the place of water flow and rainfall was also explained. The result is that the bed of natural water channels is common to the Islamic government and is not considered part of government assets and the actions of the Ministry of Energy as a member of the government are only for the purpose of maintaining and protecting and exploiting the mentioned canals and not for the sake of owning the bed of natural water canals. Emphasizing that despite the passage of dozens of laws with different titles that are related to water, unfortunately, the comprehensive water law in the country has not been approved yet, therefore, it is necessary to adopt regulations that are comprehensive and preventive with the subject of natural water channels as a container that is free from any conciseness, ambiguity and defects, an essential need. It is also important to apply the existing legal criteria and criteria in identifying the bed of natural waterways and determining its final limit and stabilizing it in nature in order to protect public rights and prevent damage to the ownership of lands adjacent to natural waterways.
Keywords: Natural water channels, special water laws, government, State, bed identification criteria -
Pages 21-33Introduction
Evapotranspiration (ET) is one of the key components of the Earth's hydrological cycle and its accurate estimation is very important in the water resources management and planning in agricultural usages. ET as a main hydrological flux, links energy, carbon and water cycles, and has an important role in meteorology, hydrology and water resource management, especially in Agricultural Water Management (AWM). Precise and accurate estimation of ET is an essential for the Integrated Water Resources Management (IWRM). Since ET is considered as water consumption over the agricultural areas, knowledge about ET (water consumption), as one of the most important features of the hydrologic cycle, plays an important role in irrigation planning and agricultural management. Quantification of water consumption in agricultural areas can be carried out using climatic and environmental variables, e.g. reference evapotranspiration (ETo), crop coefficient (Kc) and crop evapotranspiration (ETc).
MethodsOver the past few decades, satellite imagery based methods have come to the attention of researchers, which they have developed varieties of remote sensing methods to estimate evapotranspiration. In the present study, the Surface Energy Balance algorithm for Land (SEBAL) and Mapping Evapotranspiration with Internalized Calibration (METRIC)/Earth Engine Evapotranspiration Flux (EEFLux) algorithms were used to estimate ET for every pixel of the Landsat 8 at the Arak maize farm, Iran. Various observed data was used in this study. The meteorological data were first obtained from Markazi Regional Water Authority (sunny hours and solar radiation at selected dates) and Arak synoptic station to calculate actual ET and the selected satellite data and ET models were then evaluated. Moreover, wind speed, dew point temperature and daily temperature at the corresponding dates of the Landsat 8 satellite overpass time were gathered from Iran Meteorological Organization. In order to obtain the Leaf Area Index (LAI) at the overpass time of the Landsat 8 satellite over the study area, field measurements were performed. For this purpose, at each date of field operation (which was at the same date as the overpass time of the Landsat 8 satellite) and based on the Landsat pixel size, a 30*30 m plot was designed for field sampling in the selected maize farmland, and a 1*1 m square sub-plot was then designed in the center of each plot. In order to compare the used models, some quantitative criteria are required to measure model performance. In this study, daily ET from SEBAL and EEFlux were used to compare the relative performance of the algorithms for the eight Landsat images during the growth period. Based on commonly used statistical metrics, percent bias error (PBIAS), root mean squared error (RMSE), Nash-Sutcliffe coefficient of efficiency (NSE) and coefficient of determination (R2) criteria were used to evaluate the models. Taylor diagram was used to provide a visual framework and graphically summarizes how closely a set of patterns matches the observed data. In this study, Taylor diagram was used for visual comparing Evapotranspiration derived from SEBAL and EEFLux algorithms, based on the ET obtained from Lysimeter (as reference data).
ResultsThe results of estimating daily Evapotranspiration from Surface Energy Balance algorithm for Land (SEBAL) and Earth Engine Evapotranspiration Flux (EEFLux) algorithms indicated that daily ET were low at the beginning of the growing season and then came up until middle of the growing season, and then ET values have been decreased due to decreasing temperature as well as changes in maize cover in the study area. Comparison of SEBAL and EEFLux algorithms showed that SEBAL algorithm has estimated about 7.71% of daily ET more that EEFLux algorithm at Arak maize farm. The results of performance evaluation showed that RMSE, NSE, PBIAS and R2 were obtained 0.711, 0.807, 7.398 and 0.885, respectively based on SEBAL algorithm, and for EEFLux algorithm were equal to 1.046, 0.582, 15.080 and 0.793, respectively. The Taylor diagrams showed that the SEBAL model had a lower RMSE and higher correlation than the EEFLux model. Comparing the standard deviation of both models, it was found that the SEBAL model was more in agreement and closer to measured daily ET values than the EEFLux model. This can also be seen in Fig. 6, where SEBAL has a close standard deviation to the measured data, but EEFLux model has a lower standard deviation than the measured data. This indicates that the EEFLux model cannot predict the daily ET the same as SEBAL model. According to observed data (lysimeter data), evaluating the performance of SEBAL and EEFLux algorithms showed that SEBAL algorithm had higher correlation and less standard deviation than EEFLux algorithm. Therefore, SEBAL algorithm had better estimation than the EEFLux algorithm.
Keywords: Daily evapotranspiration, Remote sensing, Landsat images, SEBAL, EEFLux -
Pages 35-43Introduction
Stilling basins are a short section of a floor of channel that is constructed as special structures at the end of the spillways and any other site that creates a supercritical flow to control the hydraulic jump, and the shorter their length, they will be the more economically viable. One of the most important topics in the study of reducing the destructive energy of the flow is hydraulic jump. Hydraulic jump control is carried out in order to reduce the damage of the downstream structures. A hydraulic jump is one of the most rapidly varied flows occurring when the flow is altered from a supercritical state to a subcritical one in a part of its path. Researchers have always tried to control the hydraulic jump to prevent severe damage to downstream hydraulic structures. The high cost of building recreational pools has encouraged researchers to reduce sequent depth, jump length and reduce energy losses. There are several methods to reduce the sequent depth and length of the hydraulic jump in addition to increasing the energy loss of the hydraulic jump, such as increasing the adverse slope of the bed or using roughness in the channel floor. In addition to reducing the dimensions of the hydraulic jump for the cost-effective construction of the stilling basin, the stabilization of the hydraulic jump at the pool site is also very important. A sudden drop in the bed (negative step) stabilizes a horizontal hydraulic jump of channel adjacent to the step for a wide range of sequent depths. This paper introduced a new solution for the hydraulic jump on adverse slope and negative step to the difference between the upstream and the downstream momentum fluxes.
MethodThe channel used in this research is a rectangular channel with a length of 8, a width of 0.4 and a height of 0.6 meters. The walls and floor of this channel were made of transparent Plexiglas sheet. This channel was fed by a pump with a maximum discharge of 50 liters per second. In order to increase the initial Froude number before the upstream sliding gate, the tank height is considered to be 1.25 m. To create the stairs at the beginning of the channel, Teflon sheets with thicknesses of 3 and 6 cm were used, taking into account the zero height, a total of 3 different heights were used for the stairs. In this study, three angles of zero, 3 and 6 degrees were used for adverse slope. To change the slope of a false plate with a length of 3 meters, its sloping part continued to a distance of 2 meters from the gate, the slope of which can be changed. This plate is located at the bottom of the channel, just after the initial gate, where the jump occurs completely in this part of the channel. To create the jump, a sliding gate was installed at the inlet of the flume and another valve was used at the end of the flume to stabilize the jump. In the experiments performed, the downstream gate was adjusted so that the start of the jump occurred at the point of change in the height of the channel. To perform this study, a total of 81 experiments were performed in the range of 4.5 to 9.5 Froude numbers.
ResultsIn this research, the combined effect of using three inverse slopes and three elementary negative step elevations on hydraulic jump characteristics including sequent depths, jump length and energy loss in Froude numbers of 4.5 to 9.5 were studied. The results showed that by increasing the adverse slope of channel reduced the sequent depths, jump length and energy loss by 12.6%, 13.9% and 16.8%, respectively. When the negative step increased the ratio of sequent depths and jump length increased by 5.66% and 6.2%, respectively, and energy loss decreased by 2.6%. The combination of the adverse slope and negative step reduced the sequent depths, jump length and energy loss by 12.42%, 14.8% and 3%, respectively, and could also create a shear of 12.56 times equal to the conditions of a smooth bed. Therefore, the negative step only stabilizes the jump in the stilling basin, and the adverse slope makes this jump stabilization difficult.
Keywords: Hydraulic jump, Adverse slope, Elementary negative step, Froude number, Bed shear stress -
Pages 45-58
Reference evapotranspiration (ET0) is a major research area of both hydrology and water resources management, especially in irrigation agriculture. The most important and direct application of ET0 is in the field of irrigation. One of the conventional methods for estimating reference evapotranspiration using meteorological data is the Penman-Monteith-FAO equation. This equation due to satisfactory results has been used in a variety of climates around the world. However, the lack of necessary meteorological data makes it difficult to estimate spatially distributed ET0 using the FAO-PM method in the wider ungauged areas. Penman Monteith method requires air temperature, wind speed, relative humidity, solar radiation and etc.To overcome the existing limits of the FAO-PM model, various attempts aiming to estimate ET0 with limited observed data have been conducted. At present, remote sensing methods are the only way to obtain the various variables at the temporal and spatial scales needed to estimate evapotranspiration. In recent years, several algorithms have been proposed to estimate reference evapotranspiration using remote sensing data. Some of these models, which are based on the relationship of energy balance, are called surface energy balance methods. In addition to remote sensing, data analysis techniques based on machine learning (ML) are more frequently used in agricultural studies in recent years, especially in evapotranspiration. Therefore, analyses performed with ML algorithms, when coupled with remote sensing data, have the potential to predict the biophysical variables, mainly due to the adaptive capacity of the models to find patterns in nonlinear behavior variable, such as ET0. Machine learning methods are well known and have been widely used in other engineering sciences. The purpose of this study is to estimate the reference evapotranspiration using machine learning algorithms and remote sensing data and finally to analyze the algorithms used. In general, the final results of evapotranspiration estimation depend on factors such as the type of data and the method for estimating evapotranspiration.In this study, the standard method of estimating ET0 with meteorological data, Penman-Monteith FAO equation has been used. The NDVI vegetation index indicates the amount of vegetation on the ground and is sensitive to the early stages of phenology. But the enhanced vegetation index (EVI) minimizes atmospheric effects and differences in blue and red reflections. The SAVI index is used to calculate the vegetation of the land surface that has moderated the effect of soil on it. Three machine learning algorithms were introduced to train the ET0 models, including random forest (RF), gradient boosting regressor (GBR) and support vector regression (SVR). Random forest are one of the machine learning methods that performs classification and regression using Bootstrap and Bagging methods. In this research, three machine learning algorithms with different input data (vegetation indices and all bands of Landsat 7 and 8) are used and after comparing the results, the best model was selected. Performance Evaluation Indicators to compare and evaluate the performance of the studied models, the parameters of mean square error (RMSE), mean absolute error (MAE), coefficient of determination (R2) and correlation coefficient (CC) are used. Finally, according to the results of the two approaches used in this study, using the values of all Landsat bands, the reference evapotranspiration can be estimated with more accuracy.Accurate estimating of reference evapotranspiration is necessary to estimate irrigation needs and in general, to accurately manage water resources. Conventional methods of measuring evapotranspiration are reference using meteorological data. These measurements are point-based, so they are only suitable for very small scale areas. At present, remote sensing methods are the only non-terrestrial way to obtain the various variables at the temporal and spatial scales needed to estimate reference evapotranspiration. In order to reduce the dependence on climatic data and better resolution, machine learning methods are used to calculate the reference evapotranspiration. In this research, RF, GBR and SVR models have been used. In the present study, there are two approaches Used. In the first approach, the values of all bands of Landsat images are as model input, while in the second approach, vegetation indices are calculated with only a few bands of Landsat images and then used as model inputs. By examining, it can be seen that the information obtained from the Landsat image bands is related to the phenological behavior of the products, and it is also possible to contract very relevant information related to agricultural products that are examined temporarily and spatially. One of the factors influencing the accuracy of estimating reference evapotranspiration is the use of other Landsat bands in addition to the bands related to vegetation indices.
Keywords: Water Management, Machine learning, Vegetation indices, Remote Sensing, Evapotranspiration -
Pages 59-67Introduction
With the increase of population, migration to cities and expansion of urbanization, improvement of living standards, and expansion of industries have caused a large volume of sewage to be produced in limited areas that the environment can not be refined. However, this high volume of wastewater can be considered a source of water, materials, and energy. Today, many countries make optimal use of water resources and advance their national development programs by recycling them. The use of wastewater in agriculture should not be based on a general rule. Still, it should be based on water, soil, and environment characteristics and establish a proportion between the quality of the wastewater and the type of wastewater application according to economic issues. This subject requires access to executable standards, instructions, and criteria for each of the different sections to be used to observe environmental standards. Of course, wastewater as a stable water source in irrigation of agricultural products and obedience to ecological considerations should be considered part of sound management for the water crisis.
Materials and methodsA factorial experiment was conducted in a complete randomized design with 15 treatments and four replications in the research greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad. For this experiment, 60 pots, 6 kg containing sandy loam soil were used. Treatments include urban water (W), treated wastewater (TWS), untreated wastewater (WS), combined urban water and treated wastewater ratio of 50:50 (W + TWS), and combined urban water and untreated wastewater (W + WS) (50:50) as irrigation water and three levels of irrigation were 100, 70 and 40% of the plant's water requirement. First, treated wastewater samples, untreated wastewater, and urban water were taken to the laboratory for water quality analysis. The seedlings were transferred to the desired pots in the three or four-leaf stage. After 150 days, the plants were harvested from the pools, and traits such as leaf number, leaf area, chlorophyll a, chlorophyll b, carotenoids, and proline were measured.
Results and DiscussionAccording to the analysis of variance tables, the results show that the simple effect of water quality treatment on the leaf number, leaf area, chlorophyll a and b at the level of one percent probability have a significant difference, but there was no significant difference in proline and carotenoid traits. In simple effect of deficit irrigation treatment, all measured characteristics have a considerable difference at the level of one percent probability. But, in the interaction effect of water quality and deficit irrigation, leaf number, leaf area, chlorophyll a and b, and carotenoids trait were significant at the level of one percent probability, and proline trait was not significantly different. Therefore, due to the interaction of water quality and deficit irrigation treatments, the most leaf number related to the treatment of 100% of the plant's water requirement with untreated wastewater, and the least leaf number belongs to the treatment of 40% of the plant's water requirement with urban water. In the leaf area, the most amount is related to 100% of the plant's water requirement with untreated wastewater. The least amount is related to 40% of the plant's water requirement with urban water. In chlorophyll-a trait, the most amount of chlorophyll a is associated with the treatment of 100% of the plant's water requirement with untreated wastewater. The least amount of chlorophyll is associated with 100% of the plant's water requirement with treated wastewater. In chlorophyll b, the most amount is related to the interaction treatment of 100% of the plant's water requirement, and the combination of urban water and untreated wastewater in the ratio of 50:50 and the least number is related to the treatment of 100% of the plant's water requirement with treated wastewater. Also, in the carotenoid trait, most carotenoids were related to 100% of the plant's water requirement with untreated sewage. The least amount of carotenoid was linked to 40% of the plant's water requirement with untreated wastewater.
ConclusionAccording to the results, it can be concluded that the leaf number, leaf area, chlorophyll a, and chlorophyll b in the treatment of urban water with untreated wastewater was more than the control, and the quality of irrigation water on proline was not significantly different. Also, it is concluded that the plant's natural response to drought stress depends on the amount of water and can be short-term or long-term physiological responses. Thus, the lack of access of tomato plants to enough water reduces physiological traits such as leaf number, leaf area, and photochemical traits such as chlorophyll a, chlorophyll b, and carotenoids. But deficit irrigation increases the amount of proline, and with the drought stress intensifies, the number of proline increases. Thus, in conditions of deficit irrigation, the plant reduces its osmotic potential to absorb more water by accumulating potential osmotic regulators such as proline and soluble carbohydrates in the leaf.
Keywords: Chlorophyll a, Chlorophyll b, Carotenoids, Number of leaves, Proline -
Pages 69-82Introduction
Optimizing the sustainable use of water resources across local or regional systems is a complicated management challenge with significant implications. The world population in 2050 will be more than 9.5 billion people that it needs about 60% more food. Furthermore, the water availability for irrigation will decrease because of competing demands from other sectors, i.e., industrial, domestic, and hydroelectric generation. Pre-growing season estimation of agricultural outcomes such as water losses, net benefit and yield production can provide insights to beneficiaries and farmers to make optimum decisions. Shahhosseini et al., (2019) evaluated the potential of machine learning algorithms for maize growth simulator to develop a decision support system. Three million data such as genotype, environment and management scenarios were incorporated for predicting yields in this framework. The results provided a dynamic decision technique for pre-season management. In a case study, maize water use was measured based on the water balance in a 6-year field trial in the west-central Great Plains of the United States by Trout and DeJonge (2018). Varzi et al., (2019) presented an optimization model to allocate irrigation water for maize using crop water production functions under deficit irrigation. The problem structure was determined based on maize and sunflower water productivity data collected during 2008–2011 growing seasons in eastern Colorado. The results show that deficit irrigation does improve farm income at moderate to high leasing prices. Moreover, the proposed model can define the crop and water leasing prices for which deficit irrigation is worthwhile. Therefore, increasing the efficiency of land and water resources can be considered as the main policy to find the sustainable decision. It is necessary to develop methods to improve soil moisture capacity and increase plant biomass in arid and semi-arid areas. This study was conducted to evaluate the impact of sugarcane compost on maize yield under the climate conditions of Gotvand plain in Khuzestan province, southwestern Iran. This agricultural residue can be used for improving the soil porous media structure to increase water availability in the root zone. Economic analysis of the application of sugarcane bagasse at different levels of plant water supply needs has been done using the development of the growth simulation model and optimization technique.
MethodsIn this study, simulation of maize yield and soil water content with AquaCrop software under full and deficit irrigation managements and sugarcane bagasse utilization was evaluated. This agricultural residue can be used for improving the soil porous media structure to increase water availability in the root zone. Economic analysis of the application of sugarcane bagasse at different levels of plant water supply needs has been done using the development of the growth simulation model and optimization technique. A field experiment with three treatments of sugarcane compost application (0, 15, and 30 ton/ha) and four levels of crop water supply (50%, 75,% 100%, and 125% of total water requirement) was performed in three replications for two growing seasons (March to December 2019). Irrigation planning, cultivation costs, biomass, harvest index and canopy cover were measured at different time steps of the growing seasons to provide growth simulation models using AquaCrop software. The error statistics of calibration process were evaluated by root mean square error (RMSE), Nash– Sutcliffe efficiency index (NSE), normalized objective function (NOF), and mean absolute error (MAE) for the simulated and observed yield production values.
ResultsCalibration and verification process were carried out based on the two replications and one replication, respectively. The results presented in the scatter diagram and the coefficient of determination values close to one showed that the simulation model can be used to estimate the yield production in different scenarios of irrigation water distribution. The results showed that the use of sugarcane bagasse increases the soil water availability, harvest index and yield production at a confidence level of 1%. Optimal irrigation planning in this study was performed using the gray wolf optimization algorithm with the objective of maximizing crop yield. Optimal irrigation strategies reduce water losses, increase biomass and improve economic efficiency compared to existing conditions. Optimal planning based on daily information can determine the depth and timing of irrigation simultaneously. Increasing the water productivity and the net income for farmers and reducing the costs of bagasse application could be considered as positive implications of the developed simulation-optimization model. Future research could explore water management strategies on the farm by developing new goals for other crops or cultivation patterns.
Keywords: Harvest index, Water productivity, Canopy cover, Yield production -
Pages 83-96
Urmia Lake; the Turquoise Gem of Northwestern Iran is the second-largest permanent hypersaline lake in the world. It is situated in the northwestern corner of Iran surrounded by East and West Azerbaijan provinces, near the Turkish border. This lake was declared a Wetland of International Importance by the Ramsar Convention in 1971 and designated a UNESCO Biosphere Reserve in 1976. Its surface, unfortunately, has declined sharply in recent decades. Scientists have warned that this continuous shrinking would lead to increased salinity, the collapse of the lake’s ecosystem, loss of wetland habitat, wind-blown salt storms, alteration of local climate, and serious negative impacts on local agriculture and livelihoods as well as regional health in Iran and neighbor countries including Turkey, Iraq, and Azerbaijan.Accurate and comprehensive spatial information (such as the lake’s surface and shorelines) and descriptive information (such as salinity of water and soil) of the lake are essential to deal with current and emerging crises. This information can be obtained by ground-based and space-based measurements. While daily measurement of the lake level at ground stations is one of the most important ground-based observations, but ground measurements of the lake's surface are not a practical method. Thanks to satellite remote sensing data, space observations have been provided for accurate and continuous monitoring of the Lake's surface and its water level. Since each of the ground and space observations has its pros and cons, many efforts have been made to estimate the correlation of these observations (ground-based observations of lake’s level and space-based observations of lake’s surface). Although many studies have been conducted in this field, however, no efficient model has been proposed to relate the surface area and the water level of Urmia Lake, which is an important factor in various hydrological and environmental analyzes. This paper aims to extract the level-surface characteristics of Urmia Lake using space observations of the lake and ground-based measurements of level and analytical models. Level-surface models have been determined based on ground observation of water level and simultaneous space observation of lake surface area. As a result, daily estimates of the lake surface will be provided without the space-based observations. In the present study, 6 proposed models including Polynomials, Exponential function, Fourier transformation, Gaussian function, rational function (RF), and artificial neural network (ANN) along with the two existing models including The EAWO (Eastern Azerbaijan Water Organization) model and the Sahand University model. To evaluate the effectiveness of mentioned methods, 44 samples include the lake’s surface (from Mar. 2005 to Dec. 2015) and corresponding water levels on the same date were used in this study. All of these models were calibrated by training data and evaluated based on validation data. Used data records include water level fluctuation from 1270.43 m to 1273.9 m above mean sea level and lake area (surface) fluctuation from 1837 sq. km to 4508 sq. km.Comparing the RMSE, MAE, MAPE, and NSE of all mentioned models, it was found that the proposed RF-based model (S=(3026×L^2-3.84×〖10〗^6×L-6051)/(L^2-1991×L+9.17×〖10〗^5 )) estimates the area of Urmia Lake only with an error of RMSE = 57.8 sq. km, MAE= 46.2, MAPE=1.5%, and NSE=0.9958, which is five times better than the best previous models in terms of RMSE measure. One level below is ANN whose RMSE equals 62.3 sq. km and NSE= 0.9951. Two-degree Gaussian function (with RMSE= 86.53 sq. km and NSE= 0.9907), Fourier transformation (with RMSE= 145.30 sq. km and NSE= 0.9251), two-degree Exponential function (with RMSE= 173.46 sq. km and NSE= 0.9626) and three-degree polynomial (with RMSE= 173.68 sq. km and NSE= 0.9625) were in the lower levels, respectively. It is worth noting that all of these proposed models are more effective than the state-of-the-art models. The worst results were obtained by the Sahand University model with an error of RMSE = 856.8 sq. km and NSE= 0.088). Despite the similar accuracy of ANN and RF models, the design and computational complexity of the ANN model are much greater than the RF model. Therefore, the RF model with higher accuracy and less complexity than the ANN is introduced and recommended as the best model for estimating the level-surface characteristic of Urmia Lake. According to the proposed level-surface model and daily ground-based measurement of the water level of the lake, it is possible to estimate the daily area of the Urmia Lake surface without any space measurements. The findings of this study can be used in various hydrological and environmental analyzes and monitoring and rehabilitation programs of Urmia Lake.
Keywords: Area estimation, Remote sensing, regression, rational function, ANN -
Pages 97-105
Water is the source of life and one of the important resources for the sustainable development of countries. Population growth and consequently the need for more agricultural commodities and food products and on the other hand, the limitation of water resources, have led human beings to the optimal use of available water resources and the use of low-quality water (Dehghan et al. 2015). To make more efficient use of limited water resources in the agricultural sector, new strategies such as the use of unconventional and saline water in irrigation operations should be considered (Mardani Nejad et al. 2017). Knowing how plants respond to different degrees of salinity of irrigation water, which is used in different stages of vegetative and reproductive growth, is necessary for proper and optimal management of the use of unconventional water resources in agriculture. Beans are one of the most important crops in terms of high protein content and use in the diet. This plant is one of the annual legumes and is sensitive to water salinity, which is cultivated for seed production (Salehi, 2015b). Bean is one of the plants sensitive to salinity and tolerates salinity up to 2 dS/m, but its yield reduction starts from 0.8 dS/m (Kamel et al. 2016).This experiment was carried out to compare the effects of saline water application in vegetative and reproductive growth stage for irrigation of Derakhshan red bean cultivar, which is suitable for Shahrekord climatic conditions. Experiments of this pot study in open space, were performed in factorial form in a completely randomized design, with three replications in pots with a diameter of 40 and a height of 70 cm in the research farm of Shahrekord University with UTM coordinates (Zone = 39), X = 482573 m and Y = 3579364 m and altitude of 2070 m above sea level. The first factor of the experiment was the use of saline water at the mentioned three levels for irrigation in the vegetative growth stage and the second factor was the use of the same salinity levels for irrigation of reproductive growth stage. The data collected included yield, yield components and water productivity.The results of analysis of variance showed that salinity stress in the vegetative and reproductive growth stage of bean plant significantly reduces yield, yield components, water uptake, water productivity and biological productivity index (α <0.01). Harvest index was not affected by salinity stress at vegetative growth stage, while the effect of salinity stress at reproductive growth stage on harvest index was significant (α <0.01). The highest value of water productivity was achieved in the control treatment with a rate of 0.67 kg/m3; the lowest value of 0.39 kg/m3 was observed in the treatment of applying 2 dS/m saline water in two stages of vegetative and reproductive growth. Regardless of salinity level, the mean effects of salinity in vegetative growth stage led to the productivity of 0.64 kg/m3 and in reproductive growth stage led to the productivity of 0.59 kg/m3. The results also showed that the highest yield (3349 kg/ha) was related to the control treatment and the lowest yield with rate of 1779 kg/ha was related to the treatment of applying 2 dS/m saline water in two stages of vegetative and reproductive growth. Regardless of the salinity level, the mean effects of salinity led to the production of 3067 and 2892 kg / ha grain yield in the vegetative and reproductive growth stage, respectively. The highest amount of water uptake was observed in the control treatment with the rate of 10 mm/day and the lowest amount of 9 mm/day without significant difference in the treatment with a salinity of 2 dS/m in the whole growth period and the treatment of 2 dS/m in the vegetative growth period And 1.5 dS/m was observed during reproductive growth.The results of this experiment, like the results of Ben Usher et al., 2006, showed that increasing salinity during the vegetative growth period of the plant reduces the storage content of plant organs, which affects the yield and its components at the end of the period. On the other hand, the application of salinity stress during reproductive growth period has a direct negative effect on yield and its indicators. These effects will be exacerbated when salinity stress is applied simultaneously during the vegetative and reproductive growth stages. The effects of salinity stress on grain yield and water productivity were more significant in the reproductive growth stage. The result is that in conditions of limited water quality, in order to achieve higher yield and optimal use of water, water with suitable quality should be used in the reproductive growth stage, and saline water could be used in the vegetative growth stage.
Keywords: Unconventional water, salinity stress, Water quality, Derakhshan bean cultivar -
Pages 107-120Introduction
Generating a mathematical relationship between rainfall and runoff plays an important role in the decision-making process and control of surface flows. This structure has levels of uncertainty based on the hydrological conditions, land cover, time, depth, and rate of the rainfall events. Uncertainty analysis in systems evaluation and management has been considered as a logical aspect in engineering estimates in recent decades. Uncertainty generally implies that there is no complete knowledge of the behavior of a system and the specific values of its variables. At present, the uncertainty problem has been one of the topics of interest in research, decision-making and design in the field of water science and engineering. Different methods of uncertainty analysis in water resources have been developed. The main purpose of this study was to determine the degree of uncertainty and its role in calculating runoff generated by rainfall.
MethodsThe hydrological information used in this study includes the amount of rainfall and runoff recorded in daily time steps. Analysis of available data revealed about 37 rainfall events that led to the flood. Rainfall characteristics (maximum daily rate (mm/day) and cumulative rainfall depth in one event (mm)) and two characteristics of runoff hydrograph (hydrograph peak flow (m3/s) and runoff volume (million cubic meters (MCM)) were calculated from daily rainfall and runoff information. Therefore, a probabilistic decision model based on copula multivariate functions was developed to predict the variables at different return periods. The relationship between rainfall rate and depth with peak hydrograph flow and runoff volume for flood events over a 37-year period was formulated through fuzzy set theory. The feasible domain of the fuzzy problem was searched using a multi-objective optimization genetic algorithm based on the non-dominated sorting to find the extreme points. The obtained solutions were used as a fuzzy response to calculate the runoff of the Barz plain in Khuzestan province in southwestern Iran.
ResultsThe results showed that the correlation between the maximum daily rainfall rate and the peak discharge of runoff hydrograph with a determination of coefficient equal to 0.85 can be described as fuzzy numbers. Therefore, a combined model of fuzzy system and multi-objective genetic algorithm was used to calculate the fuzzy response of runoff characteristics to uncertainty inputs of rainfall. Consequence of the development of this method can analyze the existing uncertainty in estimating the volume and intensity of runoff based on recorded rainfall information and provide an estimate with certain levels of flood reliability. Future research should provide relationships to predict the effect of rainfall duration on runoff output hydrographs and add a new component to this decision structure.
Keywords: Uncertainty, Nondominated sorting, Multiobjective, Hydrological analysis