فهرست مطالب

  • سال یازدهم شماره 5 (آذر و دی 1396)
  • تاریخ انتشار: 1396/10/30
  • تعداد عناوین: 18
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  • محمد اسماعیل کمالی، علیرضا فریدحسینی *، حسین انصاری، محمدعلی غلامی سفیدکوهی صفحات 708-721
    در این تحقیق تهیه نقشه نیاز آبی ذرت در استان مازندران مدنظر قرار گرفت. نیاز آبی ذرت در دوره های 10 روزه به روش دو مرحله ای فائو در موقعیت ایستگاه های هواشناسی بدست آمد. تبخیر- تعرق مرجع (ET0) به روش فائو- پنمن- مانتیث و با استفاده از داده های 51 ایستگاه هواشناسی محاسبه شد. ضرایب گیاهی نیز در 4 مرحله رشد مدنظر قرار گرفت. برای تعیین تابع رفتاری داده ها، آنالیز روند و ناهمسانگردی انجام شد. پس از محاسبه نیم تغییرنمای تجربی و انتخاب بهترین مدل نیم تغییرنما بر اساس کم ترین مقدار مجموع باقی مانده مربعات (RSS)، داده ها با روش های قطعی شامل وزن دهی عکس فاصله، توابع پایه شعاعی، چند جمله ای سراسری و چند جمله ای موضعی و روش های زمین آماری از خانواده کریجینگ درون یابی شدند. خطای درون یابی با استفاده از تکنیک اعتباریابی متقابل بدست آمد و نشان داد که روش های چند جمله ای سراسری و کریجینگ معمولی نتایج مشابهی را دارا و بهتر از سایر روش ها بودند. نقشه ها نشان دادند که بیش ترین مقدار ET0 در ماه مرداد و 78/4-05/4 میلی متر در روز و کم ترین مقدار آن در ماه دی و 27/1-05/1 میلی متر در روز بدست آمد. همچنین بیش ترین مقدار نیاز آبی ذرت علوفه ای در تیرماه و 15/5-27/4 میلی متر در روز و برای ذرت دانه ای در دهه اول مرداد و 21/5-41/4 میلی متر در روز بدست آمد. نیاز آبی محاسباتی و پیش بینی شده ذرت علوفه ای برای ایستگاه دشت ناز در این تحقیق از نتایج کتاب مرجع 8/45 و 45 درصد کم تر است. همچنین نیاز آبی محاسباتی و پیش بینی شده ذرت دانه ای برای ایستگاه دشت ناز در این تحقیق از نتایج سند ملی 9/71 و 75 درصد بیش تر است.
    کلیدواژگان: تبخیر، تعرق، توزیع مکانی، درونیابی، نیم تغییرنما، GIS
  • محمد مهدی چاری، کامران داوری *، بیژن قهرمان، علی نقی ضیایی صفحات 722-735
    تعیین منحنی پسروی جهت ارزیابی آبیاری نواری دارای اهمیت بسیاری می باشد. با توجه به متغیر بودن نوع خاک و همچنین شرایط اولیه و مرزی در آبیاری نواری، سرعت پسروی آب در نوار های مختلف بسیار متفاوت می باشد. در سال های اخیر روش مقیاس سازی به عنوان ابزاری جهت کاهش داده های اندازه گیری و تدوین و فرموله کردن معادلات مربوط در مسایل آب و خاک مورد استفاده قرار گرفته است. هدف از این پژوهش، ارایه معادله ای یکتا و مستقل از شرایط اولیه و خاک، جهت پسروی آب در نوار با استفاده از مقیاس سازی است. برای این منظور، آبیاری نواری با استفاده از مدل موج سینماتیک و کاربرد معادله نفوذ فیلیپ دو جمله ای برای مولفه ی نفوذ، حل گردید. عوامل مقیاس به گونه ای تعریف شدند که معادله موج سینماتیک مستقل از شرایط اولیه و خاک گردد. نتایج نشان داد که عوامل مقیاس مورد استفاده در این تحقیق از توزیع لوگ- نرمال پیروی می کنند. از آنجا که منحنی های پسروی مقیاس شده به معادله ی مشخصی میل می کردند در نتیجه، معادله ی درجه 2 جهت پسرفت آب در نوار ارایه گردید. معادله ی به دست آمده با استفاده از مقیاس سازی، برای 25 نوار شامل نوارهای کشت نشده و نوارهای کشت شده و شیب های 001/0 تا 005/0، زبری 017/0 تا 211/0، طول 4/91 تا 100 متر و دبی 08/0 تا 16/0 مترمکعب بر دقیقه بر متر مورد ارزیابی قرار گرفت. جهت ارزیابی، از چهار شاخص آماری ضریب تبیین (R2)، توزیع نسبت به خط 45 درجه (λ)، درصد متوسط خطای پیش بینی مدل (Er) و درصد متوسط خطای نسبی مدل (Ea) استفاده گردید. نتایج نشان داد که معادله ارایه گردیده با استفاده از مقیاس سازی با 94/0R2=، 046/1=λ، 6/4=Er و 52/7=Ea به شکل مناسبی کار پیش بینی منحنی پسروی را انجام می دهد. نتایج نشان داد که میانگین درصد مطلق خطا برای زمان پسروی در نوارهای کشت نشده برابر با 78/6 و برای نوارهای کشت شده برابر 08/8 بوده و دقت معادله ارایه گردیده برای هر دو شرایط کشت شده و کشت نشده مناسب می باشد. به طور کلی، نتایج نشان داد که معادله ی به دست آمده از روش مقیاس سازی، با توجه به شکل ساده و عدم وابستگی به نوع خاک، با دقت قابل قبولی پسروی آب در نوار را پیش بینی می کند.
    کلیدواژگان: آبیاری نواری، پسروی، مقیاس سازی
  • خالد احمدالی *، هادی رمضانی اعتدالی، نازگل حسینی پژوه صفحات 736-749
    در این مطالعه به بررسی وضعیت سامانه های آبیاری تحت فشار استان قم پرداخته شد. با توجه به این که 81 درصد سامانه های اجرا شده تا سال 1395 موضعی و 19 درصد مابقی بارانی بودند بنابراین در این مطالعه 11 سامانه موضعی و سه سامانه بارانی (کلاسیک ثابت آبپاش متحرک، ویلموو[1] و سنترپیوت[2]) مورد بررسی قرا گرفت. ابتدا به بررسی خصوصیات آب و خاک مزارع پرداخته شد سپس شاخص های ضریب یکنواختی (CU)، یکنواختی توزیع (DU)، بازده پتانسیل کاربرد آب در ربع پایین (PELQ)، بازده واقعی کاربرد آب در ربع پایین (AELQ) و کفایت آبیاری (ADirr) محاسبه شد. نتایج نشان داد که درصد شاخص های مذکور به ترتیب برابر 6/74، 8/60، 6/62، 6/62 و 62 درصد برای کلاسیک ثابت آبپاش متحرک، 6/57، 7/44، 1/76، 3/71 و 86 درصد برای ویلموو، 81، 63، 85، 85، و 71 درصد برای سنترپیوت و میانگین وزنی با وزن مساحت مزرعه برای سه شاخص DU، PELQ و AELQ به ترتیب 9/53، 3/45 و 9/53 درصد برای آبیاری موضعی بدست آمد. در نهایت با بررسی مسایل و مشکلات مشاهده شده در حین کار سامانه ها ملاحظه شد که اغلب مشکلات مربوط به فاز بهره برداری و برخی نیز مربوط به فازهای طراحی و اجرا می باشد.
    کلیدواژگان: آبیاری تحت فشار، آبیاری بارانی، آبیاری موضعی، بهره برداری
  • نرگس صالح نیا *، مهدی باستانی صفحات 750-762
    امروزه مسئله ی کمبود آب با توجه به تغییرات اقلیمی و توزیع نامتوازن نزولات جوی در اکثر مناطق و کشورها از جمله ایران، به یک نگرانی جدی تبدیل شده و مهم ترین مانع توسعه اقتصادی این کشورها محسوب می شود. تجارت به مثابه ی ابزاری در جهت جلوگیری از خروج غیرضروری منابع آبی، با تمرکز بر استراتژی تجارت آب مجازی، می تواند نقش مهمی در دست یابی به توسعه ی اقتصادی کشورها ایفا می کند. هدف از مطالعه ی حاضر بررسی تجارت محصولات باغی و زراعی به لحاظ رویکرد آب مجازی می باشد. در این راستا، تلاش شده است ابتدا صادرات و واردات هر یک محصولات زراعی و باغی در سال 1393، از دیدگاه نظریه تجارت آب مجازی تجزیه و تحلیل و سپس پیشنهادات راهبردی درباره ی مدیریت بهینه منابع آبی کشور ارایه شد. نتایج نشان می دهد کشور ایران با انجام تجارت در زیر بخش زراعت و باغبانی در سال 1393 با ورود محصولات به کشور به میزان 35/9719 میلیون مترمکعب آب از منابع آب داخلی حفظ و صرفه جویی کرده است که می تواند با استفاده از آن در صنعت، با ارزش افزوده ی بیش تری ارزآوری کند. همچنین با توجه به سهم قابل توجه مبادلات کالاهای کشاورزی از تجارت و سنتی بودن نظام بهره برداری که به دنبال آن مصرف غیربهینه منابع از جمله منبع آب را به دنبال دارد، پیشنهاد می شود به مسئله ی تجارت بر مبنای آب مجازی به عنوان استراتژی راهبردی، در جهت بهبود کارایی آب و صرفه جویی در منابع توجه شود.
    کلیدواژگان: آب مجازی، تراز تجاری، صادرات، واردات
  • نفیسه قزل سفلو، مهدی بروغنی *، سمیه سلطانی گرد فرامرزی صفحات 763-771
    فرسایش پاشمانی، مرحله ی اولیه ی فرسایش آبی است که با برخورد قطرات باران به سطح خاک سبب جدا شدن ذرات خاک می گردد. در این تحقیق به بررسی تاثیر مقادیر مختلف پلی اکریل آمید (0، 2/0، 4/0 و 6/0 گرم بر مترمربع) بر روی مقدار فرسایش پاشمانی در سه مدت زمان بارندگی 10، 20 و 30 دقیقه با استفاده از باران ساز FEL3 در آزمایشگاه بر روی خاک مارنی با شدت 120 میلی متر بر ساعت پرداخته شد. نتایج حاکی از آن است که بین مقادیر مختلف پلی اکریل آمید در زمان های مختلف بارندگی از لحاظ کاهش میزان پاشمان اختلاف معنی دار آماری وجود دارد. اثر متقابل دو فاکتور مدت بارش و مقدار پلی اکریل آمید برکنترل میزان پاشمان اختلاف معنی داری در سطح 95 درصد نشان نداد. به علت فرسایش پذیری بالای خاک مارنی[s1] ، مقدار کم این ماده نتوانست تلفات پاشمان را به خوبی کنترل کند، هرچند آن را به میزان کم کاهش داد. نتایج تحلیل آماری در مدت های مختلف بارش نشان داد که مقادیر مختلف پلی اکریل آمید در زمان 10 دقیقه نسبت به تیمار شاهد اختلاف معنی دار نداشت ولی در مدت 20 و 30 دقیقه مقدار ماده در کنترل فرسایش نسبت به شاهد معنی دار بود. همچنین با تداوم بارندگی، میزان پاشمان افزایش یافت و با افزایش میزان پلی اکریل آمید فرسایش پاشمانی کاهش داشت، به گونه ای که بیش ترین تاثیر در زمان 30 دقیقه و مقدار 6/0 گرم بر مترمربع پلی اکریل آمید نسبت به شاهد می باشد که فرسایش را 2/21 درصد کاهش داد.
    کلیدواژگان: بارانساز، خاک مارنی، فرسایش پاشمانی، مدت بارندگی، FEL3
  • علی فرودی خور، مجتبی صانعی*، مهدی اژدری مقدم صفحات 772-784
    دراین تحقیق به کمک سامانه استنتاج فازی- عصبی تطبیقی و همچنین روش ماشین بردار پشتیبان مدل هایی بدون بعد برای برآورد ضریب دبی در سرریزهای لبه تیز قوس محور ارایه شده است. برای واسنجی و صحت سنجی (آزمون) رابطه پیشنهادی، داده های آزمایشگاهی کومار-همکاران (Kumar et al.، 2012)استفاده گردید و برآورد ضریب دبی از روش های ANFIS و SVM با مدل تجربی آن ها و همچنین مدل سازی برنامه ریزی ژنتیک ظهیری مقایسه شد. نتایج محاسباتی نشان داد که مدل های پیشنهادی از دقت بسیار مناسبی برخوردار می باشند. همچنین نتایج برتر مدل های مذکور متناسب با بار آبی بالادست، ارتفاع سررریز و زاویه انحنای قوس محوری، حاکی از برقراری ارتباط مستقیم میزان ضریب دبی این نوع سرریز با مشخصات جریان است و این در حالی است که در تحقیق حاضر در مدل سازی باANFIS الگوی ورودی با روش آموزش هیبریدی و تابع عضویت گوسین دو نقطه ای با دارا بودن بیش ترین ضریب تعیین 993/0 DC= نتایج دقیق تری را نسبت به روش SVM با الگوی ورودی تابع گوسی (RBF) و مقادیر γ، c و ε به ترتیب برابر 3، 10 و 1/0 با داشتن 98/0 DC= ارایه می دهد.
    کلیدواژگان: زاویه قوس، سرریز لبه تیز، ضریب دبی، هوش مصنوعی
  • توحید آقازاده سوره، محمد همتی * صفحات 785-797
    دینامیک جریان در تلاقی رودخانه ها به دلیل ایجاد ناحیه جداشدگی جریان و الگوهای چرخشی ثانویه در پایین دست تلاقی پیچیده می باشد. هدف تحقیق حاضر بررسی سه بعدی اثر اختلاف رقوم بین دو شاخه و نسبت دبی بر دینامیک جریان در محل تلاقی آن ها با استفاده از مدل عددی Flow-3D می باشد. برای رسیدن به این هدف، چهار نسبت دبی (2/0، 33/0، 5/0 و 67/0) و چهار نسبت اختلاف رقوم (0، 1/0، 2/0 و 3/0) در یک تلاقی با زاویه 90 درجه مورد استفاده قرار گرفت. در این تحقیق پارامترهایی چون ابعاد ناحیه جداشدگی، الگوی جریان، تراز آب، لایه اختلاط و الگوی سرعت مورد مطالعه قرار گرفتند. نتایج تحقیق حاضر نشان داد که تغییر در تراز بستر دو کانال، الگوی جریان را تغییر خواهد داد؛ به طوریکه اندازه ناحیه جداشدگی جریان در محل تلاقی های همکف و غیرهمکف متفاوت بود. ناحیه جداشدگی جریان در نزدیک بستر فقط برای تلاقی همکف مشاهده گردید و در حالت غیرهمکف این ناحیه اتفاق نیفتاد. با افزایش اختلاف رقوم نسبی، طول و عرض ناحیه جداشدگی به ترتیب افزایش و کاهش می یابد. همچنین با افزایش اختلاف رقوم، تراز آب در کانال اصلی (در بالادست تلاقی) افزایش و در شاخه فرعی کاهش می یابد. علاوه بر آن، افزایش اختلاف رقوم باعث افزایش انرژی تلاطمی جریان در تلاقی گردید که مقدار آن در تلاقی غیرهمکف (z/y3=0.3) 34/1 برابر همکف می باشد.
    کلیدواژگان: انرژی تلاطم، تلاقی رودخانه، دینامیک جریان، لایه اختلاط
  • احسان بهنام طلب *، مسعود قدسیان، امیررضا زراتی، علی اکبر صالحی نیشابوری صفحات 822-838
  • محمد بنایان *، مرتضی گلدانی، محمدرضا نادری، سارا اسدی صفحات 839-851
  • سیدجواد مشکواتی تروجنی، علیرضا عمادی *، امیراحمد دهقانی، محسن مسعودیان صفحات 852-864
  • الهام ضمیری، حجت کرمی، سعید فرزین * صفحات 865-875
  • علیرضا عراقی *، محمد موسوی بایگی صفحات 876-887
  • حسین باقری، حمید زارع ابیانه * صفحات 888-899
  • سید حسین رجائی، سعیدرضا خداشناس *، کاظم اسماعیلی صفحات 900-910
  • اعظم عربی یزدی *، ناصر نیکنیا صفحات 911-922
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  • M. I. Kamali, A. Faridhosseini *, H. Ansari, M. A. Gholami Sefidkouhi Pages 708-721
    Preparation of maize water requirement maps in Mazandaran province was considered in the current study. The 10-day maize water requirement firstly was computed in the weather stations postitions using the FAO 2- stage approach. Reference evapotranspiration (ET0) was computed by FAO modified Penman-Monteith method and climate data from 51 weather stations. Crop coefficients were considered in 4 satages during growing season. To evaluate the spatial structure of the data, Trend and Aanisotropy in the data were analyzed. After computing experimental semivariances and selecting the best semivariogram model on the basis of the lower Residuals Sums of Squares (RSS), data were interpolated by deterministic (Inverse Distance Weighting, Global Polynomial Interpolator and Local Polynomial Interpolator) and geostatistical (Ordinary Kriging and Universal Kriging) methods. The interpolation accuracy was compared based on cross validation technique and showed that Global Polynomial Interpolator and Ordinary Kriging had the same results and were better than the other methods. Maps showed that the highest amount of ET0 occurs in August (Mordad) and 4.05 to 4.78 mm/day and the lowest amount occurs in January (Dey) and 1.05 to 1.27 mm/day. Also, the highest amount of silage maize water requirement occurs in third decade of June and two first decade of July (Tir) and 4.27 to 5.15 mm/day. The highest value of maize water requirement occurs in third decade of July (Mordad) and 4.41 to 5.21 mm/day, too. The computed and predicted silage maize water requirement for Dasht-e-naz station in the current study is lower 45.8 and 45 percent than the Reference Book results. Also, the computed and predicted maize water requirement for Dasht-e-naz station in the current study is higher 71.9 and 75 percent than the National Water Document results.
    Keywords: Evapotranspiration, GIS, Interpolation, Semivariogram, Spatial distribution
  • M. M. Chari, K. Davari *, B. Ghahraman, A. N. Ziaei Pages 722-735
    Determination of recession curve for evaluation of border irrigation is of prime importance. Due to variability of soil types, as well as initial and boundary conditions in border irrigation, water advance rate varies considerably indifferent borders. In recent years,scaling approach has been adopted to reduce number of measurements, and to formulate governing equations. The aim of this study was to develop a unique equation, independent of initial and boundary conditions, for evaluation of water recession in borders,by using scaling approach. For this purpose,we considered kinematic wave model and Philip’s 2-termequation for border irrigation. The scaling factor was defined, so as the kinematic wave equation is independent of initial conditions and soil properties.Results showed that the scaling factor follows Log-normal distribution. A quadratic equation was fitted to define recession of water. The equation was evaluated for 25 borders under cultivated and uncultivated and inciuding different slopes of 0.001 to 0.005, roughness of 0.017 to 0.211, length of 91.4 to 100 m and flow rate of 0.08 to 0.16 m3/min.m.For indices of coefficient of determination (R2), comparison with perfect line of agreement, percentage of model prediction error (Er), and percentage of average relative error (Ea) were used. The results showed that the proposed equation based on scaling performed well (R2 =0.94, λ=1.046, Er=4.6 and Ea=7.52). Results showed that the mean absolute percent error for recession time was 6.78 and 8.08 for uncultivated andcultivated border, respectively,which are nearly the same. On the overall, border recession was simulated under scaling method which is simple and independent of soil type.
    Keywords: Border irrigation, Recession, Scaling
  • Kh. Ahmadaali *, H. Ramezani Etedali, N. Hosseini Pazhouh Pages 736-749
    In the present study, the state of pressurized irrigation systems in Qom province was investigated. Regarding the fact that by 2016, 81% of pressurized irrigation systems in this province are local and 19% are sprinkler, therefore, 11 local and 3 sprinkler irrigation systems (including solid-set with portable sprinklers, wheel move, and center pivot) were selected for investigation. First, the water and soil characteristics of the fields were studied then coefficient of uniformity (CU), distribution uniformity (DU), the yield of potential application efficiency of low quarter (PELQ), the yield of application efficiency of low quarter (AELQ) and adequacy of irrigation (ADirr) indexes were calculated. Obtained results showed that the mentioned indexes were 74.6, 60.8, 62.6, 62.6, 62% for solid-set with portable sprinkler, 57.6, 44.7, 76.1, 71.3, 86% for wheel move, and 81, 63, 85, 85, 71% for center pivot, respectively, and the weighted average of DU, PELQ and AELQ for local irrigation were 53.9, 45.3 and 53.9 %, respectively. Finally, the observed problems of system operation were analyzed and it was found that the main reasons of low performance were due to the management and some were due to the design and performance phases.
    Keywords: Localized irrigation, Pressurized irrigation, Operation, Sprinkling irrigation
  • N. Salehnia *, M. Bastani Pages 750-762
    Nowadays, water scarcity due to the climate change and uneven distribution of rainfall in most regions and countries, including Iran, has become a serious concern and the most important obstacle to the country's economic development. Trade, as a means to avoid unnecessary water resources outflow, with a focus on virtual water trade strategy, can play a key role in achieving economic development. This study aims at assessing the virtual water approach in terms of trade in agricultural and horticultural crops. In this regard, the export and the import of each horticultural and agricultural crops in 1393, has been analyzed from the point of virtual water trade theory; Then some strategic recommendations has been presented about optimal management of water resources. Results shows that, in 1393, Iran has traded in the horticultural and agricultural subsectors with crops importing; In essence of this issue it has saved the amount of 9719.35 million cubic meters of domestic water resources which can be used in industry and can make more added values. Moreover, according to the significant contribution of agricultural commodities exchanges in trade, and especially the traditional operating system which then leads to suboptimal use of resources like water, virtual water-based trade can be mentioned as a strategy with an effective role in improving water efficiency and saving resources.
    Keywords: Import, Export, Virtual Water, Trade Balance
  • N. Ghezelseflu, M. Boroghani *, S.Soltani Pages 763-771
    Splash erosion is the first stage in the process of water erosion that results of disperse particles soil with rain drops. This study was conducted to determine the effects of different rate of Polyacrylamide, PAM, (0, 0.2, 0.4, and 0.6 gram per square meter) on marl soils in rainfall different durations (10, 20 and 30 minute) using FEL3 rainfall simulator with rain intensity 120 mm/hr at laboratory. The results showed that all of the PAM levels (0, 0.2, 0.4 and 0.6) in the three rainfall durations (10, 20 and 30 minute) had significant differences in decreasing splash erosion in comparison with control treatment. However the interaction effect of rain duration and PAM levels, were not statistically significant. Low rate of PAM (0.2 g.m2) cannot control splash erosion as well as, however decreased it less. The statistical analyzes showed there was no statistical significance noted at a rain duration of 10 min, however at rain duration 20 and 30 min, with different amounts of PAM, there was a significant difference in splash erosion control. When rain duration increased from 10 to 30 minute, the splash erosion enlarged. So, the splash erosion decreased due enhancement of PAM level, as the most effect was observed in rain duration 30 min and 0.6 g.m2 PAM rate respect to control treatment which is 21.2% effective in decreasing erosion.
    Keywords: PAM, Marl soil, Rain duration, Rainfall Simulator, Splash erosion
  • A. Foroudi Khowr, M. Saneie *, M. Azhdari Moghaddam Pages 772-784
    The aim of this study is to apply different methods to investigation the discharging capacity of a sharpcrested curved plan-form weirs through the Adaptive neuro fuzzy inference system (ANFIS) and Support Vector Machines (SVM) techniques. Subsequently, For training and testing of the proposed equation, experimental data of Kumar et al, have been used and prediction of discharge coefficient through the ANFIS and SVM were compared with equations were proposed with Kumar et al and Zahiri. The result showe that proposed artificial inteligince models have sutable accuracy and also result of superior models is related to total upstream head, spillway height and the angle of curvature of axis curve which demonstrate direct relationship between discharge coefficient and hydraulic properties. Moreover, the performance of ANFIS model is a bit better than SVM technique with relatively low error and high correlation values. Determination coefficient of the proposed equation for discharge coefficient have been calculated as 0.993 for the ANFIS model with Hybrid training method and two point Gaussian membership function, Also this parameter calculated for SVM with RBF Kernel type and with having values include 3, 10 and 0.1 that is related to γ,c and ε respectively as 0.98 for testing phases.
    Keywords: Artificial intelligence models, Curveture angle, Discharge capacity, Sharp crested Weir
  • T. Aghazade-Soureh, M. Hemmati * Pages 785-797
    The dynamics of flow in river confluences are complex; in particular, immediately at the downstream of the junction, the flow creates a separation zone with secondary re-circulation patterns. This study aims at examining the influence of the relative bed discordance (z/y3) and discharge ratio (Qr=Q2/Q3) on flow dynamics in river confluence by Flow-3D model. To achieve this goal four discharge ratios (Qr= 0.2, 0.33, 0.5, 0.67) and four bed discordance ratios (z/y3=0, 0.1, 0.2, 0.3) were considered in a 90 degree junction. In this research, the parameters such as separation zone dimension, flow pattern, mixing layer, water level and velocity pattern were studied. The results showed that changing bed level affects the flow pattern in the junction; so that the dimensions of the created separation zone was different for concordance and discordance bed level. The separation zone near the bed observed only for same bed level junction and it was not occurring at the unequal bed level. By increasing the bed discordance, ration the width and length of separation zone increases and decreases, respectively. Also, the water level in the main channel increased (at the upstream of the junction) and in the tributary flume decreased with increasing the bed level. In addition, the energy turbulence at the confluence increases by increasing the bed level that its amount in unequal bed level junction (z/y3=0.3) is 1.34 times of equal bed level.
    Keywords: Turbulence energy, River junction, Flow dynamic, Mixing layer
  • M. Yasi *, Z. Gholami Pages 798-809
    Fusegate spillways dispart into two models of straight and labyrinth crest according to their plan view. Labyrinth Fusegates are consists of three types: Narrow Low Head (NLH), Wide Low Head (WLH), and Wide High Head (WHH). In this study, the effect of well with different heights and floor slope in WLH model of Fusegate spillways investigated on discharge coefficient over the spillway, and the amount of discharge coefficient calculated by artificial neural network and statistical method of multivariate regression by SPSS software, and compared with the result of physical modeling tests. Also, the sensitivity analysis of effective factors on the flow discharge coefficient has been done. To predict the flow discharge coefficient in artificial neural network, the best fit was obtained from Levenberg-Marquardt algorithm application as training function, TANSIG as transfer function for hidden layer and linear function as output layer. The results of sensitivity analysis showed that among the dimensionless parameters, the ratio of upstream water head to height of bucket is more effective than the other input variables. To estimate the discharge coefficients, the amount of relative error in statistical model is approximately 30% and in neural network is less than 5%. Therefore, the neural network model is considered as a suitable tool for estimating the discharge coefficient in Fusegate Spillways.
    Keywords: Artificial Neural Network (ANN), Discharge Capacity, Levenberg, Marquardt Algorithm, WLH Spillway
  • H., Zare Jonaghani, M.R. Khaledian * Pages 810-821
    Kerman is one of the most arid regions of Iran, and its agriculture particularly pistachio cultivation depends on groundwater resources. In recent decades, natural factors (drought and high evaporation) and human activity (non-systematic exploitation of groundwater) caused a sharp decline in the quality and quantity of groundwater in this province. The spatial and temporal variations in groundwater salinity (EC) were evaluated using geostatistical methods and ArcGIS software. To this end, the electrical conductivity data of 2000 wells and aqueducts that are scattered in Kerman province in the years since 2002 to 2011 were used. After eliminating outstanding data and data normalization in each year, collected data were analyzed, and then choosing the best model of semivariogram, interpolating, cross-validation and mapping were done using geostatistical tools in ArcGIS software. In the study, ordinary kriging and indicator kriging were used to prepare zoning and probabilistic maps, respectively. The results of spatial structure of salinity study showed a moderate spatial structure in the studied years. Results of cross-validation indicated a good accuracy of both methods of interpolation (i.e., ordinary kriging and indicator kriging). Zoning and probabilistic maps showed an increase of more than 8 dS/m from 2002 to 2011 in the area of groundwater salinity. It was also found that groundwater of Sirjan, Shahrbabak, Rafsanjan, and Zarand cities has a very bad condition in terms of salinity, using it for pistachio orchards irrigation can seriously reduce the yield of this plant, and its cultivation in the province will be questionable. Findings showed that in 2003, 13.3% of the total of the province faced a serious risk of high salinity of 8 dS/m in which this rate was approximately constant until 2006, but in 2007 this amount rose to 8.9% and had a decreasing trend until 2011, which finally decreased to 8.4% in 2011. So as to avoid lowering the quality of groundwater resources in the province, appropriate management measures are necessary.
    Keywords: Electrical conductivity, Mapping, Semivariogram
  • E. Behnamtalab *, M.Ghodsian, A.R. Zarrati, S. A.A. Salehi Neishabouri Pages 822-838
    One of the most conventional types of energy dissipators is stilling basin USBR VI. Stilling basin USBR VI is also one of the oldest basins designed for dissipating the pipe outlet flow. This stilling basin is made of a small boxlike structure with a hanging wall and an endsill. Hanging wall is to distribute the energy of incoming flow to basin width. The mentioned basin has no need to tailwater for successful performance. In this research, the Flow3D software has been used to model the specifications of flow field qualitatively and quantitatively. On the other hand, the numerical model used in this study is according to physical model built by author in the hydraulic lab at the Tarbiat Modares University. In this model, basin and downstream channel widths are constant. Three incoming pipes with different diameters were also used to investigate the effect of W/De ratios. In order to validate the numerical model, the recorded pressures on hanging wall and flow depth on endsill in physical model as well as the velocity profile of incoming pipe were compared with the corresponding experimental results of Nikuradse in 1932 [10]. The results of flow field show that the flow rate is higher in the vicinity of side walls for the hanging walls and beginning of downstream channel. The distribution of flow rate in width is however uniform at the distance of basin length from endsill in downstream channel. Furthermore, different W/De ratios have different diffusion velocities of incoming jet. Incoming jet interaction and the backward flow will cause the higher rate of jet diffusion, the higher W/De ratios, the higher rate of jet diffusion.
    Keywords: Flow Field, Flow3D, Numerical Model, Stilling Basin USBR VI
  • M. Bannayan *, M. Goldani, M. R. Naderi, S. Asadi Pages 839-851
    Climate variation is one of the major factors causing fluctuation of growth and economic yield of plants at both temporal and spatial scales. Evaluation of climate impacts on growth and yield of plants is important to achieve desirable growth pattern and highest possible yield. Pumpkin (Cucurbita pepo L.) is an economically important plant and is cultivated throughout the world for oil and medicinal purposes. The current study was conducted to investigate the impacts of annual climate variations on dry matter accumulation, yield production and radiation use efficiency (RUE) of pumpkin. The required data of pumpkin growth were collected from three years experiment (2010, 2012 and 2013) at research farm of Ferdowsi university of Mashhad. A thorough analysis was carried out between yield production and radiation use efficiency of pumpkin with climate variables (including growing degree day (GDD), precipitation, solar radiation, potential evapotranspiration and number of days with maximum temperature higher than 32 oC). This study showed that the impact of total precipitation on pumpkin dry weight was significant (P
    Keywords: Crops, environment, Cucurbita pepo L, production, Pumpkin production, Weather, crop
  • S. J. Meshkavati Toroujeni, A. R. Emadi *, A. A. Dehghani, M. Msoudian Pages 852-864
    Weirs are the structures that commonly used for the regulating of water surface and control of fluid in channels and hydraulic structures. Labyrinth weirs are the types of indirect weirs that with increasing in the effective length, transmit a certain amount of flow with less upstream water surface elevation than the linear weirs. The fundamental criteria in design of labyrinth weirs is the increasing of flow conveyance capacity over the weir with constant crest and water surface elevation at the upstream of the weir. In this research, discharge coefficient of trapezoidal labyrinth weir experimentally investigated with different length and heights in flume with 15 m length and 1 m width. Results shown that, for a certain length of weir and at the constant H P t / , with increasing of weir height, discharge coefficient decreased. In the constant height andH P t / , with increasing of weir length (decrease of weir sidewall angle with the flow direction), discharge coefficient decreased. Also results show that at the constant Froud Number, the upstream water depth of linear weir is about 2.8 times more than the labyrinth weir. Furthermore, at the constant upstream water depth, conveyance discharge of trapezoidal labyrinth weir is about 2.94 times more than the linear weir. Also with use of the experimental data are provided a relationship for the trapezoidal labyrinth weir discharge coefficient.
    Keywords: Hydraulic structures, labyrinth weirs, Discharge coefficient, Flow discharge, Length, Height of weir
  • E. Zamiri, H. Karami, S. Farzin * Pages 865-875
    Labyrinth weir is one of the nonlinear hydraulic structures that its geometrical shape increases the discharge coefficient of flow over the weir. In this study, a labyrinth weir, located in a 14.6 m long channel, was simulated and verified using an experimental model with 6 different discharges (15
    Keywords: Crest shape, Discharge coefficient, Flow, 3D, Labyrinth weir, Thickness of weir wall, Turbulence model
  • A. Araghi, M. Mousavi-Baygi * Pages 876-887
    Soil temperature is one of the most important variables in agricultural meteorology and has various effects on physical, chemical and biological processes in soil. In this study, daily soil temperature at depths of 5, 10, 20 and 30 cm were estimated using artificial neural network, adaptive network-based fuzzy inference system, multiple linear regression and also hybrid models based on the mentioned methods and discrete wavelet transform. To develop the models, daily minimum and maximum air temperature and daily soil temperature at depths of 5 to 30 cm in Ghoochan and Gonabad synoptic stations during 2010 to 2013 were employed, and for testing the performance of models, data of 2004 (wet year) and 2008 (dry year) were employed. Results of this study showed that hybrid models based on discrete wavelet transform could produce more accurate results compared to non-hybrid models in estimating daily soil temperature. Also, in most of the cases, the multiple linear regression (MLR) model had the weakest performance.
    Keywords: Discrete wavelet transform, Hybrid models, Soil temperature
  • H. Bagheri, H. Zare Abyaneh * Pages 888-899
    The simulation of nitrate and sodium transport was done in native soil and soil treatment by vermicompost under three irrigation flow rates in saturation and unsaturation states. For this purpose, 12 columns with 20 cm length and 5.9 cm diameter chopped of PVC pipes were used that soil layer in column was 10 cm. All of columns saturated at 24 hours, and leaching was immediately done with distilled water at 24 hours, too. Next, the solution consist of 1mMol KNO3 and 25.42 mg in 1 liter distilled water injected to soil columns with three different water flow rates during 570 minutes, and the nitrate and sodium concentrations were measured in effluent solutions at specified time intervals. The Advection-Dispersion model was used for simulating of solute transport, and dispersivity and distribution coefficients of nitrate and sodium were determined by inverse method. Sodium breakthrough in native soil and soil treatment with vermicompost condition occurred at 280 and 160 minutes under saturated condition with flow rate 0.0704 cm/min, 330 and 200 minutes under unsaturated condition with flow rate 0.0477 cm/min, but sodium breakthrough did not occurred in unsaturated condition with flow rate 0.0208 cm/min. Nitrate breakthrough in native soil with flow rates 0.0704, 0.0477 and 0.0208 cm/min occurred in 50, 80 and 120 minutes, and become maximum in 120, 200 and 270 minutes. Nitrate breakthrough in soil treatment with vermicompost in flow rates 0.0704, 0.0477 and 0.0208 cm/min occurred in 30, 40 and 80 minutes, and become maximum in 80, 120 and 240 minutes. The results showed the breakthrough times of nitrate and sodium and time of maximum concentration of nitrate were decreased by application of vermicompost and increasing soil water flow rate. The results of modeling showed dispersivity and distribution coefficients were increased by using of vermicompost and decreasing soil water flow rate.
    Keywords: Advection, Dispersion model, Breakthrough curve, Dispersivity coefficient, Linier adsorption, Solute transport
  • S. H. Rajaei, S. R. Khodashenas *, K. Esmaili Pages 900-910
    Energy losses in steeped spillways is one of the most important design parameters in this structure. Stepped spillways are used in high dams, diversio dams and in watershed structures. Gabion stepped spillways are usually used in diversion dams and structures of river protection. They are used in most projects, Specially in projects of stabilizing river and filling with sediment at upstream is one of the goals. Since gabion structures in many places is a good option, gabion stepped spillways are being built with a height between 1 to 3 meters and these structures usually can be built with the same form. Therefore this form of gabion in the early years are filled with sediment. In this research compare the energy losses in two form of gabions stepped spillways (gabions stepped spillways with and without sedimentation at upstream) is done. To reach this goal, models of gabion stepped spillways with and without sedimentation were built with the same geometric dimensions and were installed in a laboratory flume with 50cm width and 11m length. Spillways have 1, 2 and 3 steps. The result showed that the maximum efficiency of energy loss in the gabion stepped spillways without sedimentation, occur up to 75%. At low flow rates, in the gabion without sedimentation flow traverses through the porous body. In this mood, when discharge increases the energy losses will increase too, but in the flow passing through and upper gabion, energy losses will be reduced. In gabion stepped spillways with sedimentation, increasing flow always makes reduce energy losses. When current passes through the porous body, in gabion without sediment energy losses is less than gabion with sediment. But when current passes from the top of gabion, in gabion without sediment energy losses is more than gabion with sediment. This study present three formulas for calculating energy losses in Gabion stepped spillways.
    Keywords: Diversion dam, Gabion, Head loss, Sedimentation, Steeped spillways
  • A. Arabi Yazdi *, N. Nik Nia Pages 911-922
    More production of livestock products has been increasing pressure on water resources in the future. This study estimates the water footprint of livestock products with regard to feed each animal in Neyshabur. Results shows that to produce the equivalent of 323 tons of livestock production, about 2043 million cubic meters of water has consumed annually, which is 537 million cubic meters of blue water resources and 1506 million cubic meters of water consumption is green. Since more than 98 percent of livestock water footprint is related to the animal feed, changing in animal feed is the most important factor of livestock production water footprint. The greatest volume of the blue water footprint is related to feed original cow, sheep and chicken. The most Green water footprint was allocated to provide forage for livestock, sheep and goats. Livestock production and consumption play an important role in the depletion and pollution of scarce freshwater resources in the world, water footprint of livestock products provides information that helps us to understand the sustainable use of scarce water resources.
    Keywords: Blue, green water., Food rations source, Livestock products, Neyshabur, Water footprint
  • M. Moradi *, S. Azizi, S. Darbandi Pages 923-934
    In this study, two different input selection methods cross-correlation analysis (CCA), and a combination of mutual information and cross-correlation analyses (MICCA) were used to develop adaptive network-based fuzzy inference system (ANFIS) in Qarasoo basin, in Kermanshah province, Iran. Sixteen daily rainfall-runoff events 10-yearly (2006-2015) were selected which 12 events were used for calibration (training) and the remaining 4 events were reserved for validating (testing) the models. Then, the results of ANFIS models then were compared against the HEC-HMS conceptual model. Investigation statistical indices showed that ANFIS model developed based on MICCA input (ANFIS-MICCA) better performance (CE=0.99 and RPE=10.09%) than the developed based on CCA inputs (ANFIS-CCA) (CE=0.88 and RPE=15.41%). ANFIS-CCA and ANFIS-MICCA were able to perform comparably to HEC-HMS model where rainfall data of all 8 stations; however, in peak estimation, ANFIS-MICCA was the suitable model. Also, the results show that the HEC-HMS model performance deteriorates by reducing the number of rainfall stations to two and three stations 59.8% and 54.6% percent, respectively. In general, ANFIS was found to be a reliable alternative for HEC-HMS in cases whereby not all rainfall stations are functioning.
    Keywords: Adaptive Network, based Fuzzy Inference System (ANFIS), HEC, HMS, Qarasoo basin, Rainfallrunoff modeling