List of Articles زمان تمرکز

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  1 - Estimating Flood potential of Zilaki and Firehrud drainage basins by emphasize on Geomorphologic characters by using SCS method
  Mohammad reza Sarvati Ardavan Behzad
  Flood is amongphenomenon which bring about considerable damage each year.This has been attractedgreatly by hydrologists. The factors such as physiography,geomorphology and human factors can accelerate this phenomenon in basins. Forusing water source, flood management, d More

  Flood is amongphenomenon which bring about considerable damage each year.This has been attractedgreatly by hydrologists. The factors such as physiography,geomorphology and human factors can accelerate this phenomenon in basins. Forusing water source, flood management, damming, watershed management and themost basic hydrologic studies, peak discharge is important, so accuracy of studies andthe safeties’ level of the hydraulic structures and establishments are independent to it.In this research potential flood Zilaki and Firehrud drainage basins were studied byusing of SCS method and finally were compared together. So BasinHydrographdimensions calculated by using of 24 hour rainfall, time of concentration, CurveNumber, rainfall excess, time to peak and peak discharge.Then was designHydrograph for basins in 2,5,10,25,50,100 period time Results show, because ofphysiography of Firehrud basin, It has more ability for making flood than Zilaki basin. Manuscript profile
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  2 - Curve Number (CN) Calculating and Zonation of Subbasins Case study: Ahar Chay Basin
  بهروز Sari
  One of the most important Physical factors in basin is the time of concentration. Bacause,there is the curve number (CN) factor in calculating the time of concentration,so that is nessecity for some researches in soil penetration, landuse and surface savecoefficient fil More

  One of the most important Physical factors in basin is the time of concentration. Bacause,there is the curve number (CN) factor in calculating the time of concentration,so that is nessecity for some researches in soil penetration, landuse and surface savecoefficient filds.In this paper, the mentioned items are calculated which contain sampling all of casesurface and determining the soil penetration. Next stage contains recognizing soilpenetration Zonns, landuse of basin and those maps.Presenting the hypothesizes and subbasins recognizations were the next stages thatlead to calculating CN amount in surface basin and CN polygon maps.Finally, amount of time of concentration of basin and subbasin (by hour) based onsoil conservation service(SCS) relation are calculated that are useful in hydrologicalcalculations. Manuscript profile
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  3 - تأثیر پایداری بندهای گابیونی با سرریز پلکانی از نظر کنترل رسوب و سیلاب (مطالعه موردی: حوضه آبخیز خائیز، بهبهان، استان خوزستان)
  فرهاد سادات فرد امین بردبار
  بندهای گابیونی (Gabion Dams) سازه­های کوچکی هستند که به منظور کاهش سرعت جریان و شیب آبراهه و مهار فرسایش در آبراهه­ها احداث می­گردند. احداث این بندها در حوضه­های آبخیز  موجب تغییرات در زمان تمرکز  شده که در کنترل سیل و مهار رواناب تاثیر بسزایی More

  بندهای گابیونی (Gabion Dams) سازه­های کوچکی هستند که به منظور کاهش سرعت جریان و شیب آبراهه و مهار فرسایش در آبراهه­ها احداث می­گردند. احداث این بندها در حوضه­های آبخیز  موجب تغییرات در زمان تمرکز  شده که در کنترل سیل و مهار رواناب تاثیر بسزایی دارد. حوضه آبخیز خائیز واقع در شهرستان بهبهان استان خوزستان کشور ایران یکی از زیر حوضه­های آبخیز  بسیار مهم این شهرستان می­باشد. در این حوضه در فصول بارندگی، ایجاد سیلاب موجب فرسایش اراضی منطقه و انتقال رسوبات فراوان به پایین­دست می­گردد. در این تحقیق با مطالعه منطقه و شرایط توپوگرافی و عملیات حفاظتی صورت گرفته، تغییرات زمان تمرکز، ضریب نگهداشت و دبی سیلاب قبل و بعد از اجرای عملیات حفاظتی مورد مقایسه قرارگرفته است. در این زمینه پارامترهای تعداد و ارتفاع بندها، گروه هیدرولوژیکی خاک، شیب آبراهه، زمان تمرکز، هیدرولوژی منطقه، مساحت حوضه و حجم رسوبگیری سازه­ها مورد بررسی قرارگرفت، باتوجه به بررسی صورت گرفته می­توان نتیجه گرفت احداث بندهای گابیونی به تنهایی نمی­تواند تاثیر قابل ملاحظه­ای در کنترل رواناب داشته باشد و اجرای همزمان عملیات های دیگر آبخیزداری همچون عملیات بیولوژیک و بیومکانیکی جهت تحقق اهداف طرح بسیار ضروری است. Manuscript profile
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  4 - A Comparative Study of Transport Impact Assessment on Pollution in Tehran. Case Study of Tehran 18th and 5th Districts
  AliAsghar Ghasemi Azadeh Arbabi Sbsevari Masoomeh Sohrabi
  Air pollution is a process that depends on various atmospheric conditions and weather and climate phenomena are involved in the formation of this problem. Today, in Tehran and in many of the major industrial cities in the world, especially in developing countries, vario More

  Air pollution is a process that depends on various atmospheric conditions and weather and climate phenomena are involved in the formation of this problem. Today, in Tehran and in many of the major industrial cities in the world, especially in developing countries, various pollutants are discharged through motor vehicles, industries and commercial and household sources. The purpose of this study was to study the concentration time of carbon monoxide pollutant in different times of the day and to investigate the relationship between carbon dioxide concentration and concentration of carbon monoxide with weather variables in Tehran's 5th and 18th regions. In this study, a statistical method was used to achieve the goals. At first, the concentration time of pollutants was identified in 4 periods in the study area. In order to calculate correlation and regression analysis between carbon monoxide with wind speed, minimum temperature and maximum temperature, Pearson correlation coefficient and multivariate regression analysis were used in SPSS and Excel. The results of multiple regression and percentage of coefficient of variation explained in area 18 with the input of three wind speed variables, minimum temperature and maximum temperature in the pollutant modeling of the CO station showed that the studied variables explained the CO pollutant of Shadabad station to 0.16 They made Also, in District 5, the results of this study showed that the amount of CO contamination in the daytime is at 8 o'clock in the morning and is the lowest amount of record at 15 o'clock during the 9-year period. Manuscript profile